NBSIR 77-1214

Evaluation of Metal Volumetric

Standards Used in the

Measurement of Liquid

Hydrocarbons: A Report of a

U. S. National Bureau of

Standards and American

Petroleum Institute Research

Associate Project.

D. J. Hine

Research Associate

Institute for Applied Technology

National Bureau of Standards

Washington, D C. 20234

April 1977

Final

Issued June 1 977

Prepared for Office of Weights and Measures

Institute for Applied Technology

Washington, D.C. 20234

NBSIR 77-1214

EVALUATION OF METAL VOLUMETRIC

STANDARDS USED IN THE

MEASUREMENT OF LIQUID

HYDROCARBONS: A REPORT OF A

U. S. NATIONAL BUREAU OF

STANDARDS AND AMERICAN

PETROLEUM INSTITUTE RESEARCH

ASSOCIATE PROJECT.

D. J. Hine

Research Associate

Institute for Applied Technology

National Bureau of Standards

Washington, D.C. 20234

April 1977

Final

Issued June 1 977

Prepared for Office of Weights and Measures

Institute for Applied Technology

Washington, D.C. 20234

U S. DEPARTMENT OF COMMERCE. Juanita M. Kreps, Secretary

Dr. Sidney Harman, Under Secretary

Jordan J. Baruch, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS. Ernest Ambler. Acting Director

I
FOREWORD

No position is taken as to whether any method, apparatus, or product

mentioned herein is covered by an existing patent, nor as to the

validity of any patent alleged to cover any such method. Furthermore, the information contained in this report does not grant the

right, by implication or otherwise, for manufacture, sale, or use

in connection with any method, apparatus, or product covered by

letters patent; nor does it insure anyone against liability for

infringement of letters patent.

This report does not endorse or advocate the preferential use of any

type of equipment. Its purpose, rather, is to describe and illustrate

methods, practices, and equipment which are considered acceptable in

certain measurement circumstances. The report is not intended to

restrict in any way the future development of equipment and methods,

nor to affect in any way equipment of any type already installed

and i n operat i on

.

The material contained in this report may be used by anyone desiring

to do so, but neither the American Petroleum Institute nor the Nationa

Bureau of Standards shall be held responsible or liable in any way

either for loss or damage resulting therefrom or for the violation

of any federal, state, or municipal regulations with which it may

conf I i ct

.
TABLE OF CONTENTS

Page

ABSTRACT |

1.0 INTRODUCTION 2

2.0 PRELIMINARY RESEARCH ASSOCIATE STUDIES 5

3.0 DESIGN ANALYSIS 15

3.1 TEST MEASURE BOTTOM ANALYSIS 15

3.2 CYLINDRICAL SHELL ANALYSIS 17

4.0 CALIBRATION PROCEDURES EVALUATION 18

4.1 CONCLUSIONS AND RECOMMENDATIONS 29

5.0 ACCURACY LIMITS 31

6.0 LIQUID RETENTION OR CLINGAGE TESTS 38

6. I TEST MEASURE TESTS 39

6.1.1 EXPERIMENTAL TEST PROCEDURE 45

6.1.2 CONCLUSIONS AND RECOMMENDATIONS 46

6.2 TWO-SQUARE-FOOT CONTAINERS TESTS 46

6.2.1 EXPERIMENTAL TEST PROCEDURE 49

6.2.2 DISCUSSION OF TESTS AND FUTURE TESTS 53

6.3 TESTING WITH LIQUIDS OTHER THAN WATER 53

6.4 DISCUSSION OF RESULTS 53

7.0 EQUIPMENT SPECIFICATION 67

7.1.0 INSPECTION RECOMMENDATIONS 67

7.2.0 SPECIFICATION 73

8.0 CALIBRATION PROCEDURE 81

8.1.0 VOLUMETRIC CALIBRATION PROCEDURE ("To Deliver") 82

8.2.0 VOLUMETRIC CALIBRATION PROCEDURE ("To Contain") 95

i i i
TABLE OF CONTENTS (Cont'd)

Page

9.0 TEST MEASURE PROTOTYPE 96

9.1 FIELD TEST PROGRAM — 96

9.1.1 ADDITIONAL FIELD TESTS 99

9.2 FIELD TEST DATA 100

9.3 CONCLUSIONS FROM FIELD TESTS 100

9.4 RECOMMENDED FIELD TEST PROCEDURE 106

10.0 TEST MEASURE EVALUATION SUMMARY 112

I 1.0 INTRODUCTION TO LARGE VOLUME PROVER DESIGN AND

EVALUATION i 15

12.0 PROVER DESIGN STUDIES 116

13.0 VOLUMETRIC PROVER FABRICATION 117

13.1 EXAMINATION AND CALIBRATION 117

14.0 PLANNED FIELD TEST PROGRAM 119

15.0 INITIAL FIELD TESTS 123

16.0 TIELD TEST PROGRAM 127

16.1 TESTING PROBLEMS 129

16.1.PRODUCT PUMP-OFF 129

16.1.2 PRODUCT TEMPERATURE AND PRESSURE MEASUREMENT 130

16.1.3 FLOW-CONTROL VALVES 130

16.1.4 FLOW STRAINERS 131

16.1.5 SLOW-FLOW CONTROL 131

16.2 VAPOR RECOVERY SYSTEM TESTING 132

16.2.1 TEST OBJECTIVE 132

16.2.2 METHOD OF TESTS 132

16.2.3 TEST RESULTS 132
TABLE OF CONTENTS (Cont'd)

Page

16.2.4 DISCUSSION AND SUMMARY OF RESULTS 133

16.3 FIELD TEST DATA ANALYSIS 139

16.3.1 PROVER VOLUME VERIFICATION 139

16.3.2 PRODUCT TEMPERATURE MEASUREMENTS 139

16.3.3 STATISTICAL ANALYSIS OF FIELD TEST DATA 143

16.3.3.1 ANALYSIS OF GROSS TEST DATA 144

16.3.3.2 TEMPERATURE EFFECTS ON TEST DATA 145

16.3.3.3 SUMMER VERSUS WINTER TESTS 146

16.3.4 SUMMARY OF TEST DATA ANALYSIS 147

17.0 VOLUMETRIC FIELD STANDARDS (PROVERS) DESIGN 148

17.1 FEATURES OF THE EQUIPMENT SPECIFICATION 148

17. 1 .NOMENCLATURE 148

17. 1 .2 ANTI-SWIRL PLATES 148

17.1.3 BOTTOM LOADING ADAPTER 149

17.1.4 THROTTLING VALVE FOR BOTTOM LOADING 149

17. 1 .5 SPECIAL MARKINGS 149

17.1.6 GROUNDING LUG 149

17.1.7 SCALE PLATES 149

17.1.8 THERMOMETER WELL 150

17.1.9 DRAIN LINE REQUIREMENTS —— 150

18.0 RECOMMENDED TEST PROCEDURE 151

18. I RULES FOR TESTING 159

! 9.0 SUMMARY OF THE API/NBS RESEARCH ASSOCIATE PROGRAM 161

20.0 CONCLUSIONS AND RECOMMENDATIONS 163

v
TABLE OF CONTENTS (Con+’d)

Page

ACKNOWLEDGEMENT 167

LIST OF REFERENCES 168

BIBLIOGRAPHY 170

A1

APPENDIX
LIST OF TABLES

TABLE PAGE

I Density of Air Free Water in g/cm5 as a Function of the

Celsius Temperature Scale 24

II Uncertainty Comparisons 36

LIST OF EXHIBITS

EXHIBIT PAGE

1 Sample Gravimetric Calibration Data Sheet 21

2 Completed Data Sheet 47

3 Sample Data Sheet of a Test Sequence 52

4 Sample Data Sheet 83

5 Memorandum 86

6 Field Test Data Sheet 101

7 Summary of Data - Service Station Field Tests 102

8 Examination Procedure Outline for Retail Motor-Fuel

Dispensers — Single Product 107

9 Retail Motor Fuel Dispenser Examination Checklist 108

10 Guidelines for Testing 120

11 Truck Loading Facility Pre-Test Meter Examination

Check I i st 1 24

12 Sample Report of Meter Test 140

13 Report of Calibration 141

14 Report of Calibration 142

15 EPO No. 25 152

16 Checklist for Recommended Test Procedures . 154

vi i
LIST OF FIGURES

FIGURE PAGE

1 Volume Standards Used for Tests - Group I 40

2 Volume Standards Used for Tests - Group 2 41

3 Volume Standards Used for Tests - Group 3 42

4 Configuration for Weighing on the Russell Balance 43

5 Configuration for Weighing a 1-Gallon Measure 44

6 Two-Square-Foot Containers for Fluid Retention Tests 48

7 Configuration for Weighing Two-Square-Foot Containers 50

8 Test Set-Up for Two-Square-Foot Containers 51

9 Two-Square-Foot Surface Area Device - 20° Top Angle, 40°

Bottom Angle 54

10 Two-Square-Foot Surface Area Device - 40° Top Angle, 20°

Bottom Angle 55

11 Two-Square-Foot Surface Area Device - 35° Top Angle, 10°

Bottom Angle 56

12 Two-Square-Foot Surface Area Device - 10° Top Angle, 35°

Bottom Angle 57

13 Two-Square-Foot Surface Area Device - 25°. Top Angle, 15°

Bottom Angle 58

14 Two-Square-Foot Surface Area Device - 15° Top Angle, 25°

Bottom Angle 59

15 Elongated or Tall 10 Gallon Measure - Carbon Steel 60

16 Conventional Height 10 Gallon Measure - Carbon Steel 61

17 Conventional 10 Gallon Measure - Stainless Steel 62

18 Conventional 5 Gallon Measure - Stainless Steel 63

19 Conventional 5 Gallon Measure - Carbon Steel 64

20 Prototype 5-Gallon Measure - Stainless Steel 65

21 Bottom Drain 5-Gallon Field Test Measure 74

vi i i
LIST OF FIGURES (Cont'd)

FIGURE PAGE

22 Recommended Equipment Set-Up for Volume Calibration 84

23 Proper Draining Procedure for 5-Gallon Measure 88

24 Photograph of Prototype Test Measure

25 Meter Test Results 134

26 Meter Number Versus Meter Error Per 1000 Gallons 135

27 Meter Number Versus Difference in Meter Error 136

EVALUATION OF METAL VOLUMETRIC STANDARDS USED IN THE MEASUREMENT OF

LIQUID HYDROCARBONS: Report of a U. S. National Bureau of Standards

and American Petroleum Institute Research Associate Project.

D. J. Hine*

ABSTRACT . Weights and measures jurisdictions and the petroleum industry

have, for many years, used metal volumetric standards in the measurement

of petroleum liquid hydrocarbons. As a result of several surveys,

it was learned that a need existed to establish uniform application

procedures and investigate measurement accuracy. To answer this need,

a joint project under the Research Associate Program of the U. S.

National Bureau of Standards was established with the American Petroleum

Institute as the sponsoring agency. Equipment and techniques were evaluated and the program resulted in an equipment specification, a recommended procedure for inspection, and a recommended procedure for

the calibration of metal volumetric standards used by weights and

measures jurisdictions and the petroleum industry.

Key words: accuracy, design analysis, equipment specification, field

standard, gravimetric calibration, liquid retention or cl ingage tests,

precision, prover. Research Associate Program, Standards inspection

procedure, test measure, test measure evaluation, temperature correction, "To Contain", "To Deliver", volumetric calibration.

^Research Associate, assigned to NBS Office of Weights and Measures

and sponsored by the American Petroleum Institute.
1.0 I NTRODUCTION. In 1914 a weights and measures inspector.

responsible for testing the accuracy of gasoline dispensers, devised

a container with a graduated neck to replace the "slicker-plate"

style measure that was normally used. Within a few years that container evolved to be the more acceptable field standard due to the

ease of application or use. Available records reflect calibration

of a graduated neck measure by NBS as early as 1919. The details

of that and subsequent early calibrations were not found. There

are no records concerning any evaluation of the device for suitability

and/or accuracy other than prototype examinations in 1972 by NBS

Office of Weights and Measures. In 1972 two graduated neck measures

were examined and judged to be in compliance with NBS Handbook 105-3,

Specifications and Tolerances for Metal Volumetric Standards . [ I H*

During the mid-1960's the American Petroleum Institute Division

of Marketing conducted an engineering survey of practices in the

operation and testing of petroleum measurement systems. The objectives

were: (I) evaluate factors influencing system accuracy; and (2)

investigate the accuracy potential or capability of these systems.

