Bureau of Sfcandarab

Lain •i'9.'.ig4q
The program of research on building materials and structures, carried on by the

National Bureau of Standards, was undertaken with the assistance of the Central Housing Committee, an informal organization of governmental agencies concerned with

housing construction and finance, which is cooperating in the investigations through a committee of principal technicians.

CENTRAL HOUSING COMMITTEE

ON RESEARCH, DESIGN, AND CONSTRUCTION

A. C. Shire, Chairman. Howard P. Vermilya, Vice Chairman.

United States Housing Authority. Federal Housing Administration.

Sterling R. March, Secretary.

Pierre Blouke,

Federal Home Loan Bank Board.

Hugh L. Dryden,

National Bureau of Standards.

Louis A. Simon,

Public Buildings Administration.

Luther M. Leisenring,

Construction Division (War).

Edward A. Poynton,

Office of Indian Affairs.

John S. Donovan,

Farm Security Administration.

George W. Trayer,

Forest Service (F. P. Laboratory).

Joseph M. DallaValle,

Public Health Service.

George E. Knox,

Yards and Docks (Navy).

William R. Talbott,

Veterans' Administration.

Wallace Ashby,

Bureau of Agricultural Chemistry and Engineering.

NATIONAL BUREAU OF STANDARDS

STAFF COMMITTEE ON ADMINISTRATION AND COORDINATION

Hugh L. Dryden, Chairman.

Mechanics and Sound.

Phaon H. Bates, Gustav E. F. Lundell,

Clay and Silicate Products. Chemistry.

HoBART C. Dickinson, Addams S. McAllister,

Heat and Power. Codes and Specifications.

Warren E. Emley, Henry S. Rawdon,

Organic and Fibrous Materials. Metallurgy.

The Forest Products Laboratory of the Forest Service is cooperating with both

committees on investigations of wood constructions.

[For list of BMS publications and directions for purchasing, see cover page III.]
UNITED STATES DEPARTMENT OK COMMERCE Jesse H. Jones, Secretary

NATIONAL BUREAU OF STANDARDS • Lyman J. Briggs, Director

BUILDING MATERIALS

and STRUCTURES

REPORT BMS66

Plumbing Manual

Report of Subcommittee on Plumbing

Central Housing Committee on Research, Design,

and Construction

ISSUED NOVEMBER 22, 1940

The National Bureau of Standards is a fact-finding organization;

it does not "approve" any particular material or method of construction. The technical findings in this series of reports are to be construed accordmgly.

UNITED

FOR SALE

STATES GOVERNMENT PRINTING OFFICE • WASHINGTON • I94O

BY THE SUPERINTENDENT OF DOCUMENTS, WASHINGTON, D. C. • PRICE 20 CENTS
Foreword

This report has been prepared by a representative committee to serve as a guide for Federal agencies that design, install, or approve

plumbing. It is the product of a careful review of existing recommendations, supplemented by consideration of the results of experimental work at this Bureau and by group discussion among the committee members. The aim has been to insure adequate and healthful

plumbing at a minimum of expense. It is hoped that the report will prove useful, not only for Federal plumbing work, but also in connection with efforts to bring about greater uniformity in plumbing

requirements and to reduce the cost of construction, of which plumbing

forms a part.

Lyman J. Briggs, Director.

iiii
Plumbing Manual

Report of Subcommittee on Plumbing of the Central Housing Committee on Research,

Design, and Construction

Robert K. Thulman, Chairman. ' Vincent T. Manas, Vice Chairman.

Federal Housing AdministTation. United States Housiuo- Authority.

Sterling R. March, Secretary.

Mary Fidelia Taylor, Assistant Secretary.

Roy B. Hunter, Technical Advisor to Subcommittee

National Bureau of Standards.

Charles N. Diener,

Home Owners' Loan Corporation.

Peter J. Furlong,

Public Buildings Administration.

Arthur R. Geiger,

Office of Quartermaster General (War).

Norman C. Hepburn,

Veterans' Administration.

Robert J. Potbury,

Yards and Docks (Navy), represented by

Preston H. Barnard.

John W. Rockey,

Bureau of Agricultxu-al Chemistry and Engineering ( Agiiculture)

.

Ralph E. Tarbett,

Public Health Service.

George N. Thompson,

National Bureau of vStandards.

ABSTRACT

A manual of recommended plumbing practice is pre- sented by a committee composed of representatives of Federal agencies most concerned with the subject. The

committee has taken into consideration available rec- ommendations of other bodies and results of research performed at the National Bureau of Standards.

Part I consists of an introduction explaining the origin

of the work. Part II contains recommendations re- garding necessary sizes of piping, precautions against

pollution of water supply, permissible types of venting,

and other matters customarily covered in plumbing

codes. Part III contains information useful in applying the recommendations, including illustrative inter- pretations of the specific requirements in part II. The

recommendations are presented as suitable for adoption

by Federal agencies engaged in actual plumbing work

or in passing upon plans of structures containing plumbing.

CONTENTS

Page

Foreword ii

I. Introduction 4

II. Recommended minimum requirements for plumbing 6 Chapter I. Definitions 6

Sec. 101. Definitions 6 Chapter II. General regulations 9

Sec. 201. Installation of piping 9

Sec. 202. Changes in direction 9

Sec. 203. Prohibited fittings 9

Sec. 204. Prohibited connections 9

Sec. 205. Protection of pipes 10

Sec. 206. Protection of electrical machinery 10

Sec. 207. Protection of water tanks _ 10

Sec. 208. Workmanship 10

II. Recommended

plumbingChapter III

Sec. 301.

Sec. 302.

Sec. 303.

Sec. 304.

Sec. 305.

Sec. 306.

Sec. 307.

Sec. 308.

Sec. 309.

Sec. 310.

Sec. 311.

Page

minimum requirements for —Continued.

. Quality, weight, and

thickness of materials- 10

Quality of materials 10

Identification of m a t e

rials 10

Vitrified-clay pipe 10 Concrete pipe 10

Cast-iron soil pipe 10

Cast-iron water pipe 10

Cast-iron screwed pipe 10' Wrought-iron pipe 10' Steel pipe 10

Brass and copper pipe 10

Brass tubing 10

[1]
Page

II. Recommended minimum requirements for plumbing—Continued.

Chapter III. Quality, etc. —Con.

Sec. 312. Copper tubing 10

Sec. 313. Lead pipe 10

Sec. 314. Sheet lead 10

Sec. 315. Calking lead 10

Sec. 316. Sheet copper and brass ___ 11

Sec. 317. Zinc-coated (galvanized) sheet iron and steel 11

Sec. 318. Screwed fittings 11

Sec. 319. Soldered fittings 11

Sec. 320. Calking ferrules 11

Sec. 321. Soldering nipples and bushings 11

Sec. 322. Floor flanges 11

Sec. 323. Packing 11

Sec. 324. Setting compound 11

Sec. 325. Gaskets 11

Sec. 326. Alternate materials 11 Chapter IV. Joints and connections- _ 11 Sec. 401. Tightness 11

Sec. 402. Vitrified-clay and concrete

pipe 11

Sec. 403. Calked joints 11

Sec. 404. Screwed joints 11

Sec. 405. Joints in cast-iron pipe 11

Sec. 406. Joints between cast-iron and other piping 11

Sec. 407. Wiped joints 12

Sec. 408. Joints between lead and

other piping 12

Sec. 409. Joints in copper tubing 12

Sec. 410. Slip joints and unions 12

Sec. 411. Roof flashings 12

Sec. 412. Floor connections 12

Sec. 413. Increasers and reducers. - 12

Sec. 414. Supports 12 Chapter V. Traps and clean-outs 12

Sec. 501. Types and sizes of traps- _ 12

Sec. 502. Prohibited traps 12

Sec. 503. Traps required 12

Sec. 504. Trap seal 12

Sec. 505. Trap clean-outs 13

Sec. 506. Installation of traps 13

Sec. 507. Pipe clean-outs 13

Sec. 508. Pipe clean-outs required. 13

Sec. 509. Clean-out equivalents 13

Sec. 510. Accessibility of traps and

clean-outs 13

Sec. 511. Grease interceptors 13

Sec. 512. Oil interceptors 13

Sec. 513. Sand interceptors 13

See. 514. Floor drains 13

Sec. 515. Backwater valves 13 Chapter VI. Water supply and distri- bution 13

Sec. 601. Quality of water 13

Sec. 602. Protection of water supply 13

Sec. 603. Protection from freezing. _ 13

Page

II. Recommended minimum requirements for plumbing—Continued.

Chapter VI. Water supply—Con.

Sec. 604. Size of building main 13

Sec. 605. Quantity of water 14

Sec. 606. Size of fixture branches 14

Sec. 607. Shut-offs 14

Sec. 608. Material for water piping

and tubing 14

Sec. 609. ReHef valves 14 Chapter VII. Plumbing fixtures 14

Sec. 701. Quality of fixtures 14

Sec. 702. Installation of fixtures 14

Sec. 703. Frostproof closets 14

Sec. 704. Floor drains 14

Sec. 705. Fixture strainers 14

Sec. 706. Fixture overflow 14

Sec. 707. Swimming pools 14

Sec. 708. Miscellaneous fixtures 14

Sec. 709. Ventilation 14 Chapter VIII. Soil and waste pipes for sanitary systems 14

Sec. 801. Materials 14

Sec. 802. Minimum sizes 14

Sec. 803. Fixture units 15

Sec. 804. Stacks to be vertical 15

Sec. 805. Size of soil and waste

pipes 15

Sec. 806. Offsets 15

Sec. 807. Horizontal and primary

branches 16

Sec. 808. Sumps and receiving tanks. 16 Chapter IX. Storm drains 16

Sec. 901. General 16

Sec. 902. Leaders and gutters 17

Sec. 903. Size of storm drains and

leaders 17

Sec. 904. Separate and combined

drains 17

Sec. 905. Closed system required 18

Sec. 906. Overflow pipes 18

Sec. 907. Subsoil sumps 18

Sec. 908. Construction of subsoil drains 18 Chapter X. Vents and venting 18

Sec. 1001. Material 18

Sec. 1002. Protection of trap seals_. 18

Sec. 1003. Stack-vents required 18

Sec. 1004. Vent stacks required 18

Sec. 1005. Distance of trap from

vent 18

Sec. 1006. Dual vents permitted 19

Sec. 1007. Group vents permitted-- 19

Sec. 1008. Yoke and relief vents 19

Sec. 1009. Circuit vents and loop vents 20

Sec. 1010. Vents for flat-bottomed

fixtures 20

Sec. 1011. Vents for resealing traps. 20

Sec. 1012. Fixtures at base of main

vent 20

[2]
Page

II. Recommended minimum requirements for plumbing—Continued.

Chapter X. Vents and venting—Con.

Sec. 1013. Size and length of main

vents 21

Sec. 1014. Size and length of stack- vents 21

Sec. 1015. Size of back vents and

relief vents 21

Sec. 1016. Size of circuit and loop

vents 21

Sec. 1017. Relief vents for offsets--- 21

Sec. 1018. Frost closure 22

Sec. 1019. Location of vent ter- minals 22

Sec. 1020. Vents not required 22

Sec. 1021. Vents prohibited 22 Chapter XI. Indirect connections to waste pipes 22

Sec. 1101. Indirect wastes 22

Sec. 1102. Size of refrigerator

wastes 22

Sec. 1103. Overflow pipes 22 Chapter XII. Maintenance 22

Sec. 1201. Defective plumbing 22

Sec. 1202. Temporary toilet facili- ties 22

Sec. 1203. Condensate and blow-off connections 22 Chapter XIII. Inspection and tests- _ 23

Sec. 1301. Inspection 23

Sec. 1302. Tests required 23

Sec. 1303. Notification for test 23

Sec. 1304. Labor and equipment for

tests 23

Sec. 1305. Tests of drainage system- 23

Sec. 1306. Final test 23

Sec. 1307. Tests of water-supply

system 24

Sec. 1308. Final condition 24

Sec. 1309. Separate tests permitted- 24

Sec. 1310. Covering of work 24

Sec. 1311. Defective work 24

Sec. 1312. Tests of leaders 24

Sec. 1313. Outbuildings 24

Sec. 1314. Garages 24

Sec. 1315. Certificate of approval-- 24

Sec. 1316. Test of defective plumbing 24

Sec. 1317. Inspections and tests not

required 24

III. Explanations, illustrations, and interpre- tations 27

Par. 101. Definitions ' 27

Par. 201. Installation of piping 28

Par. 301. Quality of materials 29

Par. 303. Vitrified-clay pipe 29

Par. 304. Concrete pipe 29

Par. 305. Cast-iron soil pipe 29

Par. 306. Cast-iron water pipe 29

For explanation of paragraph numbering, see note preceding paragra;

Page

III. Exjjlanations, illuslratioiis, and interpre- tations—Continued.

Par. 307. Cast-iron screwed pipe 30

Par. 308. Wrought-iron pipe 30

Par. 309. Steel pipe 30

Par. 310. Brass and copper pipe 30

Par. 311. Brass tubing 30

Par. 312. Copper tubing 30

Par. 313. Lead pipe 30

Par. 314. Sheet lead 31

Par. 315. Calking lead 31

Par. 316. Sheet copper and brass 31

Par. 317. Zinc-coated (galvanized)

sheet iron and steel . 31

Par. 318. Screwed fittings .... 31

Par. 319. Soldered fittings 31

Par. 320. Calking ferrules 31

Par. 321(a) Soldering nipples 31

Par. 322. Floor flanges 31

Par. 323. Packing 31

Par. 324. Setting compound 31

Par. 325. Gaskets 31

Par. 402. Vitrified-clay and concrete

pipe 31

Par. 409. Joints in copper tiibing 32

Par. 413. Increasers and reducers 32

Par. 501. Types and sizes of traps 32

Par. 502. Prohibited traps 32

Par. 601. Quality of water 33

Par. 602(d). Protection from backflow- 34

Par. 604. Size of building main 35

Par. 701. Quality of fixtures 45

Par. 705. Fixture strainers 45

Par. 707. Swimming pools 46

Par. 800. Acid or chemical wastes 46

Par. 802. Minimum sizes of soil and

waste pipes 46

Par. 803. Fixture-unit ratings 47

Par. 805. Sizes of soil and waste

pipes 47

Par. 807. Horizontal and primary

branches 48

Par. 902. Gutters and leader connections 54

Par. 903. Size of storm drains and

leaders 55

Par. 903(rf). Allowance for projecting

walls 56

Par. 904. Separate and combined

drains 56

Par. 1002. Protection of trap seals 58

Par. 1005. Distance of trap from vent- 58

Par. 1008. Yoke and relief vents 58

Par. 1010. Vents for flat-bottomed

fixtures 60

Par. 1011. Vents for resealing traps- . 60

Par. 1012. Fixtures at base of main

vent 60

Par. 1101. Indirect connections 61 Par. 1305(6). Air tests 62

101, page 27.

[3]
TABLES Page

803. Fixture units per fixture or group. _ 15

805. Permissible number of fixture units on horizontal branches and

stacks 15

807. Capacities of horizontal branches

and primary branches of the

building drain 16

903(?)). Maximum roof area for leaders 17

903(c). Maximum roof area for building storm sewers or drains 17

1009(a). Limits for circuit and loop venting 20

1013. Size and length of main vents 21 201-III. Approximate velocities for given

slopes and diameters 28

313-III. Diameter and weight of lead pipe- _ 30

320-III. Size, diameter, and weight of brass calking ferrules 31

321(a)-III. Diameter and weight of soldering

nipples 31

604-III(a). Fixture-unit ratings for estimating

water-supply demands - 40

604-111(6). Allowance in equivalent length of pipe for friction loss in valves and threaded fittings 41

604^III(c). Actual diameters corresponding to nominal diameters of different kinds of pipe 41 604-III(d). Illustration of the probable effects

of corrosion and caking in service on the capacities of water pipes. _ 42

604-III(e). Water-demand estimates for resi- dential types of building (flush- tank supply) 44

805(6)-III. Permissible limits in fixture units on soil and waste stacks 47

807-III. Capacities of building drains under

section 807(6), part II 49

807(c)-III. Limits in capacities of building

drains under the provisions of section .S07(c), part II 49

Page

807(d)-III. Limits in capacities of building

drains under the provisions of section 807(d), part II 52

902-III. Maximum roof area for semicircular

roof gutters with a fall of Me inch per foot or less 55

904-III. Required diameters for combined

building drains and sewers ac- cording to number of fixture units 57

FIGURES

1. standard plumbing symbols 25

2. Illustration of definitions 26

3. Continuous waste 33

4. Depth of trap seal 33

5. Illustration of air gap 34

6. Curve for estimating supply demands 35

7. Flow cliart for smooth pipe 36

8. Flow chart for fairly smooth pipe 37

9. Flow chart for fairly rough pipe 38

10. Flow chart for rough pipe 39

11. Relation of flow to diameter of pipe for friction loss of 10 lb/in. 2 per 100 feet 40

12. Illustrative graphs for applying sections

807(c) and (d) 50

13. Distance of trap from vent 58

14. Dual vents 58

15. Group vents for lavatories and bathtubs 59

16. Stack-vented piping lay-out for one-story

house 59

17. Piping lay-out for two-story house with one bathroom 60

18. Piping lay-out for one-story duplex house.- 60

19. Piping lay-out for bathrooms in each of two stories 61

20. Piping lay-out for duplex apartments 61

21. Illustration of circuit-and-loop vents 61

22. Limits for circuit-and-loop vents 61

23. Drains and vents for flat-bottomed fixtures. 62

24. Indirect wastes 62

PART I. INTRODUCTION

Plumbing is a matter of interest to many

agencies of the Federal Government. Some of these actually design plumbing systems and

supervise their installation, while others have

a responsibility in connection with loans on

houses, in allocation of funds for public housing,

and in other ways. All naturally desire that

the plumbing with which they have to deal shall be sanitary a,nd efficient and shall be reasonable

in cost. In order to have good and economical plumbing, it is necessary that there should be some

agreement on the rules governing its design and

installation. Such agreement is not to be

foimd in local plumbing codes, which vary to a large extent in their requirements without

apparent justification. Although some progress has been made toward greater uniformity,

there is still a marked lack of agreement even among recommended plumbing requirements. In view of this situation, representatives of a number of Government agencies, acting as a subcommittee of the Central Housing Committee, have undertaken the preparation of this

[4]
manual. It is iTitendcd to serve as a guide in

their own work and as recommended procedure

where local codes do not govern. It is also offered as a contribution to efforts toward

greater uniformity in plumbing requirements.

Particular emphasis is placed upon its usefulness

in connection with low-cost housing, where there

is special need to take advantage of all legitimate economies. The field of the manual,

however, is not restricted to housing, since the same fundamental principles apply in any

structure. In developing the manual, close attention

has been paid to previous recommendations

prepared by the Subcommittee on Plumbing of the Department of Commerce Building Code

Committee and issued under the title "Recommended Minimum Requirements for Plumbing"

by the National Bureau of Standards. Similar

recommendations prepared by nongovernmental

bodies have also been consulted. The results

of research extending over a long period at the

National Bureau of Standards have been made

available to the committee, including results of experiments that have been completed since the

committee started its work. In addition, the

members of the committee have brought to the

work an experience with plumbing extending

over many years. The manual represents the consensus of the committee and is recommended

as suitable for use throughout the Federal

Government service.

The subject matter of the manual is divided

into two parts, as follows: part II, containing

general and basic requirements concisely stated

;

and part III containing many illustrated interpretations, specific citations of applicable ac- cepted standards, rules for applying exceptions

to general or basic requirements as stated in

part II, and much other information considered

valuable to the builder in complying with the

requirements and to the authorities in determining compliance. Part III also contains

illustrations of simple plumbing lay-outs per- missible under the requirements of part II and

applicable to low-cost housing. (See par. 1008

and figs. 16 to 20, pt. III.)

Several innovations or departures from the

usual form of presenting plumbing requirements have been made, to a few of which particular attention is invited. These changes

from conventional methods of presenting minimum requirements apply principally to i-cquired

sizes of soil and waste stacks and of building

drains and building sewers and to permissible

methods of venting. The changes have been

made for the purpose of permitting the engineer

to design, and the builder to install, plumbing

systems more in accord with the actual demands

of particular buildings than can be done under

tables that make no distinction for buildings of different sizes and types other than the total number of fixtures. The results to be expected

from applying the proposed methods, especially

in relation to large buildings, are (1) better

transportation of sewage, (2) safer and more

satisfactory operation in the long run, and (3) more economical consti'uction than can be

obtained under the old methods.

The arrangement of the manual in two main

parts, one containing subject matter not likely

to need frequent revision or additions and the

other containing the subject matter likely to need revision to keep abreast of current standards, will facilitate revision as experience and new developments make such revision advisable.

It is also to be expected that new data and other

information of value to the engineer or builder

will be added to part III with each revision.

Acknowledgment is made to Martin Goerl

for assistance in preparing the report, to Theodora C. Bailey for editorial review, and to E. A.

Lcdwith for assistance in preparation of the

illustrations.

[5]
PART II. RECOMMENDED MINIMUM REQUIREMENTS FOR PLUMBING

CHAPTER I. DEFINITIONS

[Note.—See fig. 2, pt. Ill, for general illustrations of definitions]

Sec. 101.

Definitions.

Accepted standards.—Accepted standards are the standards cited in this manual, or other

standards approved by the authority having

jurisdiction over plumbing. (See par. 101, pt.

III.)

Air gap.—The air gap in a water-supply sys- tem for plumbing fixtures is the vertical dis- tance between the supply-fitting outlet (spout)

and the highest possible water level in the re- ceptor when flooded. (See fig. 5, pt. III.)

If the plane of the end of the spout is at an angle to the surface of the water, the mean

gap is the basis for measurement.

Approved.—Approved means accepted as satisfactory to the authority having jurisdiction over plumbing.

Area drain.—An area drain is a drain in- stalled to collect siu-face or rain water from an open area. Backjlow.—Backflow means the flow of water

into a water-supply system from any source ex- cept its regular one. Back siphonage is one

type of backflow.

Backflow connection.—A backflow connection

is any arrangement whereby backflow can

occur. Back vent. —A back vent is a branch vent in- stalled primarily for the purpose of protecting

fixture traps from self-siphonage.

Branch.—A branch is any part of a piping

system other than a main. (See Main.)

Branch interval. —A branch interval is a length of soil or waste stack corresponding in general to a story height, but in no case less than 8 feet, within which the horizontal branches

from one floor or story of the building are con- nected to the stack.

Branch vent. —A branch vent is any vent pipe

connecting from a branch of the drainage sys- tem to the vent stack.

Building drain.—The building (house) drain .

is that part of the lowest horizontal piping of a ( building-drainage system which receives the » discharge from soil, waste, and other drainage

^ pipes inside the walls of the building and con- veys it to the building (house) sewer beginning

5 feet outside the inner face of the building ! wall. li Building-drainage system.. —The building- , drainage system consists of all piping provided

for carrying waste water, sewage, or other

drainage from the building to the street sewer

or place of disposal. , Building main.—The building main is the

water-supply pipe, including fittings and accessories, from the water (street) main or other

source of supply to the first branch of the water-

'

distributing system.

Building sewer.—The building (house) sewer jj is that part of the horizontal piping of a building- | drainage system extending from the building |: drain 5 feet outside of the inner face of the

building wall to the street sewer or other place

of disposal (a cesspool, septic tank, or other

type of sewage-treatment device or devices)

and conveying the drainage of but one building

site.Building subdrain.—A building (house) subdrain is that portion of a drainage system which

cannot drain by gravity into the building

sewer.

Circuit vent. —A circuit vent is a group vent

extending from in front of the last fixture con- nection of a horizontal branch to the vent

stack.

Combination fixture.—Combination fixture is a trade term designating an integral combination of one sink and one or two laundry trays

in one fixture. \ Continuous-waste-and-vent. —A continuous- ! waste-and-vent is a vent that is a continuation

of and in a straight line with the drain to which

it connects. A continuous-waste-and-vent is further defined by the angle the drain and vent

at the point of connection make with the hori-

[6]
r

zontal; for example, vertical contiiiuous-wasteand-vent. 45° continuous-waste-and-veiit, and

Hat (small-angle) continiious-waste-and-vent.

Continuous waste.—A waste from two or more

fixtures connected to a single ti'ap.

Cross-connection.—^See Interconnection.

Developed length. —The developed length of a

pipe is its length along the center line of the

pipe and fittings.

Diameter.—Unless specifically stated, the

term diametei' means the nominal diameter as designated commercially

.

Distance.—The distance or difference in ele- vation between two sloping pipes is the distance

between the intersection of their center lines with the center line of the pipe to which both

are connected.

Double offset. —A double offset is two offsets installed in succession or series in the same line. (See fig. 2, pt. III.)

Drain.—A drain or drain pipe is any pipe

which carries water or water-borne wastes in a building-drainage system.

Drainage piping.—^Drainage piping is all or any part of the drain pipes of a plumbing

system.

Dry vent. —A dry vent is any vent that does

not carry water or water-borne wastes. Dual vent.—A dual vent (sometimes called a

unit vent) is a group vent connecting at the

junction of two fixture branches and serving

as a back vent for both branches.

Effective opening.—The eft'ective opening is the minimum cross-sectional area between the

end of the supply-fitting outlet (spout) and the

inlet to the controlling valve or faucet. The

basis of measiu-ement is the diameter of a

circle of equal cross-sectional area.

If two or more lines supply one outlet, the

effective opening is the sum of the effective

openings of the individual lines or the area of the combined outlet, whichever is the smaller.

Fixture branch.—A fixture branch is the

supply pipe between the fixture and the waterdistributing pipe.

Fixture chain.—A fixture drain is the drain

from the trap of a fixtui'e to the jvmction of the

drain with any other drain pipe.

Fixture unit. —A fixture unit is a factor so chosen that the load-producing values of the

differcMit plumbing fixtures can be expressed

approximately as multiples of that factor. Flood level. —Flood level in refci-ence to a plumbing fixture is the level at wliicli water

begins to overflow the top or rim of the fixture. Grade. —The grade of a line of pipe is its slope in reference to a horizontal [)lane. In

pliiml)ing it is usually expressed as the fall in inches per foot length of pipe.

Group vent. —A group vent is a l)rancli vent

that performs its functions for two or more

traps.

Horizontal branch.—A horizontal l)ranch is a branch drain extending latei-ally from a soil or waste stack or building drain, with or without

vei'tical sections or branches, which I'eceives the discharge from one or more fixtiu'e drains

and conducts it to the soil or waste stack or to the building (house) drain.

Indirect waste pipe.—An indirect waste pipe

is a waste pipe which does not connect directly

with the building-drainage system, but dis- charges into it thi'ough a properly trapped

fixture or receptacle.

Interconnection.—An interconnection, as the

term is used in this manual, is any physical connection or arrangement of pipes between two

otherwise separate building water-supply sys- tems whereby water may flow fi'om one system

to the other, the direction of flow depending

upon the pressure dift'erential between the two

systems.

Where such connection occurs between the sources of two such systems and the first bi'anch

from either, whether inside or outside the

building, the term cross-connection (American

Water Works terminology) applies and is gt^nerally used.

Jumpover

.

—See Return offset. Leader.—A leader or downspout is the water

conductor from the roof to the storm drain or other means of disposal.

Loop vent. —A loop vent is the same as a

circuit vent except that it loops back and connects with a soil- or waste-stack-vent instead

of the vent stack.

Main.—The main of any system of contin- uous piping is the principal artery of the system

to which branches may be connected.

Main vent.—See Vent stack.

270988°^0 2 [7]
Nonpresmre drainage.—Nonpressure drainage refers to a condition in which a static

pressure cannot be imposed safely on the building drain. Tliis condition is sometimes referred

to as gravity flow and implies that the sloping

pipes are not completel}' filled. Offset.—An offset in a hne of piping is a combination of elbows or bends which brings one section of the pipe out of line with but into a line parallel with another section.

Plumbing.—Plumbing is the work or business

of installing in buildings the pipes, fixtures, and

other apparatus for bringing in the water supph' and removing liquid and water-borne wastes. The term is also used to denote the installed

fixtures and piping of a building.

Plumbing fixtures. —Plumbing fixtm'es are receptacles which receive and discharge water,

liquid, or water-borne wastes into a drainage

system with which they are connected.

Plumbing sijstem. —The phmibing system of a building includes the water-supply distributing pipes; the fixtures and fixtme traps; the

soil, waste, and vent pipes; the building (house)

drain and buildmg (house) sewer; and the

storm-drainage pipes; with their devices, appurtenances, and connections all within or adjacent to the building.

Pool.—A pool is a water receptacle used for swimming or as a plunge or other bath, designed

to accommodate more than one bather at a

time. Pressure drainage.—Pressm'c drainage, as used in tliis manual, refers to a condition in which a static pressm-e may be imposed safely on the entrances of sloping building drains

through soil and waste stacks connected thereto.

Primary branch.—A primary branch of the

building (house) drain is the single slopingdrain from the base of a soil or waste stack to

its junction with the main building drain or with another branch thereof. Relief vent.—A relief vent is a branch fi'om

the vent stack, comiected to a horizontal

branch between the first fixture branch and the

soil or waste stack, whose primary- fmiction is to provide for chculation of air between the

vent stack and the soil or waste stack.

Return ojfset. —A return oft'set or jumpover

is a double offset installed so as to retm'n the

pipe to its original line.

Riser.—A riser is a water-supplj' pipe which

extends vertically one full stoiy or more to convey water to branches or fixtmes.

Sand interceptor {Sand trap). —A sand interceptor (sand trap) is a watertight receptacle

designed and constructed to intercept and

prevent the passage of sand or other solids into

the drainage system to which it is directly or mdirectly connected.

Sanitary sewer.—A sanitary sewer is a sewer

designed or used only for conveying liquid or water-borne waste from plumbing fixtures. Secondary branch.—A secondary branch of the

building drain is any branch of the building

di'ain other than a primary branch.

Sewage-treatment plant. —A sewage-treatment

plant consists of structures and appm'tenances

which receive the discharge of a sanitary drainage system, designed to bring about a reduction

in the organic and bacterial content of the

waste so as to render it less oft'ensive or dangerous, including septic tanks and cesspools.

(See par. 101, pt. III.)

Side vent. —A side vent is a vent connecting

to the drain pipe thi'ough a 45° W3'e. Size of pipe and tubing. —The size of pipe or tubing, unless otherwise stated, is the nominal

size by which the pipe oi' tubing is commercially

designated. Actual dimensions of the different

kinds of pipe and tubing are given in the

specifications applying.

Soil pipe.—A soil pipe is any pipe which

conveys the discharge of water closets or fix- tmes having similar fmictions, with, or without

the discharges from other fixtiu"es. Stack. —Stack is a general term for the vertical main of a system of soil, waste, or vent

piping.