The investigators in the project used the criteria in API

Standard 1101, "Measurement’ of Petroleum Liquid Hydrocarbons by

Positive Displacement Meter", to judge the suitability and acceptability of provers utilized in the survey. Only 5 of 24 provers

^Numbers in brackets refer to List of Reference listing

- 2

-
inspected were considered to completely comply with the chosen

specifications. The results of the survey revealed non-uniformity

of prover design employed by the petroleum industry and weights and

measures jurisdictions. The inspections disclosed many serious

fabrication defects in existing volumetric prover equipment. The

report of the survey cited the lack of concise standards for the

construction and maintenance of provers. The absence of uniform

test procedures was also reported to be a serious deterrent to meter

accuracy evaluation.

At the 1953 National Conference on Weights and Measures a

report was presented of a study conducted by the National Bureau of

Standards entitled "Performance of Inspectors and Gasoline Pumps".

This study also demonstrated the need for a research program to study

prover designs and performance.

The API Division of Marketing and NBS agreed to a cooperative

research project and on April 15, 1970 a Research Associate was

assigned to work with the Office of Weights and Measures (OWM) at

NBS under the sponsorship of API.

The API sponsored Research Associate Program is one of 23

projects and 66 Research Associates that are being sponsored at NBS

by private industry and trade and professional organizations. Under

the Research Associate Program, a representat i ve from the sponsoring

organization works at NBS on specific problems that are of mutual

interest to his sponsoring organization, to the industry, and to

- 3-
the Bureau. The Research Associate Programs, initiated by NBS in

1965, provide a valuable information exchange mechanism and promote

technology development.

- 4 -
2.0 PRELIMINARY RESEARCH ASSOCIATE STUDIES. Wi+h the arrival of

the Research Associate, an outline was prepared to establish the

guidelines under which the project would proceed. The outline was

approved by both API and NBS. The approved outline was as follows

I. Program Objectives

A. Develop primary test measure design

1 . Design criteria

2. Industry comments, opinions, and suggestions

3. Analytical design analysis

4. Calibration procedures evaluation

a. Methods

b. Human factors

c. Physical data

5. Accuracy limits

a. Existing

Requ i red or des i red

Attai nab le

6. Test measure size evaluation

a. Scale or model evaluation

( 1 ) I gallon

(2) 5 ga I Ion •

(3) 10 gal Ion

(4) Larger s i zes

B. Design specifications

b.

c.

- 5-
C. Application procedure

Testing Program

A. Structural testing

1 . Mater i a I th i ckness

2. Reinforcing bands

3. Weld finishing requirements

B. Internal finish investigation

1 . Mater i a I f i ni shes

a. Metal

b. Non-metal

2 . C I i ngage tests

a. Surface finish

b. Coated surface

C. Conical section evaluation

1 . Angle optimi zation

a. Critical

b. Non-critical

. Program Terminal Report NBS-API

A. Distribution

I . A . P . I .

2. Government

a. Federal

b. States

B. Complete test measure specification

- 6 -
Materi a I

2. Geometric

3. Fabrication

4. Auxiliary permanent hardware

5. Finish

a. Internal

b. External

6. Inspection recommendations

C. Application procedure

I . Laboratory

To launch into a program of this type it was necessary to first

determine what information was available that might be applicable to

the project. Various reports and sTandards were studied with the

result being that a complete specification was non-existent and procedural write-ups were too general to establish uniform practices.

In an attempt to obtain needed material and information, a meeting

was held September 14, 1970 at NBS . Following are the minutes of that

meeti ng.

- 7 -
MEETING HELD SEPTEMBER 14, 1970, AT 11:00 A.M.

IN DJNING ROOM C

NATIONAL BUREAU OF STANDARDS

GAITHERSBURG, MARYLAND

Attending the meeting were:

R. F. Aubrey - Marathon Pipe Line Co.

Ken Challenger - F. H. Maloney Co.

P. R. DeBruyn - NBS

Stephen Hasko - NBS-OWM

D. J. Hine - (Phillips Petroleum Co.) API Research Associate

B. C. Keysar - NBS-OWM

R. P. Layton - Gu i f Refining Co.

H. L. Lewis - Sinclair Pipe Line Co.

R. M. Mills- NBS-OWM

R. C. Primley - Cities Service Co.

Howard Siebold - Liquid Controls Corp.

Dick Southers - API

T. M. Stabler- NBS-OWM

R. H. Tolson - Texaco, Inc.

H. F. Wo II in - NBS-OWM

W. C. Waterman - Shel I Oi I Co.

W. H. Yancey - American Oil Co.

This meeting was conducted by D. J. Hine in an attempt to obtain

answers to certain questions concerning the AP I -sponsored Research

Associate Program on Primary Standard Volumetric Test Measures.

The meeting opened with a brief resume of the investigations performed

thus far in the program by Hine. The program has begun with Cl ingage

- 8-
Investigations and Calibration Witnessing. Although the cl ingage

test data is limited in quantity, it has become evident that procedure

will be of paramount importance in the overall evaluation. The

calibration witnessing is to be a continuing program in order to

fully evaluate human factor dependence and must be based on as large a sample as possible.

T. M. Stabler then gave a summary of the historic background leading

up to the current Research Associate Program. He included areas of

operation of the Office of Weights and Measures with emphasis on the

current responsibility to furnish state offices with "New State

Standards"

.

At this point in the meeting, Mr. Hine began a presentation of questions

that had been developed from an "API Standard Test Measure Research

Program" outline previously furnished to all persons present.

Question: What fluids should be considered in establishing test

measure load design criteria? Beyond water. What gravity range?

The answers ranged from LPG to asphalt; however, the majority

consensus was that water must be the fill fluid of primary concern

in design calculations. The need for data at least to No. 2 Fuel

Oil (approx. API Gravity of 34°) is badly needed.

Question: Do you have a written, strictly adhered to deta i I ed

calibration procedure on primary standard use? Is it available

so that it could be submitted for evaluation?

Most answers to this question were "API 1101". There are very

few documents that will directly answer this question, due to the

limitation of deta i I ed rather than genera I- i zed procedure. Whatever

may be available within the companies represented in this meeting

will be searched out and submitted.

Question: What references are currently used by the companies or organizations represented here to determine temperature-pressure

corrections? Specifically, thermal expansion coefficient for water

and test standard material and water compressibility.

The majority reflects almost total dependence upon the table

presented in API 1101. It was pointed out that ISO is attempting

to present a correction table that may be applicable. (This will

be acceptance of ASTM-IP Petroleum Measurement Tables.) There remains

a dire need for data standardization for a I I factors used which

might in any way effect the standard test measures.

- 9-
Question: What accuracy limits are reasonable for standard test

measures? Is it necessary to go beyond the existing 0.02$?

Those present verified that improved accuracy was the omnipresent

goal in measurement. The suggested accuracy to be investigated

was 0.01%. However, the procedure recommended was to perform a statistical analysis starting with the requirements of Handbook 44

for meters and working backward to the test measure in order to

judge the compatibility of the two accuracies. If the analysis

indicates that improved accuracy was necessary for test measures,

NBS divisions performing the calibrations will be contacted in an attempt to make an estimate of the increased cost of calibration.

It is feasible that only by changing calibration procedures can the

0.01$ accuracy be achieved.

Question: Is there a preference between gravimetric or volumetric

calibrations? Currently, calibration of test measures includes

both, but is it really necessary to absorb the cost?

This question prompted questions regarding the capability of the

facilities at the Bureau of Standards. A direct answer to the stated

problem hinges on whether there is any purpose to dual calibrations

and how they are compared. Load cell linearity as well as ambient

conditions measurement are of significant relevance in gravimetric

calibration procedures. If dual calibrations improve the accuracy

they are likely warranted.

Question: Keeping in mind that the Research Associate Program is

for a stipulated time, when the I, 5, and 10 gallon primary test

measures have been evaluated, what size is of primary interest

to industry?

Agreement was reached that certainly the 50 gallon and probably

the 100 gallon size test measures must be included if at all possible,

since these sizes constitute a great majority of test measures in

field use.

Question: In view of the findings from the limited amount of testing

thus far, either an extended drain-down time or a restrictive

procedure may be the resultant solution to repeatability (precision)

of a given test measure. Do you have a preference?

It seems that a well-defined procedure would be preferable, if not

overly restrictive in application. An extended drain-down time might

be difficult to sell to all the various agencies involved.

Question: In view of recent interest by several manufacturers, an opinion is needed regarding the requirements for a "field" test

- 10 -
measure that would not be calibration quality. It would be1 another generation removed from standard.

Wollin indicated that some states are contemplating dropping

routine checking, and in so doing will transfer the liability for

accuracy to the service station operator or owner and perform only

investigative sampling. This would certainly encourage the operator

or owner to purchase a test measure which would make the availability

of a low-cost measure desirable.

It was generally agreed that the availability might be warranted

but the market was not a receptive one. The market will exist only

if and when the inspecting jurisdictions make it necessary.

SERAPH IN TEST MEASURE CL INGAGE HARDWARE PROPOSAL

(See Drawing)

Question: Are top and bottom angles sufficiently representative?

It was agreed that possibly an angle less than 15° should be

included. The top and bottom designs could be made identical by

eliminating the 4" top neck and installing a coupling instead.

This minor change would allow the angles to serve as either top or bottom depending on how installed.

Question: Does testing with this type of device have any merit?

Since it would facilitate possibly optimizing prover and test

measure design, it has definite potential significance.

Question: What liquids should be used for the tests?

It would be desirable to include Kerosene and/or No. 2 Fuel Oil.

Question: Where, if testing with other than water?

Mr.' DeBruyn pointed out that the Hazards Laboratory here at the

Bureau might be made available. This possibility will be investigated.

Additional items brought up during the meeting were as follows:

1. Need for a Measurement Terminology Standard.

2. Interpolation procedure is needed for extending a "Water

Calibrated" test measure to other fluids. No. 2 Fuel Oil

is of particular interest.

The need for standardization of recalibration intervals

-I I3.
- 12 -
for test measures and prover tanks.

4. Larger capacity ( non- i nverted ) measures are calibrated with

nipple-elbow-pipe combination attached to the drain valve,

whereas in application, field calibrations are rarely performed with a similar flow restriction. The effect of the

restrictions on cl ingage should be investigated.

5. Incremental scale maximum allowance may be too lax at 5 cubic

inches. In the interest of improved accuracy, the maximum

allowable division might be reduced to 2 cubic inches.

The answers to at least some of these questions could feasibly be

a residual benefit of the Research Associate Program as it is now outlined. Attention will be given to these and additional questions

as the program progresses.

Meeting adjourned - 3:00 P.M.

- 13-
The answers and discussions of questions did not yield direct

solutions to the defined problem areas presented but did provide

information concerning the areas of interest where additional research is required. The meeting provided additional indication

that standard test procedures and equipment specifications are

virtually non-existent and the concensus of those in attendance was

that they are badly needed.

- 14 -
3.0 DES I GN ANALYS I

S

. An analysis was performed to theoretically

predict the performance of two specific areas of a test measure.

The areas of interest were the lateral or cylindrical sides and the

bottom of a measure. The dimensions required for the calculations

were assumed to equal the minimum values appearing in NBS Handbook

105-3, Specifications and Tolerances for Metal Volumetric Field

Standards . [ I

H

3.1 TEST MEASURE BOTTOM ANALYSIS . A literature search was conducted

in an attempt to find an appropriate mathematical model that could

be used to calculate the maximum predicted deflection and the surface

stress on the formed measure bottom. The model being sought was

for a shape with an appearance as:

It was discovered that such a model was not included in the available literature. The nearest models found were for a flat-plate and

a dished plate which appeared as follows:

An exact model could not be found. The worst case between the two

models would be the flat plate which would present the worst potential

case for maximum deflection of the bottom plate of the test measure.

The model, equations used, and results are as follows:

- 15 -

7777
PROBLEM:

GIVEN:

ASSUMPTIONS:

SOLUTION:

CONCLUSIONS:

Determine the deflection of a circular flat plate

with a uniform load over the entire area.

Load to consist of 5 gal Ions of water.

Plate thickness 0.050 inches (18 gage)

Water Density - 8.34 pounds per gallon (60°F in Vacuum)

Modulus of Elasticity - 30 X 1 0& p s

Maximum Deflection: y

where m

a

E

t

y

Surface Stress: S

16 TT Em2+3

= l/Poisson f s ratio = 1/0.3 = 3.333

= radius of circular flat plate = 5.5 inches

= 30 X I0 6 psi

= thickness = 0.05 inches

= 0.018 inches

- 3 WC^m + I ) 8 mT2

= - 2585 psi

The calculated maximum deflection of the plate can be

assumed negligible. The deflection would increase

the volume by approximately 0.6 cubic inches and this

volume increase would be essentially constant with water

application. If the liquid providing the loading was

only 0.65 Specific Gravity, the deflection would be

0.012 inches and the volume increase would be 0.4 cubic

- 16 -
inches. The net change for the example comparing a

water-calibrated device when used to measure a 0.65

gravity liquid is 0.2 cubic inches. For a gasoline

application, (assuming 0.7 specific gravity) the

volume change would be approximately 0.2 cubic inches.

With a 7.0 cubic inch tolerance the volume change of

0.2 cubic inches would represent approximately 3

percent of the total tolerance.

3.2 CYLINDRICAL SHELL ANALYSIS . For the shell analysis, a cylindrical tank with uniform wall thickness was assumed. Strength

contribution from any reinforcing bands was not considered except

the bottom was assumed to be constrained.

The radial expansion near the bottom was calculated by

- y(d-x)a2

w = Et

where w = radial expansion

y

= water density (Ibs/in^)

d = water height (assumed 12 inch)

x = height of radial hoop (taken as

a = radius = 5.5 inches

E = modulus of elasticity

t = she I I th i ckness

The theoretical deflection was calculated

The shearing force was also calculated and was

than I psi. The shearing force was determined

zero)

to be 0.000014 inches,

found to be less

by the relation:

- 17 -
where Q

= shearing force

u

6

Poisson's Ratio (assumed 0.3)

constant calculated from the equation B^ =

This examination was performed to determine if the elastic limit

of the material was approached or exceeded. Theoretically, it will

not be approached with normal use.

4.0 CALIBRATION PROCEDURES EVALUATION . The purpose of including

this segment in the research project was to compare existing calibration procedures and investigate the possibility of developing an

optimum procedure. From many inquiries, it was discovered that formal

written procedures were virtually non-existent in either industry

or calibrating agencies. The lack of any procedures prompted a

series of calibration witnessings in order to evaluate the procedures

being used. As a result of witnessing calibrations performed at

the Bureau of Standards, a procedure was written to reflect the

actual method used. The observed procedure is as follows:

NBS GRAVIMETRIC/VOLUMETRIC CALIBRATION PROCEDURES

(I, 5, and 10 Gallon Measures)

The test measures are thoroughly cleaned by the following process:

1. Rinse with degreasing solvent to remove any soldering flux

or other foreign residue.

2. Rinse with alcohol.

3. Wash with hot water and a bio-degradable glassware detergent.

Rinse with clear water until detergent is removed.

- 18-
4. Ri nse with a I coho I

5. Air dry

During the cleaning, the test measures are examined for leaks or

any visible defects.

The test measures are then weighed on an Equal Arm Balance. This is

a five-step procedure as follows:

Left Side Load Right Side Load Records Made

I . Weights of

unknown qual

& quantity

ity Test Measure w/cover None

2. Weights of Total load, turning

unknown qual ity Standard Weights points, relative

& quantity humidity & temperature

barometric pressure & balance enclosure

temperature.

3. Weights of

unknown qual

& quantity

ity Test Measure w/cover Turning points

4. Weights of Turning points, relaunknown qual ity Test Measure w/cover tive humidity & tem-

& quantity plus sensitivity weight perature, barometric

pressure & balance

enclosure temperature.

5. Weights of

unknown qual ity Standard Weights plus Turning points

& quantity sensitivity weight

Following the dry weighing, the test measure is filled to about

zero on the neck scale (plus or minus 5 i n^ acceptable) with distilled

water. The water temperature is determined with matched electronic

quartz thermometer probes. The scale reading is then taken and recorded. This reading is performed with a meniscus reading device

- 19 -
that has a pair of crosshairs which aid in maintaining the eye

level with meniscus if properly used. This also magnifies the

scale, thereby enhancing estimation of the nearest one-tenth scale

division.

The full test measure is then covered with the cover used in

the dry weight determination and weighed following the same 5-step

procedure described above.

The water is carefully transferred by approximately maximum

flow through a glass funnel (2" drain opening, 12” top diameter, and

9" height-volume = 1.75 gal) into a "to contain" "Check Standard".

The neck scale reading is determined using the meniscus reading

device and the water temperature is determined with the thermometer

probes. The values are recorded on the data sheet. The test measure,

covered with the cover or cap, is again weighed using the 5-step

procedure previously described.

The volume determined by the calibration is calculated by means

of a computer program. The actual water density determination,

air buoyancy, and temperature correction information (program listing)

were not evaluated. If not specified by the customer, the assumed

Thermal Coefficient of Expansion for a standard "Terneplate" test

measure was reportedly 0.000018 per degree Fahrenheit, however, this

number was later changed to 0.0000186 to reflect current tecnnology.

Gravimetric calibrations can be calculated with the use of

proper equations and a desk top calculator. Exhibit I is a Sample

Gravimetric Calibration Data Sheet which reflects the data required

- 20 -
Observe Teat No.’

Sensitivity vt. £j//cZ/n Started X Finished /

- 21 -
for the calculation when using an equal -arm balance.

The calculations are performed as follows: (The equations are

from publications listed as Q2]], L3H , and in the List of

References )

.

The Sample Data Sheet shows values of 0| , O

2 , O

3 , and O 4 for each

weighing series. These values represent the sum of the average turning

points divided by 2. from Reference

X-S =

<-) l“^2 + S.W _ ^

2 O 3-O2

*

Solving the 3 weighings shown on the data sheet:

. _ I I .3-12. 125 + 9.925-10.925 0.5

1 2 10.925-12.125

A | = -0.3802

A _ _ 10.225-1 I .2 + 8.9-10.05 0.5

2 2 10. 05-11.

2

A

2

= -0.461957

A 9.775-11 .675 + 8.525-10.5 0.5

3 2 10. 5-11. 675

A

3

= -0.824466

From Reference [3'H and C4 U the mathematical representation for air

density (pa) and water density (pw) respectively, are:

pa mg^ = 0.464554 g-H(0.00252ta -0. 020582)

cTM5

t a + 273.16

where 8 = barometric pressure i n mm of mercury,

H = relative humidity, and

t

a

= air temperature

*Abso I ute va I ue

- 22 -
pw 9

ran

; s = 0.001 *ZC n +

n cm3 n=o

where C n values are:

H Cn

0 999.8395639

cm3

1 0.06798299989 -S_

cm 3 °C

2 -0.009106025564 -2_ 0

cm3°c2

3 I .00527299- I0“ 4 -Kn , cm

3o C

3

4 -I . 126713526- I0~ 5 9 , ^°C4

5 6. 59 1 795606x1 0~ 6 _2_

cm3 °C3

and where

tw

= water temperature in °C

For convenience the equation values for t = 0°C to 39.9°C are presented in Table I

.

Solving for the air density of the three data sets gives:

pal = 0.000011756 mg/cm3 = 0.0011756 grams/cm3

pa2 = 0.0000117495 mg/cm3 = 0.00117495 grams/cm 3

pa3 = 0.00001 17516 mg/cm3 = 0.001 17516 grams/cm3

and the water density from Table I is:

pw = 0.9981602 grams/cm3

It is now possible, using A|, A

2 , A^, pal, pa2, pa3, and pw, to calculate the volumes reflected by the calibration. From Reference [21

the volume contained at test temperature and scale reading is:

- 23-
T 0.0 c 0.1 C 0.2 C 0.3 C 0. 4 C 0.5 C 0.6 C 0.7 C 0.8 C 0.9 C

.e .95534 0 .559846 . 995853 .999859 .959865 .599871 .559877 .595883 .555888 .999893

1 .c . 95589 9 .555503 .559508 .95551

3

.555517 .599921 .999525 .595529 .555933 . 595937

2.0 .55554 0 .559943 . 50505.6 .995549 .995552 . 595954 .555556 .555559 .555961 . 999963

3.0 .59596 4 .555566 .995567 .995968 . 955569 . 595970 .599971 .595971 .995972 . 595972

4 .0 .55557 2 .555972 .599972 .559971 .599971 . 595570 .559569 .999968 .555967 . 999965

s.c .55556 4 .555962 .955560 .599958 .555556 . 955554 .599551 . 599949 .995946 . 959943

6. C .55594 O .555937 . 555533 .995530 .559526 .599922 .559518 .999914 .995910 .555906

7.C .55590 1 .955896 . 955852 .595887 .595881 .599876 .599871 .959865 .599860 . 999854

e.c .95984 8 .555842 .595335 .559829 .955822 .999816 .595 805 .959802 .955795 .999787

5.C .5 9978 0 .599773 .999765 .999757 .955749 . 959741 .599733 .999725 .995716 . 959707

10.C .59969 5 .595690 .599681 .995672 .995662 . 599653 .555643 .995634 .959624 .9996 14 11.0 .55560 4 .955594 .999583 .595573 .995562 .999552 .55954

1

.595530 .955519 . 999507

1 2 .0 .55545 6 .559485 .955473 .559461 .599449 , 555437 .595425 .59541

3

.959401 .555388

1 3.C .55537 6 .559363 .559350 .999337 .595324 .55531

1

.559257 . 999284 .595270 .595256

14.0 .55524 3 .555225 .595215 .999200 .9991 86 . 5951 72 .595157 .999142 .995128 .9991 13

1 5.C . 55509 8 .995083 .595067 .995052 . 959036 . 995021 .999005 .998989 .598973 . 998957

16.0 .59854 1 .958925 . 598908 .958892 .958875 . 598858 .99884

1

.998824 .558807 .598790

17.C .558 7 7 3 .558755 .958738 .558720 .558702 .998684 .558666 .556648 .958630 .998612

1 8.C . 5 5655 3 .558575 .598556 .598537 .958515 . 998500 .558480 .99846

1

.558442 .998422

19.C .55860 3 .558383 .998364 .998344 .596324 . 5583 04 .959284 .558263 .958243 . 998222

2 0.0 . 55820 2 .5981 81 .598160 .998139 .5581 1

8

.958097 .558076 . 558055 .993033 .598012

2 1 .0 .95755 O .557968 .597947 .597925 .557003 . 557681 .997358 .997836 .557814 . 997791

2 2 .0 .59776 8 .557746 . 597723 .557700 .557677 . 997654 .997630 .597607 .957584 . 997560

23.

C

. 5 5753 6 .55751

3

. 997489 .997465 .957441 .597417 .557392 .557368 .557344 . 997319

24.0 . 55729 4 .5572 70 .5572*5 .597220 .557195 . 997 1 70 .557145 .5971 19 .957094 . 597068

25.

C

.5 9704 3 .957017 .956551 .996566 . 996540 .996513 .996887 .596861 .956835 .596808

26.0 .55678 2 .556755 .596728 .556702 .556675 .996648 .556621 .596593 .556566 .996539

27.0 .55651 1 .556484 .556456 .996428 . 556401 .556373 .996345 .596316 .596288 .556260

28.0 .55623 2 .9962 03 . 9561 75 .5561 46 .9961 1

7

.596088 .596060 .996031 .956001 , 995572

25.0 .55594 3 .955914 .995884 .595855 .995825 . 955795 .995765 .995736 .595706 .995676

30.0 .55564 5 .99561

5

.955585 .995554 . 995524 . 595453 .555463 .955432 .955401 .995370

31 .0 .55533 5 .59S308 .955277 .595246 . 995214 . 595.1 83 .995151 .555120 .955088 .595056

32.0 .55502 4 .954592 .554960 .554523 . 554896 . 954864 .994831 . 594755 .954766 . 594734

33 .0 .59470 1 .554668 .994635 .994602 .994565 .594536 .594 503 .994470 .554436 . 594403

34.0 .56436 9 . 954336 .594302 .994268 . 954234 » 994201 .594 167 .554132 .954098 .994064

35.0 .59403 O . 553995 .993561 .993926 . 953891 . 993857 .593822 .993787 .953752 .993717

36.