Stack-vent.—A stack-vent is the extension of a soil or waste stack above the highest horizontal or fixture branch connected to the stack.

Stormt drain.—A storm ch'ain is a drain used

for conveying rain water, subsurface water,

condensate, cooling water, or other similar dis- charges.

Storm sewer.—A storm sewer is a sewer used

for conveying rain water, subsm'face water,

condensate, cooling water, or other similar

discharges.

Subsoil drain.—A subsoil drain is a dram in- stalled for collecting subsurface or seepage

[8]
water and conveying it to a place of disposal.

Trwp.—A trap is a fitting or device so designed

and constructed as to provide a liquid trap seal which will prevent the passage of air through it. Trap seal. —The trap seal is the vertical

distance between the crown weir and the dip of the trap. Vent.— vent is a pipe installed to provide a

flow of air to or from a drainage system or to provide a circulation of air within such system

to protect trap seals from siphonage and back

pressure. Vent stack.—A vent stack, sometimes called a main vent, is a vertical vent pipe installed

primarily for the purpose of providing circulation of air to or from any part of the buildingdrainage system.

Waste pipe.—A waste pipe is a drain pipe

which receives the discharge of any fixture other

than water closets or other fixtures receiving

human excreta. Water main.—^The water (street) main is a water-supply pipe for public or community use. Water-service pipe.—The water-service pipe

is that part of a building main installed by or under the jurisdiction of a water department or company.

Water-supply system.—The water-supply sys- tem of a building consists of the water-service

pipe, the water-distributing pipes, and the

necessary connecting pipes, fittings, and control

valves.

Wet vent.—A wet vent is a soil or waste pipe

that serves also as a vent. Yoke vent. —^A yoke vent is a vertical or 45°

relief vent of the continuous-waste-and-vent

type formed by the extension of an upright wyebranch or 45° wye-branch inlet of the horizontal

branch to the stack. It becomes a dual yoke

vent when two horizontal bi'anches are thus

vented by the same relief vent. (See fig. 2, pt. III.)

CHAPTER II. GENERAL REGULATIONS

Sec. 201. Installation of Piping. —Horizontal drainage piping shall be run in practical

alinement and shall be supported at intervals

not exceeding 10 feet. The minimum slopes

shall be as follows : Not less than }{-inch fall per

foot for V/{- to 2-inch diameters, inclusive;

not less than ^s-inch fall per foot for 2)2- to

4-inch diameters, inclusive; not less than Ke- inch fall per foot for 5- to 8-inch diameters,

inclusive; and a slope that will maintain a

velocity of at least 2.0 fps in a pipe of 10-inch

diameter or largei' as computed by the pipe

formula given in paragraph 201, part III. Stacks shall be supjiortcd at their bases, and

shall be rigidly secured. Piping shall be

installed without undue stresses or strains, and

provision made for expansion, contraction, and

structural settlement. No structural member

shall be weakened or impaired beyond a safe

limit by cutting, notching, or otherwise, unless

provision is made for carrying the structural

load.

Sec. 202. Changes in Direction.—Changes

in direction in drainage piping shall be made by

the appropriate use of cast-iron 45° wyes, half

wyes, long-sweep quarter bends, sixth, eighth, or sixteenth bends, or by combinations of these

fittings, or by use of equivalent fittings or their

combinations ; except that sanitary tees may be

used in vertical sections of drains or stacks, and

short quarter bends may be used in drainage

lines where the change in direction of flow is from the horizontal to the vertical. Tees and

crosses may be used in vent pipes and in waterdistributing pipes. No change in direction

greater than 90° in a single turn shall be made

in drainage pipes. Sec. 203. Prohibited Fittings.—^No double

hub, or double-tee branch, shall be used on soil or waste fines. The drilling and tapping of building drains, soil, waste, or vent pipes, and

the use of saddle hubs or bands, are prohibited.

Any fitting or connection which has an en- largement, chamber, or recess with a ledge,

shoulder, or reduction of the pipe area, that

oft'ers an obstruction to flow through the drain,

is prohibited. (See par. 413, pt. ill.) Sec. 204. Prohibited Connections.—(a) No

fixture, device, or construction shall be installed

which will provide a backflow connection between a distributing system of water for drinking and domestic purposes and a drainage sys- tem, soil, or waste pipe so as to permit or make

possible the backflow of sewage or waste into

the water-supply system.

(6) No interconnection or cross-connection

shall be made between a water-supply system

carrying water meeting accepted standards of

[9]
purity and any other water-supply system.

Sec. 205. Protection OF Pipes.—Pipes pass- ing under or through walls shall be protected

from breakage. Pipes passing through or under

cinder concrete or other corrosive material

shall be protected against external corrosion.

No soil or waste stack shall be installed or permitted outside a building or in an exterior

wall unless adequate provision is made to protect it from freezing. Sec. 206. Protection of Electrical Machinery.—No water or drainage piping shall be

located over electrical machinery or equipment

unless adequate protection is provided against

drip caused by condensation on the piping.

Sec. 207. Protection of Water Tanks.—

Drainage piping shall not pass directly over water-supply tanks or reservoirs unless such

tanks or reservoirs are tightly closed. Sec. 208. Workmanship.—Workmanship

shall be of such character as fully to secure the

results sought in all sections of this manual.

CHAPTER III. QUALITY, WEIGHT, AND

THICKNESS OF MATERIALS

Sec. 301. Quality of Materials.—Materials used in any plumbing system, or part thereof,

shall meet accepted standards and shall be free from defects. Refere ces made in the following sections to standards and specifications shall be taken to mean the latest issues thereof. (See par. 301,

pt. Ill, for information about such issues and for similar and equivalent specifications.) Sec. 302. Identification of Materials.—

Each length of pipe, and each fitting, trap, fix- ture, and device used in a plumbing system shall be cast, stamped, or indelibly marked with the

maker's mark or name ; and also with the weight

and quality thereof, when this is required in the

specification that applies. Sec. 303. Vitrified-Clay Pipe.—Vitrifiedclay pipe shall conform to Federal Specification

for Pipe; Clay, Sewer.

Sec. 304. Concrete Pipe.—Concrete pipe

shall conform to Federal Specification for Pipe;

Concrete, Non-Pressure, Non-Reinforced and

Reinforced.

Sec. 305. Cast-Iron Soil Pipe.—Cast-iron

soil pipe and fittings (calked joints) shall con-

[

form to Federal Specification for Pipe and PipeFittings; Soil, Cast-iron, provided that, when

approved by the authority having jurisdiction over plumbing, lighter pipe and fittings of equal

quality may be used.

Sec. 306. Cast-Iron Water Pipe.—^Cast- iron water pipe shall conform to Federal Specification for Pipe; Water, Cast-iron (Bell and

Spigot and Bolted Joint). Sec. 307. Cast-Iron Screwed Pipe.—Castiron screwed pipe shall conform to Federal | Specification for Pipe, Cast-iron; Drainage,

Vent, and Waste (Threaded).

Sec. 308. Wroxjght-Iron Pipe.—-Wroughtiron pipe shall conform to Federal Specification

for Pipe; Wrought-Iron, Welded, Black and

Galvanized.

Sec. 309. Steel Pipe.—Steel pipe shall con- form to Federal Specification for Pipe; Steel,

Seamless and Welded, Black and Zinc-Coated.

Sec. 310. Brass and Copper Pipe.—^Brass and copper pipe (I. P. S.) shall conform to

[ Federal Specifications for Pipe, Brass, Seamless, j Iron-Pipe-Size, Standard and Extra-Strong;

and for Pipe, Copper, Seamless, Iron-Pipe-Size,

Standard, respectively.

Sec. 311. Brass Tubing.—Brass tubing for fixture connections and fittings shall conform to Federal Specification for Plumbing Fixtures;

(for) Land Use.

Sec. 312. Copper Tubing.—Copper tubing , for use with flared or soldered fittings shall con- form to Federal Specification for Tubing; j Copper, Seamless (for Use with Soldered or , Flared Fittings) (types K, L, and M). Copper

tubing for use with flanged flttings or with i silver-brazed joints shall conform to Federal i Specification for Tubing, Copper, Seamless (for

| General Use with I. P. S. Flanged Fittings)

(types A, B, C, and D). j Sec. 313. Lead Pipe.—Lead pipe shall con- , form to accepted standards. (See table 313- j III, pt. in.) I Sec. 314. Sheet Lead.—Sheet lead shall

; conform to Federal Specification for Lead;

Sheet, and shall weigh not less than 4 pounds

| per square foot. |, Sec. 315. Calking Lead.—Calking lead shall conform to Federal Specification for Lead, [ Calking.

t

]
Sec. 316. Sheet Copper and Brass.—Sheet

copper and brass shall conform to Fedei'al

Specifications for Copper; Bars, Plates, Rods,

Shapes, Sheets, and Strips, and for Brass,

Commercial; Bars, Plates, Rods, Shapes, vSheets,

and Strips, respectively, and shall be not lighter

than No. 18 AWG (Brown & Sharpe gage).

Sec. 317. Zinc-Coated (Galvani/,ed) Sheet

Iron and Steel. —Zinc-coated (galvanized)

sheet iron and steel shall conform to Fedei-al

Specification for Iron and Steel; Sheet, Black

and Zinc-Coated (Galvanized) ; and shall be not

lighter than the following AWG (Brown &

Sharpe gage)

No. 26 for 2- to 12-inch pipe.

No. 24 for 13- to 20-inch pipe.

No. 22 for 21- to 26-inch pipe.

Sec. 318. Screwed Fittings.—(a) Screwed

fittings shall be of cast iron, malleable iron, or

brass. Cast-iron fittings shall conform to Federal Specification for Pipe Fittings; Castiron (Threaded). Malleable-iron fittings shall conform to Federal Specification for Pipe-Fittings; Malleable-Iron (Threaded). Brass fit- tings shall conform to Federal Specification for Pipe-Fittings; Brass or Bronze (Threaded),

125-lb.

(6) Drainage fittings shall be of cast iron,

malleable iron, or brass. Cast-iron fittings

shall conform to Federal Specification for PipeFittings; Cast-iron, Drainage. Malleable-iron

and brass fittings shall conform to the applicable

requirements of the same specification. Sec. 319. Soldered Fittings.—Soldered fit- tings shall conform to American Standards

Association Standard for Soldered-Joint Fittings. Sec. 320. Calking Ferrules.—^Brass calking ferrules shall be of the best quality cast red

brass of approved weights and dimensions (see table 320-III, pt. III). Iron-body ferrules

shall conform to Federal Specification for Pipe

and Pipe-Fittings; Soil, Cast-iron.

Sec. 321. Soldering Nipples and Bushings.—(a) Soldering nipples shall be of red

brass pipe, iron-pipe size, or of heavy cast red

brass of approved weights. (See table 321 (a)-

III, pt. III.)

(6) Soldering bushings shall be of red brass

pipe, iron-pipe size, or of heavy cast red brass.

Sec. 322. Floor Flanges.—^Floor flanges for plumbing fixturc^s shall conform to Fcdciiil

Specification for Plumbing Fixtures; (forj LjiikI Use.

Sec. 323. Packing.—'Packing for hiib-iindspigot joints shall coufoi-ni to Federal Specification for Packing; Jute, Twisted.

Sec. 324. Setting Compound.—Setting com- pound for connecting fixtures to door llanges

shall conform to Federal Specification for Compound ; Plumbing-Fixture-Setting.

Sec. 325. Gaskets.—^Gaskets for connecting

fixtures to floor flanges shall coTiform to Federal

Specification for Gaskets; Plumbing-FixtureSetting.

Sec. 326. Alternate Materials.—Any material other than that specified in this manual

which the authority having jurisdiction over plumbing approves may be used.

CHAPTER IV. JOINTS AND

CONNECTIONS

Sec. 401. Tightness.—Joints and connections shall be made gastight and watertight.

Sec. 402. Vitrified-Clay and Concrete

Pipe.—Joints in vitrified-clay and concrete

pipe, or between such pipe and metals, shall be

hot-poured or cemented joints. Hot-poured

joints shall be packed with approved packing

and filled with an approved jointing compound

at one pouring (see par. 402, pt. III). Cemented joints shall be packed with approved

packing and secured with portland cement (see par. 402, pt. III). Sec. 403. Calked Joints.—Calked joints

shall be firmly packed with approved packing,

secured with well-calked lead, not less than 1 inch deep; and no paint, varnish, or putty

shall be permitted until after the joint is tested.

Sec. 404. Screwed Joints.—Screwed joints

shall be made with a lubricant on the male

thread only. All biu-rs or cuttings shaU be

removed.

Sec. 405. Joints in Cast-Iron Pipe.—

Joints in cast-iron pipe may be either calked

or screwed and shall be made as required in this chapter.

Sec. 406. Joints Between Cast-Iron and

Other Piping.—Joints between cast-iron and

wrought-iron, steel, or brass piping may be

either screwed or calked joints made as required

11
in this chapter. The end of threaded pipe for

callving shall have a ring or half coupling

screwed on to form a spigot end.

Sec. 407. Wiped Joints.—Wiped joints m

lead pipe, or between lead pipe and brass or copper pipes, ferrules, soldering nipples, bushings, or traps, in all cases on the sewer side of the trap and in concealed joints on the inlet side of the trap, shall be full-wiped joints, ^vith an exposed surface of the solder on each side of the joint not less than three-quarters of an

inch, and a miniimun thiclvuess at the thickest

part of the joint of not less than three-eighths

of an inch. Where a roimd joint is made, a thickness of not less than % of an inch for bushings and flange joints shall be provided.

Sec. -iOS. Joints Between Lead and Other

Piping.—Joints between lead and cast-iron,

steel, or wrought-iron piping shall be made by

means of a caU^ing ferrul(\ soldering nipple, or bushing.

Sec. 409. Joints in Copper Tubing.—Copper-tubing joints shall be made m accordance

with approved practice. (See par. 409, pt. III.) Sec. 410. Slip Joints and Unions.—Slip

joints and unions shall be used only in trap

seals or on the inlet side of the trap, except that

expansion joints of approved type may be

permitted. Unions on the sewer side of the

trap shall be ground faced, and shall not be

concealed or enclosed.

Sec. 411. Roof Flashings.—Joints at the

roof shall be made watertight by use of copper,

lead, or zinc-coated (galvanized) iron flashings,

cast-iron plates, or other approved materials.

Sec. 412. Floor Connections.—Floor connections for water-closets and other fixtures

shall be made by means of an approved brass

or cast-iron floor flange soldered securely or calked to the drain pipe. The joint between

the fixture and fioor flange shall be made tight

by means of an approved fixture-setting com- pound or gasket.

Sec. 413. Increasers and Reducers.—

Where dift'erent sizes of drainage pipes or pipes

and fittings are to be connected, proper sizes of stantlard increasers and reducers shall be

employed. Reduction of size of drain pipes

in the direction of flow is prohibited, except as indicated in paragraph 413. part III. Sec. 414. Supports.—Connections of wall

hangers, pipe supports, or fixture settings to masoniy or concrete backing shall be made Avith approved bolts without the use of wooden plugs.

CHAPTER V. TRAPS AND CLEAN-OUTS

Sec. 501. Types and Sizes of Traps.—

Every trap shall be self-cleaning, shall be of the same nominal size as the dram to which it is connected, and shall conform to accepted standards. (See par. 501, pt. III.)

The minimum size (nominal inside diameter)

of trap and fixture dram for a given fixtiu'e shall be not less than shown m the following table:

Size of trap and fix- ture drain, Fixture: inches Bathtubs lii Combination fixtures l}i

Drinking fountains 11-4 Floor drains ^ 2 Latmdry trays l^i Lavatories I1-4 Shower stalls 2 Sinks, kitchen, residence

Sinks, hotel or public 2 Sinks, small, pantry or bar P4

Sinks, dishwasher lli Sinks, service 2 Urinals, trough 2 Urinals, stall 2 For water closets and other fixtures with in- tegral traps, the fixture drains shall be not smaller than the fixture-trap outlet. (See par. 501, pt. III.) Sec. 502. Prohibited Traps.—No form of trap which depends for its seal upon the action

of movable parts, or partitions that cannot

be exposed for inspection, except in a trap

integral with a fixtiu-e, shall be used for fixtures. No fixture shall be double-trapped. (See par. 502. pt. III.) Sec. 503. Traps Required.—Each fixture shall be separately trapped by an approved

trap placed as near to the fixtiu'e as possible

or integral therewith, except that a set of not more than thi'ee fixtures such as lavatories or lainulrv trays, or a set of two laimdry trays

and one sink, may connect ^vith a single trap,

provided the trap for three fixtm'es is placed

centrally. (See fig. 3, pt. III.) Sec. 504. Trap Seal.—Each fixture trap shall have a water seal of not less than 2 inches and

not more than 4 inches. (See fig. 4, pt. III.)

[12]
Sec. 505. Trap Clean-Outs.—Each trap,

except those in combination with fixtures in which the trap seal is plainly visible and accessible, shall be provided with an approved

clean-out plug conforming to Federal Specification for Plumbing Fixtures; (for) Land Use.

Sec. 506. Installation of Traps.—Traps

shall be set true with respect to their water

seals and protected from freezing. Sec. 507. Pipe Clean-Outs.—Pipe cleanouts, ferrules, and plugs shall conform to Federal Specification for Pipe and Pipe-Fittings;

Soil, Cast-iron.

Sec. 508. Pipe Clean-Outs Required.—

Accessible clean-outs shall be provided at or near the foot of each vertical waste or soil stack and each inside leader that connects to the building drain, and at each change in direction of the building drain greater than 45°.

The distance between clean-outs in horizontal

soil lines shall not exceed 50 feet. Clean-outs

shall be of the same nominal size as the pipes

up to 4 inches and not less than 4 inches for larger pipes. Sec. 509. Clean-Out Equivalents.—Any

floor or wall connection of fixture traps when

bolted or screwed to the floor or wall shall be

regarded as a pipe clean-out.

Sec. 510. Accessibility of Traps and

Clean-Outs.—Underground traps and clean- outs of a building, except where clean-outs are

flush with the floor, and exterior underground

traps that are not readily accessible shall be

made accessible by manholes with proper covers.

Sec. 511. Grease Interceptors.—Grease

interceptors shall be installed when required

by and in accordance with the regulations of

the authority having jurisdiction over plumbing.Sec. 512. Oil Interceptors.—Oil interceptors shall be installed when required by and

in accordance with the regulations of the authority having jurisdiction over plumbing.

Sec. 513. Sand Interceptors.—Sand interceptors, when installed, shall be so designed and

placed as to be readily accessible for cleaning.

Sec. 514. Floor Drains.—Floor and area

drains shall conform to Federal Specification for Plumbing Fixtures; (for) Land Use, where

applicable.

Sec. 515. Backwater Valves.—Backwater

valves shall have all l)cai iiig pails of coiTosionresisting metal, and l)e so constructed as to provide a positive mcschanical seal against backwater. The area of valve s(\at shall b(> equal to the cross-sectional area of the \n\)(' eomicction.

CHAPTER VI. WATER SUPPLY AND

DISTRIBUTION

Sec. 601. Quality of Water.—The quaUty

of the water supply to each building shall meet

accepted standards of purity. Development of private sources of supply shall be in accordance

with approved practice. (See par. 601, pt.

III.) Sec. 602. Protection or Water Supply.—

(a) Potable and nonpotable water supplies

shall be distributed through systems entirely

independent of each other.

(b) Water pumps, wells, hydrants, filters, softeners, appliances, and devices shall be

protected from surface water and outside con- tamination by approved covers, walls, or

copings.

(c) Potable water-supply tanks, whether

storage, pressure, or suction tanks, shall be

properly covered to prevent entrance of foreign

material into the water supply. (See also sec. 207.)

(d) Every supply outlet or connection to a

fixture or appliance shall be protected from

backflow by means of an approved air gap or backflow preventer between the control valve of

the outlet and the fixture or appliance. (See

par. 602 {d) , pt. III.) Sec. 603. Protection From Freezing.—

Water pipes, storage tanks, flushing cisterns,

and appliances, when subject to freezing temperatures, shall be protected. Water pipes

underground shall be placed below freezing

level, or shall be otherwise insulated to protect

them from freezing. Interior piping shall be

insulated, when necessary, for protection.

Sec. 604. Size or Building Main.—The

building main, including the water-service pipe,

shall be of suflftcient size to permit a continuous

ample flow of water to the building under the

average daily minimum service pressure in the

street main. The required size for each building shall be determined by the rules given in

paragraph 604, part III. No building main of

less than %-inch diameter shall be installed. If

[13]
flush valves are installed, the building main

shall be of not less than 1-inch diameter.

Sec. 605. Quantity of Water.—Plumbing

fixtures shall be provided with a sufficient supply of water for flushing and keeping them

in a sanitary condition.

Sec. 606. Size of Fixture Branches.—The

minimum size of fixture branches and other

supply outlets shall be as follows:

Inch

Sill cocks Yi Domestic water heaters Y2 Laundry trays Yt Sinks__l___^ Yi Lavatories %

Bathtubs M

Water-closet tanks %

Water-closet flush valves 1 Flush valves for pedestal urinals 1 Flush valves for wall or stall urinals Y^ Sec. 607. Shut-Offs.—Accessible shut-oft's with drains shall be provided on the building

main and on branches for each dwelling unit

and in freezing climates for each outdoor connection. Additional shut-off's may be installed. Sec. 608. Material for Water Piping and

Tubing.—Material for building water-supply

pipes and tubes shall be of brass, copper, cast

or wrought iron, lead, or steel, with approved

fittings. All threaded ferrous pipe and fittings shall be galvanized (zinc-coated). No pipe,

tubing, or fittings that have been previously

used shall be used for distributing water except

for replacement in the same system.

Lead piping in water-supply lines shall not

be used unless it has been definitely determined

that no poisonous lead salts are produced by

contact of lead with the particular water supply.

Sec. 609. Relief Valves.—An approved relief valve shall be installed in each hot-water

system and so located that there is no shut-oft' or check valve between the tank and the relief valve.

CHAPTER VII. PLUMBING FIXTURES

Sec. 701. Quality of Fixtures.—Plumbing

fixtures shall conform to accepted standards.

(See par. 701, pt. III.) Sec. 702. Installation of Fixtures.—

Plumbing fixtures shall be installed in a manner

to aft'ord access for cleaning. Where practicable, pipes fi-om fixtures shall be run to the

wall, and no lead trap or lead pipe shall extend

nearer to the floor than 12 inches unless protected by casing.

Sec. 703. Frostproof Closets.—Frostproof

closets may be installed only in compartments

which have no direct access to a building used

for human habitation or occupancy. The soil pipe between the hopper and the trap shall be of not less than 3-inch diameter and shall be of

lead, or cast iron enameled on the inside. The

waste tube from the valve shall not be connected

to the soil pipe or sewer.

Sec. 704. Floor Drains.—A floor drain or a shower drain shall be considered a fixture and

provided with a strainer. Sec. 705. Fixture Strainers. — Fixtures

other than water closets and pedestal and blowout urinals shall be provided with approved

strainers. (See par. 705, pt. III.) Sec. 706. Fixture Overflow.—The overflow pipe from a fixture shall be connected on

the inlet side of the trap and be so arranged

that it may be cleaned.

Sec. 707. Swimming Pools. — Swimming

pools shall be constructed in accordance with

accepted practice. (See par. 707, pt. III.) Sec. 708. Miscellaneous Fixtures.—Baptistries, ornamental and lily ponds, aciuaria,

ornamental fountain basins, and similar constructions shall have supplies thereto protected

from backflow as required in section 602.

Sec. 709. Ventilation.—No plumbing fix- tures shall be located in any room not provided

with proper ventilation. Ventilating pipes

from toilet rooms shall form an independent

system.

CHAPTER VIII. SOIL AND WASTE PIPES

FOR SANITARY SYSTEMS

Sec. 801. Materials.—{a) Soil and waste

piping for sanitary drainage systems within a building shall be of brass, copper, iron, steel, or

lead.

(6) The building drain when underground

shall be of cast iron.

(c) The building sewer shall be of cast iron, vitrified clay, or concrete.

Sec. 802. Minimum Sizes.—The minimum

required sizes of soil and waste pipes, depending

2 See par. 800, pt. HI, for acid wastes.

14
on location and conditions of service, shall be

in accoi'dance with the following sections and

tables of this chapter and the principles, rules,

and tables relating to drains and sewers in part

III. (See par. 802, pt. III.) Sec. 803. Fixture Units. — The following

table of fixture-unit values designating the rela- tive load weights of different kinds of fixtui'es shall be employed in estimating the total load

carried by a soil or waste pipe and shall be used

in connection with tables of size for waste and

drain pipes in which the permissible load is given

in terms of fixture units.

Table 803.

Fixture iinits per fixture or group '

Fixture and type of installation

Lavatory or washbasin:

Public . Private _ Water closet: Public

Private Bathtub, public Shower head:

Public

Private

Pedestal urinal, public Wall or stall urinal, public

Service sink- _ Kitchen sink, private 2 Bathtub, private Bathroom group, private Bathroom group with separate shower stall, private.. Two or three laundry trays with single trap, private 2 Combination sink and laundry tray, private - Sewage ejector or sump pump, for each 2.5 gpm

Number of fixture units

2

1

10

6

4

4

210

5

32

2810

3

350

1 See par. 803, pt. Ill for fixture-unit weights not included in table 803.

2 These fixtures and groups may be omitted in determining the total

fixture units to be applied for soil pipes but the fixture-unit weights as- signed must be applied for separate waste lines for groups of these fixtures.

Sec. 804. Stacks To Be Vertical.—Soil

and waste stacks shall extend in a vertical line from the highest to the lowest horizontal branch

or fixture branch connected thereto, except as provided for in section 806, and shall be vented

in accordance with the requirements of chapter X.

Sec. 805. Size of Soil and Waste Pipes.—

(a) Except as provided in (b) of this section, the

total number of fixture units installed on a soil or waste stack or horizontal branch of given

diameter shall be in accordance with table 805.

No soil or waste stack shall be smaller than the

largest horizontal branch connected thereto.

(6) If the total fixture units are distributed on horizontal branches in three or more branch

intervals of the stack, the total number of fix- ture units on a straight soil or waste stack of a

given diameter may be incireased from the

values given in table 805 within the limits of

table 805(/!))-III, part III, provided the maximum fixture units for one branch iuteiwal as computed in accordance with table 805(6)-III

is not exceeded in any branch interval of the

system.

Table 80.5.

Permissible nurnher of fixture units on

horizontal branches and stacks

Diameter of pipe

(inches)

Fixture

units on 1 horizontal branch

Fixture

units on 1 stack

Number Number

1J4 1 2 Wx 3 4

2 6 10

3 waste only 32 48

3 soil 20 30

4 160 240

5 360 540

6 640 960

8 1,200 2, 240

10 1,800 3, 780

12 2,800 6, 000

Sec. 806. Offsets.—{a) A single offset, a double offset, or a return offset, with no change

in direction greater than 45°, may be installed

in a soil or waste stack with the stack and

branches vented as required for a straight stack,

provided that the total number of fixture units on such stack does not exceed one-half the limit permitted by section 805(a) and table 805,

and no horizontal branch connects to the

stack in or within 4 diameters (stack) above

or below a sloping section of the offset.

(b) If an offset is made at an angle greater

than 45°, the required diameter of that portion

of the stack above the offset shall be determined as for a separate stack. Tlie diameter

of the offset including fittings shall be deteimined as for a primary branch, and the portion

above the offset shall be considered as a horizontal branch in determining the diameter of that portion of the stack l)elow the offset. A

relief vent shall be installed in accordance with

the requirements of section 1017 at the offset or between it and the next lower horizontal branch.

(c) An offset above the highest horizontal

branch in a soil or waste stack system is an

offset in the stack-vent and shall not be considered in this connection other than as to its effect on the developed length of vent.

{d) In case of an offset in a soil or waste

stack below the lowest horizontal branch, no

270988°—40 3 [1-5]
change in diameter of the stack because of the

offset shall be required if it is made at an angle

of not greater than 45°. If such an offset is made at an angle greater than 45°, the required

diameter of the offset and the stack below it shall be determined as for a primary branch.

Sec. 807. Horizontal and Primary

Branches.—(a) The required sizes of horizontal branches and primary branches of the

building drain shall be in accordance with

table 807, except that the permissible number

of fixture units on primary branches as given

in table 807 may be increased as provided for in section 807 (c/).

Table 807.Capacities of horizontal branches and

primary branches of the building drain

Diameter of pipe

(incties)

Permissible number of fixture units ^

Horizontal branch

at mini- mum

permissible slope or greater

Primary branch '

M 6-inch

fall pe r foot

^Mnch

fall per

foot

1-4 -inch

fall per

foot

Va-inch

fall per

foot

Number Number Number Number Number IH 1 2 2 Wi 3 6 7 2 6 21 26

3 waste only _

.

32 36 42 50

3 soil . _ . .. 20 24 27 36

4 160 180 216

480

250

5 360 360 400 560

6 600 600 660 790 940

8 1, 200 1,400 1, 600 1,920 2, 240

10 1, SOO 2,400 2, 700 3, 240 3, 780

12 2, 800 3. 600 4, 200 5, 000 6. 000

1 See par. 807, pt. Ill, for method of computing permissible number of fixture units for other slopes than those given in this table.

(6) In case the sanitary system consists of one soil stack only or of one soil stack and one or more waste stacks of less than 3-inch diameter,

the building drain and building sewer shall be

of the same nominal size as the primary branch

from the soil stack as given by table 807, except

that {d) of this section and the applicable rules

in paragraph 807, part III, relating to pressure

drainage may apply when the prescribed

conditions are complied with.

(c) In case the plumbing system has two or more soil stacks each having its separate primary branch or has one or more soil stacks and

one or more waste stacks of 3-inch diameter or

larger, each soil and waste stack having its sepaxate primary branch, the number of fixture

units for a secondary branch, the main building

drain, or the building sewer of a given diameter

and slope may be increased from the A^alue given

in table 807 for a primary branch of the same

diameter and slope to the value given in table

807(c), part III, of this manual, provided that

the increase is made strictly within the principles

and rules of paragraph 807, part III.

{(I) In case there is no fixture drain or

horizontal branch connecting directly with the

building drain or a branch thereof and the lowest

fixture branch or horizontal branch connected

to any soil or waste stack of the system is 3

feet or more above the grade line of the building

drain, the permissible number of fixture units on primary branches, secondary branches, main

building drain, and building sewer, may be

increased within the limits given by table

807(</), part III, provided the increases are made in accordance with the principles and rules

given in paragraph 807, part III.