C

.553682 .553647 .55361

1

.953576 . 953541 . 993505 .593469 . 593434 .553398 . 593362

37.0 .59332 6 .653250 .993254 .99321

8

.953182 .993146 .553109 .593073 .993036 . 993000

38.

C

.55296 3 .552926 .992839 .952852 .952315 .552778 .592741 . 552704 .992667 .992629

39.0 .95255 2 .952554 . 95251

7

. 992479 . 992442 . 5924 04 .592 366 . 552328 .552290 .992252

Table 1 Density of Air Free Water in Based on the g/em as a Function of the Celsius Temperature

Work by H. Wagenbreth and W. Blanke„

FTB-Mitteilungen 6-71,

Scale

24
V w

: A

2 -A| + Ms 2 -Ms , + p a | V s |-p a2 V s2

= cm3

where M s 2

:= Standards Mass Data Set 2

Ms 1

:= Standards Mass Data Set 1

v

sl

:= Standards Volume Data Set 1

V S 2

== Standards Volume Data Set 2

vw

: -.46 1 957- (- .3802) +2 37 95-4 887+. 00 1 1756(531 .8)-. 001 17495(2832.7)

0.9981602-0.001 17495

vw

= 18960.481 cm3

The volume V.. must be corrected to reflect the volume at zero scale W

read i ng.

vw

:= 18960.481 cm3 x 0.00026417 S£L-1 - 2 in ^ cm5 231 i

n

3 ga lion

V w

== 5.00879 gal-0.00519

VW

:= 5.00360 gallons at 20.299°C

The volume at 60°F (conventional reference temp) may be determined

as fo 1 lows

:

Vw60°F := V w [l-3(tw -60)]

where 6

:= cubic coefficient of thermal expansion

6

:= 28.8 x I0”6 per degree F (changed to 26.5 x I0~5 - 1973)

+w

= 20 . 299°C = 68 . 54°F

v w60°F = 5.00360 [1-28.8 x I 0“ 6 ( 68 . 54-60)] = 5.00247 gallons

The volume of the residual water (Vrw ) may be determined [2] from the

equation

V D = A 3-A I + Ms3" Msl" p a3v s3 = p al V

sl

’Kw _— 3 _ crrr p w“p a3

- 25 -
where M

s ^

= Standards Mass in Data Set 3

V

S 3

= Standards Volume in Data Set 3

v _ -0.824466- (-0.3802) +4897-4887-0. 000 I I 75 I 6( 583.0)+0.000 II 756( 53 I .8)

Rw 0.998145-0.0001 17516

V Rw = 9.51456 cm 3

V Rw = 9.51456 cm 3 x 0.00026417 9£i‘' = 0.00251 gal Ions

cm3

From V w gQOp and V Rw the final volume of interest, the delivered volume

Vq, can be calculated:

V D

= Vw60°F " v Rw

V D

= 5.00247-0.00251 = 4.99996 gallons

All calibrations witnessed essentially followed the outlined

procedure with the exception that the first calibrations witnessed

were performed with water drawn from the tap and all later calibrations

were with distilled water. This change was considered significant

due to the questionable quality of the water supply both from density

considerations and air entrainment.

Review of the procedure and repeated calibrations with the

same measure indicate that uniform calibration can be realized if

the procedure is not varied. No attempt was made to evaluate either

the effect or magnitude of deviations in the procedure. The procedure

was not judged to be overly restrictive and potential variations in

the procedure would only be variable characteristic of the ambient

conditions and the personnel performing the calibration.

Testing reflected that a calibration value could be repeated

by different individuals if the procedure was conscientiously followed.

- 26 -
Calibration of volumetric test measures is necessarily a manual

operation and is somewhat dependent on the mental attitude of the

individual performing the calibration. Mental attitude could affect

the calibration but the effect cannot be measured or estimated. Care

in cleaning, drying, reading, and recording balance readings and scale

readings are some of the features that could fluctuate with mental

attitude. It is considered, however, that an experienced technician

will strive for optimum accuracy.

Since the calculations to establish the NBS calibration values

are performed using a computer program, complete examination of the

physical data was not attempted beyond the manual calculation which

yielded good agreement with computer values. The computer program

includes corrections for ambient temperature, humidity, and barometric

pressure in the weighing process and is considered highly acceptable.

One value used in the computer program that was judged questionable was

the cubical thermal expansion coef f i ci ent- for low-carbon steel measures.

Report of tests indicated a value of 0.000018 per °-F was assumed.

This value reportedly came from the 1945 edition of Metals Handbook

and NBS Monograph 62 (issued April I, 1963). (The computer value

was changed to 0.0000186 in 1972.) The National Bureau of Standards,

at the request of the American Society for Testing Materials,

developed a set of equations to represent the thermal expansion of

mild steel from -40 to +400°F. The equations were published in Volume

45, No. 4, April 1961 Technical News Bulletin C5j as well as ASTM

DI750-62, API Standard: 2541, Tables for Positive Displacement Meter

- 27 -
Prover Tanks. The Technical News Bulletin article appeared as follows:

Equations Representing Steel Expansion

THE BUREAU has developed a set of equations to represent the thermal expansion of mild steel from — 40 to +400 °F, at the request of the American Society for Testing Materials. These equations were de- rived to assist ASTM Committee D-2 on Petroleum Products and Lubricants in the development of steel standards involving volume. They may also be used in preparing specifications for the steel containers

used for storing various types of petroleum products.

To make these equations generally available, they are published here: Lt = Lco [l +6.2 X 10‘ 6 (/— 60) +2.0X 10'9 (/-60) 2 ] am — [6.0X 10- 6 + 2.0X lO-^ + fj) ]/°F

Vt — F60 [l +18.6X 10‘6 (f — 60) +6.1 X 10~° — 60) 2 ]

J3,n = [ 17.9 X 10' 6 + 6.1 X 10-°^ +t2 ) ]/°F

where Lt and L„0 are the lengths at temperatures t and 60 °F; a,„ is the mean or average coefficient of

linear expansion per degree Fahrenheit between temperatures f, and t 2 ; Vt and V00 are the volumes and

/?„, is the mean or average coefficient of cubical expansion per degree Fahrenheit.

The values used in these equations are believed to be representative for mild steels to the accuracy of the

digits given. ______________________

U.S. GOVERNMENT PRINTING OffICE: 1961 O—567453

Examination of the equations reveals values of 0.000062 for the

linear coefficient and 0.0000186 for the cubic coefficient (average).

In an attempt to determine if the typical test measure exhibited

an expansion coefficient consistent with the equations, a material

sample was obtained from a test measure manufacturer. The sample

was submitted to the Crystallography Section of NBS. The following

is the pertinent portion of the test report received:

The following values have been determined for the mean coefficient

of linear thermal expansion of a steel plate parallel and perpendicular to the direction of roll.

- 28-
Para 1 lei Perpend i cu 1 ar

68 to -40°F 6.2 x I0~ 6 /°F 6.3 x I0~ 6 /°F

68 6.4 6.5

68 to 212 6.7 6.8

These values were obtained with a vitreous silica dilatometer

following the ASTM Method of Test E 228. The specimens were

4 inches in length and the dilatometer was calibrated with two

standard reference materials, SRM 736 (Copper) and SRM 739

( Fused Silica).

A mathematical average of the six values yields 6.48 x ICT^ for

an average linear coefficient from -40 to 2I2°F. Multiplying the

linear value by three to obtain a close approximation of the cubic

expansion coefficient gives 19.4 x I0~6 or 0.0000194. Certainly no

definite conclusion can be drawn from a single test other than that

0.000018 is not appropriate for use and further tests may be advisable

to determine the best average value for test measure application.

It is interesting to note that two manufacturers of test measures

requested coefficients from the steel mills from which they obtain

thei r ternep I ate material. The steel mills furnished values of

0.0000196 and 0.0000195 per degree F. Further study in this area

was beyond the scope of the Research Associate Program.

4.1 CONCLUSIONS AND RECOMMENDATIONS . The calibration procedure

employed by NBS is judged to be acceptable for use by others. A

significant item is, however, neglected. It is generally accepted

and has been experimentally verified that a test measure calibration

- 29-
is dependent on the emptying time as well as the a Noted drain time

following cessation of flow. Historically, only the drain time

following cessation of flow is noted, recorded, and reported.

This condition should be corrected. For invertable style measures

the emptying time would reflect the NBS Calibration Procedure.

For bottom-drain measures the device owner would have the responsibility of requesting a specific emptying time when submitting the

measure to NBS for calibration. Only the owner knows in what piping

configuration the equipment will be used and consequently he should

include this time requirement in his request. The actual emptying

time during calibration would then become part of the permanent documentation. Devices submitted without an accompanying drain time

request would be calibrated with a minimum of hardware attached and

the resulting drain time would be reported.

In considering the differences of values for the thermal expansion

coefficient it must be pointed out that the differences in total

calculated volumes would be slight (I cubic inch in'500 gallons with a

I5°F temperature differential). It does reflect non-uniformity but

is considered insignificant if all parties will use consistent coefficients. Until additional research is conducted, the values of

18.6 X I0“6 per °F for low-carbon steel and 26.5 X ICT^ per °F for

18-8 or Type 304 stainless steel should be used by all individuals.

- 30-
5.0 ACCURACY LIMITS . Accuracy limits are extremely important in

every measurement process, especially when dealing with standards

calibration and traceability. In dealing with any measurement process,

it is essential to determine whether accuracy or precision is the

desired quality. The definitions may be simply stated in that

precision is the measure of the closeness together of two or more

measured quantities and accuracy is a measure of the nearness of a ' measured value or values to the intended value. Accuracy is the most

important character istic for volume measurement applications. For

the purposes of this study, accuracy has been divided into three

phases. These phases are: Existing accuracy, required or desired

accuracy, and theoretically attainable accuracy.

The existing accuracy is assumed to coincide with and is limited

to the estimated uncertainty furnished to a customer on a Report of

Calibration. This uncertainty reportedly reflects a standard deviation

based on an expected range of two calibrations and assumed negligible

systematic error. As the review on this phase progressed, a statement of "Maximum uncertainty" was alluded to by several individuals.

Based on information received, an API Task Force assigned to study

calibration of Primary Vo I ume" Standards prepared a report following

a visit to NBS in 1966. The report quoted that the-maximum uncertainty

which would be reported on Standards of volumes one to fifty gallons

would be ±0.02$ and for a one-hundred gallon Standard the maximum

uncertainty would be ±0.01$. These values were not exactly substantiated by the calibration reports reviewed. (See Table II, page 36.)

- 31 -
The desired accuracy for volumetric test measures is difficult

to determine. Referring to the information obtained from the September

1970 meeting at NBS (Page 7), the desired accuracy was ± 0.01%.

This statement implies a reduction of the estimated uncertainty

by one-ha I f

.

From discussions with individuals in various areas of measurement

responsibility, one will find that the desired accuracy for volume

calibrations of standards is the unattainable absolute accuracy.

In actual field applications of volume standards it would appear

that absolute accuracy is often assumed since the nominal volume

values are employed in checking meter accuracy. Only when such an

assumption is questioned is it disclosed that tolerance values for

determining equipment acceptability are "interpreted" as including

some tolerance contribution from the test equipment. This contribution

must necessarily include the 0.02$ (if such be the number and it is

a first generation calibration) in addition to the allowable tolerance

from the nominal value of the Standard. This may reflect a dangerous

procedure or philosophy. This very fact is one of the prime justifications for the sponsorship of the Research Associate Program by the

American Petroleum Institute. One of the goals of the entire program

was to define what portion of a tolerance is contributed by the

test equipment and procedure and what portion is actually attributed

to the system being tested.

If the mi s-measurement contribution can be isolated through

the Research Associate Program, meter system evaluation will be

- 32 -
much more meaningful. For comparison purposes. Table I! was prepared

for values from available Reports of Calibration. This table shows

the reported uncertainty, the quoted 0.02 % maximum uncertainty, and

the 0.01% desired uncertainty.

Review of available Certificates (discontinued during the 1960’s)

and Reports of Calibration reflect a change in reporting of values.

The Certificates stated a quantity at a specific temperature and

cited no uncertainty. Statisticians generally emphasize that when

no statement of accuracy or precision accompanies a reported number

the usual convention is to assume that the last significant figure

given is accurate within ±1/2 of that unit. An example in the comparison of two actual reports is as follows:

Certificate 50.00 Gallons at 60°F

Statistical Uncertainty +.005 Gallons or 1.2 cubic inches

Report of Calibration 49.997 U. S. Gallons, 11549.5 i n^

Estimated Uncertainty +.02 U. S. Gallons, 4.6 in'*

When the Certificates were discontinued and Report of Calibrations substituted, the uncertainty applied to the volume standards

was greater than the uncertainty inferred by the Certificates which

leaves a wide variation between similar equipment in the field with

different calibration documentation. This will be resolved with

time and eventually there will be no operating equipment with Certificates

being used.

Attainable accuracy is also a difficult character i st i c to

evaluate since there must be a starting point. An attempt to determine
values for an attainable accuracy would be nothing more than a

personal estimate. Uncertainty could be theoretically estimated if

any single uncertainty previously listed was selected as a starting

point. Such a procedure would necessarily be arbitrary and the

resulting values could be meaningless. National Bureau of Standards

Report NBS I R 73-287, "Procedures for the Calibration of Volumetric

Test Measures", reports on an extensive series of calibrations that

were performed in an attempt to evaluate uncertainties. The uncertainties

derived from those tests are generally acceptable but not applicable

to every calibration process.

To determine if statistically predicted uncertainties would

reflect improved values, calculations were performed using the

fol lowi ng equation:

U =3 n 2 a2 + nU

x s where is the uncertainty of the device being calibrated,

n is the number of times the standard was used,

o is the standard deviation of the standard, and

is the uncertainty of the standard.

Assuming a 100 gallon standard with a standard deviation of

0.0067 and an uncertainty of 0.02 gal, calculations were performed

for build-up calibrations of a 200 and a 500 gallon measure. The

resulting values of uncertainty were 0.16 gallons and 0.4 gallons,

respectively. The values are not considered to be representative

of the actual calibration procedure performed at NBS. Comparison

of these calculated values with the values listed for 200 and 500

- 34 -
gallon measures in Table II shows that the calculated values are

significantly greater than the reported values.

From a discussion in NBS Report 10396, "Pressure Type Liquid

Level Gages", the uncertainty for a "build-up" calibration was

taken to be equal to:

Uv

= NLL + U (AT)NV A b 01 5 where U x

= Uncertainty of the unknown

N = Number of dumps

U

s = Uncertainty of the Standard

V

s = Volume of Standard

U a

= Uncertainty in the cubic thermal expansion coefficient

AT = Temperature difference between calibration temperature

and same base temperature.

For the NBS 100-gallon Stainless Steel Standard an uncertainty

of 1.38 cubic inches or 0.00574 gallons is stated. For compar i son

with the previous example, assume U

a

= 4 x IO -fV°C = 2.22 x I0“^/°F,

AT = 60°F-40°F = 20°F, then

Ux | oo

= 1 x 0.00574 + 100 x I x 2.22 x I0~ 6 x 20

= 0.00574 + 0.00444

= 0.01018 gal '= 2.35 in 3

and for a 200 gal Ion

u x200 = 2 x 0.00574 + 2.22 x I0

-6

x 20 x 2 x 100

= 0.01148 + 0.00888 = 0.02036 gallons

= 4.70 cubic inches

Comparison of these values with the values in Table II shows much

-35-
TABLE

||

UNCERTAINTY

COMPARISONS

va. oo in ^ c — LH in CM

— o o o o — m LH — o >

o o o o CM in o o o o — o 1— — Z CU o o o o o o o o o o o o — cd o o o o o o o o o o o o <I

cm. LUo

&«. CMOO 0)c

CMo Csl soNco CN

CNo

>- o o o o o o o o — o CM o

I—

— o o o o o — o o o o o o z — • • • • • • • • • • • • <

03 CD o o o o o o o o o o o o I

cm

LUoz3

>- 4- h- c CM CM CM

—

— CM z CD o o O o o O — (J • • • • . • < L_ o o o o o o

h- 0 * cr q_ —J LU < o

03

N" N" CM CM LH

10

CD o O O O O — 4- • • • • • (0 o o O o o O (J

4-

h- 3 O< Q 0O

lu in 1— c

cm o o —

CMOO o o o CM o CM CM

CMO CM

ino Co

4—

a.

— o o o o o — o o O

O

OO (U LU (0 • • • • • • • • L_ cm cd o o o o o o o o o o O O _Q

co LU u Z3 0

_J 4- O C C C c e c c C e c c C CO > o o o o o o o o o o o o L.

fD 1 CL < CO (0 CO (0 (0 CO co co CO CO CO CO 0 z CD CD CD CD CD CD CD CD CD CD CD CD cn s — m in o O o O CM o o o 4- o — O o m •m3" in — o c z CM in — 0

in z z z JL z z z Z z z 0 o o CD o o u o u u o o o L. LU 0) CD 4- CD 0 0 0 0 0 0 0 0 CL

CL z Z CO z z z z z z z z z 0

>-

— l_ h- ~o T3 Cl T3 X) T3 "O T3 TD 13 “O 13

CD CD o 0 0 0 0 0 0 0 0 in UJ 4- 4- L_ +- +- 4- +- -i- +- +- 4- 4- 0

QC (0 CO CD CO co CO (0 CO CO CO (0 co 3 3 13 ZJ Z5 3 3 3 3 3 3 3 3 —

03 "O "O o T

~o ~o TD TD TD “O TD 13 (0 < co CO . 

co CO CO CO (0 CO CO co CO >

LU L. L_

— L. L_ L_ L_ L_ L_ L_ L_ L_ z CD CD CO CD CD CD CD CD CD CD CD CD 4 - 36 -
better agreement. If the relationship used in this example is valid,

then by using an accurate, wel l-known cubic thermal coefficient of

expansion that uncertainty contribution would approach zero. That

would represent an uncertainty reduction of 40 percent or more.

The ultimate goal for uncertainties associated with volumetric

measures, in the eyes of most people involved in measurement, would

be for the values to be decreased. It is impossible for any individual

to predict that such a reduction could be realized. The actual ability

to decrease the estimated uncertainty has been studied with the resulting conclusion that the unknown variance of the cubic thermal

coefficient of expansion and the predicted readability of the

graduated neck may prevent a reduction of estimated uncertainty.

The calibration data of the "check standard", described in the

calibration procedure of Section 4.0, has been collected for I,

5, and 10-gallon calibrations with good agreement between predicted

uncertainty and uncertainty based on a large test population.

Similar data for the larger volume is not taken due to the absence

of "Check Standards" in the procedure. The resolution of this problem

will only come about when an exhaustive study is conducted by persons

knowledgeable in statistical’ evaluation and volumetric calibrations.

Such an evaluation is far beyond the scope of the Research Associate

Project.

The research project included calibrations to evaluate design

and operating character i st i cs of test measures and included repetitive

calibrations of prover standards.

- 37 -
6.0 LIQUID RETENTION OR CL INGAGE TESTS. In order to evaluate test

measure character i st i cs that affect liquid retention, it was necessary

to devise a test series that would provide the required information.

Preliminary tests were conducted in an attempt to determine which

characteristics of a given procedure would measureably affect the

amount of liquid remaining in a measure following emptying. It was

learned that three variables dominated or controlled this liquid

residue. They were:

1. The angle between the vertical axis of the test measure

and true vertical during drainage,

2. The time from the beginning of, the emptying of a measure

to the cessation of flow, and

3. The time from the cessation of flow until the measure is

returned to an upright position Op the drain valve closed.

The preliminary tests provided an indication that the basic

characteristics of test measures could be studied while performing

the retention of liquid tests. The most significant feature of test

measures concerns the reproduc i b i I i ty of performance and a large

contributing factor would be the liquid retention. It was found

that this factor could be significantly changed by slight variations

of the three variables previously mentioned. Admittedly, there can

be other factors that could influence the accuracy of a test measure

such as dirt film, corrosion, denting damage, etc. These factors

were not considered to be true variables since their effects would

be unstable and completely uncontrollable. The tests were limited

- 38-
to clean, reasonable quality volume standards suitable for a commercial measurement process. A test series was planned using carbon

steel test measures, both bare and epoxy-coated, stainless steel

test measures, and specially designed containers of two square feet

surface area. Figure I, 2, and 3 are photographs of the instruments

that were subjected to retention test studies.

6.1 TEST MEASURE TESTS . The testing involved a weighing process

to determine the weight of liquid remaining in a measure following

a carefully controlled emptying procedure. Weighing of the 5 and

10 gallon test measures was performed with a 2500 pound capacity

Russell Equal-Arm Balance. The right arm of the balance was loaded

w.ith a 500-pound weight while the left arm was loaded with the test

measure and cover, a weigh pan, and sufficient weights to balance

the 500-pound weight. The weight of water retained was determined as

being equal to the amount of trim weights required on the right arm

to balance the left arm which included the wetted test measure.

Figure 4 shows the configuration for weighing of the test measures.

The weighing of the I gallon test measures was done on a 10 kilogram

Chr i st i an-Becker Equal-Arm Balance. Figure 5 is a photograph of

that balance with a test measure on the left side pan and weights

on the right pan. For each device tested, the tests were repeated

numerous times in order to establish the reproducibility of the

results and to properly document that the variables under investigation

were indeed contributing factors if subsequently applied to calibration

procedures. Since the variable factors seemed to be independent of

- 39-
Figure 1. Volume standards used for tests - Group 1.

40 -
Figure 2. Volume standards used for tests - Group 2.

41



one another it was necessary to vary only one factor at a time in

order to establish what would be considered to be the optimum times

and angle. From these tests it was possible to determine at what

upper and lower limits the resulting data would exhibit a nonreproducible scatter. The ultimate goal of the test series was to

establish the limits within which the variables should be controlled

in order to achieve a repeatable calibration and at the same time

not be overly restrictive.

6.1.1 EXPERIMENTAL TEST PROCEDURE . All test measures, except the

epoxy-coated measures, were cleaned using a degreasing solvent rinse,

alcohol rinse, warm water with detergent, clear water rinse, alcohol

rinse, and air drying. The cleaning of the epoxy-coated measures

was accomplished using only warm water with detergent, clear water

rinse, and air drying. The cleaning provided chemically clean dry

surfaces for test evaluation.

The test measure with a cover was placed on the balance left

arm and weight was added to the appropriate side to achieve a new

balance condition. Turning points were observed and recorded on

the data sheet. A sensitivity weight (0.005 pound) was added to

the right arm load to establish a deflection per unit weight for the

test series. The turning points were observed and recorded on the

data sheet.

The test measure was removed from the weigh pan and filled with

tap water to near zero on the graduated neck. The measure was then

emptied in a manner such that the time for emptying, the angle between the vertical axis of the measure and true vertical, and the
drain time following cessation of flow could be repeated. Following

the completion of the drain, the cover plate was placed on the measure

and the wetted container was replaced on the balance. Trim weights

were added to the right side of the balance until a near balance

condition was achieved. The turning points were observed and recorded on the data sheet.

For each measure the angle of the vertical axis from vertical,

the time for emptying, and the drain time following cessation of

flow were varied one at a time for the test series.

Exhibit 2 is a completed Data Sheet for one of the series of tests.

6.1.2 CONCLUSIONS AND RECOMMENDATIONS . This test series revealed

some interesting information concerning procedures. By varying the

time required for emptying a measure the amount of water retained

by the measures was significantly changed. This was true as long

as the time allotted for drain following cessation of the main flow

was held constant. From the data collected, it appears that the

procedure for emptying water from a test measure must include a time

factor. A procedure that requires 25 to 40 seconds for the emptying

of a 5-gallon measure followed by 10 seconds after cessation of the main

flow will result in consistent values.

6.2 TWO-SQUARE-FOOT CONTAINERS TESTS . Three test containers were

designed and fabricated to evaluate the influence of top and bottom

cone angles. The containers were designed such that the cones could

be alternately used as top or bottom. (See Figure 6).