(e) The provisions of sections 807(c) and

807 (c?) shall not apply unless plans drawn to scale showing the proposed installation in detail in regard to the diameter, dnection,

length, and slope of the building drain and its branches and of the building sewer have been

submitted to and approved by the authority

having jurisdiction over plumbing.

Sec. 808. Sumps and Receiving Tanks.—

All building subdrains shall discharge into an

airtight sump or receiving tank so located as to receive the sewage by gravity, from which

sump or receiving tank the sewage shall be

lifted and discharged into the building sewer by

pumps, ejectors, or any equally efficient method.

Such sumps shall either be automatically dis- charged or be of sufficient capacity to receive

the building sewage and wastes for not less than

24 hours.

CHAPTER IX. STORM DRAINS

Sec. 901. General.—Roofs and paved areas, yards, courts, and courtyards shall be drained

into the storm-sewerage system or the combined sewerage system, but not into sewers intended for sanitary sewage only. When con- nected with a combined sewerage system, storm

drains, the intakes of which are within 12 feet of any door, window, or ventilating opening, if not at least 3 feet higher than the top of such

opening, shall be eft'ectively trapped. One trap on the main storm drain may serve for all such

[16]
connections. Traps shall be set below the frost hne or on the inside of the building. Where

there is no sewer accessible, storm drainage shall discharge into the public gutter, unless otherwise permitted by the proper authorites, and in

such case need not be trapped.

Sec. 902. Leaders AND Gutters.—(a) Leaders, when placed within the walls of a building

or run in a vent or pipe shaft, shall be of castiron, zinc-coated (galvanized) wrought-iron or

steel, brass, copper, or lead pipe, or of copper

tubing.

(b) Outside leaders may be of sheet metal.

When of sheet metal and connected with a building storm drain or storm sewer, they shall be

connected to a cast-iron drain extending not

less than 1 foot above the finish grade. A sheetmetal leader along a public driveway without

sidewalk shall be properly protected against

injury.

(c) Roof gutters shall be of metal or other

materials suitable for forming an effective open

channel for collecting water and conducting it to the leaders and suitable for making a tight

connection with the leaders. (See par. 902, pt.

IIL)

Sec. 903. Size of Storm Drains and Leaders.—(a) Storm drains of a building shall be of ample size to convey the estimated storm water

from the roof gutters to the street sewer or other

approved place of discharge without overflow

and without producing dangerously high pres- sures in any building drain or leader. The esti- mated flow shall be based on the maximum ex- pected rate of rainfall and estimated rate of flow

of storm sewage from other sources. The tables

in this section pertaining to leaders and buildingstorm drains are based on the horizontal projection of the roof area, a rate of rainfall of 4

inches per hour and limited slopes as indicated

in the tables. (See par. 903, pt. Ill, for methods of computing the requirements for conditions not covered by or in these tables.)

(b) The area drained into or by a vertical

leader or a sloping leader or connecting pipe

having a slope of K-inch fall per foot or greater

shall not exceed the values given in table

903(6).

(c) The roof area drained into a building

storm sewer or into a main storm drain or any

Table 903(^;). —Maximum roof area for leaders

Diameter of Maximum

leader or pipe roof area

IncheK Square feel 2 .500 900

3 1, riOO

2, 20(1 1 3, 100

5 f), -100 0 S, 400

8 17,400

» Drainage fittings are not generally available. Table 903(c).

Maximum roof area for building storm

sewers or drains

Diameter

of pipe

(inches)

2

3 •31/2

4

5

68

1012

Maximum roof area for drains of various slopes

He-inch

fall per

foot

Sguare feet

1,800 3.000

5,900 9,800

15, 900

!.8-inch

fall per

foot

Square feel "480

750

1, 100

1. 560

2, 700

4, 200

8, 700

15. 200

24. 700

}^-inch

fall per

foot

Square feet 350

670 1,050

1, 550

2, 150

3, 000 6,000

11, 900

19, 600

31, 800

'/i-mch

fall per

foot

Square feet 500

960

1. .500

2. 200

3. 100

.5, 400

8, 400

17, 400

30, 400

49, 400

» 2,''2-inch and 3;4-inch east-iron soil pipe and fittings and :JH-inch drainage fittings are not generally available.

of its branches shall not exceed the values

given in table 903(c).

{d) Roof area or drained area as applying

in the preceding tables of this section shall be

the horizontal projection of the area, except

that where a building wall extends above the

roof or court in such a manner as to drain

onto the roof or court, due allowance for the

additional run-oft' shall be made. (See par. 903 ((i), pt. Ill, for methods of computing

allowance.

)

Sec. 904. Separate and Combined

Drains.—(a) The sanitary- and storm-di'ainage

systems of a building shall be entirely separate,

except that where a combined sanitary-andstorm street sewer is available the storm drains

may connect to a combined sanitary-andstorm building drain or sewer at least 10 feet downstream from any primary branch of the

sanitary system. Connections between the

sanitary and storm systems shall be made at the same grade by means of a single wye

fitting. (See par. 904, pt. Ill, for explanation

of this requirement.)

(b) Lip to the point of combining into one

system, the sizes of the storm and sanitarv

[17]
branches shall be as required for separate

storni and sanitary systems.

In the case of a combined sanitary-andstoi'm building drain or sewer, or of a branch

formed by the junction of a single storm drain

or sewer and a single sanitary drain or sewer when neither the storm nor the sanitary drain

carries more than one-half of its allowable

load as given in table 903(c), part II, and table

807(<?)-III, part III, the diameter of the combined drain or combined sewer shall be at least equal to that of the larger of the two

branches emptv'ing into it, except that m no

case shaU a combined sanitary-and-storm building di-ain or building sewer be less than 4 inches

in diameter. If either or both of the storm or sanitary branch di-ains carry more than one-half

the allowable load, the combined drain or combined building sewer shall be in accordance

with table 904-III and rules of paragraph

904, part III. Sec. 905. Closed System Required.—When

connected mth a combined sanitary-and-storm

sewerage system, the building storm-drainage

piping shall form a closed system with watertight jomts, except for its outlet and intake

openings.

Sec. 906. Overflow Pipes. —Overflow pipes

from cisterns, supply tanks, expansion tanks,

and drip pans shall connect vrith any building

sewer, buildmg drain, or soil pipe only by means

of an indirect connection.

Sec. 907. Subsoil Sumps.—Subsoil drains below the main-sewer level shall discharge into a sump or receiving tank, the contents of which

shall bo automatically lifted and discharged

into the drainage system through a properl_y

trapped fixtiu-e or drain.

Sec. 908. Construction of Subsoil

Drains.—T^Tiere subsoil drams are placed under the cellar floor or used to encircle the outer

walls of a building, they shall be made of openjointed dram tile or earthenware pipe, not less than 4 inches in diameter. When the building

drain is subject to backwater the subsoil drain

shall be protected by an accessibh^ located

automatic back-pressure valve before entermg

the building sev^er or drain. If such drains

are connected with the sanitary sewer or with

a combined system they shall be properly

trapped. They may discharge to an area drain.

CHAPTER X. VENTS AND VENTING

Sec. 1001. Material.—Vent pipes or tubing

shall be of cast iron, zmc-coated (galvanized)

wrought iron or steel, brass, copper, or lead. Sec. 1002. Protection of Trap Seals.—

The seal of eYeiy fixture trap m a plumbing

system shall be adequately protected by a properly mstalled vent or system of venting.

A stack-vent, back vent, relief vent, dual vent,

cu'cuit or loop vent, or a combination of two or more of these forms installed in the manner and

within the limitations specified in sections 1006

to 1012, inclusive, shaU be considered as adequate protection of trap seals in the sense of

this section. (See par. 1002, pt. III.) Sec. 1003. Stack-Vents Required.—Every

soil or waste stack shall be extended vertically

as a stack-vent to at least 6 mches above the

highest horizontal branch and then to the open

air above the roof or otherwise terminated in the open air outside the building; or the stackvent and vent stack may be connected together

within the building at least 6 inches above the

flood level of the highest fixture, with a single

extension from the connection to the open air. Sec. 1004. Vent Stacks Required.—A vent

stack or main vent shall be instaUed with a soil or waste stack whenever relief vents, back vents, or other branch vents are requhed in two or more branch intervals. The vent stack shall terminate independently in the open air outside

the building or may be connected s\dth the

stack-vent as prescribed in section 1003, and

shall connect with the soil or waste stack

through, at, or below the lowest horizontal

branch or with the primary branch of the

building drain.

Sec. 1005. Distance of Trap From Vent.—

Except as provided for particular fixtm-es and

forms of construction in sections 1010 and 1011,

and excepting water closets, pedestal urinals,

trap-standard service sinks, and other flxtures which depend on siphon action for the proper

fimctionmg of the fixtm'e, each fixture trap

shall have a protecting vent located so that the

total faU in the fixtm'e drain from the trap weir

to the vent fittmg is not more than 1 pipe diameter, and the developed length of drain from

trap weir to vent fitting is not less than 2 nor more than 48 pipe diameters. A back vent or

[18]
relief vent, preferably in the form of a continuous-waste-aiid-vent, shall be installed witiiin these limits as may be necessary for compliance

with this requirement. (See par. 1005, and

fig. 13, pt. III.) Sec. 1006. Dual Vents Permitted.—A dual

vent for two fixture traps installed as a vertical

continuous-waste-and-vent, or a stack-vent in a dual capacity, may be employed under the fol- lowing conditions and no additional vents for the traps thus vented shall be required:

(a) When both fixture drains connect with a

vertical drain or stack at the same level, and

the developed length and total fall of each of the two fixtm'e drains are within the limits

given in section 1005. (See fig. 14A, pt. III.)

(6) When the two fixture drains connect with

the vertical drain or stack at dift'erent levels, the

difference in level of the two connections is not

gi'eater than five times the diameter of the

vertical section of drain or stack, the diameter

of the vertical section or stack up to and including the higher connection is not less than that

requu-ed for the horizontal drain for both fix- tures, the cross-section of the higher of the two

fixture drains is not greater than one-half that

of the vertical drain, and the developed length

and total fall of each of the two fixture drains is within the limits given in section 1005. (See

fig. 14B, pt. III.) Sec. 1007. Group Vents Permitted.—(a) A lavatory trap and a bathtub or shower-stall

trap may be installed on the same horizontal

branch with a back vent for the lavatory trap

and with no back vent for the bathtub or

shower-stall trap, provided the vertical section

of the lavatory drain is of not less than iK-inch

diameter, connects with the tub or shower-stall

drain in a vertical plane, and the developed

lengths of both fixture drains are within the

limits given in section 1005. (See fig. 15A,

pt. III.)

(b) Two lavatory traps and two bathtub or shower-stall traps may be installed on the same

horizontal branch with a dual vent for the

lavatory traps and with no back vents for the

bathtub or shower-stall traps, provided that

the horizontal branch, except the separate

fixture drains, shall be at least 2 inches in

I diameter and the fixture drains for bathtubs or shower stalls connect as closely as practicable

upstream from l.lic vent by means of n (li aiiiage

wye. (See fig. 1.5B, pt. III.)

(c) A lavatory trap, kitchen-sink trap, and a bathtub or shower-stall trap may be installed on the same horizontal bi-uiich, as in (a), pro- vided the dual vent for the lavatory and sink

traps is installed in accordance with section

1006. (See fig. 15C, pt. III.) Sec. 1008. Yoke and Relief Vents.—Bath- room groups, each consisting of a water closet,

lavatory, and a shower stall or bathtub with

or without shower head, may be installed on a

soil stack with any of the following forms of group venting:

(a) Two bathroom groups, or one bathroom

group and kitchen sink or kitchen-sink-andtray combination, may be installed in the highest branch interval of the soil stack or on a

vertical yoke-vented branch not less than 3 inches in diameter with no branch vents other

than the yoke vent, provided each fixture

drain connects independently to the soil stack

or with the water-closet drain (closet bend) in the highest branch interval and each fixture

drain in all except the highest branch interval

connects independently with the yoke-vented

branch or with the water-closet drains (closet

bends) within the limits given in section 1005.

(See fig. 16, pt. III.)

(b) One bathroom group with group venting in accordance with section 1007(a) and with

the horizontal branch connected to the soil stack at the same level as the water-closet drain

or connected to the water-closet drain (closet

bend), or a bathroom group and kitchen sink

with connections to the stack in the same manner and with group ventmg in accordance

with section 1007(c), may be installed m the same branch interval of a soil stack within the

limits of permissible fixture units for one soil stack and branch intervals (sec. 805(6)), provided that a relief vent is installed from the

water-closet branch drain in the third branch

interval from the top and in each lower branch

interval. (See fig. 19, pt. III.)

(c) Two bathroom groups with group venting in accordance with section 1007(a) or

1007(6), or two bathroom groups and two

kitchen sinks with group venting in accordance

with section 1007(c), may be installed in the same branch interval of a soil stack, provided

]
a relief vent is installed for the second and

lower branch intervals from the top. (See figs.

18 and 20, pt. III.)

(d) In all cases the relief vent required

under (a), (b), or (c), may be a dual vent and

the size shall be in accordance with section 1015.

Fittings that combine the effects of two or more

standard fittings in one casting may be per- mitted. (See also par. 1008 and figs. 13 to 20,

pt. III.) Sec. 1009. Circuit Vents and Loop

Vents.—(a) A group of fixtures in line (battery) on the same floor or level may be installed on one horizontal branch with a circuit or loop

vent connected to the horizontal branch in front of the last fixture drain, within the Hmits

given in table 1009(a), provided relief vents

connected to the horizontal branch in front of the first fixture drain are installed as follows:

In each branch interval, if the total fixture

units installed in the branch exceeds one-half

the number given in table 1009(a), except that no relief vent shall be required in the highest

branch interval of the system or in any branch

interval if the total number of fixture units on

the stack above the horizontal branch does not

exceed the limits for one stack given in table

805 and the number of fixtures on the circuit- or loop-vented horizontal branch does not ex- ceed two for a 2- or 3-inch horizontal branch or does not exceed one-half the permissible number in column 2 of table 1009(a) for 4-inch and

larger horizontal branches. A dual relief vent

for two circuit- or loop-vented horizontal

branches in the same branch interval may be

installed.

Table 1009(a).

Limits for circuit and loop venting

(1) (2) (3)

Diameter of horizontal

branch!

W ater closets, pedestal

urinals, or trap-stand- ard fixtures

Fixture units

for fixtures other than

designated in column 2

Inches

2

3

Number None

2

Number

G20

45

6

8

1624

60

120 180

(6) The limits for circuit- or loop-vented

horizontal branches may be increased to one and one-half times the values given in table

1009(a) for 3-inch and larger branches when

relief vents are installed so that there is a relief vent inside the first fixture drain, the number

of fixtures or fixture units outside the last relief vent does not exceed the limits given in columns

2 and 3 of table 1009(a), and the number of fixture drains between any two successive relief vents does not exceed two for a 3-inch, three

for a 4-inch, five for a 5-inch, or eight for a 6-inch or larger horizontal branch.

(c) Two lines of fixtures back-to-back (double

battery) shall not be circuit- or loop-vented on

one branch, but each line may be installed on

a separate branch and circuit- or loop-vented.

(See figs. 21 and 22, pt. III.) Sec. 1010. Vents for Flat-Bottoivied Fixtures.—The trap and fixture drain not exceeding 2 inches in diameter of a single fixture

having a relatively flat bottom at least 200

square inches of which slopes toward the outlet

with a fall not exceeding )i inch per foot, or the trap and fixture drain from a group of not more than thi'ee such fixtures, may be installed

with a vertical section of the fixture drain not

exceeding 24 pipe diameters in length at a dis- tance not exceeding 10 pipe diameters from the

trap weir, with a total length of sloping drain

not exceeding 72 pipe diameters, with no back

vent, provided that the fixture drain is the

highest drain on the soil or waste stack or on a yoke-vented vertical section of a horizontal

branch. If the total developed length of the

sloping sections of the drain from the fixture to the stack-vent or relief vent exceeds 72 pipe

diameters (9 feet for iK-inch diameter or 12

feet for 2-inch diameter), a back vent to the

first vertical section of the drain or a continuouswaste-and-vent relief vent at or within this prescribed maximum distance shall be installed. (See par. 1010, and fig. 23, pt. III.) Sec. 1011. Vents for Resealing Traps.—If a resealing trap of approved design is installed for a fixture or a group of not more than three

fixtures, the limits given for venting in section

1010 shall apply. (See par. 1011, pt. III.) Sec. 1012. Fixtures at Base of Main

Vent.—A group of not more than three fixtures, none of which discharge greasy wastes, may be

installed on a main vent or vent stack below

the lowest branch vent, provided the load does

not exceed one-half the allowable load by table

[20]
807 oil a horizontal brancli of llic saiuc (liaiiu'ter as the mam vent. (See par. 1012, pt. 111.) Sec. 1013. Size and Length of Main

Vents.—Vent stacks or main vents shall have

a diameter of at least one-half that of the soil or waste stack, and shall be of larger diameter in accordance with the limits of length and number

of fixture units as given in table 1013. The

length of the main vent for application with

table 1013 shall be the total developed length as follows

(a) From the lowest connection of the vent

system with the soil stack, waste stack, or primary bi'anch to the terminal of the vent, if it terminates separately to the open air;

(6) From the lowest connection of the vent

system with the soil stack, waste stack, or primary branch to the stack-vent plus the

developed length of the stack-vent to its ter- minal in the open air, if the stack-vent and vent

stack are joined with a single extension to the

open air.

Table 1013.Size and length of 7nain vents

Diameter

of soil or waste stack

(inches)

Number

of

fixture

units

on

soil

or

waste

stack

Maximum permissible developed length of vent

a

>o

a

c

>

a

2-inch

vent 0

>O

a

3-inch

vent

4-inch

vent

5-inch

vent

'

6-inch

vent

8-inch

vent

VA 2

8

244080

310 620

750 1,500

1,440 2,880

3, 100 6,200

Feet

75

70

28

Feet Feet Feet Feel Feet Feet Feet Feet m 150

7020

18

2 300

80

7530

22

3 260 240

95

70

28

20

650

600

240

18070

5020

18

3

4 1,000 750 320

240

95

7030

25

4

5 1,000

750 240

18080

60

5

1,000^ 750 350

250

6^ - 6

8 1, 100 8- 800

Sec. 1014. Size and Length of StackVents.—Stack-vents shall be of the same diameter as the soil or waste stack, if the soil or waste stack carries one-lialf or more of its permissible load by table 805 or has horizontal

branches in more than two branch intervals.

If the soil or waste stack carries less than onehalf its permissible load and has horizontal

branches in not more than two bi'anch intervals,

the stack-vent may be of a diameter not less and a length not greater than required by table

1013.

Sec. lOlfj. Sizi-: ok Hack Veni's and liKi>noF

Vents.—The nominal diameter of a back vent,

when required, shall be not less than 1 '4 inches nor less than one-half the diameter of I lie ili nin

to which it is connected, and under conditions

that require a relief vent for approved forms of group venting (see sees. 1007, 1008, and 1009),

the sum of the cross sections of all vents in- stalled on the horizontal branches in one l)ranch

interval shall be at least equal to that of cillnT

the main vent or the largest horizontal bi-anch

in the branch interval. Sec. 1016. Size of Circuit and Loop

Vents.—(a) The nominal diameter of a circuit

01' loop vent and the first relief vent as required

by section 1009(a) shall be not less than onehalf the diameter of the horizontal branch thus

vented. Under conditions that requii-e a relief vent (see sec. 1009) the sum of the cross- sections of the circuit or loop and relief vents

shall be at least equal to that of either the main

vent requii-ed or the horizontal brancli. In determining the sum of cross sections for this requu'ement all relief vents connected to the

horizontal branch may be included.

(b) Additional relief vents, installed in compliance with section 1009(6), shall be not less in diameter than one-half that of the largest

fixture branch connected to the horizontal

branch.

Sec. 1017. Relief Vents for Offsets.—

The relief vent requii'ed for an oft'set, as pre- scribed by section 806(6). shall be installed

either as a vertical continuation of the lower

section of the soil or waste stack or as a side

vent connected to the lower section of the soil or waste stack between the oft'set and the next

fixture or horizontal branch b<>low the oft'set. The size of the required relief vent shall be

determined as follows:

(a) If the stack-vent from the upper section

of the soil or waste stack is equal to that of the

upper section, the relief vent shall not be

smaller than the main vent of the stack system;

(6) If the stack-vent from the upper section

of the soil or waste stack is smaller in diametei'

than that section, it may be the same diameter

as the main vent required, in which case the

diameter of the relief vent for the oft'set shall be equal to that of the lower section and shall be extended to the open air without reduction

[21]
ill size or may hi' conncctt'd to tlie main vent or stack-vent, provided the one to which it is connected is of eqnal or greater diameter.

If horizontal branches connect to any soil or waste stack between two offsets each offset shall be vented as required in this section. Sec. fOfS. Frost Closure.—In cold climates

ade(|uate provision shall be made to guard

against frost closure of vents.

Sec. f0f9. Location of Vent Terminals.—

(a) No vent terminal from the sanitary drainage system shall be within 12 feet of any door,

window, or ventilating opening of the same or an adjacent builcHng unless it is at least 3 feet

liigher than the top of such opening. Extensions of vent pipes through a roof shall ternu- nate at least 1 foot above it and shall be propei'ly flashed. Vent terminals extending througli

walls shall not terminate within 12 feet horizontalh' of any adjacent building line, shall be

tiu'iied to provide a horizontal opening downward, shall be effectively screened, and shall be

properly flashed, calked, or otherwise sealed.

(6) In the event that a structure is built higher than an existing structiu'e, the o\\aier of the structure shall not locate windows within

12 feet of any existing vent terminal on the

lower sti'uctm'e, unless the owner of such higher

structure shall defray the expenses of, or shall himself make, such alterations as are necessary

to conform with the provisions of this section. Sec. 1020. Vents Not Required.—(a) No

vent shall be required for a leader trap, backwater trap, oi' STibsoil catchbasin trap.

(6) No vent shall be required for the trap

of a basement or cellar-floor drain or area

drain, provided such (h'ain branches mto the

building drain or a branch thereof at least o feet downistream from any soil or waste stack,

the length and fall of the floor or area drain are within the limits of section lOOo, the load on the budding drain or any of its branches

does not exceed the limits in table 807. and the

builduig drain is not subject to backwater

effects. Sec. 1021. Vents Prohibited.—(a) No back

vent shall be installed within two pipe diameters

of the trap weir.

(b) Except as permitted in sections 1006,

1007, 1008, 1009, and 1012, no wet vent shall be uistalled.

CHAPTER XI. INDIRECT CONNECTIONS

TO WASTE PIPES

Sec. 1101. Indirect Wastes.—Waste pipes

from the following shall not connect directly

with any building drani, soil, or waste pipe: a

refrigerator, ice box, or other receptacle where

food is stored; an appliance, device, or apparatus

used in the preparation or processing of food

or drinlv; an appliance, device, or apparatus

using water as a cooling or heating medium;

a sterilizer, water still, water-treatment device, or water-operated device.

Such waste pipes shall in all cases empty

into, and above the flood level of, an open

plumbing fixture or shall be comiected indiI'ectly to the inlet side of a fixture trap. In-

(Urect waste connections shall not be located

in inaccessible or unventilated cellars or other

spaces. (See par. 1101, pt. III.) Sec. 1102. Size OF Refrigerator Wastes.—

Refrigerator waste pipes shall he not less than

1/4 inches in diameter for one opening, VA

inches for 2 or 3 openings, and 2 inches for 4

to 12 openings. Each opening shall have a trap

and clean-out so installed as to permit proper

flushing and cleaning of the waste pipe. Sec. 1103. Overflow Pipes.—Overflow pipes

from a water-supply tank or exhaust pipes from

a water lift shall not be directly connected with

any building dram or with any soil or waste

pipe, but shall discharge outside the building, or into an open fixture as provided in section

1101.

CHAPTER XII. MAINTENANCE

Sec. 1201. Defective Plumbing.—Any part

of the plimibuig system foimd defective or in an insanitary condition shall be repaired, renovated, replaced, or removed within 30 days

upon written notice from the authority having

jurisdiction over pluml>ing.

Sec. 1202. Temporary Toilet Facilities.—

Toilet facilities provided for the use of workmen

during the construction of any building shall be maintained in a sanitary condition.

Sec. 1203. Condensate and Blow-Off Conxections.—No direct connection of a steam

exhaust, boUer blow-off, or drip pipe shall be

made with the building-drainage system. Waste

w ater when discharged into the building-drain-

[22]
age system shall be at a temperature not higher

than 140° F. Where higher temperatures exist

proper cooling methods shall be provided.

CHAPTEE XIII. INSPECTION AND

TESTS

Sec. 1301. Inspection.—All piping, traps,

and fixtures of a plumbing system shall be in- spected by the authority having jurisfliction over plumbing to insure compliance with the

requirements of this manual and the iiistallation and construction of the system in accordance

with the approved plans and the permit.

Sec. 1302. Tests Required.—Every plumbing system shall be subjected to tests for tightness. The complete water-supply system of the

building shall be subjected to a water or air- pressure test. The drainage system within or under the building shall be subjected to a water

or air-pressure test before the pipes are concealed or the fixtures are set in place, and the

sanitary-drainage and vent system shall be

subjected to a final smoke or air-pressure test after the system has been completed and the

fixture traps have been connected. The authority having jurisdiction over plumbing may re- quire the removal of any plug or cap duiing the

test to determine whether the pressure has

reached all parts of the system. He may modify

or change the order of any of the tests prescribed

in sections 1305, 1306, and 1307, or may substi- tute a different test to meet special conditions;

provided that the tests used are, in his opinion,

as effective as those required in the sections

enumerated.

Sec. 1303. Notification for Test.—(a) It shall be the duty of the plumber to notify the

authority having jurisdiction over plumbing

and the owner, or his authorized agent, orally,

by telephone, or in writing, not less than one working day before the work is to be inspected

or tested.

(b) It shall be the duty of the plumber to make sure that the work will stand the test prescribed before giving the above notification.

(c) If the authority having jurisdiction over plumbing finds that the work will not stand

the test, the plumber shall be required to re- notify the authority.

(d) If the authority having jurisdiction over plumbing fails to appear within 24 hours of

the time set foi' any inspccttoii or test,, llie inspection or test shall be iiiiuh' by the plumber

and the plumber requinid to file an affidavit

with the authority having jurisdiction over plumbing and with the owner. T\\(' ,iffi(l;i vit shall state that the work was installc'd in accoi-dance with this manual and the approved

])lans and permit, that it was free from defects,

and that the required tests were made and the

system is free from leaks; also wluither the owner or his authorized agent was present

when such inspection or tests were made, or was didy notified. Sec. 1304. Labor and Equipment for

Tests.—The equipment, material, power, and

labor necessary for the inspection and test shall be furnished by the plumber, unless

otherwise provided by the authority having

jurisdiction over iilumbing.

Sec. 1305. Tests of Drainage System.—

(a) A water test may be applied to the system

in its entirety or in sections. If applied to the

entire system, all openings in the piping shall be tightly closed, except the liighest opening,

and the system filled with water to the point

of overflow. If the system is tested in sections,

each opening shall be tightly plugged (except

the highest opening of the section under test)

and the section shall be filled with water. In

testing successive sections, at least the uppei

10 feet of the next lower section shall be re- tested (except the uppermost 10 feet of the

system) and shall have been subjected to at

least a 10-foot head of water. The water level shall remain constant without any further addition for sufficient time to inspect the entire section imder test, but in no

case less than 15 minutes.

(b) In place of the water test, an air test may be applied as follows: With all openings

tightly closed, air shall be forced into the

system until there is a uniform pressure suffi- cient to balance a column of mercury 10

inches in height (or 5 pounds per square inch) on the entire system or section under test. The air pressure shall be maintained on the

system or section without any further addition

of air for a sufficient time to determine tightness

but in no case for less than 15 minutes. (See

par. 1305 (b), p. III.) Sec. 1306. Final Test.—After all fixtures

2709S8°-^0 4 [23]
hare been permanontlT connected and all trap

seals filled with water, a smoke or air test mider

a pressure of approximately 1-incli water

cohunn shall be applied to the sanitary system.

In the case of a smoke test, a thick penetrating smoke produced by one or more smoke

machines (not by chemical mixtures'! shall be

introduced into the entu'e system through a suitable opening. As the smoke appears at the

stack openings, they shall be closed and a pres- sure equivalent to 1-inch water colunni shall be applied.

Sec. 1307. Tests of the Watek-Sffplt

System.—The water-supply system shall be

tested in its entirety by filling the entire system

with water under a pressiu'e of at least 100

pounds per square inch, or by applying air pressiu'e of at least 35 poimds per square inch

(70 inches of merciuy colunm) in case the water

test is not feasible or not desirable. The test in either case shall be applied for sirfficient time to determine tightness.

Sec. 1308. FiXAL Coxditiox.—All parts of the plumbing system and associated equipment

shall be other^^^se tested and adjusted to work

properly and be left in good operating condition.

Sec. 1309. Separate Tests Permitted.—

Tests may be made separately, as follows:

(a) The building sewer and all its branches

from the property luie to the building drain.

(6) The building drain and yard drams, mchiding all piping to the height of 10 feet above

the highest pomt on the house di'ain. except the

exposed connections to fixtm-es.

(c) The soil, waste, vent, inside leader, and

drainage pipes which would be covered up

before the building is inclosed or ready for completion. The test required for (b) and (c) may be combined.

(d) The final test of the whole system.

After each of the above tests has been made

and proved acceptable the authority having

jmisdiction over plumbing shall issue a wiitten

approval.

Sec. 1310. CovERixG OF Work.—Xo drainage

or plumbing system or part thereof shaU be

covered untU it has been mspected. tested, and

approved as prescribed in this chapter. If any

building-drainage or phunbing system, or part

thereof, is covered before being regularly mspected, tested, and approved, as prescribed in

this chapter, it shall be uncovered upon the

direction of the authority having jmisdiction over plumbing.

Sec. 1311. Defecth-e Work.—If inspection

or test shows defects, such defective work or material shall be replaced and inspection and

the tests repeated.

All repairs to piping shall be made with new

material. Xo calking on screwed joints, cracks, or holes wiU be acceptable.

Sec. 1312. Tests of Leaders.—Leaders and

their roof connections within the walls of buildings, or their branches on an outside system

where such branches comiect with the building

dram or are less than 3 feet from the wall of the

building, shall be tested by the water or ah test. Branches on the outside system may be tested

m connection with the house draui.

Sec. 1313. OrTBuiLDixGS.—If a stable, barn,

or other outbuilding or any part thereof is used

for human habitation, the specified inspections

and tests of the plumbing system shall be made.

Otherwise. aU drains shall be inspected, but need

not be tested. Sec. 1314. Garages.—^For a garage or any

part of a garage the specified tests and mspections of the phunbing system shall be made.