Tests similar to those performed with the test measures were

- 46-
CliMGAGE Test Jjeta Sheer (m):

°}fjjksr Lev/cel !Q..Ql^E^ ~EePAE CpiiVEE Page /Jo. /

Material. _ Manufacturer^S^sdBt/LE

Observer 12-1/$ll£i Ieea/t'/f/cat/o/VEji1EL
Figure 6. Two- square-foot containers for fluid retention tests.

48
conducted on the conical test pieces. Weighings were made on a

Chr i st i an-Becker 10 Kilogram Equal-Arm Balance. The left weigh pan

was replaced with a bracket to hold the test section in an upright

position while weighings were made. Figure 7 is a photograph of

the weighing set-up. The initial weighing was made balancing a bottle

with lead shot against the holding fixture and the dry test pieces.

In the ensuing tests the weight of water retained by the container

was determined as the amount of trim weights necessary to achieve

a balance condition.

6.2. I EXPERIMENTAL TEST PROCEDURE . The test pieces were al I cleaned

in accordance with the procedure discussed in 6.1.1. The cleaned

equipment was weighed on the balance with a pipe cap on one opening

and a rubber stopper on the other. Due to weight variation of the

cap and stoppers the same cap and stopper were used in all weighings.

The weighed dry container was placed in the ring stand (See

Figure 8) and the container was filled with tap water. A cap with

a small diameter hole was placed on the container and then the rubber

stopper was removed allowing the water to drain. The time for the

draining was varied by exchanging caps with different hole diameters.

Following cessation of flow, the container was allowed to drain

for 10 additional seconds after which the dried stopper was replaced,

the closed cap was substituted for the flow cap and the container

was removed to the balance where the weight of water remaining in

the container was determined.

Exhibit 3 is a sample data sheet of one test sequence.

- 49 -
Figure 7. Configuration for weighing two-square-foot containers.

50
Test set-up for two- square-foot containers.

- 51 -
ANGLE EVALUATION EXPERIMENT SERIES

EXPERIMENT BY -for/SAr

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-52-

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6.2.2 DISCUSSION OF TESTS AND FUTURF TESTS. The test series with

the 2-square-foot surface area containers has not resulted in conclusive information concerning optimum angles for measure design.

It has shown the marked influence of the time to empty on the amount

of liquid retained. It has also provided indication that the smaller

bottom angles are quite susceptible to residue buildup.

6.3 TESTING WITH LIQUIDS OTHER THAN WATER . To further extend the

evaluation of the test measures as well as the 2-square-foot surface

area containers, additional testing was performed with liquids other

than tap water. The liquids used and their corresponding viscosity

and gravity is as follows:

Liquid Kinetic Viscosity @25°C Spec i f i c Grav i ty

No. 2 Burner Oi 1 0.0332 stokes 0.8626

Gasoline 0.0055 stokes 0.7503

Varsol 0.0120 stokes 0,7892

Kerosene 0.0193 stokes 0.8044

I0W Motor Oil 0.6724 stokes 0.8735

The testing was performed as discussed in Sections 6. 1 . 1 and 6.2.

of this report in order to have consistent procedures for eva 1 uat ion

of all liquids including tap water. The results of the tests are

presented in Figures 9, 10, II, 12, 13, 14, 15, 16, 17, 18, 19, & 20.

6.4 DISCUSSION OF RESULTS . Review of the data reveals that for

small measures or provers the use of water-ca I i brated equipment with

non-viscous liquids is probably acceptable. The water calibrated

equipment would not be acceptable for use with more viscous liquids

than the No. 2 Burner Oil. For such an application a special

- 53 -
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- 54 -
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- 55-
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- 56 -
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- 58-
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- 59 -

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Liquid

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Liquid

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n:

Conventional 5 Gallon Measure

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- 64 -
Liquid

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-65-
calibration and test method would be required if a "To Contain"

measure were not employed.

An attempt was made to correlate surface area with liquid

retention. It appeared that for devices of similar geometric

configuration an estimate of retention could be made within 10-15

percent. It might be possible to predict the liquid retention of

large provers in this manner if a small scale model was tested

beforehand with the desired liquid. The need for such a procedure

is questionable for most liquids. If the amount of water retained

in a 1000 gallon prover was found to be 30 in^, it is unlikely

that the prover would retain ±25 percent different than that amount

of gasoline, varsol, or kerosene. Although this 7.5 cubic inches

per 1000 gallons is not totally insignificant, it represents less

than 2 percent of the current meter system tolerance for a 1000

gallon test draft and would normally be considered beyond the scale

readability for a prover of this volume.

The amount of liquid retained by a prover is influenced by

the liquid, prover geometry, surface area, surface condition, and

the drain procedure. The benefit from an extens i ve i nvest i gat i on

of these factors does not warrant further testing at this time.

- 66 -
7.0 EQUIPMENT SPECIFICATION . One of the primary goals of the

research associate program was to collect information that could be

used to develop a specification, that if submitted to any fabricator,

the result would be an acceptable metal test measure.

As the test measure evaluation program proceeded, it was decided that prior to developing a complete specification it would

be necessary to establish the methods and conditions under which

equipment would be inspected to judge compliance with a specification.

7.1.0 INSPECTION RECOMMENDATIONS . While conducting the tests

associated with the research program and witnessing calibrations

by several individuals, it was noted that no consistent examination

or inspection procedure was followed. This was considered to be

undesirable since it would indicate that the quality of equipment

was left entirely up to the judgement of the individual and that

acceptance/rejection criteria were non-uniform.

In an attempt to promote uniform practices, an inspection guide

was written. After numerous revisions, the draft was sent to over

50 individuals involved in various phases of volume measurement.

The individuals who were requested to review the draft represented

large segments of the petrol-eum industry; state, federal, and foreign

governments, and equipment manuf acturers . The nearly 40 returns of

the review request recommended very few changes. Only one negative

review was received. That reviewer questioned the usefulness of

such a listing until meaningful quantitative limits could be established

for the acceptance or rejection of a particular prover. On the other

- 67 -
hand, another reviewer requested a copy of the final revised draft

in order to implement the inspection process in the company measurement manual. Since the procedure dealt primarily with quality,

cleanliness, and potentially ever-changing corrosion and the overwhelming concensus favored publication of the document, a final

draft was prepared which incorporated the pertinent recommendations

of the reviewers. The following is the text as submitted to the

American Petroleum Institute for publication consideration:

- 68-
INSPECTION OF METAL VOLUMETRIC STANDARDS

Me+a I Volumetric Standards include all non-pressur i zed containers em- ployed in determining volume, i.e., test measure standards and meter

prover standards. Measurement activities often include inspection or examination of metal volumetric standards. Inspections or examinations are most often required when: I) a new device is received from

the manufacturer; 2) a device is to be used in a transfer transaction

or displacement prover calibration; and 3) a device is to be submitted

for calibration or recalibration.

The basic design and requirements of metal volumetric standards have

been reviewed and evaluated in order to develop an inspection guide

that will promote "uniformity and standardization".

I. DESIGN. The basic design must conform to published or recommended specifications of recognized authority.

A. National Bureau of Standards (Handbook 105-3).

B. American Petroleum Institute.

C. Other.

II. SUPPORTING DOCUMENT EXAMINATION. Certain documents must be

furnished for examination by the inspector.

A. Report or Certificate of Calibration.

B. Material Identification (Certified Mill Reports for

equipment complying with NBS Handbook 105-3, May 1971).

C. Interior Coating Identification (if applicable).

D. Drawings.

E. Gage glass size and material specification.

F. Other documents required by individual company policy.

III. VISUAL INSPECTION OF STANDARD. The device must be subjected

to a complete visual inspection of all pertinent features.

A. Exterior.

1. All surfaces affecting volume must be dent-free.

2. Non- i nvertab I e measures must be equipped with a suitable operating drain valve with leak check

capability (double block & bleed).

3. Non- i nvertab I e measures must be equipped with two

adjustable spirit levels, mounted at right angles

to each other on the upper cone. Levels to be of

reasonable quality, shielded style or provided

with a hinged protective cover.

a. must have adjustable legs to allow leveling.

4. Surface finish must be clean and free of mill scale,

grease, etc.

a. if exterior surface is painted, the paint

coating must be reasonably free of scratches

and corrosion damage.

- 69 -

I
5. Weld quality must conform to an appropriate

welding code

a. American Petroleum Institute (Guide for

Inspection of Refinery Equipment Appendix - Inspection of Welding).

b. American Society of Mechanical Engineers

(ASME Boiler and Pressure Vessel Code).

c. American Welding Society (Inspection of

Welding, Chapter 6 of Welding Handbook,

Section I, American We I d i ng Society, New

York 1968).

d. American National Standards Institute,

ANSI B-3 I .3.

e. Others.

6. Non- i nvertab I e measures must have a rigid,

sloping (minimum pitch 5°) drain line.

7. (NBS Handbook 105-3, Section 6.2) "Each standard

shall bear, in a conspicuous place, the name or

trade mark of the manuf acturer , the nominal

volume (gallons, cubic inches, liters, etc.),

and a serial or identification number. The

material from which it is constructed shall be

identified together with the cubical coefficient

of thermal expansion per degree (F or C) for

that mater i a I

.

8. Material identification must be indicated on an inspection plate and must agree with documentation

( Sect ion II -B)

a. Carbon Steel (type)

b. Stainless Steel (-type)

1 . magnet i

2. non-magnetic

c. Non-metals.

B. Interior.

1. Joints and seams must be smooth and uniform.

2. Surfaces, including joints and seams, must be

clean and free of grease, dirt, or oil film.

3. Surfaces must be smooth and free of rust corrosion.

4. Potential air or water traps either by design

or damage are not permissible.

5. Coating material, if used, must be uniformly

applied, completely coated, and free of voids

or bubbles.

6. Any coating material used, i.e., epoxy, phenolic,

etc., must be resistant to the effects of alcohol,

benzene, petroleum products, and water.

7. Non- i nvertab I e measures must be equipped with a fixed anti-swirl plate (optional API 1101,

required NBS Handbook 105-3).

- 70 -
C. Graduated Neck.

1. The neck must be cylindrical and uniform in

d i ameter

.

2. Scale ( non-corros i ve metal).

a. must be firm and secure.

b. must be easily adjustable.

c. provision must exist for affixing a lead

and wire seal which will detect unauthorized

scale adjustment.

d. scale divisions or graduations must be linear.

e. scale length must be appropriate to the measure.

f. applicable volume units must be clearly

indicated ( i . e .

,

cubic inches, fluid ounces,

ga I I ons , etc . )

.

g. scale markings must be legible.

3. Gage Glass.

a. must be clean and clear after wetting

( no drop I ets )

.

b. must be capable of being removed, cleaned,

and replaced (see Section I I — E )

.

4. The top surface must be ground, machined, or

formed smooth in order to serve as a level

"benchmark"

.

V. CASE OR SHIPPING CONTAINER. Any standard normally transported to various locations should be protected with a case,

shipping container, or other suitable protective means.

A. Must provide sufficient protection to instrument during

storage or transport (protect against dents and scale

damage)

.

B. The container design must provide for rigidity.

V. STANDARD INTEGRITY INSPECTION PROCEDURE. Periodically,

a measure should be checked to verify integrity (in addition

to the initial test when new). A step-by-step procedure

is recommended.

A. Making certain that no thermometers installed will

be damaged by exceeding their range, fill with warm to hot water (100 to 140 degrees F). A I low to stand

for 30 to 60 minutes.

1. Check all seams, joints, pipe fittings, gage

glass, and overall measure for leaks.

2. Check drain valve for leaks or air entrapment.

Open and close the valve several times to verify

positive sealing of the valve. (Optional:

Take and record a level reading, then crack

drain valve open and draw off approximately I gallon into a wetted measure and return the

water to the prover. If the level in the

- 71 -
prover standard is lower, either there was air

in the piping ahead of the valve, or some part

of the valve body cavity previously filled with

air is now filled with water.)

B. Drain the standard.

I. Observe the effectiveness of the anti-swirl

plate while the fluid is draining.

C. Fill the standard with the calibrating medium.

I. Repeat the checks listed in Sections V-A- I and

V-A-2

D. The thermometers to be used with the standard should

routinely be subjected to a calibration or a com- parison with a standard thermometer.

- 72 -
7.2.0 SPECIFICATION. As a result of tests conducted with metal

volumetric test measures, it was determined that existing 1, 5, and

10 gallon measures are capable of good quality measurement only if

the recommended procedure is carefully followed. The uncertainty

of their calibration is meaningless if improper emptying procedures

are used and insufficient emphasis is made in neck scale reading.

These two potential problem areas could be improved by designing

a bottom drain measure with a smaller diameter neck. These changes

would provide more consistent drains and improve scale resolution.

A specification for such a measure was prepared and is presented

here for consideration.

EQUIPMENT SPECIFICATION

METAL VOLUMETRIC FIELD STANDARDS

(BOTTOM DRAIN STYLE)

( See Figure 21)

Field Standard Size - This specification covers I, 5, and 10 gallon

capacity field standards.

Type and Design - The standard shall have a barrel of uniform circular cross-section with a smaller diameter neck of uniform circular

cross-section connected to the barrel by a conical breast section.

The bottom must be deep-dished or conical downward with a drain

tube connected to the lowest point and extending outward and downward beyond the circular barrel. A base, which is an integral part

of the standard, must be provided and 3 adjusting legs must be

attached to the base to enable leveling. The legs must provide

a stable footing for the standard. A gage glass and adjustable scale

plate assembly must be permanently attached to the upper cone or

- 73 -
Z-/Z-73

-74-
breast section and the neck. Potential air or contamination entrapments must be avoided.

Mater i a I - The mini mum low carbon steel or stainless steel material

required is 18 gauge ( 0 . 0478" nominal), except 16 gauge ( 0 . 0598 "

nominal) material for bottom cone and base. Aluminum, fibre-glass,

high impact plastics, or other materials must be of sufficient

thickness to equal or exceed the strength characteristics of low

carbon steel of specified thickness. Physical properties of any

material used must be certified.

The material must be impervious to any hydrocarbon liquid or

organic solvents. Dissimilar materials in a measure (i.e., 300 &

400 Series Stainless Steel) are not acceptable.

Fabrication - Field standards must be assembled to withstand reasonable field and transit application.

Joints - All joints must provide strength equal to unjointed

material. Joints may be welded, brazed, or soldered. (Order of

preference as listed). Joints must be smooth, fully filleted

connections. Sharp protrusions or voids are unacceptable. If

metal is overheated during fabrication the device must be annealed

(heat-treated). NOTE: Soft solder is not permissible for achieving

the bottom joint. It can be used to fillet interior seams.

Forming or Shaping - All formed sections (top and bottom cone) must

be smooth continuous surfaces. Pockets, dents, or crevices that

may entrap air, liquid, or contami nents shall be judged unacceptable.

SPECIAL FABRICATION REQUIREMENTS

Handles - A pair of smooth handles shal I be attached to a top

- 75 -
reinforcing band. These handles should be located to facilitate

lifting the standard.

Reinforcing Bands - External reinforcing bands shall be attached to

the cylindrical barrel as judged necessary by the manufacturer

for strength and potential damage protection. Minimum 16 gauge

(0.0598" nomi na I )

.

Surface Preparation - If the standard interior and/or exterior is

to be coated or plated, the surface must be peened, sandblasted,

pickled, etc., in accordance with the recommendations of the coating

or plating manuf acturer . Standards that are not coated must be

completely free of foreign matter and chemically clean.

Coating, interior - The interior surface must be corrosion resistant

and impervious to hydrocarbons and organic solvents. Surface may

be coated with galvanized, terne-coated (lead-zinc), baked phenolic,

or epoxy resin. Epoxy or phenolic coatings must be 0.005 to 0.007

inches thick. Chemical resistance properties of coatings must be

documented to owner.

Coating, exterior - The exterior surface must be corrosive resistant

and impervious to hydrocarbons, organic solvents, and normal exposure

to atmosphere. Rust resistant materials do not require auxiliary

coatings unless specified. Painted measures must be primed with a

metal primer (zinc-chromate or equal) prior to painting.

SPECIAL REQUIREMENTS

I. The top surface of the standard must be a rolled edge or fitted

with a reinforcing ring. The top surface must represent a

level plane when the standard is placed on a level surface.

- 76 -
2. The gage glass must be borosilica+e or other material certified

to be impervious to extended service in hydrocarbons or organic

solvents. The minimum diameter shall be 0.50 inches.

3. The gage assembly must be rigid and shall include a gage glass

open at the top for cleaning and positively sealed at the bottom

without cement, a scale plate of appropriate divisions above

and below zero level, adjusting rods to provide 1/4 scale

division adjustments, and have provisions for attaching a

"lead and wire" seal such that adjustment or scale removal will

destroy the seal. The value of the scale divisions must be

clearly indicated on the scale, i.e., cubic inches, cubic

centimeters, etc.

4. Each standard shall bear a permanent conspicuous plate upon

which the following information appears:

a. Address, name or trademark of manufacturer.

b. Material identification (type and thickness).

c. Cubical coefficient of thermal expansion per degree

Fahrenheit or Celsius. (Reference shall be documented).

d. Manufacturers model number (optional).

e. Non-repet i ti ve serial or identification number.

f. Statement of nominal volume and reference temperature.

5. Device must comply with the requirements of Inspection Guide,

Section 7. I .0.

6. A positive sealing, fast acting valve shall be attached to the

drain line. The valve must be stamped with the same identification number as the standard or provided with means to affix a

- 77 -
lead and wire seal between the valve and drain line. If a

ball valve is used it must have both upstream and downstream

seals. A short length of metal braided hose or a similar

conductor shall be installed on the downstream side of the

valve. The end of this hose shall not be threaded.

Anti-Swi rl Plate - A baffle or anti-swirl plate must be attached

to the bottom to reduce swirl during emptying.

Level Mounting Plate - A two- i nch-square flat surface must be provided

directly below the scale assembly. This surface may be soldered

to the gage assembly bottom nipple and the top cone. A "Bulls-eye"

level no greater than I” diameter is to be mounted on the plate to

indicate level when the measure is so adjusted.

Scale Assembly - The scale assembly shal I consist of a gage glass,

a graduated scale (I or 2), adjusting rods, fittings to seal the

gage glass such that the glass can be replaced without difficulty

(cementing is not acceptable), brackets for mounting the assembly

on the test measure, and brackets to hold the scale plate rigid.

The top bracket, the left-side adjusting rod, and the left-side

graduated scale should be drilled to accept a I ead-and-w i re seal.

The assembly must be designed so that the I ead-and-w i re seal will

be broken if the graduated scale is removed or adjusted. NOTE:

Right or left side notation refers to the side when viewed from the

f ront

Scale Plate - The basic scale on al I standards shal I be cubic inches

or cubic centimeters. If dual scales are used to include other units

- 78-
of volume simultaneously, the basic scale must be mounted on the left

side and the secondary scale mounted on the right. The scales

must be individually adjustable. Only one scale is permitted on

a single pi ate.

Sea I e Marki ngs - The markings on a scale plate shal I be permanent

and of contrasting color to the color of the plate. The markings

shall include graduation lines and numbers and if only one plate

is used for graduations, the second plate can be used for manufacturer

identification information.

Scale Graduations - The graduations must provide a minimum indication

of fifteen (15) cubic inches above and below the zero line for I

and 5 gallon and twenty (20) cubic inches for 10 gallon (or metric

equivalents). The graduation lines must be of uniform width, not

more than 0.025 inch or less than 0.015 inch in width. The minimum

distance between scale graduation lines shall be 0.0625 inch (1/16)

or minimum 0.070 center to center. The graduation lines shall consist

of intermediate lines, major lines, and the zero line. The graduation

lines for front mounted scales must extend to the edge of the scale

plate nearest the gage glass. The minimum length of these lines is

as foil ows

1 ntermed i ate L i nes Major L i nes Zero L i ne

1 f mounted i

front of glass

0.125 i nch 0.25 i nch Entire w i dth

1 f mounted beh i nd

the glass

0.50 inch 0.75 i nch Ent i re width

- 79 -
For the 2" neck measures described in this specification, the

intermediate graduations should reflect 1/2 cubic inch and the major

divisions should reflect each cubic inch or metric equivalent.

Each 5 major divisions should have an adjacent number to indicate

the value of that division.

Dimensional Requirements -

S i ze

Mini mum

Meta 1 Gage

<U. S.)

Neck

Di ameter

(Inside)

1 nch

Gage

Tube

Di ameter

( Inside)

1 nch

Mini mum

Top Cone

P i tch

Mini mum Bottom

Cone

Pitch

Mini mum

Dra i n S i ze

1 nch

Apcroximate

Measure

Di ameter

1 nch

Approximate

Overa 1 1 He i ght

1 nch

1 ga 1 18* (.0478") 2 1/2 35° K> O

o 1/2 8 17.5

5 gal 18* (.0478") 2 1/2 35° 20" 1 I 1 27.

10 gal 18* (.0478") 2 1/2 35° 20° 1 13.5 33.

•Minimum ( .0598") U.S. Metal Gage for bottom cone 1

s

16

Operating Conditions - This specification may be used for Volumetric

Standards intended for use with liquids which may include but is

not limited to the following:

1 . Gaso I i ne

2. Jet fuel

3. Kerosene or stove oi

I

4. Di ese I oil

5. Alcohol

6. Commercial solvents

7. Water

8. Di I ute aci

d

CAUTION: The material of construction must be suitable for the

specific liquid application.

- 80 .
8.0 CALIBRATION PROCEDURE . As evaluation tests were being conducted.

information was collected concerning procedural requirements to

establish repeatable measurements with metal volumetric standards.

It developed that a series of recommendations was considered

necessary for calibration activity. In evaluating the potential

audience for such a listing it was agreed that laboratory metrologists

would be the primary interested reader. The problem as to how best

to present a calibration procedure recommendation was discussed with

a number of State weights and measures laboratory metrologists.

The concensus of those contacted was preference of a step-by-step

procedure of the entire calibration procedure. A logical benefit

of such a presentation is larger acceptance and subsequently greater

calibration uniformity.

Two distinct calibrations may be encountered in volume calibration activity. These different values are the amount of liquid

a vessel is able to hold or contain and the amount of liquid that

may be poured out or delivered from the vessel under specified

conditions. The two calibration values are commonly referred to as

"To Contain" and "To Deliver". The following descriptions are presented in an attempt to eliminate any misunderstanding of the two

types of calibration:

A "To Deliver" (WET) calibration reflects the volume that the

standard will deliver when emptied in a prescribed manner.

This calibration requires that the standard be initially filled

and emptied in accordance with prescribed procedures (wetted)

prior to the filling and emptying process of the calibration.

- 81 -
A "To Contain" (DRY) calibration reflects the volume that a standard will contain when filled to a specified level. This

calibration requires that the standard be completely dry prior

to each filling.

8.1.0 VOLUMETRIC CALIBRATION PROCEDURE ("To Deliver") . Volumetric

Calibration of Field Test Measures should be performed in a stable

environment laboratory or calibration facility. The following

materials are required prior to beginning this procedure:

1. Clean volume standard (preferably slicker plate).

2. Calibration data for standard.

3. Stop watch.

4. Spirit level of reasonable quality.

5. Thermometers (2) - Immersion Type, l/2°F divisions or

l/4°F di vis ions.

6. Powder or liquid detergent.

7. Brush to clean gage glass.

8. Alcohol and degreasing solvent.

9. Compressed air supply.

10. Flashlight or small portable lamp.

11. I nspect ion mi rror.

12. Data sheet for recording observed data. (See Exhibit 4

for sample data sheet)

13. Water stored at ambient temperature.

14. Room thermometer.

15. Extra glass slicker plate or measure cover.

An important preliminary to performing a calibration is to have

everything ready and convenient. (See Figure 22). The pertinent

- 82-
VOLUME CALIBRATION DATA SHEET

Descr i pt i on Manufacturer

Size Material Interior Coating

Identification Number Customer

Calibration by Date

Condition of Measure

Calibration Fluid Time beginning Time ending

Standard used for calibration

No. I No. 2

Fluid Temperature in Standard

Meniscus Level (Memo only)

Meniscus Level

Fluid Temperature in Measure

GRADUATED NECK CALIBRATION

Va 1 ue of each sea 1 e d

vision i s

Initial1 Scalei Read i ng

Add cubic i nches Actua

Sea 1 e Read i ng

Add cubic i nches Actua

Scale Read i ng

Add cubic i nches Actua

Scale Read i ng

Add cubic i nches Actua

Sea 1 e Read i ng

Add cubic i nches Actua

Sea 1 e Read i ng

Add _ cubic i nches Actua

Sea 1 e Read i ng

Exhibit 4 Sample Data Sheet

- 83 -
Figure 22: Recommended equipment set-up for volume calibration.