Sec. 1315. Certificate of Approval.—Upon the satisfactory completion and final test of the phunbing system a certificate of approval

shall be issued by the authority havmg jurisdiction over plumbing to the phmiber to be dehvered to the owner.

Sec. 1316. Test of Defectr'e Pli-mbixg.—

The smoke or an* test shall be used in testing the

sanitary condition of the plumbing system of a buildmg where there is reason to believe that

the system has become defective. In plumbing

fomid defective by the authority having jurisdiction over plumbing the alterations requhed

shall be considered as new pliunbmg.

Sec. 1317. Ixspectioxs axd Tests Xot ReQriRED.—Xo tests or mspections shall be

requhed where a phunbing system or part

thereof is set up for exliibition piuposes and is not used for toilet purposes and not directly

connected to a sewerage system; nor after the

repairing, or the replacement by a new one to be

used for the same purpose, of an old fixture,

faucet, or valve: nor after forcing out stoppages

and repairing leaks.

[24]
PLUMBING SYMBOLS

Symbol Plan Initiak o

o

o

o

o

o

o

O

0

-oooo —

VCO /CO

r.D

^ VAC i-@H

m

D. VS.

C.W.

hMQ.

Q

DM

DA

F.L. I.W. IS

AW

V

R

CO.

F.D.

R.D. RtF.

S.D. 01

S.C

VAC. M

H.Q.

nw.T.

Wli. W.M

P.b.

Item

Drainage Line Vent Line

Tile Pipe

Cold Water Line

Hot Water Line

Hot Water Return Gas Pipe

Ice Wafer Supply Ice Water Return

Fire Line

Indirect Waste

Industrial Sewer

Acid Waste

Air Line

Vacuum Line

ikfricjerator Waste Gate Valves

Cliecli Valves Cleanout

Floor Drain

Roof Drain

Refriqerafor Drain

Shower Drain

Grease Trap

Sill Cock

Gas Outlet

Vacuum Outlet

Meter

Hydrant

Hose Rack

Hose Rack' BuiIf in Leader

Hot Water Tank

Water Heater

Washing Machine

Range boiler

Freestanding

of TrShowtr

Corner

5ATH TUBS

o

Built-in

Pedestal Wall Hung Corner Manicure Dental LAVAJORILS

Kitchen

Double Drain board

\\yN\\\\\\\'.\N\\\\\\\

Pantry Kitchen

Single Dr Board

Combination

Sinl< 6 Tub

Vegetable

SINKS

Slop Sink

o

Tank Flush bidet

LAUNDRY Valve SHOWLR TUBS TOILLTS

stall Types Wall Hung

^

Wall Recessed

Pedestal

URINALS DRINKING FOUNTAINS

Figure 1.

Standard plumbing symbols.

[25]
Poof /i'oof Drain

Third Floor

5€cor?d floor

Firjf Floor

dido Wall

basemenl

'fither

Conned lo Dtack Vent \ Arronqemenf

! w®

0

2:

®

W\ f ! ^1

r®

® (ETi

2

1=

4=

CO. 5-0"

k ' branch Interval

5 ' branch VenI C ' buildinq Drain

D ' buildinq 5eiver

t ' buildinq 3ub-drain

F - Circuit i^ent 0 ' Continuous Wasted Vent

H • Dry Vent

H'- Double Offsel

1 = Dual Vent Cl/nit Vent)

J ' Fixture Drain

J' = Group Vent K ' Horizontal 5rone//

L

' Leader

^Check

-ilahe

til ' Indirect Waste H -- Loop l/ent 0 - Olfset

P ' Primary branch

Q

-- Pel/ef l/ent R ' Return Olfset or Jumpoyer

5 = Secondar/ 3ranch

7 -- J/de l/ent U -- 5oit Stack

1/ = yen! Stack ^

-- VIef Vent

t • Stock Vent r • Yoke Vent 1 ' back Vent

OH

Discharge

Sump

Ft Drain

co'CleaefOuf

Figure 2.

Illustration of definitions.

[26]
PART III. EXPLANATIONS, ILLUSTRATIONS, AND INTERPRETATIONS

[Note.—Part III is divided into subdivisions called paragraphs, each of which is numbered to correspond

with the section in part II to which it applies. Since not all sections of part II are discussed in part III, the paragraph numbering in part III is not necessarily consecutive. Tables also carry the same number as the section in part II to which they apply, with the addition of the suffix "-III" so that when reference is made to them it will be readily understood that they

are to be found in part III.]

Par. 101. Definitions.

Accepted standards.—Since this manual is primarily for Federal use, preference is given to Federal specifications in stating requirements.

These do not cover all plumbing fixtures and

materials, however, and there may be special

conditions requiring the use of other specifications. In part II, the Federal specification is given where it exists. Where there is no such

specification and a suitable one is available

from another source, this is given. Where

there is no suitable specification that can be

definitely ideutified, the matter is left to the

authority having jurisdiction over plumbing.

In a few cases available information not in the

form of a specification is given in the form of

tables. Sewage-treatment plant.—The term "sewage"

is a general inclusive term used to designate the

combination of liquid-borne waste originating

in residences, business buildings, mstitutions,

and industrial establishments with or without

such gromid, surface, or storm water as may

become mixed with it as it is admitted into or passes through the sewers. It may be further

defined to indicate the character of the liquid

waste carried, as sanitary sewage, industrial

sewage (more commonly called industrial waste)

,

and storm sewage.

Sanitary sewage is that which originates hi the sanitary conveniences of dwellings, business

buildings, factories, institutions, and the like. Industrial sewage or industrial waste origmates

in an industrial process and is usually designated

by the name of that process, as for example,

"brewery wastes." Storm sewage is that

flowing in combined or storm sewers (hiring or following a period ol rainfall aiul i-esiilting from

such rainfall. Sewers are often designated as to type of

sewage carried. Sanitary sewers carry sanitary sewage, which may or may not be mixed

with some ground water which percolates into

the sewers. Storm sewers carry roof and

surface rim-ofl' following rains. Industrial

sev/ers carry industrial wastes. Where a single sewer is designed to carry both sanitary

sewage and storm water, it is referred to as a combined sewer. "Sewage treatment" is a term used to designate any artificial process to which sewage is subjected in order to remove or alter its objectionable constituents and to render it less dangerous from the public-health standpoint. The

term "sewage purification" is also used in this same connection.

Occasionally in designing a plumbing system

for a building or an institution, it is necessary

to include plans for final disposal of the sewage.

Many factors enter into any plan for treatment

of sewage; and the proper operation of the

treatment plant, no matter how small, depends

upon the careful consideration of these factors

in the design. When it is not possible to place

the design in the hands of a competent sanitary

engineer, the advice of the health agencies,

either State or Federal, should be obtained.

The usual method of disposing of sewage

where the amount is small is through cesspools

or small septic-tank subsurface disposal sys- tems. While definite recommendations rela- tive to design of these two types of disposal

should be obtained from the health agencies,

certain information may be of value to the

designing engineer in preparing preliminary

plans.

A leaching cesspool is one in which the solids present in the sewage are retained and the liquid

leaches or seeps into the surrounding sod. The

success of this type of disposal is dependent

upon the character of the soil and its suitabilit}^

[27]
for rapid dispersal of the liquid entering it. Cesspools tend to seal themselves, the time re- quired being dependent upon the character of the surrounding soil. The solids entering the

cesspool in the sewage accumulate and at intervals must be removed. In the design, therefore, the character of the soil must be considered

and allowances made for the storage of solids. Where water supplies are developed in the same area, cesspools should be located at least 100 feet away from wells or other sources of water supply and on ground which slopes away

from such sources. Cesspools should not extend

into the ground-water table. Septic-tank installations generally consist of a watertight tank and a subsurface system for disposal of the effluent from the tank. The

subsurface disposal system may consist of openjoint tile, filter trench, or subsurface sand

filter. A septic tank is a settling tank in which it is intended to retain the sewage solids (sludge) in immediate contact with the sewage flowing

through the tank for a sufficient period to secure a satisfactory decomposition of organic

solids by anaerobic bacterial action. Septic

tanks should not be confused with other types

of tanks used in connection with sewage

treatment. The solids (sludge) retained in a septic tank

must be removed whenever there is a sufflcient accumulation to reduce materially the liquid

capacity of the tank. The effluent from the

septic tank is only partially treated sewage and

is in a septic condition.

The effluent of a septic tank should not be

discharged to a small stream nor can it be

discharged to the surface of the ground without

nuisance.

A septic tank should be located as close as practicable to the subsurface disposal field. It should be located, if possible, at least 100

feet, but never less than 50 feet, from wells,

springs, or underground water-storage basins; at a lower elevation ; and where there will be the

least danger of sewage overflowing or leaking

in such a way as to contaminate a water supply.

Grease interceptors should normally be

omitted on small septic-tank installations.

Septic tanks should be designed with a minimum liquid capacity equal to 24 hours'

flow of sewage. The minimum-size tank should

be not less than 500-gallon liquid capacity.

When the effluent of a septic tank having a capacity in excess of 1,000 gallons is discharged

to a subsurface tile disposal field, a dosing

tank and an automatic sewage siphon is advisable. Tanks of less than 1,000-gallon liquid

capacity do not require automatic siphons.

Subsurface disposal of the effluent from septic

tanks is possible where the character of the soil will permit its absorption. The percolation

test is the most logical and practical method of determining the suitability of the soil for this method of disposal. Par. 201. Installation of Piping.—When

a building drain or sewer is installed with a fall of less than Ke inch per foot as permitted by

section 201, part II, for 10-inch and larger

diameters, the minimum permissible velocity

should be computed by the formula h/12l=

0.0008385 v^/d (for rough pipe), where h is the

fall in inches per foot, I the length of pipe in

feet, V the velocity in feet per second, and d

the diameter in feet. If it is desired to install a building drain or building sewer at a slope

that will maintain a velocity above some

selected minimum within the specified minimums for the difl'erent diameters, the following

table 201-III applying to rough pipe may be

consulted. In general, the required fall in inches per foot is given approximately by

-y/s/si —v/vi or s =Si{v/vi)'^, in which s is the fall

in inches per foot necessary to give a selected

velocity v, and Si and Vi are the fall and result- ant velocity for pipe of the same diameter.

Table 201~III.—Approximate velocities for given slopes

and diameters

Velocities Diameter of pipe

142-inch

fall per

foot M6-inch

fall per

foot

^s-inch

fall per

foot

H-inch

fall per

foot

J^-inch

fall per

foot

Indies

l\i Jps

0. 57 0.80

.88

fps

1.14 fps1. 61 fps

2.28

\y, .62 1. 24 1. 76 2. 45

2 .72 1.02 1.44 2.03 2. 88 M — .81

.88

1. 14 1.61 2. 28 3.23

3 1. 24 1. 76 2.49 3. 53

4 1.02 1.44 2.03 2.88 4. 07

5 1. 14 1.61 2. 28 3. 23 4. 56 6 1.24 1. 76 2.49 3. 53 5.00

8 --- 1. 44 2.0s 2. 88 4. 07 5. 75

10 1.61 2.28 3. 23 4. 56 6.44

12 1. 76 2.49 3. 53 5. 00 7.06

[28]
Par. 301. Quality of Materials.—Frequent

reference is made in chapter III, part 11, to Federal specifications. The title of the specification as given in the Federal Standard Stock

Catalog is presented but the specification symbol

has been omitted. This is for the reason that

such symbols change from time to time. It is to be understood that the latest revision of the

specification, together with any subsequent

amendments, is meant. For the convenience

of the user of this manual, a list of specifications

cited in chapter III, part II, together with the

symbols m effect at the time of publication of

this manual, is given in paragraphs 303 to 325

for more positive identification. It is recom- mended that the latest edition of the Federal

Standard Stock Catalog be consulted from time

to time to guard against the use of obsolete

symbols. When there is any occasion for doubt, inquiry should be directed to the Federal

Specifications Executive Committee, Washington, D. C.

Reference is also made in section 301, part II, to similar and equivalent specifications. These

are for use primarily when no suitable Federal

specification is available and may be made

applicable, through the power of the authority

having jurisdiction over plumbing, to fix acceptable standards. There are several sources

of such standards. The chief ones are as follows

American Society for Testing Materials,

260 South Broad Street, Philadelphia, Pa. American Standards Association, 29 West

Thirty-ninth Street, New York, N. Y.

Industrial associations.

Individual manufacturers.

In the case of these standards also, the symbo'

iesignations (particularly the part referring to year of adoption) change frequently and should

be checked to see that the latest issue is being

used.

In addition to the standards already cited,

there is other useful material available for consultation by authorities having jiu'isdiction over plumbing. Included in this is a series of Commercial Standards and a series of Simplified

Practice Recommendations, published by the

National BnicHii of St iMidiii-ds. Examples of each series appear below:

COMMEHCIAL StaNDAKDS

Pipe nipples; brass, oopper, steel, and

wrought-iron. (1940) Standard weight malleable iron or steel screwed unions. (1929) CS7 29

Simplified Practice Recommendations

Eaves trough, conductor pipe and fittings, and ridge rolls. (1939) R29 39 Wrought-iron and wrought-steel pipe valves and fittings. (1932) R57-32

Range boilers and expansion tanks. (1929) _ R8-29

Structural slate for plumbing and sanitary

purposes. (1928) R13~28

Brass lavatory and sink traps. (1925) mimeographed R21

Hot water storage tanks. (1925) mimeographed R25

Metal partitions for toilets and showers.

(1929) RlOl-29

Publications not indicated as mimeographed

may be obtained by purchase from the Government Printing Office, Washington, D. C.

Other publications and information may be

obtained from the Division of Trade Standards

and the Division of Simplified Practice, respectively, both at the National Bureau of Standards, Washington, D. C.

Par. 303. Vitrified-Clay Pipe.—Federal

Specification for Pipe; Clay, Sewer. SS-P-361,

with Amendment 1, June 1935.

Standard Specifications for Clay Sewer Pipe.

A. S. T. M. Designation: C13-35.

Par. 304. Concrete Pipe. —Federal Specification for Pipe; Concrete, Non-Pressure, NonReinforced and Reinforced. SS-P-371, February 19, 1937.

Standard Specification for Concrete Sewer

Pipe. A. S. T. M. Designation: C14-35.

Par. 305. Cast-Iron Soil Pipe.—Federal

Specification for Pipe and Pipe Fittings; Soil,

Cast-iron. WW-P-401, with Amendment 1, January 1937.

American Standard for Cast-iron Soil Pipe

and Fittings. A. S. A. No. A40. 1—1935.

Tentative Specifications for Cast-iron Soil Pipe and Fittings. A. S. T. M. Designation:

A74-39T.

Par. 306. Cast-Iron Water Pipe.—Federal

Specification for Pipe; Water, Cast-iron (BeU

[29]
and Spigot and Bolted Joint). WW-P-421,

with Amendment 3, April 1940.

American Standard for Cast-iron Pipe, PitCast for Water or Other Liquids. A. S. A.

No. A21.2—1939.

Tentative Specifications for Cast-Iron PitCast Pipe for Water or Other Liquid. A. S. T. M. Designation: A44-39T.

Standard Specifications for Cast-Iron Water

Pipe and Special Castings of the American

Waterworks Association, adoptedMay 12, 1908. Par. 307. Cast-Iron Screwed Pipe.—Federal Specification for Pipe, Cast-iron; Drainage,

Vent and Waste (Threaded). WW-P-356,

August 19, 1936. Par. 308. Wrought-Iron Pipe. —Federal

Specification for Pipe, Wrought-Iron, Welded,

Black and Galvanized. WW-P-441a, December 28, 1939.

American Standard for Lap-Welded and

Seamless Pipe. A. S. A. No. B36.3—1939.

American Standard for Welded WroughtIron Pipe. A. S. A. No. B36.2—1939.

Standard Specifications for Welded WroughtIron Pipe. A. S. T. M. Designation: A72-39.

Par. 309. Steel Pipe.—Federal Specification

for Pipe, Steel, Seamless and Welded, Black

and Zinc-Coated. WW-P-403a, December 28,

1939.

American Standard for Welded and Seamless

Steel Pipe. A. S. A. No. B36. 1—1936.

Standard Specifications for Black and HotDipped Zinc-Coated (Galvanized), Welded and

Seamless Steel Pipe for Ordinary Uses. A. S. T. M. Designation: A120-36.

Par. 310. Brass and Copper Pipe.—Federal Specification for Pipe, Brass, Seamless,

Iron Pipe Size, Standard and Extra Sti-ong.

WW-P-351, with Errata 1, October 1930.

Tentative Specifications for Brass Pipe,

Standard Size. A. S. T. M. Designation:

B43-39T.

Federal Specification for Pipe; Copper, Seamless, Iron Pipe Size, Standard. WW-P-377,

May 31, 1932.

Tentative Specifications for Copper Pipe,

Standard Size. A. S. T. M. Designation: B42-

39T.

Par. 311. Brass Tubing.—Federal Specification for Plumbing Fixtures; (for) Land Use. WW-P-541a, March 30, 1940.

Par. 312. Copper Tubing.—Federal Specification for Tubing; Copper, Seamless (for Use | With Soldered or Flared Fittings). WW-T799, with Errata 2, April 1934.

Federal Specification for Tubing; Copper,

Seomless (for General Use With I. P. S. Flanged

Fittings). WW-T-797, with Errata 1, August

1933.

American Standard for Copper Water Tubing.

A. S. A. No. H23. 1—1939.

Standard Specifications for Copper Water | Tubing. A. S. T. M. Designation: B88-39.

Par. 313. Lead Pipe.

Table 313-III.

Diameter and weight of lead pipe

(The following thicknesses and minimum weights are taken from the standard of the Lead Industries Association] LEAD SERVICE AND SUPPLY PIPE

A or S (for pressures up to 50 lb/in. 2)

Inside Weight per Outside diameter foot diameter

Inches Pounds Inches 0.798 % 1,019 H 3 1. 156

1 4 1.428 IM iVi 1.670 m 6V2 1. 984

2 SH 2. 503 AA or XS (for pressures between 50 and 75 Ib/in.z)

Inches Pounds Inches

¥2 2 0. 876 % 3 1.082 % 3H 1. 212

1 1.492 IM 6 1. 705 8 2. 076

2 13M 2. 751 AAA or XXS (for pressures between

75 and lOOlb/in.2)

Inches Pounds Inches

V% 3 1.012 % 3% 1. 137 M 1.336

1 6 1. 596 IM 1.889 UM 2. 272

2 19}^ 3.008 LEAD WASTE PIPE

Minimum recommended weight, "D" or "XL

Inside Weight per Outside diameter foot diameter

Inches Pounds Inches iM 2V2 1.486

IV2 iVi 1.776

2 i'A 2.284

5 2.75

3 6 3.25

4 7% 4. 25

6 9% 5. 25

6 1113-16 6. 25

[301
A more extended table is available from the

Lead Industries Association, 420 Lexington

Avenue, New York, N. Y.

Par. 314. Sheet Lead.—Federal Specification for Lead; Sheet. QQ-L-201, January

10, 1933. Par. 315. Calking Lead.—Federal Specification for Lead, Calking. QQ L-156, June 5, 1934. Par. 316. Sheet Copper and Brass.—Federal Specification for Copper; Bars, Plates,

Rods, Shapes; Sheets, and Strips. QQ-C-501,

with Amendment 1, November 1936.

Federal Specification for Brass, Commercial;

Bars, Plates, Rods, Shapes, Sheets, and Strips.

QQ-B-611a, April 27, 1938.

Tentative Specifications for Brass Sheet and

Strips. A. S. T. M. Designation: B36-39T.

Par. 317. Zinc-Coated (Galvanized) Sheet

Iron and Steel.—Federal Specification for Iron and Steel; Sheet, Black and Zinc-Coated

(Galvanized). QQ-I-696, March 6, 1934. Par. 318. Screwed Fittings.—Federal Specification for Pipe Fittings; Cast-iron (Threaded). WW-P-501a, June 7, 1939.

Federal Specification for Pipe Fittings; Malleable Iron (Threaded). WW-P-521a, June

20, 1939.

Federal Specification for Pipe Fittings; Brass

or Bronze (Threaded), 125-lb. WW-P-448,

May 26, 1931.

Federal Specification for Pipe Fittings; Castiron, Drainage. WW-P-491, October 20, 1938.

Federal Specification for Pipe Threads, Standard. GGG-P-351, January 9, 1934. Par. 319. Soldered Fittings.—American

Standard for Soldered Joint Fittings. (Inquire

of American Standards Association. Also sec

par. 409.) Par. 320. Calking Ferrules.—The following

represents customary recommended practice for brass ferrules

Table 320-III.

Size, diameter, and weight of brass calking ferrules

Pipe size

Actual

inside diameter Length Weight

Inches

2

3

4

Inches 2M

3M

Inches lb oz

1

1 12

2 8

Foj- iron-body fcrrnhss, niferisiicc slioiild l)c made to Federal Specification for Pipe and Pipe

Fittings; Soil, Cast-iron. WW-P-401, wiili Amendment 1, January ]937. Par. 321(a). Soldering Nij'ples. —Tlie fol- lowing ropn'sents customary recommended

practice for soldering nipples:

Table 321(a)-III.

Diameter and weight of soldering

nipples

Diameter Weight

Inches lb oz m 6 VA 8

2 14 2H 1 6 3 2 0

4 3 8

Par. 322. Floor Flanges.—Federal Specificatioii for Plumbing Fixtures; (for) Land Use.

WW-P-541a, March 30, 1940. Par. 323. Packing.—Federal Specification

for Packing; Jute, Twisted. IIH-P-117.

Par. 324. Setting Compound.—Federal

Specification for Compound ; Plumbing-FixtureSetting. HH-C-536, June 5, 1936. Par. 325. Gaskets.—Federal Specification

for Gaskets; Plumbing-Fixture-Setting. HHG-116, June 5, 1936. Par. 402. Vitrified-Clay and Concrete

Pipe.

Jointing Compounds for Vitrified-Clay Pipe.—

There are no generally accepted specifications

for jointing compounds for clay pipe. There

are available a number of proprietary compounds prepared for this purpose. Hot-poured

jointing compounds should liquefy and flow

freely at the pouring temperature, should adhere

to the pipe, and should be sufficiently elastic when cold to permit slight movement without

injury to joints. The compound should be of a composition that will not deteriorate in water

or sewage. Directions in regard to packing of joints and to heating and pouring temperatures

are usually supplied with these prepared compounds and should be followed faithfully in making the joints. Joints in horizontal or sloping pipe are made with joint runner in the same manner as lead joints in cast-iron except

that just enough packing to liold the pipe in position and prevent the compound from

entering the interior of the pipe should be used

270988°-40 5 [31]
and the joint should not be calked after pouring.

One or more joints may be poured in a vertical

position without using- a joint runner, allowed

to set (harden), the joined pipes carefully

lowered into position in the trench, and the

remaining joints completed using a joint runner

as described. The joint space and packing

should be thoroughly dry and the joint space

should be completely filled with one pouring.

Cement Joints in Vitrified-Clay Pij>e.—The

mortar should be freshly mixed, and of one part

Portland cement and two parts sand by weight.

A layer of mortar should be placed in the bottom

of the bell and the packing calked into it. The

remainder of the joint should then be completely filled with the mortar and the outer face

of the joint beveled. Earth should be packed

around the joint until the mortar has set, to prevent sagging of the mortar, and the interior

of the pipe cleared of any mortar that has been

forced through the joijit. Par. 409. Joints in Copper Tubing.—Inas- much as no standard exists for joints in copper

tubing, reference is made to the proposed

standard of the American Standards Association, Soldered-Joint Fittings, which is now in preparation. Recpiirements suggested by one manufacturer for material for fittings call for use of cast red brass or wrought metal containing at least 85-percent copper. Soldered fittings

should be of such size that joints will be completely filled with solder by capillary action.

For further information, it is recommended that

National Bureau of Standards Building Materials and Structures Report BMS58 "Strength

of Soft-Soldered Joints in Copper Tubing" be

consulted. This report contains most of the

data upon which the proposed American

Standard is based. It is obtainable from the

Government Printing Office, Washington, D. C,

for 10 cents a copy.

Par. 413. Increasers and Reducers.—The

prohibition of an enlargement chamber or recess with ledge, shoulder, or reduction in size of pipe in section 203, part II, and section 413,

part II, is not to be construed as prohibiting

enlargements such as formed by standard wye

or other standard branch fittings, as prohibiting the recess formed in the vertical run of

fittings in soil or waste stacks in oi'der to accommodate several branch connections unless

a definite ledge is formed thereby, or as prohibiting the enlargement of a 3-inch closet bend to 4 inches at its inlet in order that a standard 4-incli floor flange may be used in making floor connections for water closets. It is to be construed as prohibiting any enlargement, recess, or ledge through faulty design of

fittings or poor workmanship that would form

a dam or otiier obstruction in the direction of flow. Par. 501. Types and Sizes of Traps.—The

provisions of section 501, part II, are intended

in general to require the use of properly vented

P-traps with plumbing fixtures whenever conditions make the installation of that form of

trap feasible. The provision regarding "self- cleaning" is relative, since there is no form of trap that does not become fouled by deposit or sediment under certain conditions of service.

A trap having a tubular water passage of uniform cross-section, as exemplified by tubular

P-traps, is generally regarded as being the nearest possible approach to self-cleaning.

To a limited extent, standards for fixture

traps are covered by Federal Specification for Plumbing Fixtures; (for) Land Use, WW-P541a. A standard covering traps for plumbing

fixtures is in course of preparation by Sectional

Committee A40 of the American Standards

Association. A Simplified Practice Recommendation (No. 21) is available covering brass

lavatory and sink traps. Recommendations for lead traps and lead bends may be obtained

from the Lead Industries Association. Such

material should be useful to the authority

having jurisdiction over plumbing in determining proper standards.

Par. 502. Prohibited Traps.—The provision relative to "partitions" in traps, section

502, part II, applies only to traps constructed

separately from and attached to fixtures in the

process of installation. The purpose of the

provision is to prevent the use of traps with

inner partitions not accessible for inspection

through which, if defective, the water seal of the trap might be lost without giving any

indication that it had been lost. It is assumed

that each trap acceptable under this provision

will have been carefully inspected or tested

during the process of manufacture and that the

administrative authority will have inspected a

[32]
Figure 3.

Continuous waste.

sufficient number of traps before approval to

satisfy himself that the quality and workmanship of traps installed in accordance with the

requirement are uniformly good and that the

hidden walls are uniformly without defects, are

of sufficient thickness, and are accessible for inspection. The provision of section 502,

regarding double-trapping, is not to be construed as preventing the installation of a

grease interceptor, sand interceptor, or oil interceptor in addition to a fixture trap or

traps, provided a vent intervenes between such

interceptor and fixture traps. Par. 601. Quality of Water.—Where the

water supply of a building or institution is obtained from a public supply, the designing

engineer of the plumbing system or the engi- neer or plumber making the installation has no

control over the quality of the water. When an

independent supply is to be installed, it is then

the responsil)ility of both the designing and

installing agencies to make sure that the water

is satisfactory from the standpoint of quality

(both bacterial and chcmicalj and of quantity.

Independent supplies are generally from

ground-water sources, either wells or spi'ings.

Development of indepen(h>nt supplies fi'om surface sources should be undertaken only

under the direction of a sanitary engineeiversed in water treatment. In the development of a ground-water supply

there are many factors to consider if a safe and

satisfactory supply is to be obtained. It is suggested that the advice of state or Federal

health services be obtained before plans for developing a supply are formulated.

The publication entitled "Ground Water

Supplies," Supplement 124 to the Public

Health Reports, covers the subject thoroughly.

This publication can be obtained from the

Superintendent of Documents, Washington,

D. C, for 5 cents per copy.

The bacterial quality of any supply should

conform to the "Drinking Water Standards"

adopted by the Department of the Treasury,

June 20, 1925, on recommendation of the U. S. Public Health Service, as they exist at present

or may be modified in the future. Information

relative to standards may be obtained from the

U. S. Public Health Service, Washington, D. C.

Bacteriological examination of water from

newly developed wells and springs quite generally indicates contamination, even where the

S//p Joint Inkf

Ouf/ct

Croivr? We/r

Figure 4.

De-pth of trap seal.

[33]
installation is properly made, if care is not taken

to sterilize the well and pumping equipment

thoroughly after the installation has been completed. It is also desirable to sterilize the enthe

system after installation and before use. Sterilization may be accomplished by introducing into the well or spring one of the chlorine

compounds in amounts sufficient to give a

clilorine dosage of 50 parts per million in the water. The chlorinated water should be cir- culated throughout the entire system and

allowed to remain in the system 8 to 10 hours,

after which the system should be flushed with

water from the well or spring.

No samples of water for bacteriological ex- amination should be taken until after steriliza- tion of the supply and equipment and the re- moval of all traces of chlorine from the water. Dnections regarding sterilization may be obtained from any of the'health agencies. Par. 602 (<i). Protection From Backflow.

Air Gaps.—An approved ah gap shoidd be

provided in all overrim supplies. The following

extract, from Federal Specification WW-P541a, gives accepted standards of aii- gaps for overrun water supplies

:

Fixtures with faucets or other supply fittings properly

assembled shall provide between the level of all supply

openings and the water level at point of unrestricted

external overflow a mean vertical distance or air gap

as specified in table X.

Table X.

Air gaps

^3idz Wall

A Outlet Horizontal

Fixture and fitting

(1)

Minimum air gap

For ordi- nary conditions. (See notes 1 and 2)

(2)

For spout

near wall. (See notes

1 and 2)

(3)

Lavatory supplies with effective opening not

greater than J 9 inch _ .

InchesLOO L 50

2. 00

(')

0. 75

Inches

1. 50

2. 25

3.00

Sinlf, laundry tray, and bath (gooseneck) faucets with effective opening not greater than ?4 inch_

Overrim bath fillers with effective opening not

greater than 1 inch. _ . __. Any fitting with effective opening greater than

1 inch _ . ... Drinklng-fountain nozzles

> 2x effective opening.

i> 3x etTective opening. Note 1.

Spout near wall.—If any vertical wall ex- tending to or above the horizontal plane of the spout

opening is closer to the nearest inside wall of the spout

opening than four times the diameter of the effective opening, the air gap shall be as specified above for spout

near wall, column 3. Note 2.

Spout set at an angle.—Should the plane of the end of the spout be at an angle to the surface of the

water, the mean gap is to be taken as the basis for measurement, except for drinking-fountain nozzles, in which

case the gap to the lowest point of the nozzle opening

shall be taken.

Backflow Preventers.—When any supply pipe

is installed with a fixture or receptacle in such

a manner that an approved air gap is not

provided, an approved backflow preventer

should be installed in the supply fitting or con- nection on the outlet side of the control valve.

3 Outlet at an AnqU

FiGUBE 5.Illustration of air gap.

[341
Approval of a backflow preventer should l)e given on the basis of tests made by a reeognized

testing laboratory to determine its effectiveness

under the conditions under which it is to be

installed and used. Requirements for backflow

preventers for ballcocks for flush tanks are given in Federal Specification WW-P-541a,

paragraphs E-37c, F-7a, and F-7b, and requirements for flush valves for water closets and

urinals in paragraphs E-38f, F-8a, and F-8b.

Par. 604. Size of Building Main.—The

mandatory requirement of section 604, part II, that "the building main, including the waterservice pipe, shall be of sufficient size to permit

a continuous ample flow of water to the building

under the average daily minimum service pres- sure in the street main," states a desirable

attainment rather than one that can be pro- vided for with certainty, since the rate of flow

in a pipe of given size depends on many factors,

some of wliich caiuiot be determined accurately

in advance. The term "ample flow" in tins requirement means a flow ecpial to or gi'eat(!r

than the estimated demand. In (h-signing tlie water-supply system of a large building and to a lesser extent that of a small building, the

engineer will of necessity exercise his judgment

in the selection of the matoi-ial to use, the siz(!S of pipe to install, and the most efficient pipe

lay-out, based on available information pertaining to the particular locality and building. It

is assumed that the authority having jurisdiction over plumbing will exercise correspondingly

intelligent judgment in inspecting plans and

specifications for approval, if the plans for the

water-supply system are subject to his approval.

For the use of the engineer in laying out the

water-supply system of a building, there are given in the foUowing pages a table (table

604-III(a)) of load-weight values in fixture

500

O 500 1000 1500 2000 2500 JOOO

fixture. Units

Figure 6.

Curve for estimating supply demands.

[35]
10000 0000

6000

5000

4000

Friction Lo55 in H(zad in Lbs per 3q. In per 100 Ft Length

0.1 2 J .4 .5 6 .0 I 2 J 4 J 6 d 10 20 JO 4050BO 00 100

0.1 .2 .5 .4 .5 .6 .0 I 2 5 4 5 B Q 10 20 50 40 50 60 00 100 Friction Loss in Hzad in Lbs. per Jq. In. per ZOO Ft. Lenqtf?

Figure 7.Flow chart for smooth pipe.

[36]
Friction Loss in Hzad in Lbs. pzr 5q. In per 100 Ft Length

0.1 .Z .J .4 .3 .6 .6 I 2 J 4 5 6 0 10 ZO 30 ^0 5060 00 100 Friction Loss in I4zad in Lbs. per Jq. In per 100 Ft Length

Figure 8.Flow chart for fairly smooth pipe.

[37]
Friction Loss in Head in Lbs. per 5q. In. per 100 M Lcnqtli

0.1 .2 J .4 .J .6 .0 i 2 J 4 3 6 d 10 20 30 40 JO60 00 lOD Friction Loss in Head in Lbs. per 3q. In per 100 Ft Lenqtti

Figure 9.Flow chart for fairly rough pipe.

[38]
Friction Loss in Nead in Lbs per Jo In per 100 Ft Length

ai ./ J .4.3.B .6 1 2 J 4 5 6 d 10 20 JO 40 50BO dO 100 Friction Loss in Head in Lbs per J<? In per 100 Ft Lenqtti

Figure 10.

Flow chart for rough pipe.

[39]
tion useful in the selection of serviceable pipe

sizes. Table 604-III(a).

Fixture-unit ratings for estimating

water-supply demands '

J .4 .S 6 .S / 2 3 4 JG7

Diameter in inc/ies

Figure 11.Relation of flow to diameter of pipe for

friction loss of 10 Ib/in.'^ per 100 feet.

units; a curve (fig. 6) for estimating the ex- pected demand in gpm for total load in fixture

units; four charts (figs. 7 to 10) giving the

capacity of pipes relative to diameter, roughness, and friction loss in head; a chart (fig. 11)

showing the relation of flow to diameter for a given friction loss and for different degrees of pipe roughness; and a table (table 604-111(6))

giving suggested allowances for standaixl pipe

fittings, in equivalent lengths of pipe of the same diameter. A table (table 604-III(c))

giving the nominal and actual diameters of new copper tubing, new steel pipe, and new

brass pipe (I. P. S.) and a table (table 604-

III((i)) illustrating the eftects of corrosion

and caking on the capacities of water-supply

pipes are included as pertinent general informaFixture and type of installation 2

Lavatory or washbasin:

Public or office toilet Private

Water-closet flush valve: Public or office toilet Private

Water-closet flush tank: Public or office toilet Private

Urinals, public or office toilets: Pedestal-urinal flush valve Wall- or stall-urinal flush valve Wall- or stall-urinal flush tank Bathtub or separate shower head: Public or office Private Bathroom group, private: With flush-valve supply With flush-tank supply

Separate shower head

Kitchen sink: Public, hotel, or restaurant Private

Service sink ' , Laundry trays (1 to 3) or corribination fixture

Number

of fixture units '

' For supply outlets likely to impose a continuous demand when other

fixtures are in extensive use, add the estimated continuous demand to the

total demand for fixtures. For example, 5 gpm for a sill cock or hose con- nection is a liberal but not excessive allowance.

2 Fixtures not listed in the table, if installed in relatively small numbers

compared to the rated fixtures, may usually be safely ignored in estimating

for the building main and large distributing branches. If installed in sulTiciently large numbers to justify their consideration, they may be

assigned flxture-rmit ratings on the basis cf a comparison with a rated

fixture that uses water in similar quantities and at similar rates. For

example, if washsinks or washtroughs with multiple supply outlets are

to be installed, each supply outlet may be considered as comparable in demand to that of a washbasin in public service.

' The ratings given in the table are for the total hot- and cold-water demand. The engineer will need to exercise judgment in estimating

separately for hot- and cold-water demands, depending to a large extent on conditions. The following is suggested as ample allowances under

favorable conditions: For main hot-water branches allow % of the total fixture units as given by the table for all fixtures using hot water: for main

cold-water branches compute the total fixture units separately for fixtures that are and are not supplied with hot water and add H of the total for fixtures that are supplied with hot water to the total for fixtures that are supplied with cold water only. If the character of the water is such as to produce corrosion and caking in the hot-water lines, it may be advisable

either to allow the full table rating in estimating the demand for hot- water branches or to allow for a decrease in diameter by selecting the next

larger size of pipe than that indicated by the computed estimate.

< Ignore demands for service sinks except for hot-water supply and

that for the cold-water branch to the fixture itself. Other fixtures, similarly used out of hours, may be treated similarly.

Application oj Flow Charts, Figures 7 to 10. —

The chart in figure 7 applies to smooth new

copper tubmg v/ith recessed (streamlined)

soldered joints and to the actual sizes of the

types indicated on the diagram. It may be

applied also to any correspondingly smooth

pipe such as brass pipe (I. P. S.) with recessed

fittings by taking into account any differences

in actual diameter from the diameters shown

[40]
in figure 7. (See fig. 11 for variatioi) in How

with variation in diameter for different degrees

of roughness.)

The ciiart in figure 8 apphes to new wroughth'on or steel (fairly smooth) pipe and to actual

diameters of standard -weight pipe.

The chart in figure 9 applies to fairly rough

pipe and to actual diameters which in genei'al

will be less in service than the actual diameters

of the new pipe of the same kind. Hence, for close estimates in the selection of pipe sizes it will be necessary also to estimate the probable

change in diameter in service and to apply a

correction, or otherwise to make an ample

allowance.

The chart in figure 10 applies to very rough

pipe and actual diameters. Again, close esti- mates in the selection of serviceable sizes will require estimates of the probable condition of

the pipe and change of diameter in service.

In this connection , if the character of the water

is such as to produce a material change in diameter by reason of corrosion or caking or both, it will be safe to assume that the pipe

falls in the category of very rough pipe.

In many cases, for either moderately or extremely bad conditions, it will be possible to make a satisfactory selection of serviceable pipe

sizes for water-distributing systems without

making specific estimates of the probable change

m diameter. For example, if the amount of

corrosion or caking to be expected is small, it will, in most instances, be sufficient to refer to figure 9. Likewise, it will be sufficient in many

cases to refer to figure 10 without specific cor- rections for bad conditions in respect to corrosion and deposit. If there is a wide margin of capacity over the estimated demand,

it will ordinarily be safe to select the size indicated by the applicable chart. If the

indicated size is on the border line, either the

next larger size than that indicated should be

installed or the effects of probable changes in

diameter in service should be investigated.

In all cases the engineer should bear in mind

that small distributing pipes, especially hotwater pipes, are likely to be completely closed

after a few years in service if corrosion and

caking are excessive. (See table 604-111(6?),

pt. Ill, for relative effects on different pipe

sizes.)

[

Table (iOI JJI(/(j.Allowance in cquivaleiU Uru/lh of pipe for friction loss in valves and threaded jitiings

Equivalent length of pipe for various fittings

Diameter

of fitting 90° stand- ard ell

45° standard ell

90° side

tee

Coupstraight

tG6

Gate

valve Qlobovalve Anglevalve

Inches Feel Feet Feet Feel Feel Feel Feet % 1 0.6 1.6 0.3 0.2 8 4 Yl 0 1. 2

QO , c . 4 15 8

Va. 2.5 1.5 4 .8 . 5 20 12

1 3 1.8 5 .9 .0 25 15 M 4 2.4 6 1.2 .8 35 18 iM 5 3 7 1.5 1.0 45 22 2_. 7 4 10 2 1.3 55 28 7>A 8 5 12 2.5 l.H 65 34

3 10 6 15 3 2 80 40 3^- 12 7 18 3.0 2.4 100 50

4 14 8 21 4.0 2. 7 125 55

5 17 10 25 5 3.3 140 70

6 20 12 30 6 4 105 80

The friction loss in threaded fittings relative

to the friction loss in straight pipe of the same

diameter for the same velocity of flow through

both will vary widely depending on the smoothness to which the ends of the pipe are reamed

and on the space left between the ends of the

pipe in making the joints. The allowances in

table 604-111(6), given for the most part in

round numbers, are reasonable allowances for reasonably good workmanship with nonrecessed

threaded fittings. For recessed threaded fit- tings and streamlined soldered fittings one-half

the allowances given in the table will be ample.

Ordinaiily, for small buildings (residences) and

for small sizes of pipe (1/2-inch and smaller)

allowances for loss in fittings may be safely

ignored if the available pressure for friction loss

is large with respect to the maximum allowable

friction loss on which the selection of sizes

is based.

Table 604-III(c).

Actual diameters corresponding to nominal diameters of different kinds of pipe

Actual inside diameters

Nominal Types of copper tubing Steel 1 Brass (I. P. S.) diameters L M

Stand- E.xtra Stand- E.\tra K ard strong ard strong

Inches Inches Inches Inches Inches Inches Inches Inches % 0.40 0.43 0.45 0.49 0.42 0. 49 0.42 H .53 .55 .57 .62 .55 .63 .54 M .75 .79 .81 .82 .74 .82 .74

1 1.00 1.03 1.06 1.05 .96 1.00 .95 Wi 1.25 1.27 1.29 1.38 1.28 1.37 1.27 iM 1.48 1. 51 1.53 1.61 1.50 1.60 1.49

2 1.96 1.99 2. 01 2. 07 1.94 2. 06 1.93 2^ 2. 44 2. 47 2. 50 2. 47 2. 32 2, 50 2. 32 3__ 2. 91 2. 95 2.98 3.07 2. 90 3. 06 2. 89 3H

4

3. 39 3. 43 3. 47 3. 53 3. 36 3. 50 3. 36

3.86 3.91 3. 94 4. 03 3.83 4.00 3. 82

5 4.81 4.88 4. 91 5. 05 4. 81 5. 06 4.81

6 5. 74 5. 85 5.88 6. 07 5. 76 6. 13 5. 75

' For the most part, wrought-iron pipe corresponds in size to the corre- sponding weights iif slei'l pipe, differing by not more than 0.01 inch in diameler for iinmiiial ilianietors of 2J i inches and smaller and by not more

than U.02 inch for nominal diameters of from 3 to 6 inches.

]
Table 604-III(d).

Illustration of the probable effects of corrosion and caking in service on the capacities of water pipes

[Steel or iron pipe (standard))

NomiDal diameter (inches)

2.... 2HNew, fairly smooth

Actual

diameter

Inches

0. 488 .618

.820

1.04

1.37

1.60

2. 06 2.46

3. 06

4. 02

5. 04

6. 05

Flow 1

gpm

2. 45

4. 55

9. 60

18.0

37.6

56.0

108.0 173.0

310 630

1, 125

1, 805

Corroded, slightly caked,

fairly rough

Assumed

diameter

Indies

0. 438

. 568 .770

1. 32

1.65

2. 01 2.41

3. 01

3. 97

4. 99 6.00

Flow 1

gpm

1.75 3.30

7.20

13.6

28.5

42.5

82.4

134

238

1, 420

Percentage of flow in new

71.4

72.6 75.0

75.6

75.8

75.9 76.4

76.6

76.8

77.0

77.7

78.6

Badly caked, very rough

Assumed

diameter

Indies

0. 338

.670

1.22

1.45

1.91

2.31

2. 91 3.87

4. 89

5. 90

Flow 1

gpm

0. 97

2. 02

4. 65

8. 75

19.1 29.8

59. 1 94.5

170

345 617

993

Percentage of flow in new

39.6

45.4

47.4

48.6

50.7

53. 2 54.6 54.7

54.8 54.8

55.0 55.2

Very badly caked, very rough

Assumed

diameter

Indies

0. 188

. 318 .520

.74

1. 07

1. 30

1.76

2. 16

2.76 3.72

4.74

5.75

Flow 1

gpm

0. 26

.84

2. 60

5. 85

13.7 22.6 47.7

79.0

147 310

575

930

Percentage of flow in new

10.6

18. 5

27.

1

32.5

36.4

40.4

44.0

45.7

47. 4

49. 2

51. 1 51.5

1 Flow is approximate for friction loss of 10 lb/in. 2 per 100 feet of pipe. Estimating for Continuous Dernands on the Building Water Main.—The water demand for

hose connections or sill cocks is frequently the cause of inadequate water supply and sometimes of complete failure in water supply on the

upper floor of a building, especially if the

branches to the hose connections are sized for the same permissible friction loss per hundred feet of pipe as the branches and risers to the highest

level in the building. Somewhat the same

condition exists in regard to the branches to

fixtures taken oft' from the building main.

There are several ways by which robbing of upper-floor fixtures of water by hose connections

and other branches from the building main can

be prevented: (1) by selecting the sizes of pipe

for the dift'erent branches so that the total friction loss in each lower branch is equal to or greater than the total loss in the riser including

both friction loss and loss in static pressure;

(2) by throtthng each such branch by means of a valve until the preceding balance is obtained;

(3) by increasing the sizes of the building main

and risers over that required merely to meet the

maximum permissible friction loss; or (4) by any

combination of these ways. It will materially

aid in obtaining the desired result if all branches

from the building main for basement fixtures

and other demands on approximately basement

level are taken oft" from the side branches of tees and all branches to risers are taken oft" from

the straight runs of dividing tees. (See table

604-111(6), pt. Ill, for comparative friction

losses in side branches and straight run of tecs.)

In buildings where the service pressure is suffi- ciently greater than required to supply the upper floors of the building, thus permitting the use of pressure-reducing valves, a better balance

of pressure in the dift'erent levels will be obtained

by installing pressure-reducing valves on aU

branches of the building main except those

leading to risers and on the lower branches from

risers to groups of fixtures than by installing a

single pressure-reducing valve on the building

main.

Rules for Determining Sizes of Water-Sujjply

Pipes.—Because of variable conditions encountered it is impractical to lay down definite

detailed rules of procedure for determining the

sizes of water-supply pipes. The following

steps are suggested as a logical order of procedure for large buildings:

1. Obtain the necessary information regarding

the minimum daily service pressure in the

area where the building is to be located.

2. If the building supply is to be metered, obtain

information regarding friction loss relative to rate of flow for meters in the range of sizes Hkely to be used. Friction-loss data in the

form of curves can be obtained from most

manufacturers of water meters.

3. Obtain information regarding the character

of the water as to hardness and acidity. This

information should be available from the

water department and is important in determining material suitable for use.

4. Obtain all available local information regarding the use of different kinds of pipe with

42
respect both to durability and to decrease in

capacity with length of service in the particular water supply.

5. Determine the kind of pipe (material) to be

used. This decision will ordinarily be made

from considerations of the probable life of the

buUding, durability of material, relative cost and availability of difl'erent materials, and

ease of replacement in case of failure.

6. Estimate the supply demand for the building

main and for risers by totaling the fixture

units on each, table 604-III(a), and then by

reading the corresponding ordinate from

applicable curve of figure 6.

7. Estimate continuous-supply demands in

gpm such as that for lawn sprinklers and air conditioning, and add the sum to the total demand for fixtures. The result is the esti- mated supply demand for the building main.

8. Decide what is the desirable minimum pres- sure that should be maintained at the valve

of the highest fixture in the water-distributing

system under the estimated maximum demand. If the highest group of fixtures contains automatic flush valves, the pressure for the group shoidd be at least 15 lb/in. ^ for satisfactory operation. For flush-tank supplies and fairly constant service pressure, it may be safely reduced to 8 or 10 Ib/in^. 9. Determine the elevation of the highest fix- ture or group of fixtures above the street main or other source of supply. Midtiply

this difference in elevation in feet by 0.434.

The result is the loss in static pressure in

pounds per square inch.

10. Subtract the sum of loss in static pressure

and the pressure to be maintained at the

highest fixture from the average minimum

daily service pressure. The result will be

the pressure available for friction loss in the

supply pipes, if no water meter is used. If a water meter is to be installed, the friction

loss in the meter (see step 2) for the esti- mated maximum demand should also be

subtracted from the service pressure to determine the pressure available for friction loss in pipes.

11. Lay out a sketch of the building watersupply system from the street main or other

source of building supply, and determine:

(a) the developed length of the building main

;

(b) the dc^vclopcd IciiglJi from I si red niiiiii to the foot of each liscr l)i-iiiicliii:g lioiii the

biiihhng m;iin ; and (c) tiie greatest developed

lengtii of piiKi from tlie street main to the toj)

of any riser. If close estimates are desired,

compute the "equivah^iit length of pipe" for

all fittings in each developed length of pipe

and add the sum to the developed length.

The ])ressure available for friction loss in

pounds per square inch, divided by the greatest developed length of pipe in feet, times 100,

will be the average permissible friction loss per 100-foot length of pipe. If a pressure- reducing valve is used in the building main,

the permissible friction loss will be computed

from the pressure on the building side of the

reducing valve and the developed length from

the valve. In general, a velocity greater than

15 feet per second in the building main should

not be employed, as objectionable line noise is likely to result.

12. To find the size of building main needed,

turn to the flow chart (figs. 7 to 10) applicable

to the conditions of the particular case. The diameter of pipe on or next above the

coordinate point corresponding to the esti- mated total demand (see steps 6 and 7) and

the permissible friction loss (see step 11) will be the size needed up to the first branch from

the building main.

13. The required size of the water-distributing

pipes within a building may be determined

by sections, by referring to the applicable

flow chart, using the average permissible

friction loss and the estimated maximum

load carried by the section. If quiet of operation is an essential consideration, line noises

and water-hammer can be guarded against

by basing the sizes of risers and branches on

a low maximum allowable velocity in the

system. The latter is a practical and safe method of selecting sizes of supply pipes, if care is also taken to see that the permissible

friction loss for the system as a whole is not

exceeded in risei's or branches of the distributing system.

Building Mains and Water-Distributing Pipes

for Small Buildings.—It may be more desirable

at times to select water-supply pipes, including

the building main, from considerations of velocity as well as on the basis of the permissible

[43]
friction loss. This method of selecting pipe

sizes for building mains and water-distributing

pipes may be illustrated by applying it to particular types of buildings in table 604-III(e).

Table 604-III(e).

Water-demand estimates for resi- dential types of buildings (flush-tank supply)

Building

types as to number

and Icind

of fixtures

A

B

C,D

E

F

Kind of demand

Batli- rooms

Number

12

34

b

16

Kitchen

sinlcs

Number

1

12

4

8

16

Groups

of 1 to

3 laun- dry

trays

Number

1

1

12

34

Total fixture units

Main

and

cold- water branch

Number

11

1726

38

73

140

Hotwater branch

Number

Total demand

Main

and

ccld- water branch

gpm

12

162025

35

52

Hot- water

branch

gpm

10

12

1624

34

• Add any continuous demand to fixture demand to obtain total de- mand on building main. Reasonably satisfactory estimates for total demands for garden-hose connections or sill cocks are as follows: Number of outlets; Estiviuted demnnd, gpm

1 5 2 9

3 12

4 14

5 or more 3 gpm per outlet.

Table 604- III (e) gives the estimates of water demands for several types of residential

buildings obtained by applying table 604-III(a),

part III, and figure 6. Types A, B, and C

represent separate dwellings with from 1 to 3 bathrooms, and types D, E, and F represent

small apartment houses.

The following examples illustrate the uses of the tables and curves in estimating pipe sizes:

Example 1 Assume for the buildings A, C, D, and F

(table 604-III(e), pt. Ill) that a maximum

developed length of pipe from the street main

to the highest fixture will have to be 110 feet,

that the minimum service pressure is 45 Ib/in^', that the elevation of the highest fixture above

the water main is 30 feet, that it is desirable

in order to avoid annoying line noises to hold

the maximum velocitj^ in the water supply to 10 fps, that all water closets have flush-tank

supply, and that the character of water is such

as to make figure 8 most applicable for determining the sizes needed. The loss in static

pressure is 30X0.434 = 13.0 Ib/im'. Then, 100

(45— 13— 15)-^110=15.4 lb/in-', is the allowable friction loss per hundred feet. From

these assumed data and the data in table 604-

III (e), the requirements for the building main

and for the cold-water and hot-water branches

from the building main may be tabulated for each type of building by reference to figure 8

as follows:

Building type

Building main Hot-water branch

Supply

re- quired

Di- ameter

of pipe

re- quired

Velocity

for re- quired supply

Supply

re- quired

Di- ameter

of pipe

re- quired

Approximate

velocity

gpm Inches fps gpm

8 Inches fps A 12 7.5 H

M

4.9 C 20 1 7.6 12 7.5 D 25 5.5 16 1 5.9 F 52 1)4 8.3 34 IH 7.2

If the water-supply pipes are selected for a maximum limit of velocity of 10 fps, the sizes selected would be as given in the table above.

If selected for a maximum limit of 6 fps, a size larger than given in the table would be selected

for the building main of buildings A, C, and F

and for the hot-water branch of buildings

C and F. Example 2

Assume an office building of four stories and

basement, pressure on building side of pressure- reducing valve of 55 Ib/in.^, an elevation of highest fixture above pressure-reducing valve

of 45 feet, a developed length of pipe from

the pressure-reducing valve to the most dis- tant fixture of 200 feet, and fixtures to be

installed as in the following table with flush valves for water closets and stall urinals.

Fixture units and estimated demands

Kinds of fixtures Building main Branch to hot-water system

Fix- tures Fixture

units De- mand

Fix- tures Fixture

units De- mand

Water closets-- -. Number130

30

12 13027

Number

1,300

15048 260

gpm Number Number gpm

Urinals Shower heads 12 130

27

36

195

61 Lavatories - Service sinks.

Totals 1,758 300 292 86

Ignored.

Allowing for 15 Ib/in.^ at the highest fixture

under maximum demand of 300 gpm, the

pressure available for friction loss is found by

[44]
55- (15+45X0.434) =20.47 Ib/iir. The al- lowable friction loss per 100 feet of pipe is therefore 100X20.47^200 = 10.23 Ib/in^

If copper tubing or brass pipe is to be used

and the character of the water is such that

only slight changes in the hydraulic characteristics may be expected, the sizes needed for the building main and branch to the water

heater may be determined safely on the basis

of 10 lb/in. ^ friction loss by referring the demand estimates to figure 7. The following

tabiUation shows the results of referring the

demand data to each of the four figures:

Required size indicated by

Demand

Figure

7 Figure

8 Figure9 Figure

10

Inches Inches Inches Inches Building main, 300 gpm_ 3 3 3M 4 Branch to heater, 86 gpm _ 2 2 2 2!4

If steel or hon pipe is to be used, figure 8 is appropriate for determining sizes for the most

favorable water conditions. If the water is hard or corrosive, figure 9 or figure 10, depending on the estimate of conditions, will be found more appropriate. For extremely hard water,

it will be advisable to make additional allow- ances for reduction of capacity of hot-water

pipes in service. The sizes of risers and branches to risers may

be determined in the same manner as the size of building main—by estimating the demand for the riser from the estimate curve and applying

the total demand estimate for the branch, riser,

and sections thereof to the appropriate flow

chart, with additional allowances, if considered

necessary, for decrease in diameter in service.

Emmple 3

Assume that building type C, table 604-

III (e), part III, has an expanse of lawn and

that three outside hose connections are to be

installed. It is assumed that all three outlets

may be in use simultaneously for fairly longperiods of time. The estimated demand for

I lawn-sprinkling purposes will therefore be 12 gpm. The estimated demand for the fixtm-es

of the building will be the same as given in example 1, 20 gpm. The total demand on the

building main will be 20-1-12, or 32 gpm.

Par. 701. QirALTi Y of Fixtures.—Federal

Specification WW-P-541a is t]u; accepted

standafd I'or plumbing fixtures insofar as it covers the material, khid, quality, size, and

style of the different fixtures used. In cases where this does not apjjly, howc^ver, the authoi--

ity having jurisdiction, ovei- |)Juiul)iiig may

approve other standards, wliich may be those

developed by a governmental department, by

tlie industry concerned, or otherwise. As in the

case of plumbing materials, a number of Commercial Standards and Simplified Pi-actice Recommendations, which may be directly

applicable or may furnish useful infoi'mation,

have been developed, and have been pul>iislied

by the National Bureau of Standards. These

include the following:

Commercial S'J'andards

Staple porcelain (all-clay) plumbing fixtures (1929) mimeographed CS4-29

Staple vitreous china plumbing fixtures (1936) CS20-36

Staple seats for water-closet bowls (1931) CS29-31

Sanitary cast-iron enameled ware (1940) CS77-40

Simplified Practice Recommendations

Hospit.<;J plumbing fixtures (1930) R106-30

Inquuies concerning these publications should

be addressed to the Division of Trade Standards

and to the Division of Simplified Practice, re- spectively, both at the National Bureau of

Standards, Washington, D. C.

Par. 705. Fixture Strainers.—^In order to obtain quick emptying and thorough drainage

of the fixture and eftective scouring of the fixture

drain, the outlet from the fixture and the passages through the strainer should have cross- sections at least equal to that of the fixture

drain. There are no generally recognized

standards covering fixture outlets and strainers.

Hence, it is not feasible to state in this manual

definite detailed specifications for strainers.

Inadequate passages through the strainers

and outlets of such fixtures as kitchen sinks,

lavatories, bathtubs, and laundry trays are probably the most common cause of sluggish

drainage and clogged fixture drains. Careless- ness in the use and care of fixtiu-es, such as allowing materials (food fragments, lint, hair,

etc.) to coUect and be retained on the strainers

[45]
will liasten aiul aggravate tlie tlrainage difficulties caused by inadequate fixture outlets, and

will induce these difficulties in a well-designed

fixture and drain.

The manufacturer, builder, and plumber can- not entirely guard against the troubles arising

from careless use. The practice of increasing

the size of the fixture drain relative to that of the

fixture outlet, as is sometimes resorted to, is likely to inci'ease rather than to alleviate drainage difficulties, because of lower velocity in the

drain. (See par. fOlO, pt. Ill, for further dis- cussion of sink installations.) Par. 707. Savimming Pools.—Standards for design, equipment, and operation of artificial swimming pools are included in the regulations

of many state departments of health. These

for the most part are based on the "Report of the Joint Committee on Bathing Places,"

Conference of State Sanitary Engineers and

American Public Health Association. This

report is published by the U. S. Public Health

Service as Supplement No. 139 to the Public

Health Reports and is obtainable from the

Superintendent of Documents, Washington,

D. C, for 10 cents per copy.

In the design of any artificial swimming pool

the standards above referred to should be fol- lowed. A summary of those sections applying

to piping systems follows

:

Under no circumstances should piping systems

be so designed and constructed as to permit

pool water to enter a potable-water-supply

system nor waste water or sewage to enter the

pool through backflow connections or interconnections.

Cross-connections or interconnections in the

pool piping system whereby pool water may

under some conditions enter a potable-watersupply system should be avoided (f) by pro- viding for the admission of make-up water

above the overflow elevation of the pool or by

pumping from a pump suction well; (2) where

filters are installed and filter washing with the

recirculation pump is not feasible, a washwater

pump of proper capacity should be installed

and a suction weU or small elevated tank used

to supply water to the pump, the discharge to the suction well or tank being above the flow

line. In no case should valved cross-connections, whereby water from a potable-water

supply may be admitted directly to the re- circulation system for the purpose of filter

| washing, be permitted.

No pool drains or drains from filters, where

the recirculating system is used, should be I directly connected to sewers. Such drains

should discharge by an indirect connection to a properly trapped simip. (See ch. XI, pt. II.) Where such indirect connections are not possible, pumping of pool and filter-wash drainage

may be necessary.

Par. 800. Acid or Chemical Wastes.—The

disposal of acid or chemical waste requires

special consideration. The materials to be I used and the method of disposal may vary ac- cording to conditions and should be subject to the approval of the authority having jurisdiction over plumbing.

Par. 802. Minimum Sizes of Soil and

Waste Pipes.—In a simple table of sizes applying generaUy to buildings of various sizes and

plans, it is impossible to give the minimum sizes of soil and waste pipes actually required in particular buildings. In a building-drainage

system the load or volume rate of flow in its different parts is not the sum of the rates of ji flow from the fixtures in which the load originated. As the sewage load passes through a building-drainage system there is a continuous

increase in the time of flow over the time of flow into the system, with a corresponding

decrease in the volume rate of flow past any | given point in the system. For this reason, I as the size of building-drainage systems in- - creases (a greater nimiber of fixtures and longer

drains), there is a tendency toward continuous

uniform flow as the distance from the flxtures increases. In a very large building the flow in the main building drain becomes continuous

during the periods of heavy use of fixtures and

fiuctuates around the average rate of flow from

all fixtures during such periods.

For example, assume that in fOO bathroom

groups a water closet discharges 4 gallons once every 5 minutes, a bathtub 8 gallons every f6

minutes, and a lavatory 1.5 gallons every 3 i: minutes. The average flow from 1 bathroom

group wiU be /5 + /i6 + '-%= 1.8 gpm. The aver- age flow from 100 bathroom groups during the

whole time afl fixtures are being used at those

average rates wifl be 100X1.8 or 180 gpm and

[46]
the flow ill the buikUiig drain from KM) such

groups will be contimious over that time and

wUl fluctuate around that average. In order to provide in a measure for the dif- ferences in capacity in terms of the number of fixtures (or fixture units), the requirements for

sizes of plumbing drains are stated in five steps,

two applying to stacks and three applying to building drains, as follows: (a) A simple table

(table 805, pt. II) giving the permissible limits

in fixture units for dift'erent sizes of soil and

waste stacks when detailed plans of piping and

distribution of fixtures are not submitted for approval; (b) a tal)le (table 805(6)-III, pt. Ill) of limits for soil and waste stacks when detailetl plans showing the complete proposed piping

lay-out and the complete distribution of fixtures are submitted for approval of the authority

having jurisdiction over plumbing; (c) a simple table (table 807, pt. II) giving the limits

in fixture units for building drains and building sewers of different sizes when detailed plans

are not submitted for approval; (d) a table of

limits (table 807(c)~III, pt. Ill) for secondary

branches, main building drains, and building sewers under nonpressure-drainage conditions

when detailed plans showing the slopes, lengths,

and diameters of the pipes of the proposed

installation and showing the distribution of

fixture units for each drain and branch are submitted to the authority having jurisdiction over plumbing for approval; and (e) a table

(table 807((/)-III, pt. Ill) giving limits for primary branches, secondary branches, main

building drains, and building sewers under

pressure drainage when detailed plans showingslopes, lengths, diameters, and elevations of the

lowest horizontal branch on each stack of the

proposed installation are submitted to the

authority having jurisdiction over plumbing

for approval.

Par. 803. Fixture-Unit Ratings.—In general, fixtures are rated in fixture units on the

basis of the average volume discharged, the

average rate of discharge, and the average

frequency of use. Fixtures not given a rating

in table 803, part II, when installed in sufficient numbers to justify their consideration relative

to the total load to be provided for, may be

given the rating of some comparable fixture

given in the table. For example, a bedpan

Wiisliei' niiiy be iissigued (lie s;unc riiliii;^- as a

wiit(>,r closet in public, use. Siinil.ii'ly, other

fixtures may Ix' iissign(Ml the siime rating iis some

fixture given in tnble 803, which has tlic siune

size of trap and fixture (h'ain and uses watei- in comparable volumes and frecpKuicies; or fixtures

may be assigned ratings j)i-op()rtional to the

cross-sections of fixture drains, ft siiould be

noted that ratings are given in integeis in tiic scale of 1 to 10, and tluit no greater accin-acy is required hi assigning nitings for iiinisual or unlisted fixtures. Par. 805. Sizes of Soil and Wastk Pipes.

(a) Table 805, part II, is particularly applicublc

for buildings of one or two stories (one or two

branch intervals) in which nothing is to be

gained by considering the distrif)ution of

fixtures further than as controlled by the limits

set on the number of fixture units on one

horizontal branch. The table may be applied

safely, but not economically, to buildings of

any height.

Table 805(6)-III.—Permissible limits in Jixlnre units on soil and waste stacks

Limits in fixture units

Diameter

In any brancii interval for

Maximum

on 1 stack One branch

interval only N

Two or more

branch intervals NI2n+N/i

Indies m

2

34

5

68

10

12

Number

13

632

240

540

960 1.800

2, 700

4. 200

Number

126 16/m+8

120/n+60

270/n4-135 480/n+240

900/n+450

1, 350/71+675

2, 100/71 +1,050

Number

2

82480

600

1, 500

2, 800

5, 400 8,000

14, 000

(b) The provisions of section 805(6), part II, and table 805(6)-III, part III, are intended to permit an economical use of pipe in regard to

sizes when the building is of sufficient height

to render it safe to install a greater number of

fixtures on a stack of given diameter than is permitted under table 805, part II; and they

are especially applicable to buildings of three

stories (three branch intervals) or more in

height and to systems with relatively small

horizontal branches. It is essential in applynig

section 805(6), part II, that the number of

fixture units in any one branch interval shall be

[47]
ill accordiuice witli the quantity (A''/27i. +

(where n is the number of branch intervals and

A^^ is the permissible number of fixture units for a stack having one branch interval only) and

that the total number of fixture units on the

entire stack shall be within the limits of table

805(6)-III, part III.

Illustration oj Application of Table 805{h)-III

Assume a total of 580 fixture units to be

installed on 1 stack of a building of 10 branch

intervals (10 stories) in which the maximum in any one branch interval will be 76 fixture units.

Referring to table 805 (6) -III, the maximum

permissible number of fixture units on one 4- inch soil stack is found to be 600, provided that

the permissible number of fixture units in 1 branch interval as computed by the formula,

120/ri+60, is not exceeded. 120/10 + 60 = 72

fixture units which is less than 76, the actual

number to be installed. A 4-inch stack would

not be permissible; but without further computation it is obvious that a 5-inch stack would be

permissible under the provision. Likewise, it

is obvious from the preceding computation that

a 4-inch stack would be permissible in a 10- story building where the total fixture units on

the stack does not exceed 600 and the total in any branch interval does not exceed 72. Referring to table 805, part II, which repre- sents the conventional form of stating minimum requirements in plumbing codes and is the requirement applying in this manual in case detailed plans are not submitted for approval, it will be seen that a 6-iiich stack

would be required for 580 fixture units under the

requirements of that table. Par. 807. Horizontal and Primary

Branches.—Section 807, part II, provides for three difl'erent limits for the maximum permissible number of fixture units on building drains

and building sewers in the sanitary system,

each applicable under specifically defined conditions. Table 807, part II, which is repeated in

this part of the mariual for convenience in reference, gives mandatory limits for the

number of fixtures on primary branches for nonpressure drainage. These limits also apply

to the main building drain and building sewer

for nonpressure-drainage conthtions in case the

building drain has only one primary bi'anch of 3-inch or greater diameter.

Section 807(c), part II, provides for (and

table 807(c)-III, on p. 49, gives) permissible

limits in fixture units for secondary branches of the building drain, the main building drain, and

building sewer of given diameter and slope,

applicable when the building drain has two or more primary branches of 3-inch or greater

diameter and when the lowest horizontal

branch or fixture drain is less than 3 feet above

the grade line of the building drain.

Section 807 ((i), part II, provides for (and

table 807(f/)-III, on p. 52, gives) limits applicable when all fixture branches and horizontal

branches connected directly to the stacks are

3 feet or more above the grade line of the

building drain and no fixture branch or horizontal branch is connected directly to the

building drain.

The limits given in the tables applicable under the provisions of sections 807(6), 807(c),

and 807 (f/), in part II, are in general based on

the estimated peak load and on one-half the

estimated flow capacity of old pipes under the

defined applicable conditions in each case. The

permissible rate of increase in allowable load

under provisions of sections 807(c) and SOI id)

is also based on one-half the theoretical rate of

increase in the flow capacity of the drains.

Hence, it is to be assumed that a buildingdrainage system designed and constructed in accordance with these tables and rules will operate safely and eft'ectively unless the esti- mated peak load (design load) is exceeded by

| more than 100 percent, which, by an examina-

[ tion of the probability of its occurrence, may be } shown to be an extremely remote possibility.

The purpose of this proposed innovation in design methods is to enable the engineer to specify sizes of pipes for building drains that

will provide eft'ectivc transportation of sewage

as well as effective scouring action. This end

cannot be attained with both economy and

reasonable assurance of safety if the sizes of building drains are limited by a single simple

table of limits applying to all sizes and types

of buildings, such as table 807-III.

[48]
Table 807-JlJ.

Cayacilkn nf liinliliiKj under section 807 (b), part II

Diameter of pipe (inches)

IJi n«.- -. 2

3 waste only

3 soil 4

568

10

12

Permissible number of fixture units

Horizontal branch

at min- imum

per- missible slope or greater

Number

13

632

20

IGO 300

600

1.200

1, 800 2,800

Primary branch

Me-iuch

fall per

foot

Number

300

600

1, 400

2,400

3, eoo

Js-ineh

fall per

foot

Number

36

24 180 400

660

1,600 2,700

4,200

}4-ineh

fall per

foot

Number

2

5 2142

27 216

480

790 1,920

3, 240

5. 000

J.j-iiK,-li fall per

foot

Number

2

726

.50 36 250 500

940

2, 240

3. 780

6, 000

Table 807-III is particularly applicable to comparatively simple systems with few stacks

and branches but the limits may be applied

to systems of any size without the restrictions

governing tlie application of section 807(c) and

section 807 (c/), part II.

Table 807(c)-III.—Limits in capacities of building drains under the provisions of section 807 {c), part II

[Nonpressure drainage]

Diameter

(inches)

10_

12,

Limits in fixture units

Primary branch

yi6- inch

fall per

foot

Number

360

600

1,400 2,400

3,600

winch

fall per

foot

Number

1824

180 400

060

1. 600

2, 700 4,200

Minch

fall per

foot

Number

2127 216

480

790 1.920 3.240

5.240

inch

fall per

foot

Number26

36

250 560

940

2. 240 3.780 6.080

Secondary branch or main

inch

fall per

foot

Number

600

950

1.950 3.400

5,600

inch

fall per

foot

Number

90 450

850

1,350

2. 800 4.900 8,000

Hinch

fall per

foot

Number

125 630

1,200

1.900 3,900

6.800

11.200

^2- inch

fall per

foot

Number

180 900

1.700

2. 700 5.600 9.800

16. 000

Table 807(c)-III is particularly applicable

to the plumbing systems of buildings covering

a relatively large area with several widely

separated soil stacks. It will be noted that in accordance with the rules governing the application of the table, the limits for primary

branches will determine the size of pipe required

unless the total length of all branches (primary

and secondary) of the building drain is more

than 40 feet.

Rules for A iipl If I iKj Section. HOlic), I'drl. H,

and TaUc 807{c)-JfJ, /'art III

1. Lay out the fouiHlntiou phin of llic to scale, as in ligiire I2i\, and inark I ticrcton the position of all soil and waste st.icks in vertical projection.

2. Lay out on the i)lan the most direct practiciil lines for the })uilding draiii and its branclies

that can be readily obtained by use of standard bend and wye fittings, observing re()uircments regarding bearing walls. Make, if possible, no turn in direction greater than 45°

and not greater than 90° in any case, with no angle between branches greater than 45°.

3. Scale off the developed length of each

primary and secondary branch to the nearest

foot and mark its length on the plan.

4. Determine the total number of fixture units on each soil and waste stack, from table 803,

part II, and note the numbers on the plan.

5. Determine the required size of each soil and

waste stack in accordance with section 805,

part II, taking into account the restrictions as to limits in one branch interval in relation

to the height of the stack system and the fact that each stack shall be at least equal in diameter to the largest horizontal branch

connected thereto.

6. Determine the most convenient continuous

slope between the minimum permissible and

}2-inch per foot fall that can be installed in relation to the elevation of the street sewer.

7. Determine the required size of each primary

branch for the selected slope by table 807-111

and note on the plan.

8. Starting with the two primary branches

farthest upstream, compute the permissible

number of fixture units for each successive

secondary branch and the main building

drain by means of the following equation

:

FU=P [l+a (2i-40)],

in which

/'T''=the maximum permissible fixlui'c units on the secondary brancli in question

;

P =the permissible fixture units on one primary branch of the selected

slope by table 807-III;

[49]
100'

^fack No. IddOFU.

Soil 5fack

Dram Pipe

bidq. Wall

to Sewer

Elevation of LoiA/esf

honzonfal Branches.

Stack Na I = 14 ft

Stack No.l- 9 ft

Stack Nad' 10 ft Stack No. 4- 9ft

C

Figure 12.Illustrative graphs for applying sections 807{c) and (d).

[SO]
a —Si numorical factor (Icpcndinii- on

the slope as shown in the following tabulation ; and

Si =the sum of the lengths of all primary and secondary branches

greater than 10 feet in length upstream from the particular sec- ondar}' branch for which a computation is being made.

Values of a Fall in inch/foot

0.010 Ke

.007 }i .005 %

.004 ){

9. The diameter of the building sewer shall be

the same as for the main building drain if

it is laid at the same slope as or at a greater

slope than the building drain. If the building sewer is laid at a smaller slope than the

building drain, its capacity in fixtm-e units

by table 807(c)-III, part III, shall be equal

to or greater than the total fixtm'e units on the

system.

10. The preceding rules assume that all primary

branches enter the building drain from the

side at the selected slope. If any primary

branch, horizontal branch, or stack enters the building drain from the top or at a slope

greater than that of the building drain, rule 8

for increase in permissible number of fixtures

shall not be applied to the primary or secondary branch immediately upstream from such

entry or to the secondary branch or main

immediately downstream from such entry

connection, but the lengths of an upstream

secondary branch and of a downstream

branch from the entry coimection may be

employed in evaluating SL for succeeding

downstream branches and the main building

drain.

11. Rule 8 also assumes a clear passage thi-ough

the building drain at the selected slope. If any obstruction is built into the building

drain, as for example, a running trap (house

trap) or a backwater trap, rule 8 shall not be

applied to that part of the building di-ain in which such obstruction is set unless the

last branch thereto enters the building drain

at least 20 feet developed length upstream

from such obstruction, and the limit in permissible fixture units on tiic iiiiiin Wnilding

drain shall not exceed the value gi\en Ijv the

last computed hmit by this ride (!XC(:[)t as provided in section 807 (c/j, part II, foi- pres- sure drainage. This rule is not to be construed as prohiV)iting the us(i of a iiousc ti'aj) or a backwater trap when driiinagc coruhtions

require it, or as proiiihil iiig the connecting of a primary branch or scconcUiry ijraiicii within 20 feet from a house trap or hiick- water ti'ap, but merely as a stateniciil of the

necessary modifications of the genci iil nilc if these devices are installed.

12. In no case shall the number of lixlui-es installed on a building drain of given diameter

and slope exceed the limits given in table

807 (c)-III, part III, unless all fixture branches

or liorizontal branches are more than 3 feet above the grade line of the building drain,

thus permitting the application of the principles and rules for pressure drainage as provided for in section 807 (ri), part II. 13. When the limit in permissible number of fixture units for a given diameter and slope of a building drain has been exceeded by the

application of rule 8, or where a junction with

a larger branch of the building drain occurs, the value of P in the equation, FU—P

[1 +a(2i—40)], will become the value for the

larger diameter and succeeding computations

will proceed as by rule 8, except that if the

larger branch is a primary branch there shall be no increase in the permissible number of

fixture units for the secondary branch or main

immediately downstream from the junction over the permissible number of fixture units

for a primary branch of that diameter and

slope unless the ])rimary bi'anch exceeds 20

feet in length.

//lustrative Computation

Referring to figure 12A, assume that the

building drain and building sewer are to be laid with a uniform fall of }i inch per foot. By table

807(c) III, part III, the permissible load for a

4-inch primary branch with that slope is 180

fixture units, and by rule 8 the value of a for that slope is 0.007. Hence the equation (rule 8)

becomes: Permissible fixture units, FU= 180

[1 +0.007 (2i— 40)]. If the actual number of

fixture units on each stack is as indicated in

[51]
figaire 12A, all primary branches of the building

drain may be 4-inch since the maximum is 128 on any bi'anch and the limit by table 807(c)-

III is 180 fixture units. Starting with primary

branches Nos. 1 and 2, the necessary computation for determining permissible limits for the

various secondary branches a, b, c, and d and

on the main building drain e, may be summarized as follows:

Branch 2£ Permissible fi.xture units P[1+0.007(2L-40)]

Actual fix- ture units

a.b

0d

e (main)

Feet

58

121 169 230

278

180[1+0.007(58-40)] =202 180[1+0.007(121-40)] = 282

180[ 1 +0.007(169-40)] = 342 180[l+0.007(230 -40)] = 419 180[l+0.007(278-40)] = 480

128+64 = 192 192+04 = 256 256+64 = 320 320+64 = 384 384+64 = 448

It will be noted that for the main building

drain e the computed limit, 480 fixture units,

is greater than the limit for nonpressure drainage set in table 807(c)-III, part III, for a 4-inch

building drain with a uniform fall of }g inch per

foot, 450 fixture units. However, since the

actual number of fixture units to be carried

(448) is less than the limit (450), the rules

would permit the use of a 4-inch drain at the

assumed slope for the entire building, which

corresponds to an eight-story apartment house

with seven apartments on each floor. Assume again that the same floor plan is employed for a nine-story building, increasing

the total number of fixture units on the difi^erent stacks to 144 for stack 1 and to 72 for each of stacks Nos. 2 to 6, inclusive, and that the

building drain is to be laid at a uniform fall of /4 inch per foot. In the same manner as for the first illustration, the equation for computing permissible limits for a 4-inch branch

at }^!-inch fall per foot becomes

Ff' = 216[l + 0.005(2Z-40)];

and for a 5-inch branch at the same slope

becomes

irL' =480[l +0.005(2L^40)].

Branch

b

ccd

e (main)

Si

Feet

58

121 169

169 230

278

Permissible fixture units P[l+0.005(2i-40)]

216ri+0.005 ( 68 -40))= 235

216[1 +0.005(121-40)]= 303

210fl +0. 005(169-40)] = 355

480[1 +0.005(169-40)]= 790 480[l+0. 005(230 -40)]= 936 480fl+0. 005(278 -40)] = 1, 051

Actual fix- ture units

144+72=216 216+72=288 288+72=360

288+72 =360 360+72 = 432 432+72=504

Since for secondary branches a and b the

actual number of fixture units is less than either

the computed permissible number or the set limit of 630 fixture units by table 807(c)-III,

part III, a 4-inch building drain with }{-inch

fall per foot may be installed to the beginning

of branch c. For branch c the computed limit

for a 4-inch drain is less than the actual number

of fixture units, hence the size of branch c must be greater than 4-inch diameter and it becomes necessary to try 5 inches. Obviously,

as shown by the second computation for branch

c, it would not be necessary for the engineer to make any further computation in the case illus- trated to determine the sizes required for branch

d and the main building drain e, since the actual

number of fixture units (504) on the system

does not exceed either the computed limit (790)

for branch c or the fixed limit (1,200) for a

5-inch drain as given by table 807(c)-III.

However, the complete summarized computation is given by way of illustration. Application of these rules to drains of K-inch

fall per foot and for other sizes of drain will be

made in the same manner for all sizes of primary branches and for all lengths of primary

and secondary branches.

Table 807(d)-III.Limits in capacities of building drains under the provisions of section 807 (d), part II

[Pressure drainage]

Diameter

(inches)

Limits in fixture units

Primary branch

Heinch

tall per

foot

Number

720

1,200 2,800 4,800

7,200

inch

fall per

foot

Number

48 360

800

1,320 3,200

5, 400

8, 400

inch

fall per

foot

Number42

54 432

960

1, .580

3, 840

6, 480

10, 400

inch

fall per

foot

Number52

72 500

1, 120

1, 880

4, 480

7, 560

12, 000

Secondary branch or main

/16- inch

fall per

foot

Number

1,200

1,900

3, 900

6, 800

11, 200

inch

fall per

foot

Number

180 900

1,700

2, 700 5,600

9, 800

16, 000

Hinch

fall per

foot

Number

250

1,250 2,400

3, 800

7,800

13, 700

22, 400

Hinoh

fall per

foot

Number

360

1,800

3, 400

5, 400 11,200

19, 800

32, 000

Table 807(rf)-III is particularly applicable

to large buildings in which basement fixtures

and possibly first-floor fixtures are to be drained

into a sump in such a manner that all direct

connections of fixture branches and horizontal

branches will be materially greater than 3 feet above the grade line of the building drain. In

[52]
computing the permissible limits for particular

systems xmder the rules (which see) applying

to pressiire draiuag-e, both sections 807(c) and

807 (d), part II, apply.

Rnles for Apph/ivg Section S07(d), Port IT, (ind

Table 807 {d) III, Part III

1. Lay out the building plan to scale as for the

application of section 807(c), part II (see

fig. 12B), and scale off the developed lengths

of each primary and secondary branch.

2. For each stack in the system, determine the

elevation of the lowest horizontal branch

above the grade line of the building drain.

3. Scale off the developed length of pipe from

the intersection, B, of the branch with the

building drain to the lowest horizontal branch

connection to the stack farthest upstream.

Also, determine the developed length from B

to the lowest horizontal branch on each of the other soil and waste stacks.

4. Lay off to a convenient scale a horizontal

line {BiB in fig. 12C) equal to or greater than

the greatest developed length obtained by

applying rule 3. Also, lay off in order on line BiB from point B aU other developed lengths

as obtained by the application of rule 3 and

designate the points on line BiB as B2, -63, etc. At each of the points Bi, Bo, B3, etc., erect lines perpendicular to BiB. Also, on hne BiB, or on BiB extended if necessary,

lay off a length BJ equal to that in which a

total fall of 1 foot would be given for the

slope involved and erect the perpendicular

hnejf/' equal to 1 foot and draw the straight

hne Bf to intersect the perpendicular line from Bi. Designate the intersection as i. Then on each of the perpendicular lines from

Bi, B2, B3, etc., lay off lengths from the line Bf equal to the elevation of the lowest

branches on each of the corresponding stacks

above the grade line and designate the

resultant points as Si, S2, S3, etc. Then

draw a straight line from point B such that

at least one of the points Si, S2, S3, etc., lies on the line and none of them lie below it. Extend the line to intersect the vertical line from point Bi, which intersection (designated

as 7) may be at or below point Si, depending on the relative elevations of the lowest

braucbes on tli(! dilfci'ent stacks involved.

Scale off the lengths Bil and Bii.

5. Select a value P from table 807(c)-in, part

III, for pi'iriiiiiv branches corresjjondinjr to the sloj)!' i)f I he (Iriiin such that the pi-odiici

PyjBJlAB{i is to or greater tlian the

numbei- of fixture units to be carried by a primary branch and that the cori-('S|)()nding

product Pi-^BJ/4Bii for the next smaller

size is less than the numl)er of fixtui-e luiits to be carried by tlie primary bj-ancli in (|ues- tion. The larger of the two sizes will be

the minimum permissible size for the piimary branch in the particular case, provided

that both the product P^jB^lWBj and the

limit for a primary brancli of that diameter

in table 807((i)-III, part III, are each equal

to or greater than the number of fixture units

actually carried.

6. To obtain the permissible load limits for secondary branches and the main building

drain of the particular system, proceed as by

rule 8 applying to section 807(c), part II, starting in each case with the computed limits for primary branches as given by rule

5 above instead of the limits given in table

807(c)-III, part III.

7. If the slope of the buildmg sewer is equal to or greater than the slope of the main building

drain, it may be of the same nominal diameter

as the main building drain arrived at by the

application of the preceding ride 6. If at any

point the slope of either the mam building

dram or the building sewer is decreased, the

drain laid at the lower slope shall be mcreased

in diameter, if necessary, so that its limit in

capacity by table 807(f/)-III, part III, at the slope laid, is equal to or greater than

the load to be carried.

Illustration of Application of Rules for Pressure Drainage

For this ilhistration, assume that the building

has a base area 60 by 100 feet, as illustrated in

figure 12B; is 20 stories high; and wiU contain

fixtures that total 3,528 miits, distributed

among four stacks, and a sump located as indicated in the figure. In this illustration, the

drain from the sump pump, entering- the main

building drain at pomt B, is the last branch.

[53]
Now assume that the elevation above grade

line of the lowest branch connected to each of the stacks is as follows: Stack 1, 14 feet; stack

2, 9 feet; stack 3, 10 feet; and stack 4, 9 feet; and that the slope of the building drain is '/8-inch fall per foot. The developed length of drain from B to the lowest branch on stack 1 is 5+14+14 +30 +28 + 14 = 105 feet. We now

have the data for the scale laying out figure 12C

as prescribed by rules 3 and 4. From the figure,

i5i 7=13.8 feet and 5,/= 1.1 feet; from which

^jBJlABii = V13.8/4.4 = 1 .77, the factor by

which the limits foi' primary branches as given

in table 807(c)-III, part III, are to be multiplied

to determine the allowable loads within the

limits for primary branches by table 807(rf)-III,

part III, for the particular building and conditions assumed. Ordinarily, the required minimum size of a primary branch can be predicted

by comparing the permissible loads for pressure

drainage, table 807(c^)-III, and the number of fixture units to be carried in the case at hand

without going through the details of computation prescribed in rule 4. For example, in the

present illustration the basic size for computing

secondary branches will obviously be determined by the primary branch from stack 2, and

the load, in this case 1,880 fixture units, lies between the permissible load of 1,320 fixture

units for a 6-inch primary branch with }^-inch

fall per foot by table 807(r/)-III, and the hmit

in load, 3,200 fixture units, for an 8-inch primary branch at that slope. Hence, the sec- ondary branch must be at least an 8-inch pipe

and the trial computation becomes

1.77X1,600 =2,832 fixture units. Since 2,832 fixtm'e imits is less than the limit

(table 807(r/)-III) for an 8-inch primary branch

of }s-inch fall per foot under j^ressure, and

greater than the actual number (1,880), the

size required for the primary branch from

stack 2 is 8-incli diameter.

Similarly, for stacks 1, 3, and 4, the limits

lor a 5-inch primary branch at ^g-inch fall per

foot are 400 fixture units for nonpressure drainage (table 807 (c) III) and 800 fixture units

for pressure drainage (table 807 (rf)-III).

Again, 1.77 X 400 = 708 fixture units is greater

than the load to be carried (480 fixture

units) and less than the limit (800 fixture

units) for pressure drainage, and hence a

5-inch primary branch will be required from

stacks 1, 3, and 4. Starting with stacks 1 and 3 and applying rule 5 for pressure

drainage, page 53, and then rule 8 for nonpressure drainage, page 49, the computation may

be summarized as shown in the following table. In this case there will be three different values » of P (the permissible number of fixture units on

the primary branch) to be used in the equation,

F[7=P[l+a(2i-40)]; Pi =708 fixture units, \ applying to the secondary branch a for stacks '

1 and 3; ^0= 1.77 X660 = 1,168 fixture units,

[ applying to the secondary branch b for stacks

1, 3, and 4; and P3= 1-77 X 1,600 =2,832 fixture

units, applying to the primary branch from

stack 2, to the secondary branch c, and to the

main building drain d.

Branch 2i

Permissible fixture units P[l+0.007(2i-40)]

Actual

fixture units

Diameter re- quired

Feet Inches

a-

.

86 708(1+0.007(86 -40)] =935 960 6 b 130 1, 168[1 +0. 007(130 -40) ] = 1 , 904 1,440 6 c 190 2, 832(1+0. 007(190-40)1 = 5, 805 3, 320 8 d (main) .

.

219 2. 832(1+0. 007(219-40)1 =6, 380 3, 528 8

Summarizing, the requirements in sizes are

as follows:

5-inch for primary branches from stacks 1, 3, and 4; 8-inch for primary branches from stack 2; 6-inch for secondary branches a and b;

8-inch for secondary branch c; and

8-inch for main building drain d. Since the number of fixture units carried by

the main building drain and building sewer

(3,320 + 208 =3,528 fixture units) does not ex- ceed either the ultimate limit (5,600) for an 8- inch drain or the computed limit (5,805) for the

secondary branch c immediately upstream from

the junction point B, the main building drain

d and the l)uilding sewer may also be 8-incli pipe if they are laid with not less than }^-inch

fall per foot. It should be noted that the computed limit may sometimes exceed the ultimate

permissible limit given by table 807(('/)-III,

part III, as is the case in the computation for branch c. In these cases, the permissible limit

in the table shall apply. Par. 902. Gutters and Leader Connec-

[54]
TiONS.—Roof gutters are not ordiiuirily considered a part of the plumbing work and are usually installed under a separate contract and

bv different workmen. However, the requirements for and installation of roof gutters are

related to the plumbing in that they are the

principal collectors of storm water and are

directly connected to the leaders of the Stormdrainage system of the building. Hence, the

capacities of roof gutters and their outlets to leaders should be consistent with the capacities

of the leadei'S. The following information is included here as an aid to the engineer in specifying the proper sizes of roof gutters and

outlets. Table 902-IJI.—Maximum roof area for semicircular

rooj gutters with a fall of yie inch per foot or less

Diameter of Maximum

gutter roof area

Inches Square feet 3 170

4 360

5 625

6

7 960 1,380

8 1, 990

10 3,600

12 6,800

The capacities in the preceding table are based on the flow capacities of gutters of semicircular sections, no slope, one outlet, and a

rate of rainfall of 4 inches per hour. If the

faU is greater than inch per foot or if the

gutter has two or more outlets (leaders), the

permissible roof area as given in table 902-III

may be increased by multiplying it by one or both of the following factors as they apply:

(a) by -y/sj {1/16), where s is the actual fall in

inches per foot; and (b) by n, the ninnber of

outlets, provided the roof area drained into

any one leader does not exceed the value given

in table 902-III or the permissible roof area as computed by (a). For example, assimie that a

3-inch semicircular roof gutter is pitched with

a fall of }i inch per foot so as to divide the roof area equally between two leaders. The per- missible roof area on the 3-inch gutter becomes

170^^X2= 340V2 =479 sq ft.

For roof gutters with rectangidar or other

polygon-shaped cross-sections, table 902-III

in ay be used safely, provided the gutter has a

depth ('<|ual to the I'adiiis jmd iiii average uidlli equal to the diameter of tiie semicircular section; or the capacity of a roof gutter of any

shape may be safely assumed as equal to tliat of a semicircular gutter equal in radius to that

of the largest semicircle that can be insci-ibcd wholly within the cross-section of the gutter

in question.

Roof aiT'a for application to requirements for roof guttei's will be computed in the same manner as for storm drains. (See sec. 903(c), pt.

II.)The capacities of roof gutters as given in table 902-III, part IH, assume an outlet of at least equal capacity. Insufficient outlet through

the leader connection, improperly formed leader

outlet and strainer, and clogged strainer or leader connection are the usual causes of an

overflowing roof gutter, except in cases of

rainfall in excess of the rates provided for. There are no generally recognized standards

governing the forms and sizes of leader connections. The outlet of a roof gutter flowing

at capacity should be at least equal in cross- section to the gutter. Likewise, the total intake area of the strainer should be at least equal to the cross-section of the gutter. The

required intake area may be obtained by doming the strainer or by increasing the dimensions

of the strainer and leader connection.

Par. 903. Size of Storm Drains and Lead- ers.—Tables 903(6) and 903(c), part II, are, as stated, based on a rate of rainfall of 4 inches

per hour. Whether it is essential to make

allowances for greater rates of rainfall in certain

localities wiU depend on the maximmn rates and

frequency of rates higher than 4 inches per

hour of rainfall recorded for these localities and

to some extent on whether any particular

damage to health or property would result from

overflow. Likewise, whether it is advisable to increase the allowable load on leaders and storm

drains of given diameters and slopes will depend on the weather records and on what

maximum rate of rainfall is to be expected. In

either case, the tables given can be utilized for detennining the size of pipe needed by simply

multiplying the allowable roof areas as given

in the tables by ~> where x is the rate of rainfall

' X

to be provided for. For example, if a rate of

[55]
only 2 inches per hour is to be provided for, the

allowable roof areas may be doubled; and if a

rate of 6 inches per hour is to be provided for, the allowable roof area would become 2/3 of the values given in the tables. Par. 903(d). Allowance for Projecting

Walls.—In case a wall projects above a roof

in such a manner that storm water drains from

the wall onto the roof, the following allowances

to be added to the roof area are suggested:

(1) For total roof area applied to a leader or storm drain receiving total flow from the roof:

a. For one wall only, add 50 percent of the

wall area;

b. For two adjacent walls only, add 35 per- cent of the sum of the wall areas if both are of the same height. If the two adjacent walls are

of different heights, allow 35 percent of the

combined wall area below and 50 percent of the

waU area above the top of the lower wall

;

c. For two opposite walls only, make no

allowance if both are of the same height. Add

50 percent of the wall area extending above the

lower wall if the two are of dift'erent heights;

d. For walls on tkree sides, add 50 percent

of the area of that part of the inner wall that

lies below the lowest of the three walls, and

allow for the portions of the two walls extending

above the lowest, as in b if the walls are adjacent, or as in c if the walls are opposite;

e. For walls on four sides, ignore all wall areas lying below the top of the lowest wall, and add

for those extending above it according to whether they fall under a, b, or d. (2) For api^lication to leaders or storm drains

receiving only part of the roof drainage:

a. Determine the portion and dimensions

of the roof area drained into each leader

connection;

b. Compute allowance for projecting walls

separately for each leader connection, as for

total allowance to be added, ignoring walls not

directly adjoining and extending above the

section of the roof drained into the leader for which the computation is being made.

(3) For application to the main building drain

and building sewer:

a. Ignore walls not extending above the

building;

b. For one wall only extending above the

building, ignore the wall area if it is less than

that of the roof, or add 50 percent of the differ- ence if it is greater than the roof area;

c. For two adjacent walls only, ignore the

combined wall area if less than that of the roof, or add 35 percent of the difference if it is greater

than the roof area;

d. For two opposite walls only, ignore wall area if the area of that portion of the higher

wall above the top of the lower is less than the

roof area, or add 50 percent of the dift'erence

if it is greater;

e. For three walls extending above the building, ignore wall area below the top of the lowest

wall and then apply c or d above according to whether the walls extending higher are adjacent

or opposite. In all cases, the importance of applying an

allowance for walls extending above the building

and draining onto its roof depends largely on the

relative areas of the extending walls and the

roof. If the roof area is large relative to the

total area or to that part of the total area for which allowance would be made under the

preceding rules, the matter is not likely to be of great importance. It may be very important

to make an allowance for wall area if a low

building is built at the side of a tall one or into an angle formed by two tall buildings, or if a low-roofed portion of a building has a similar

relation to dift'erent wings. It will be of less importance in any case if the leaders and storm

drains required by the regulations for roof area alone are more than ample than if they are near

the limit in capacity.

The allowances given in the preceding rules were selected to provide for a driving rain at an

angle of 30° with the vertical. Regardless of the angle at which the rain falls, the portions of projecting roofs ignored under the rules given can be safely ignored in regard to their eft'ects on the building storm sewer. Par. 904. Separate and Combined Drains.—

The provisions of section 904(a), part II, are intended to require separate sanitary and storm

systems until they can be conveniently con- nected at grade. The sanitary system should

be collected into one sanitary drain and the

storm system into one storm drain, and the two

connected at grade, if it can be conveniently

done without crossing over. If the preceding

[56]
is not convenient or economical, the sanitary

and storm drains on each side of the combined

sewer of the building may be joined at grade as described and the two combined drains thus

formed connected to the building sewer. Connections should not be made through doublewye hi-iiiiclics. If the street S(!Wer is siiljjcci to overcharging or submergence, tliere \\ ill he

less likelihood of detrimental efl'ects to tiie sanitary system if the storm (li iiinage and sanitary drainage are carricid sepai'ately to tlie street sewer.

Table 904-III.

Required diameters for combined building drains and sewers according In number of fixture units FOR DRAINS AND SEWERS HAVING ).ii-INCH FALL PER FOOT ^\ Fixture \ units \

Roof

area

0...

775..--

1,350.-

1,550..

2,100..

2,700.. 4,200..

4,350..

7,600-.

8,700. - 12,400- 15,200-

24,800-

225 425 450 675 850 1,350 1,400 2,450 2,800 4.000 4,900 8,000

. in. in. in. in. in. in. in. in. in. in. in. in.

4 4 4 5 5 6 8 8 8 10 10 12

4 4 0 5 6 6 8 8 8 10 10 10 12

4 5 5 6 6 6 8 8 10 10 10 10 12

4 5 6 6 6 8 8 8 10 1(1 10 12 12

5 6 6 6 6 8 8 8 10 10 10 12 12

5 6 6 6 8 8 8 8 10 10 12 12 12

6 8 8 8 8 8 8 S 10 1(1 12 12 12

8 8 8 8 8 8 8 8 10 10 12 12 15

8 8 10 10 10 10 10 10 10 12 12 12 15

8 8 10 10 10 10 10 10 12 12 12 12 15 10 10 10 10 10 10 12 12 12 12 12 15 15

10 12 12 12 12 12 12 12 12 15 15 15 15

12 12 12 12 12 12 12 12 15 15 15 15 15

FOR DRAINS AND SEWERS HAVING J4-INCH FALL PER FOOT

\^ Fixture \ units \

area Roof \\

\

0 315 595 630 950 1,190 1,900 1,950 3,400 3,900 5,650 6,800 11.300

sqft in. in. in. in. in. in. in. in. in. in. in. in. in. 0 4 4 4 5 5 6

8

8 8 8 10 10 12

1,075 4 4 5 5 6 6 8 8 10 10 12 12

1,800 4 5 5 6 6 6 8 8 10 10 10 12 12

2,150 4 5 6 6 6 8 8 8 10 10 10 12 12

3,000 5 6 6 6 6 8 8 8 10 10 10 12 12

3,600 5 6 6 6 8 8 8 8 10 10 12 12 15

5,950 6 6 8 8 8 8 8 8 10 10 12 12 15

6,000 6 8 8 8 8 8 8 10 10 10 12 12 15 9,800 8 8 8 8 10 10 10 10 10 12 12 12 15

11,900 8 10 10 10 10 10 10 10 12 12 12 12 15

15,900 10 10 10 10 10 10 12 12 12 12 12 15 15

19,600 10 10 12 12 12 12 12 12 12 12 15 15 15

31,800 12 12 12 12 12 15 15 15 15 15 15 15 15

FOR DRAINS AND SEWERS HAVING ^-INCH FALL PER FOOT ^\ Fixture \^ units \

Roof \

area \^

0 450 850 900 1,350 1,700 2,700 2,800 4,900 5,600 7,500 9,800 15,000

89 /( 0

in. in. 4

in. 4in. 4in. 5in. 5

in. 6

in. 8

in. 8in. 8in. 10

in. 10in. 12

1,550 4 4 5 5 6 6 8 8 8 8 10 10 12

2,700 4 5 5 6 6 8 8 8 10 10 10 10 12

3,100 4 5 6 6 6 8 8 8 10 10 10 12 12

4,200 5 6 6 6 6 8 8 8 10 10 10 12 12

5,400 5 6 6 6 8 8 8 8 10 10 10 12 15

8,400 6 8 8 8 8 8 8 8 10 10 12 12 15

8,700 8 8 8 8 8 8 8 8 10 10 12 12 15

15,200 8 8 10 10 10 10 10 10 10 12 12 12 15

17,400 8 10 10 10 10 10 10 10 12 12 12 15 15

24,700 10 10 10 10 10 10 12 12 12 12 12 15 15

30,400 10 10 10 12 12 12 12 12 12 12 15 15 15

49,400 12 12 12 12 12 15 15 15 15 15 15 IS 15

[57]
-vent

'fixture drain

a, not less than 2orgreater than 48 diameters

h, notgreater t/ian ore d/ameter

-dra/n Figure 13.

Distance of trap from vent.

Par. 1002. Protection of Trap Seals.—

The requirements of chapter X, part II, are designed to give the maximum flexibihty in the

design of a building-drainage and venting

system consistent with an adeqiiate protection

of the seals of fixture traps. This flexibility is accomplished by a more complete classification

of vents as to their functions, locations, and

forms, and a more detailed statement of the

limits of use of different forms than is to be

found in the usual plvimbing code. Par. 1005. Distance of Trap From Vent.—

Section 1005, part II, applies particularly to vents for separate traps, usually termed "back

vents." The most effective point for venting a

fixture drain depends on the form of the drain.

If the fixture drain turns to the vertical within

48 pipe diameters from the trap weir, a vertical

continuous-waste-and-vent at that point is the

most effective vent that can be installed. If the fixture drain slopes continuously from the

trap weir, the requirement, assuming a fall of

}^ inch per foot, limits the pei'missible length of drain between trap and vent to: 5 feet for a

l}^-inch di-ain; 6 feet for a l}^-inch drain;

8 feet for a 2-inch drain; and 12 feet for a 3-inch

drain. If a fixture drain connects with an

adequate relief vent or with a stack-vent within

these limits, the relief vent or stack-vent will perform the functions of a back vent. (See

fig. 13.) Par. 1008. Yoke and Relief Vents.—Section 1008, part II, gives the details and neces- sary restrictions for group venting the plumbing

fixtures, ordinarily installed in residences, by means of a stack-vent, yoke vents, or relief vents. The application of section 1008 in con- junction with sections 1005 to 1007 makes many

simplifications in piping possible and offei^s inviting opportunities for standardization and

pi'efabrication. Figures 16 to 20 illustrate a few simplified lay-outs for residential construction wliich may be varied to a considerable extent in arrangement of fixtures without conflicting in any respect with the minimum

requirements of tliis manual.

Figure 16 illustrates the simplest lay-out, and

in general the most effective venting obtainable,

for a single bathroom group and a kitchen sink

or combination fixture all in one story or branch

interval. The figure illustrates one arrangement of the fixtures about the stack, and illus- trates the type of fittings required. The line sketches of figures 17 to 20 merely indicate

typical drain lay-outs and venting required

under section 1008 for these lay-outs.

The group venting illustrated in figure 16 may be used on a yoke-vented section of a

horizontal branch not less than 3 inches in diameter, in any branch interval of a soil stack, and

the order of the fixtures around the stack or yoke-vented branch may be varied as necessary

dual vent

-I \/ 7- -fixture drain

-drair?

—dual vent

not greater ftfan 5 diameters

Figure 14.

Dual vents.

[58]
back ventvent

dualback ventp-

-drain

vent

daafback vent

- drain

8

Figure 15.Group vents for lavatories and bathtubs. c

for accommodation to the floor plans of any

particular building.

Figure 17 illustrates essential venting for a two-story lay-out with kitchen sink on the first floor and bathroom group on the second floor. Figure 18 illustrates two lay-outs for duplex

construction as permitted by section 1008(c).

The lay-out for lavatories and bathtubs illus- trated in the lowest branch interval of figure 20

may be used in lieu of that illustrated in figure

18B.

Figure 19 illustrates the permissible lay-out

under section 1008(6) for two bathroom groups

and two kitchen sinks in the two highest stories or branch intervals of a building. Alternate

connections for the sinks are shown in dotted

lines with the vents required in case the sinks

are connected to a separate stack or to the soil stack below the highest water-closet branch.

Figure 20 illustrates permissible lay-outs for duplex construction for any number of floors or branch intervals for fixtures of the same kind

located back-to-back. If the fixtures are not

located back-to-back, the lay-out represented

in figure 18A may be installed in any branch

interval with relief vents of the yoke-vent type

as shown in figure 20. Figures 13 to 20 illustrate the main essentials

for eft'ective group venting and may be used in

any combination so long as these essentials are preserved. Under section 1008((^), any number

of the fittings and the pipe necessary to make the

installations illustrated in figures 13 to 20 or

permitted by the requirements of part II mny

be standardized for particidar or typical floor plans and cast in one fitting or otherwise prefabricated.

Ve/?/ at least

12"above roof

Kitchen 5/nk

t/z Trap

Tapped 3on/tory

bath

lii'Trap"^

^Floor

Water

_ Closet bend

5Long 3weep bend'

Figure 16.

Stack-vented piping lay-out for orie-siory house.

[59]
^ -stack- vent

Figure 17.Piping lay-out for two-story house iviih one

bathroom.

Par. 1010. Vents fok Flat-Bottomed Fixtures.—Section 1010, part II, is intended to apply particularly to installations for kitchen

sinks and to provide for more effective drainage

of the fixture and scouring of the fixture drain

than can be obtained in some cases by an instal- lation back-vented near the trap.

Clogging of the fixture drains of kitchen

sinks by deposits from greasy waste water is a source of annoyance and a cause of frequent

servicing. In this connection it should be

noted that, in general, the shorter and the more

direct the fixture drain is, from the trap to its

connection to a stack or to another drain that is thorouglily washed by the discharge from other

fixtures, the more effective the drainage will be

in respect to both quickness of emptying of the

fixture and freedom from clogging. However,

the location of the kitchen relative to stacks or drains that are thoroughly washed by other

fixtures may make it necessary to install a

fixture drain from the sink with a relatively long

sloping section. The installation of a back vent on the fixture side of the sloping section of the

fixture drain wUl reduce the effective head on

the drain, result in sluggish action, and induce

deposition which will usually result in clogging

both the fixture drain and back vent. Omission

of the vent will ordinarily provide more effec- tive drainage which, in some cases, m^ij be

noisier in operation than if the back vent were

installed. Section 1010, part II, simply gives

the buUder a wider latitude in designing for

effective and safe operation of sink installations

than is given in section 1005, part II. (See

fig. 23.) Par. 1011. Vents for Resealixg Traps.—

Section 1011, part II, is intended to provide for cases where no space is available for a properly

installed vent for a P-trap. A group of lavatories located in the middle of a washroom floor would be an example of such a case. Par. 1012. Fixtures at Base of Main

Vent.—The purpose of the provisions of sec- tion 1012, part II, is to permit the installation

of a limited nimiber of fixtures at the base of

Figure 18.Piping lay-out for one-story duplex house.

60
long vertical vents to wash out nist or other

products of corrosion. Fixtures discharging

greasy or other waste water likelv to congeal

and deposit and fixtures in excess of the limits

set in section 1012 should not be so connected.

Par. 1101. Indirect Connections.—Any in- du'ect connection whereby the continuity of the

- shcM- vent

; -x-a/fernafe h/ouf fors/nkj /

Figure 19.

Piping lay-out for bathrooms in each of two

stories.

-stack- vert

alferm/e for lowrormtermed/ategroup Figure 20.

Piping lay-out for duplex apartments.

\ Stack Vent

Vent

Circuit Vent

V \\ Soil5tack Branch Vent Relief VentVent5tack

Figure 21.Illustration of circuit-and-loop vents. _J I /?oof

h \

Note: Vent 5tac/<: may loop ] fo Stack Vent or extend

direct/y thru roof

5tacli Vent c H

W.C- \w.c.

- Relief Wnt^ I

^ ^ ^ ^

Soil Stack

\Rdiefknt^^ Circuit Venta floor

b Floor

Vent Stack

c Floor

d Floor

a Top floor without relief b Intermediate floor triftj one relief /e/?f c Intermediafe or lower floor tvitti two

rel/ef ye/?ts d Intermediate or lower floor for double line of ffiturej

Figure 22.

Limits for circuit-and-loop vents.

[61]
—venf

u

,1 u

a, nof more than 10 d/amefers

b. nof more fhan^^ diameters

a*c. not more than 7£ diameters

Figure 23.

Drains and vents for Jlat-ltotUnncd fixtures.

waste line from an appliance, device, or apparatus having a diip or drainage outlet is broken

by an air gap of such spacing as will prevent

backflow, is approved if the waste water is not

contaminated with human or household wastes

and if the waste line discharges on the inlet side

of a fixture trap. Such fixture trap may be a

part of the plumbing installation of the appli- ance, device, or apparatus, or it may be the

trap of a regular plumbing fixture. In the

latter case the air gap should be above the flow

line of the fixture. Appliances, devices, or apparatus where such

indirect connections are required are stills,

sterilizers, equipment requiring cooling water,

and the like. Examples of such indirect connections are shown in ftgure 24. Par. 1305(6). Air Tests. —In applying air

tests, it shoidd be noted tliat a slowly falling

pi'cssure is not necessai'ily an indication of a leaking system. If the air introduced is of a higher temperatiu-e than that of the piping

system or than that of the air already in the

system, the pri'ssure will fall slowly until temperature equilibriimi is reached. In such cases, before searching for definite leaks, the pressure

should again be brought to the test value without changing the air in the system. If the rate

of fall is materially lower on the second or on

repeated trials, it may be taken as an indication

of a tight system. On the other hand, if the

temperature of the air introduced is lower than

that of the piping system or the air already in the system, a slowly rising pressure may occur. A rising pressure or constant pressure for a 15- minute period may be taken as a positive

indication of tightness. In case of a rapidly

falling pressure, a search for leaks should be

made before repeating. The same precautions

apply to smoke tests.

^\Jlir dap nof Ifss

than iw/ce effecfive opening

Fixed ^I'r break

Figure 24.

Indirect wastes.

[62]
INDEX

A Page

Accepted standards ._ 27 Definition G

Accessibility: Offixtures for cleaning 14 Of indirect-waste connections 22 Of overflow pipes for cleaning 14 Of sand interceptors 13 Of traps and olcan-outs_._ 13 Acid wastes 46 Adjacent buildings, relation of vent terminals to 22 Adjustments after test 24 Affidavit for plumber's test 23 Air gap 34, Gl Definition ; 6 Illustration of 34 Air-pressure test: Of drainage system 23 Of sanitary-drainage system 23 Of vent system _ 23 Of water-supply system 23 Air test, final 23 Air tests 62 Of defective plumbing 24 Of drainage system 23 Of leaders 24 Of roof connections 24 Pressure in 23, 24 Time required for 23, 24 Alterations , considered as new work 24 Alternate materials 11 American Society for Testing Materials 29 American Standards Association 29 Ample flow, definition 35 Apartment houses, water-demand estimates for small 44 Application of flow charts 40 Approval:

Before covering work 24 Certificate of 24 Of alternate materials 11 Of plans for building drain 16 Of plans for building sewer. _ IG Of plans for drainage svstem 16 Written, of tests 24 Approved, definition 6 Aquaria _ 14 Area drain: Definition G Trap, need not be vented... 22 B

Back siphonage, definition. See Backflow. Back vent 58 Definition.. li Distance from trap weir 22 For flat-bottomed fixtures 20

Location of 18 On fixture drain of kitchen sink GO Prohibited 22

Size of 21 Backflow:

Definition _. _ 6 Protection against - -- 13,14, 34 Backflow connection:

Definition 6 Prohibited 9 Backflow preventers 34 Back-pressure valve for subsoil drain 18 Backwater, protection of subsoil drain against 18 Backwater traps, need not be vented 22 Backwater valves 13 Baptistries 14 Bar sinks, small, size of trap and drain for _-_ 12 Barns used for human habitation _. 24 Basement drain trap, need not be vented 22 Bath fillers, air gaps for 34 Bathroom group:

Private, fixture-unit value of 15, 40 Venting of 19 Bathrooms, water-demand estimates for 44 Bathtub: Group vents for 59 Private, fixture-unit value of 15, 40 Public, fixture-unit value of 15, 40 Size of supply outlets for 14 Size of trap and drain for 12 Trap, venting of 19

Battery: Page

Circuit and loop venting of 20 Double, circuit and loop venting of "III."""'"'' 20 Blow-offs, connections of 22 Boiler blow-ofTs, connections of 22 Branch:

Definition _ g Fixture, definition ""I"'"'"!'" 7 Sanitary, of combined drain size of _ " 17 Storm, of combined drain, size of 17 To heater, required sizes of if. Yoke-vented, independent connections with 10 See also Fixture branch; Horizontal branch; Hot-water branch; Primary hriiiiches; Secondary branches. Branch iiilcr\ ;il, <lcflnition 6 Branch veiil,, ilulinition g Brass:Calking ferrules _ 11 31 Fittings 11' 31 Pipe _._ lojao Jheet —- 11,31 lubmg.... _ 10,30

Buildm!.' dram:

Capacity of 16,57 Capacity of branches ig

( '(iiripnting capacity of 49, 52, ,54

I >('fliiil . ' g Material of underground 14 Xonpressure drainage, fixture-unit value of 49 Pressure drainage, fixture-unit value of 52 Separate tests of 24 Size of 16,54

Size of, for given roof area 57 Submittal of plans for ig Building-drainage system, definition 6 Building line, relation of vent terminals to 22 Building main:

Definition 6 Fixture units and estimated demands on 44 For .small buildings 43 Required sizes of . 45

Size of 13, 35, 44 Sui)ply required for 44 Velocity of supply of 44 Building sewer: Capacity of 16 Definition 6 Fixture-unit capacity of 57

A'lalerial of_ _ 14 Separate tests of 24 Size of 16, 54 Size of, for given roof area 57 Submittal of plans for 16 Building subdrain;

Definition 6 Discharge of 16 Building water main, estimating for continuous demands on._ 42 Bureau of Standards, National 29,45 Bushings, soldering 11 C

Calked joints 11 Calking:

Ferrules 11,31 Lead 10,31 Not acceptable in repairs 24 Of vent terminals 22 Cast iron: And other piping, joints between 11 Fittings 11,31 Pipe joints 11 Screwed pipe 10,30

Soil pipe 10. 29 Water iiipe 10.29

Catcliliiisiii trap, subsoil, need not be vented 22

Cellar-lldor drain trap, need not be vented 22 Cement joints in vitrified-clay pipe 32 Cenioiitod joints U

Certificate uf approval 24 Cesspool, leaching, definition 27 Cesspools 27 Changes in direction 9 Changes in size of pipe... 12,32 Chemical mixtures, use of, prohibited in tests 24 Chemical wastes 46 Circuit-and-loop venting, limits of 20, 61 Circuit-and-loop vents, illustration of. 61

[63]
Page

Circuit vent 20 Definition fi Size of 21 Cisterns: Overflow pipes from 18 Protection from freezing 13 Clay pipe:

Joints-.. 11,31

Vitrified 10,29 Clean-out equivalents 13 Clean-outs:

Accessibility 13 For refrigerator wastes 22 Pipe 13 Pipe, location of 13

Pijje, size of 13 Trap 13 Traps and 12 Clogging of sinli; drains 60 Closed system required 18 Closets, frostproof 14 Closing of openings in tests 23, 24 Combination fixture: Definition _ _ : 6 Size of trap and drain for 12 Combination kitchen sink and tray, venting of 19 Combination sink and laundry tray, private, fixture-unit value of.. 15 Combined drains 17,56

Size of 17, 57 Combined drainage system, connection of subsoil drain to 18 Combined fittings 20 Combined sewer 57 Size of 17,57 Combined sewerage system to be closed 18 Combined tests 24 Commercial Standards 29, 15 Compliance, inspection to assure 23 Compound, setting 11 Concrete pipe 10, 29 Joints 11,31 Condensate connections 22 Conductors. See Leaders. Connection: Of liorizontal branch to soil stack 19 Of horizontal branch to water-closet drain 19 Of relief vent to main vent 21 Of relief vent to stack-vent 21 Of sanitary and storm drains 17 Of stack-vent and vent stack 18 Connections: Backflow, definition 6 Backflow, prohibited 9 Blow-off 22 Condensate 22 Floor 12 Independent. See Independent connections.

Indirect. See Indirect connections.

Indirect waste, accessibility of 22 Indirect waste, location of 22 Joints and 11 Overflow pipe -— 18 Prohibited 14 Roof, tests of 24 Tightness of 11 Construction, inspection of 23 Construction workers, toilet facilities for 22 Continuous waste 33 Definition 7 Continuous-waste-and-vent 19 Definition 6 Location of 18 Relief vent, for flat-bottomed fixtures 20 Cooling of waste water, methods for 22 Copper:

Pipe 10,30 Sheet 11.31 Tubing 10,30 Tubing, actual and nominal diameters of 41 Tubing, joints 12,32 Corrosion:

Effect of, on pipe capacity 42 Protection against 10 Courts, drainage of 16 Covering of work 24 Tests before 24 Cross-connection, definition, .5ef Interconnection.

Cross-connections: Prevention of 46 Prohibited 9 D

Defective material 24 Defective plumbing 22 Alterations of, considered new work 24 Test of 24 Defective work 24 Definitions 6,27

Illustration of 26 See also index entry for specific terms defined. Developed length, definition 7

Page

Diameter, definition ; Direction, changes in " 9 Dishwasher sinks, size of trap and drain for I ___ 12 Distance:

Definition 7 Of trap from vent I..

I'

18, 58 Of vent terminals from building openings 22 Distribution, water supply and 13 Domestic water heaters, size of supply outlets for 1} Doors, relation of vent terminals to 22 Double battery, circuit and loop venting of 20 Double offset 15 Definition 7 Downspouts. See Leaders. Downward opening of vent terminals 22 Drain. See Drainage; Drains. Drain pipe: Definition. See Drains. Estimating size of 15 Drain traps not requiring vents 22 Drainage: Of courts Ki Of paved areas

..

16 Of roofs 16 Of yards 16 See also Pressure drainage. Drainage fittings 11 Drainage pipes, separate tests of 24 Drainage piping: C hanges in direction of 9 Definition 7 Drainage system:

Air-pressure tests of 23 Combined, connection of subsoil drain to 18 Material of pipes for 14 Submittal of plans for

.

16 Tests of 23 Water test of 23 Drained area, defined 17 Drains:

Area. See Area drain. Building. See Building drain. Combined. See Combined drains. Definition 7 Fixture. See Fixture drain.

Floor. See Floor drains. For flat-bottomed fixtures 62 House, See Building drain. Requirements for sizes of 47 Sanitary, to be separate 17 Separate 17, 56 Separate and combined 17 Shower 14 Stable, inspection of 24 Storm. See Storm drain.

Subsoil. See Subsoil drain. Water closet. See Water closet. Water-closet branch , relief vent from 19 Yard, separate tests of 24 Drinking fountains: Air gaps for nozzles of 34 Size of trap and drain for 12 Drip pans, overflow pipes from 18 Drip pipes, indirect connections for 22 Dry vent, definition 7 Dual relief vents 20 Dual vents 19,58 Definition 7 Permitted 19 Duplex apartment, plumbing lay-out for 61 Duplex house, plumbing lay-out for 60 E

Effective opening, definition 7 Electrical machinery, protection of 10 E quipment

:

Adjustment after test 24 For tests 23 Estimating for continuous demands on the building water main 42 Estimating supply demands 35 Exhaust pipes: From water lift, discharge of.__ 22 To discharge into open fixtures 22 To discharge outside the building 22 Exhibition plumbing need not be inspected or tested 24 Expansion joints 12 Expansion tanks, overflow pipes from 18 F

Faucets

:

Air gaps for 34 Replaced, inspections or tests not needed 24 Federal specifications 10, 27, 29 Federal Specifications Executive Committee 29 Federal Standard Stock Catalog 29 Ferrules 13 Calking 11,31 Final condition 24 Final test 23 Approval certificate 24 Of whole system 24

[64]
Page

Fittings: Allowance for friction loss in_ _ 41 Brass _ 11,31 Cast-iron 11,31 Combined _ ___ .1/./... '20 Drainage 11 Malleable-iron _ _ 11,31 Prohibited _

' y Reuse of, prohibited __ 14 Screwed 11,31 Soldered.. 11,31,32 Tixture, combination, definition _ 6 Fixture branch:

Definition ___ 7 Size of 14 Fixture drain: Definition __. 7 Number between relief vents... ._ 20 Of kitchen sinks __ _. 60

Size of 12 Tixture overflow __ 14 Fixture strainers 14,45 Fixture units 15 Definition 7 Number on soil or waste stack 21 Permissible number on branches Ki Permissible number on horizontal branches or stacks 15 rixture-unit ratings: Of building drains and sewers 57 Of fixtures 15,35,47 Of small buildings.. _ 44 Fixtures: At base of main vent 20,60

Installation of 14 Number on horizontal branch 20 Plumbin?, definition _ _ _ 8 Quality of 14,45 Replaced, inspections or tests not needed 24 Requirements for 14 With integral traps, size of drains for . 12 Flanges, floor 11, 31 Flashing of vent terminals 22 Flashings, roof 12 Flat-bottomed fixtures: Drains for 62 Vents for 20, 60, 62 Flood level

:

Definition 7 Of highest fixture, distance of vent connection above 18 Floor connections 12 Floor drains 13, 14 Size of trap and drain for 12 Floor flanges U,31

Flow, relation of, to pipe diameter 40 Flowcharts 36-39 Application of 40 Flush valves: Fixture-unit value of 40

Size of supply outlets for 14 Food receptacles, waste pipes from 22 Freezing, protection from 10, 13, 14 Friction loss in valves and fittings, allowance for 41 Frost closure of vents 22 Frostproof closets 14 G

Garages:

Inspection of 24 Tests of 24 Garden-hose connections, water-demand estimates for 44 Gaskets 11,31 General regulations 9 Grade, definition 7 Gravity flow. See Nonpressure drainage. Grease interceptors 13 Omission of 28 Ground-w;iter supply 33 Group venting 19,58 Group vents 19 Definition 7 For lavatories and bathtubs 59 Permitted... 19 Ser nhn Circuit vent; Dual vents. Gutters: Capacity of 54 Material of 17 Outlets of 55 H

Horizontal branch: Capacity of 15, 16 Circuit and loop venting of.. 20 Connected to soil stack 19 Connected to water-closet drain. 19 Definition 7 Fixture-unit value of 48,49

Size of 16 Size of, for circuit and loop venting 20

Hose i-(jiinoctions, water-demand estimates for M Hiilcl sinks, si/0 of trap and drain for 12

I lut-pouriMl joints 11 31 Hot-water branch:

'' Fixture units and estimated demands on 44

Size of " 4,, Supply, required for 44 Velocity of supply of I."" 44 Hot-water system, relief valves on 14 House drain. Sec Huilding drain. House sewer. See Building sewer. ITouse subdrain. See Building subdrain. Housing, low-cost, plumbing for 5), Hub-and-spigot joints. _. \\

lee box waste pipes 22

Identification of materials , '-'-"""11""

10 Illustration of application of rules for pressure drainage. 53

' ^ 48 12,32

Illustration of application of table 805(b)-ni

Increasers Independent connections: To soil stack With water-closet drains.. With yoke-vented branch.

Indirect connections For boiler blow-offs Fur driji pipes For overflow pipes... For steam exhaust.. To waste pipes

Indirect waste pipe, definition Indirect wastes "II. ^^111 22,62 To discharge into open fixtures. Indirect waste connections:

.Accessibility of . . . . . Location of Industrial sewage, definition Insanitary conditions Inspection

-Vnd tests. Before covering work Not retiuired..' Of garages Of stable-yard drains Of stables

Installation: Inspection of.. Of fixtures _ Of piping

Interceptor: Grease

Grease, omission of Not prohibited

Oil _.

22

22

22

2722

23

23

24

24

2424

24

23

1428

132832

13 Sand 13 Sand, definition Interconnection:

Definition ___ 7 Prohibited 9 Interval, branch, definition 6 Iron, sheet ._ __ ___ 11,31 Iron-body ferrules 11,31

Jointing compounds for vitrified-clay pipe 31

Joints: And connections 11 Calked 11 Cast-iron and other piping U

Cast-iron pipe 11 Cemented . 11 Chy pipe 11,31 Cnnerete pipe 11. 31 Copper-tubing 11,32 Expansion 12 Hot-poured 11,31 Hub-and-.spigot 11 Lead and other piping 12 Round 12 Screwed 11 Slip 12 Tightness of 11 Vitrified-clay pipe 11,31 Watertight, on combined sewerage system.. 18 Wiped 12 Jumpover. See Return offsets. E

Kitchen sinks: Fixture drains of 60

Private, fixture-unit value of 15, 40

" ' 40

12

1944

19

Public, fixture-unit value of. Size of trap and drain for Venting of Water-demand estimates for. Kitchen-sink trap, venting of

[65]
Page

Labor for inspection and test Laundry trays: Fixture-unit value of Private, fixture-unit value of Size ofsupiily outlets for Size of trap and drain for __ Water-demand estimates for _._ Lavatories: Fixture-unit value of _ Group vents for Private, fixture-unit value of 15, 40 Public, fixture-unit value of 15.40

23

40

15

14

12

44

40. 44

59

Size of supply outlets for^ Size of trap and drain for Venting of trap of __. Water-demand estimates for Lavatory supplies, air gaps for Lawn sprinkling, water demands for_ Lay-outs for residential plumbing

Lead:And other piping, joints between.

11

12

1944

34

45 5y-61

12 Calking 10, 31 Pipe. 10,30 Pipe, distance from floor Piping in water-supply lines

Salts, poisonous

Sheet 10, Trap, distance from floor Lead Industries Association Leaders: Connections of gutters to Definition

Inside, material of Inside, separate tests of Material of Outside, material of Outside, protection of Size of 17. Size of. for given roof area , Test of Traps, need not be vented

Leaks, no inspections and tests after repair of Length, developed, definition Loads, design Loop vent

Definition

Size of Loop venting, limits of Low-cost housing, plumbing for M

Machinery, electrical, protection of Main:

Definition Water, definition See aho Building main; Water main. Main vent: Connection of relief vent to._ Definition. See Vent stack. Fixtures at base of Required

Size and length of Maintenance.

21

20.60

182122 Malleable-iron fittings 11,31 Manholes for underground traps and clean-outs 13 Material: Of building sewer 14 Of leaders and gutters 17 Of soil and waste pipes 14 Of underground building drain 14 Of vents 18 Of water pipes_ 14 Materials:

-Alternate 11 Defective 24 For test of system 23 Identification of 10 New, for repairs 24 Quality of 10,29 Quality, weight, and thickness of: 10 Specifications for 10 Standards for 10 Metals. See name of specific material. N

National Bureau of Standards 29, 45 New materials for repairs 24 Nipples, soldering 11. 31 Noises, reduction of 43 Nonpressure drainage:

IJuilding drain capacities in 49 Definition 8 Notice

:

Of defective plumbing 22 Of insanitary plumbing 22 Notification for test 23

O

Obstruction to drain flow 9 Office building, water-demand estimates for __ __ _ ___ ' 44

Offsets. Above highest horizontal branch Below lowest horizontal branch

Oefinition Double

liouble, definition

Relief vents for Return

Return, definition

Size of Oil interceptors Open fixtures : Exhaust pipes to discharge into Overflow pipes to discharge into To receive indirect wastes Opening, effective, definition Openings, closing of. in tests^ Outbuildings used for human habitation__. Overflow, fixture _._ Overflow pipes Connections of From water-supply tank, discharge of_ To discharge into open fixtures To discharge outside the building Overrim water supplies, air gaps for Owner: To be notified regarding test To receive final approval certificate

15

15

815

7

2115

8

15

13

22

22

22

7 23,24

24

14

14

182222

22

34

23

24

Packing 11,31 Pantry sinks, size of trap and drain for 12 Paved areas, drainage of ig Pedestal urinals. See XJrinals. Percolation test of soil Permit, inspection to assure conformance to Pipe:

.\ctual and nominal diameters of Brass

28

23

10,30 Drain, estimating size of Drainage, separate tests of. Drip, indirect connections for Effect of corrosion on capacity of : Flow charts for 36-39, Ice box waste . .. Indirect-waste, definition Protection of 10, 13, Reuse prohibited Sanitary system, material of Sewer, concrete __ Size of, changes in 12, Size of, definition

Soil and waste, for sanitary systems

Specifications Vent, separate tests of Water-distributing, for small buildings Water-supply, determining sizes of Wrought-iron 10, See nho Cast-iron; Clay pipe; Concrete pipe; E.xhaust pipes; Lead; Overflow pipes; Piping; Soil pipe; Tubing; Waste pipes; Water pipe; AVater-service pipe. Pipe clean-outs Location Pipe size: Changes in 12, Definition Economical Examples in estimating Flow charts on ^ 36-39. Reduction of i Piping:

Installation of Repairs to Plans:For building drain, submittal of For building sewer, submittal of For drainage system, submittal of Inspection to assure conformance to Plumber: To deliver final approval certificate to owner To furnish necessities for inspection and for test To make notification for test To make tests Plumbing:

Definition _ 8 Fixtures, definition 8 Fixtures, requirements for 14 System, definition 8 Ponds 14 Pools:Definition 8 Swimming 14,46 Power for test of system __ 23

[661
Page

Prefabricated plumbing 58 Pressure: In air tests 23, 24 In smoke tests- ._ 24 In water tests 23,24 Pressure drainage 10 Definition 8 Illustration of application of rules for__ 5;i Primary branches: Capacity of l(i Connection of vent stack to _ 18 Definition 8 Fixture-unit rating of _.. 48, 49, 52 Size of , 16,54 Private sources of water supply 13 Prohibited: Connections 9,14 Fittines 9 Fixtures fiO Interconnections.. 9 Traps 12,32 Vents 22 Prohibition of: Greasy wastes 20 Reuse of pipes or fittings 14 Use of chemical mixtures in tests 24 Projecting walls, allowance for, in roof drainage .__ 56 Protection: From backflow 1 3, 34 From corrosion 10 From freezing 10, 13, 14 From frost closure 22 Of electrical machinery 10 Of outside leaders 17 Of pipes 10 Of reservoirs 10 Of subsoil drain against backwater 18 Of trap seals 18 Of water supply 13,28,46 Of water tanks 10 Public gutters, storm drainage into 16 Public sinks, size of trap and drain for 12 Purity of water 13 Q

Quality: Of fixtures 14,45 Of materials 10,29 Of water 13,33 Quantity of water 14

Rainfall, size of storm drains based on rate of Receiving tanks Reducers

Reduction of pipe size Refrigerator waste pipes

Refrigerator wastes: Clean-out for Size of Traps for Regulations, general —

Reinspection

Relief valves, location of Relief vents Connected to main vent Connected to stack vent

Definition For flat-bottomed fixtures For offsets From water-closet branch drain _ Location of On horizontal branch

Size of Renotification for test Renovation of plumbing system

Repairs: Calking not acceptable --- To piping To plumbing system Replacement

Inspections or tests not needed- Of defective material Of defective work

Resealing traps, vents for Reservoirs, protection of Residential plumbing lay-outs 58, Responsibility for meeting tests Retesting Of drainage-system sections Return offsets Definition Reuse of pipes or fittings prohibited

Riser:Definition

Size of Roof, relation of vent terminals to

17,55

16, 18 12,32

12

22

2222

22

924

14

19, 58

21

21820

15, 21

191820

20, 212322

24

24

22

22

24

2424

20

10 59-6123

2423

15

814

„ , Page

Roof area: Defined - . . 17 For semicircular gutters. 65

Sizes of building drains and sewers for given 57 Sizes of li-iiilrr< fur _ . 17 Sizes (. I loi Mi I wers and drains for 17 Roof coniii n I,,]] . hstsof. 24 Roof drainage _ _ 16,55,50 Roof llasliings 12 Roof gutters, material of 17 Rooiri ventilation.. 14 Rouml jdiiits 12 Rules r(jr detormining sizes of water-supply pipes 42 Rules for applying section 807(c), part II, and table 807(c)-III, i)art III 4!) Rules for applying section 807 (d), part II, and table 807 (d), part

III 63 S

Sand interceptors 13 Definition , 8 Sand trap. See Sand interceptors. Sanitary branch of combined drain, size of 17 Sanitary drain to be separate. 17 Sanitary sewage, definition. 27 Sanitary sewer 14 Definition 8 System, connection of subsoil drain to 18 Sanitary system pipes, material of 14 Sanitary-drainage system: air-pressure test of 23 Smoke test of 23 Screening of vent terminals 22 Screwed fittings 11,31 Screwed joints _ _ 11 Screwed pipe, cast-iron 10, 30 Sealing of vent terminals 22

Seals, trap. See Trap seals. Secondary branches: Capacity of... 16 Computing capacity of

49,

52. 54 Definition 8 Fixture-unit rating of 49,52

Size of 54 Sections of drainage system, tests of 23 Septic tanks 28 Defined 28 Service sinks: Fixture-unit value of 40,44 Public, fixture-unit value of 15 Size of trap and drain for 12 Water-demand estimates for 44 Setting compound 11,31 Sewage, definition 27 Sewage ejector, fixture-unit value of 15 Sewage purification _ „. 27 Sewage treatment: Defined 27 Plant 27 Plant, definition 8 Plant, design of 27 Sewer:

Building, definition 6 Combined, size of 17 Combined sanitary-and-storm street.. 17 House. See Building sewer. Sanitary 14 Sanitary, definition 8 Storm, definition 8 Storm, sizes of. for roof areas 17 Types of - 27 Sewer pipe, concrete 29 Sewer system, sanitary, connection of subsoil drain to. 18 Sewerage system, combined, to be closed 18 Sheet:Copper and brass 11, 31 Iron and steel, zinc-coated.. 11, 31 Lead 10.31 Shower drains 14 Shower head:

Fixture-unit value of 40. 44 Private, fixture-unit value of 15 Public, fixture-unit value of.. 15 Water-demand estimates for.. 44 Shower stall: Size of trap and drain for 12 Trap, venting of 19 Shut-offs, location of 14 Side vent: As relief vent 21 Definition 8

Sill cocks:

Size of supply outlets for — 14 Water-demand estimates for 44 Simplified Practice Recommendations 29, 45

[67]
Page

Sink trap, ventine of _ 19 Sinks:

Size of supply outlets for 14 Size of trap and drain for 12 See also Kitchen sinks; Service sinks. Size of pipe and tubing, definition 8 Slip joints 12 Small buildings, water-demand estimates for 44 Smoke test 02 Final. 23 Of defective plumbing _ 24 Of sanitary-drainage system 23 Of vent system . 23 Pressure in.,, 24

Soil, percolation test of 28

Soil and waste pipes for sanitary systems 14

Soil pipe: Cast-iron 10, 29 Definition 8 Estimating size of 1,5 Material of 14 Minimum .sizes of 14, 46 Separate tests of 24 Sizes of 15, 47

Soil stack: Capacity of 15 Connection of horizontal branch to _ 19 Connection of vent stack to 18 Fixture-unit rating of 47 Independent connections to 19 Minimum size of 15 Number of fixture units on 21 Number of offsets on 15 Size of, as related to main vent 21 To be vertical 15 Ventine of 15, 18 Soldered fittings 11.31,32 Soldering bushings 11 Soldering nipples 11,31 Specifications: Federal 10,27,29 Material 10 Pipe 10 Stables: Inspection of 24 Need not be tested 24 Tests of 24 Used for human habitation 24 Stacks: Definition 8 Multiple, capacity of Ifi Size of, above offset 15 Size of, below offset 15 To be vertical _-_ 15 Venting of 15 Stack-vent; Connection of relief vent to 21 Connection to vent stack 18 Definition 8 In dual capacity 19 Required IS Size and length of 21 Stall urinals. .See Urinals. Standards: Accepted 27 Accepted, definition 6 For materials- . _ 10 Steam exhausts, indirect connections for 22

Steel:Pipe 10,30 Zinc-coated slieet _ _ 11,31

Sterilizers: Indirect connections for 62 Waste pipes from 22

Stills, indirect connections for 02 Stoppages, no inspections and tests after removal of 24 Storage tanks, protection from freezing 13 Storm branch of combined drain, size of 17 Storm drain 10 Definition 8 Size of 17,55

Sizes of, for roof areas 17 Traps 16 Storm drainage to discharge into public gutters 16 Storm sewage:

Definition 27 Estimated rate of flow 17 Storm sewer:

Definition 8 Sizes of, for roof areas 17 Storm-drainage piping system, closed 18 Strainers: Fixture 14,45 Gutter, area of 55 Structural members not to be weakened 9 Subdrain, building or house. See Building .subdrain. Subsoil catchbasin trap need not be vented.. 22

Page

Subsoil drain

_

^

Definition ___ 8 Material of ..III..... _ _ 18 To be trapped 18 Substitute tests . _

~ 23 Sump pump, fixture-unit value of _'" 15 Sumps I.II"i;i"''i;rr 16,18 Supply outlets, size of 14 Supply tanks, overflow pipes from 18 Supports '_ 9.12 Surface water, protection of water supply against l'_

' 13 Swimming pools 14 46 Symbols, plumbing 25 System, plumbing, definition ......... 8 T

Tanks:

Expansion, overflow pipes from _ is Receiving II"'!""!" 16,18 Storage, protection from freezing _ _ 13 Supply, overflow pipes from 18 Water, protection of 10 Water-closet, size of supply outlets for ........ 14 Water-supply, discharge of overflow pipe from 22 Water-supply, protection of 13 Temperature of water entering building-drainage system.. . ."I 22 Temporary toilet facilities

__

_ 22 Test, final 23 Approval certificate of

..."

24 Of whole system . . . .. ..

.. - Tests:

'

.•Adjustments following 24

\iT. See Air tests.

" "

-\ir-pre5sure. See Air-pressure test. Before covering work 24 Change in order of 3'. "".I. 23 Closing of openings in '_ 23,24 Combined "._ '24 Ki|uipment, material, power, and labor for I-II]3.!!"."_II3 23 Inspections and

_

23 Made by plumber 1.31. "...3."". 23 Miiiiification of 23

N'dt required 3. .31 24

Xot, required for stables 24 Notification for 31 23 Of building drain 33333 3333 24 Of building sewer 3 24 Of defective plumbing 33.33 ' 24 Of drainage pipes 3.333333333 24 Of drainage system

33

23 Of drainage system sections 33' .

" 23 Of garages

_

" 24 Of inside leaders 3333 24 Of leaders 33... 3 24 Of outbuildings 333333. .33 24 Of roof connections 24 Of soil pipes 333.. 24 Of stables 33333". 24 Of vent pipes 33.3.33.33 24 Of waste pipes 3 333... 24 Of water-supply system 333333. 3 24 Of yard drains 3. 24 Recjuired 33333 23 Separate, See Tests, separate. Smoke. See Smoke test. Substitute 23 Csc of chemicals in, prohibited 24 Water. .See Water tests. Written approval of 24 Tests, .separate 24 Of building drain 24 Of building sewer 24 Of drainage pipes 24 Of inside leaders 24 Of soil pipes 24 Of vent pipes 24 Of waste pipes 24 Of yard drains 24 Permitted 24 Tightness: Of joints and connections 11 Tests for 23 Time required: For air tests 23, 24 For water tests 23, 24 Toilet facilities, temporary 22 Toilet-room ventilation 14 Trap clean-outs 13 Trap seals 12 Definition 9 Depth of 33 Protection of 18, 58 Trap weir, distance of back vent from 22 Traps:

.Accessibility 13 .And clean-outs 12 Definition 9

[68]
Traps^Continued. Page

Distance of. from vent ___ 18, f'S For more than one fixture. __ 12 For refrigerator wastes _ 22 For storm drains 16 For subsoil drains 18 Installation 13 Location of _ 12,18 Not requiring vents 22 Prohibited 12,32 Quality and workmanship 32 Required for subsoil sumps !8 To be self-cleanin? .__ , 12,32 Types and sizes of 12,32 Venting of 19 Vents for resealing 20,60 See also Interceptor. Trap-standard fixtures, number permissible on horizontal branches.. 20 Treatment plant, .sewage, definition. _ _ 8 Trough urinals, size of trap and drain for 12 Tubing:

Brass 10,30 Copper 10,30 Copper, actual and nominal diameters of 41 Copper, joints 12 Material of 14 Size of, definition. __ 8 U

Uncovering of work not inspected, tested, and approved- 24 Underground traps and clean-outs, accessibility of 13 Unions 12 Unit vent. See Dual vents. Urinal flush valves: Fixture-unit value of 40

Size of supply outlets for 14 Urinals: Fixture-unit value of 44 Flush valve, fixture-unit rating of 40 Pedestal, fixture-unit value of 40 Pedestal, number permissible on horizontal branches 20 Pedestal, public, fixture-unit value of 15 Pedestal, size of supply outlets for flush valves 14 Size of trap and drain for 12

Stall, fixture-unit value of 40

Stall, public, fixture-unit value of 15

Stall , size of supply outlets for flush valves 14

Stall, size of trap and drain for ._ 12 Trough, size of trap and drain for 12 Wall, fixture-unit value of 40 Wall, public, fixture-unit value of 15 Wall, size of supply outlets for flush valves 14 Water-demand estimates for 44 V

Valves: jUlowance for friction loss in 41 Back-pressure, for subsoil drain 18 Backwater 13 Flush, fixture-unit value of 40 Flush, size of supply outlets for 14 Relief, location of 14 Replaced, inspections and tests of, not needed for 24 Vent pipes, separate tests of 24 Vent stack: Connection to soil stack 18 Connection to primary branch 18 Connection to stack-vent 18 Connection to waste stack 18 Definition 9 Required 18 Size and length of 21 To terminate in open air 18 Vent system:

Air-pressure test of.. 23 Smoke test of . 23 Vent terminals: Alterations to 22 Downward opening of 22 Location of 22 Location of windows in relation to existing 22 Screening of 22 To be calked 22 To be flashed 22 To be sealed 22 Ventilating openings, relation of vent terminals to 22 Ventilation 14 Venting: Group s- 19 Limits of circuit and loop 20 Of bathroom groups 19 Of bathtub trap 19 Of combination kitchen-sink-and-tray. 19 Of kitchen sink 19 Of kitchen-sink trap 19 Of lavatory trap 19 Of shower-stall trap 19 Of soil and waste stacks 15 Of soil stacks 18 Of waste stack 18 Vents and 18

Page

Vents:And venting. is Back. See Back vent. Between interceptor and fixture traps , Slj Branch, definition ll Circuit. See Circuit vent. Definition 9 Distance of trap from 18, Dry. definition 7 Dual. See Dual vents. Dual relief. See Dual relief vents. For flat-bottomed fixtures ... 20, (K), 02 For resealing traps 2f). 60 Frost closure of. 22 Group. See Group vents; See also Circuit vent; Dual vent. Location of 58 Loop. See Loop vent. Main. See Main vent. Material of. 18 Not required 22 Prohibited 22

Relief. See Relief vents.

Side. See Side vent.

Size of 21 Traps not requiring 22 Unit. See Dual vents. Wet. See Wet vent. Yoke. See Yoke vents. See oUo Stack-vent.

Vitrified-clay pipe 10,29 Joints 11,31 W

Wall hangers 12 Wall urinals. See Urinals. Walls, allowance for projecting, in roof drainage .16 Washbasin:

Private, fixture-unit value of l.i Public, fixture-unit value of 15 Washroom lavatories 60 Waste, continuous 33 Waste pipes: Definition 9 Estimating size of 15 From food receptacles 22 From ice boxes 22 From refrigerators 22 From sterilizers 22 From water-cooling devices 22 From water-heating devices 22 From water-operated devices 22 From water stills 22 From water-treatment devices 22

Indirect, definition 7 Indirect connections to 22 Material of 14 Minimum sizes of 14, 46 Separate tests of 24 Sizes of 15, 47

Soil and 14 Waste stacks: Capacity of 15 Connection of vent stack to 18 Fixture-unit ratings of 47 Minimum size of 15 Number of fixture units on 21 Number of ofTsets on 15 Size of, as related to main vent 21 To be vertical 15 Venting of 15,18 Waste water, cooling methods for 22 Wastes: Acid or chemical 46

.see also Indirect wastes: Refrigerator wastes. Water:

Qiiality of 13,33 Quantity of 14 Temperature of, entering building-drainage system 22 Used in drainage-system tests 23 Water closet: Branch drain, relief vent from 19 Drain, connection of horizontal branch to 19 Drain, independent connections with 19 Fixture-unit value of 44 Flush valves, fixture-unit value of 40 Flush valves, size of supply outlets for 14 Flush tanks, fi.xturo-unit value of 40 Number permissible on horizontal branches 20 Private, fixture-unit value of. 15 Public, fi-xture-unit value of 15

Size of drain for 12 Tanks, size of supply outlets for 14 Water-demand estimates for 44 Water-cooling devices, waste pipes from 22 Water-distributing pipes for small buildings.. 43 Water-hammer 43 Water heaters, domestic, size of supply outlets for 14 Water-heating devices, waste pipes from 22 Water lift, discharge of exhaust pipes from 22

[69]
Page

Water main, definition 9 Water-operated devices, waste pipes from 22 Water pipe, cast-iron 10,29 Water piping, material of._ 14 Water seal. See Trap seals. Water-service pipe: Definition 9 Size of 13, 3.5 AVater stills, waste pipes from 22 Water supply And distribution 13 Demand, estimating for 35 Demand, estimating for continuous 42 Pipes, determining sizes of 42 Pipes, rules for determining sizes of 42 Protection of 13,28,46 System, air-pressure test of 23 System, definition 9 System, tests of 24 System, water test of 23 Tanks, discharge of overflow pipe from 22 Tanks, protection of 13 Water tanks, protection of 10 Water tests: Of drainage system 23 Of leaders _ 24 Of roof connections 24 Of water-.supDlv system 23 Pressure in 23,24 Time required for 23, 24 Watertight joints on combined sewerage system 18

Page

Water-treatment devices, waste pipes from 22 Wet vent:

Definition 9 Prohibited 22 Windows:

Location of, in relation to existing vent stack 22 Relation of location of vent terminals to 22 Wiped joints 12 Wooden plugs prohibited 12 Work:

Covering of 24 Defective 24 Uncovering if not inspected, tested, and approved 24 Workmanship 10 Workmen, toilet facilities for 22 Written approval of tests 24 Wrought-iron pipe 10,30 Y

Yard drains, separate tests of 24 Yards, drainage of 16 Yoke-vented branch, independent connections with 19 Yoke vents 19, 58 Definition 9 Z

Zinc-coated sheet iron and steel 11, 31

Washington, October 4, 1940.

o

[ 701
BUILDING MATERIALS AND STRUCTURES REPORTS

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The following publications in this series are available by purchase from the

Superiatendent of Documents at the prices indicated:

BMSl Research on Building Materials and Structures for Use in Low-Cost Housing 10^ BMS2 Methods of Determining the Structural Properties of Low-Cost House Constructions.. 10^ BMS3 Suitability of Fiber Insulating Lath as a Plaster Base lOji BMS4 Accelerated Aging of Fiber Building Boards IQ^

BMS5 Structural Properties of Six Masonry Wall Constructions 15^ BMS6 Survey of Roofing Materials in the Southeastern States 150 BMS7 Water Permeability of Masonry Walls 100 BMS8 Methods of Investigation of Surface Treatment for Corrosion Protection of Steel 100 BMS9 Structural Properties of the Insulated Steel Construction Co.'s "Frameless-Steel" Constructions for Walls, Partitions, Floors, and Roofs 100 BMSIO Structural Properties of One of the "Keystone Beam Steel Floor" Constructions Sponsored by the H. H. Robertson Co 100 BMSll Structural Properties of the Curren Fabrihome Corporation's "Fabrihome" Constructions for Walls and Partitions 100 BMS12 Structural Properties of "Steelox" Constructions for Walls, Partitions, Floors, and Roofs

Sponsored by Steel Buildings, Inc 150 BMS13 Properties of Some Fiber Building Boards of Current Manufacture 100 BMS14 Indentation and Recovery of Low-Cost Floor Coverings 100 BMS15 Structural Properties of "Wheeling Long-Span Steel Floor" Construction Sponsored by

Wheeling Corrugating Co 100 BMS16 Structural Properties of a "Tilecrete" Floor Construction Sponsored by Tilecrete

Floors, Inc 100 BMS17 Sound Insulation of Wall and Floor Constructions 100 BMS18 Structural Properties of "Pre-Fab" Constructions for Walls, Partitions, and Floors Sponsored by the Harnischfeger Corporation "_ 100 BMS19 Preparation and Revision of Building Codes 150 BMS20 Structural Properties of "Twachtman" Constructions for Walls and Floors Sponsored by

Connecticut Pre-Cast Buildings Corporation 100 BMS21 Structural Properties of a Concrete-Block Cavity-Wall Construction Sponsored by the National Concrete Masonry Association 100 BMS22 Structural Properties of "Dun-Ti-Stone" Wall Construction Sponsored by the W. E. Dunn Manufacturing Co 100 BMS23 Structural Properties of a Brick Cavity-Wall Construction Sponsored by the Brick

Manufacturers Association of New York, Inc 100 BMS24 Structural Properties of a Reinforced-Brick Wall Construction and a Brick-Tile CavityWall Construction Sponsored by the Structural Clay Products Institute 100 BMS25 Structural Properties of Conventional Wood-Frame Constructions for Walls, Partitions,

Floors, and Roofs 150 BMS26 Structural Properties of "Nelson Pre-Cast Concrete Foundation" Wall Construction

Sponsored by the Nelson Cement Stone Co., Inc 100 BMS27 Structural Properties of "Bender Steel Home" Wall Construction Sponsored by The

Bender Body Co 100 BMS28 Backflow Prevention in Over-Rim Water Supplies lOji

[List continued on cover page iv]
BUILDING MATERIALS AND STRUCTURES REPORTS

[Continued from cover page iii] BMS29 Survey of Roofing Materials in the Northeastern States 10|6

BMS30 Structural Properties of a Wood-Frame Wall Construction Sponsored by the Douglas

Fir Plywood Association lO^S BMS31 StrAictural Properties of "Insulite" Wall and "Insulite" Partition Constructions Sponsored by The Insulite Co 150 BMS32 Structural Properties of Two Brick-Concrete-Block Wall Constructions and a Concrete- Block Wall Construction Sponsored by the National Concrete Masonry Association. 10^ BMS33 Plastic Calking Materials 10^ BMS34 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 1 100 BMS35 Stability of Sheathing Papers as Determined by Accelerated Aging 100 BMS36 Structural Properties of Wood-Frame Wall, Partition, Floor, and Roof Constructions

with "Red Stripe" Lath Sponsored by the Western Paper and Manufacturing Co.. 100 BMS37 Structural Properties of "Palisade Homes" Constructions for Walls, Partitions, and

Floors Sponsored by Palisade Homes 100 BMS38 Structural Properties of Two "Dunstone" Wall Constructions Sponsored by the W. E. Dunn Manufacturing Co 100 BMS39 Structural Properties of a Wall Construction of "Pfeifer Units" Sponsored by the Wisconsin Units Co 100 BMS40 Structural Properties of a Wall Construction of "Knap Concrete Wall Units" Sponsored

by Knap America Inc 100 BMS41 EflFect of Heating and Cooling on the Permeability of Masonry Walls 100 BMS42 Structural Properties of Wood-Frame Wall and Partition Constructions with "Celotex"

Insulating Boards Sponsored by the Celotex Corporation 100 BMS43 Performance Test of Floor Coverings for Use in Low-Cost Housing: Part 2 100 BMS44 Surface Treatment of Steel Prior to Painting 100 BMS45 Air Infiltration Through Windows 100 BMS46 Structural Properties of "Scot-Bilt" Prefabricated Sheet-Steel Constructions for Walls,

Floors, and Roofs Sponsored by the Globe-Wernicke Co 100 BMS47 Structural Properties of Prefabricated Wood-Frame Constructions for Walls, Partitions, and Floors Sponsored by American Houses, Inc 100 BMS48 Structural Properties of "Precision-Built" Frame Wall and Partition Constructions

Sponsored by the Homasote Co 100 BMS49 Metallic Roofing for Low-Cost House Construction 100 BMS50 Stability of Fiber Building Boards as Determined by Accelerated Aging 100 BMS51 Structural Properties of "Tilecrete Type A" Floor Construction Sponsored by the

Tilecrete Corporation 100 BMS52 EflFect of Ceiling Insulation on Summer Comfort 100 BMS53 Structural Properties of a Masonry Wall Construction of "Munlock Dry Wall Brick"

Sponsored by the Munlock Engineering Co 100 BMS54 Effect of Soot on the Rating of an Oil-Fired Heating Boiler 100 BMS55 Effect of Wetting and Drying on the Permeability of Masonry Walls 100 BMS56 A Survey of Humidities in Residences 100 BMS57 Roofing in the United States—Results of a Questionnaire 100 BMS58 Strength of Soft-Soldered Joints in Copper Tubing 100 BMS59 Properties of Adhesives for Floor Coverings 100 BMS60 Strength, Absorption, and Resistance to Laboratory Freezing and Thawing of Building

Bricks Produced in the United States 150 BMS61 Structural Properties of Two Nonreinforced Monolithic Concrete Wall Constructions.. 100 BMS62 Structural Properties of a Precast Joist Concrete Floor Construction Sponsored by the Portland Cement Association 100 BMS66 Plumbing Manual 200