- 84-
portions of the data sheet should be completed and placed in a

position convenient for the metrologist to record his observations.

The first step in the calibration procedure is the visual and

physical examination of the device submitted for calibration. The

volumetric device should be examined for appropriateness for the

intended application. Any discrepancies should be noted in the

appropriate section of the data sheet. If acceptance and rejection

criteria are not clearly established, discrepancies should be discussed with the proper official before proceeding with the calibration

or at least prior to releasing the measure and the calibration

report

.

A complete physical inspection should encompass a thorough

cleaning process. (See Exhibit 5 before proceeding). This can be

accomplished as follows:

1. If the test measure is epoxy coated, clean thoroughly

with water and detergent; perform steps 5, 6, 7 and 8;

inspect as in step 10; then proceed to step II.

2. Pour approximately 50 mL of degreasing solvent into the

dry measure.

3. Rotate and tip the measure to ensure wetting the interior

surfaces

.

4. Drain solvent from measure, rinse with approximately 50 mL

of alcohol as in step 2, and fill about 1/3 full of warm

to hot water. Add detergent.

5. With a brush or cloth, wash the interior surface.

6. Clean the gage glass with the detergent and water.

- 85 -
U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

Washington. D.C. 20234

MEMORANDUM

To: State Metrologists

From: / thKeysar, Engineering Technician

Office of Weights and Measures

Subject: Epoxy-Coated Test Measures

Mr. D. J. Hine, API Research Associate, assigned to the Office of

Weights and Measures, has pointed out that there is a high probability that an epoxy-coated test measure submitted for examination

and calibration might be subjected to cleaning with an organic solvent in accordance with NBS Monograph 62. Monograph 62 did not include any specific consideration of epoxy-coated equipment ar.d it is

likely that the cleaning procedures prior to calibration might easily

be construed to include all types of test measures.

Monograph 62 specifies, "After cleaning with an organic solvent,..."

and if alcohol is used as the organic solvent, as it is in most cases,

a reaction with the epoxy coating will result in permanent damage.

There are reportedly some epoxy materials that are not affected by the

alcohol or other solvent cleaning but none of these have been evaluated

by this office. We recommend that you not clean any epoxy-coated test

measures with alcohol unless the manufacturer of the coating specifically

states that the material is impervious to alcohol and other organic

solvent solutions. The pre-calibration cleaning of epoxy-coated test

measures can be accomplished with a bio-degradable detergent and water

followed by a clean water rinse until all traces of the detergent are

removed and then rinsed with distilled water. This procedure should

provide a clean test measure for the subsequest calibration.

Exhibit 5

- 86 -
7. Add warm water un+M the level is well up in the neck.

Let stand for 15 minutes and observe for leaks.

8. Empty the measure and flush with cool water until all

suds disappear.

9. Pour 50 to 100 mL of alcohol. Rotate and tip as in step 3.

0. Drain alcohol from measure, fill with water, inspect for

leaks and then empty measure.

1. Fill the standard (slicker-plate) with calibration quality

water. Use a thermometer to determine the water temperature

and record on the data sheet. Transfer this water to the

measure to be calibrated using the prescribed 30-second

drain following the cessation of flow. Close the drain

valve.

2. Using a thermometer, determine the water temperature and

record on data sheet. Slowly empty the test measure and

when the first drip appears on the lip, time 10 seconds.

NOTE: The vertical axis of the measure should never

exceed 85° from the horizontal. (See Figure 23). At

the end of 10 seconds, return the measure to the upright

position and place the extra glass slicker or cover on

the top of the neck of the measure to avoid excess evaporation. The measure and standard are now prepared to receive

ca I i brat i on water.

3. Fill the standard with calibration water. Determine the

water temperature and record. Add water to the standard

and slide the slicker plate into position. Verify that no

- 87 -
Figure 23, Proper draining position for 5-gallon measure.

- 88-
14 .

air bubbles appear under the plate.

Place the test measure, with cover removed, in position

such that the' top of the neck is slightly above and not

quite touching the open drain pipe of the standard. Open

the drain valve and immediately slide (don't lift) the

slicker plate off the top of the standard. Allow standard

to drain 30 seconds ' after cessation of flow as in step II.

Close the drain valve.

15. Carefully transfer the test measure full of water to a level

bench such that the meniscus in the gage glass is approximate I y at eye I eve I

16. Tilt the measure to raise the meniscus about I inch, then

return to level condition. This will insure that the

level in the neck is the same as the gage glass. NOTE:

This can also be accomplished by either blowing gently

into the top of the glass or by inserting a finger into

the top of the glass and removing quickly, causing the

water in the glass to rise.

17. When the meniscus has come to rest, estimate and record (Memo only

the scale reading correspond i ng to the meniscus level when

viewed at a distance of several feet. (ALWAYS READ AND

RECORD THE BOTTOM OF THE MENISCUS LEVEL).

18. Placing the eye close to the scale and gage glass (approximately 5 inches), read and record the scale value corresponding to the level of the meniscus bottom. (Levels between

scale divisions should be estimated 1o the nearest 0.1

- 89 -
division.) A convenient aid to scale reading is a rectangular

piece of white paper with a line drawn through the center.

(See 5-Gallon measure - Figure I). The paper is inserted

between the scale plate and the adjusting rods and in

back of the gage glass. Starting with the line on the

paper below the meniscus, slowly raise the paper until the

line exactly coincides with the bottom level of the meniscus.

Record the observed level and compare with data from item

17. This will eliminate gross reading errors.

19. Insert a thermometer on a string into the gage glass and

slowly raise and lower the thermometer for approximately

20 seconds. Slowly raise the thermometer until the

/ indicated temperature is just visible in the gage glass

and can be read. This reading will be the water temperature.

Remove the thermometer and record the observed water

temperature.

20. Empty the test measure as described in step 12.

21. Repeat steps 13 through 20 recording data as indicated.

22. Compare the data from Run #1 with Run #2. If the temperature has remained virtually constant and the scale readings

do not differ by more than 1/2 of a scale division, the

calibration is finished. If the temperature is different,

the temperature corrected volumes must be calculated to

judge agreement between the two determinations.

23. Calibration of the graduated neck is accomplished by

removing water until the scale reading is significantly

- 90-
(15 in^ if possible) below zero. Add liquid from a flask

calibrated in increments of 5 scale divisions, reading

and recording each incremental level, until the fluid

level is well above zero. This should be performed twice

to establish proper accuracy.

24. If a test measure is to be stored for an extended period

in an environment that could promote rusting, the measure

should be adequately protected. It can be thoroughly

dried and stored in a sealed box containing a desiccant

or it could be thoroughly wetted with kerosene prior to

storage

.

25. Perform calculations as follows:

CHANGE IN CAPACITY CAUSED BY CHANGE OF TEMPERATURE

If the capacity of a measure at any temperature, for example

60°F, is known, the capacity at another temperature may be determined by the use of the following formula:-

V+ = V 60 [I + a(t-60)]

where V-(- = Capacity at t°F,

V 50 = Capacity at 60°F,

a = Coefficient of cubical expansion of the material

of which the measure is made, per degree F and

r t = Water temperature °F

Average coefficients (per °F) for the metals most widely used

in capacity standards are:

Brass 0.000030 (7)

Copper .000028 (7)

- 91 -
Low carbon steel .0000186 (5)

18-8 stainless steel .0000265 (8)

(Numbers in parentheses indicate reference numbers.)

CORRECTION FOR DIFFERENCE IN TEMPERATURE

If the temperature of the water in the standard differs from

that of the water in the measure being calibrated, a correction

must be applied to bring the volumes of water to the same temperature

bas i s

.

A table for this purpose has been incorporated (Table I) in

API Standard 1101 D'9ll. Lacking such a table, factors for the

adjustment of water volumes to a common temperature may be derived

from the density values. Water density tables are available from

various handbooks as well as Table I, page 24 of this report.

Any correction to the water volume is partly offset by the

volume change in the metal measures. (The temperature of a measure

is assumed to be the same as that of the water contained.) To

adjust the capacity of one measure to the capacity it would have

at the temperature of the other, a modification of formula (I) may

be used.

Correction = Va(t-t|) (2)

Where V = measured volume

a = coefficient of cubical expansion of the measure

whose volume is being adjusted,

t— t | = temperature difference between measures.

As an example of the correction for a difference in temperature,

let us assume that the average temperature of the water in a standard

- 92 -
calibrated to deliver 5 gallons at 60°F was 74°F, but after being

emptied into the test measure it was measured at 76°F. Both measures

are of mild (low carbon) steel.

The change in the volume of water from 74 to 76°F may be computed

f rom the formu I a

w _ ,, w density of water at 74°F - V 7 / X - — ' density of water at 76 F

= 5 gal X MiZ£L

0.99721

= 5.001304 gal

The change is 5.001304 - 5.000, or 0.001304 gal.

While the volume of water was increasing, the capacity of the

proven also increased by an amount represented by formula ( 2 ), or

5 X 0.0000186 X 2 = 0.000186 gal

The net correction for the temperature difference, therefore,

is 0.001304 - 0.00186 or 0.001118 qa I (0.2583 in 3 ). Because the

water in the measure is warmer than when in the standard, the level

in the gage will be higher than it would be if the temperature had

remained the same, and must be lowered by 0.0011168* gal before adjusting the scale to the water level.

If the two measures are made of materials having the some thermal

*When performing correction calculations all significant digits should

be used, however; prior to any adjustments the resulting value should

be rounded to two decimal places due to the scale readability limitations.

- 93 -
expansion coefficient, no further correction is necessary since the

standard is correct at 60°F.

CORRECTION FOR DIFFERENCE IN THERMAL EXPANSION OF MEASURES

If a standard is being used to calibrate a measure made of

material having a different thermal expansion coefficient, and the

temperature is other than the standard temperature (usually 60°F),

a correction must be applied to account for the difference in volume

change of the two instruments. The correction may be represented

by the following equation:

C = V ( t-60) ( a

| -a2

) (4)

where C = correction,

V = measured volume,

t = temperature of observations (°F),

oi| = cubical coefficient of thermal expansion of metal

in standard per degree Fahrenheit, and

0.2 = cubical coefficient of thermal expansion of metal

in measure being calibrated per degree Fahrenheit.

For example, suppose that a 5-gallon measure made of low-carbon

steel is being calibrated with a 5-gallon standard made of 18-8

stainless steel. The average temperature (measured in the water when

the instruments are full) is 75°F. The correction would be:

C = 5 (75-60) (0.0000265-0.0000186)

= 0.00059 gal= .1369 in 3

The standard, having a larger expansion coefficient, will, when

filled and emptied into the measure, fill the prover to a higher

- 94 -
level by 0.1369 i than it would if both measures were at the

standard temperature of 60°F. If the water level in the measure

was lowered by 0.1369 in^ and the zero line on the scale adjusted

to that level, the measure would be correct at 60°F.

When working at a temperature below 60°F, the scale should be

adjusted upward when other conditions are as in the preceding example.

At 50°F the correction would be 5 X 10 X 0.000079 or 0.0004395 gal

(0.0912 i n^) . If 0.0912 in^* of water were added to the prover and

the zero line on the scale adjusted to that level, the prover would

be correct at 60°F.

26. If the calculated equivalent scale reading does not reflect

need for scale adjustment the test measure should be sealed

with a I ead-and-w i re seal and returned to the owner along

with a report of calibration.

27. If the scale requires adjustment, the measure should be

retested using steps II through '20, inclusive, to verify

that proper adjustment had been performed'.

8.2.0 VOLUMETRIC CALIBRATION PROCEDURE ("To Contain") . "To Contain"

calibrations are best accomplished using a gravimetric technique.

If a gravimetric calibration is to be performed, it is recommended

that the procedure outlined in Section 4.0 be used.. If a volumetric

"To Contain" calibration is to be performed, the procedure outlined

in Section 8.1.0 should be modified such that the standard is thoroughly

dried prior to performing step 14 of the calibration procedure.

- 95-
9.0 TEST MEASURE PROTOTYPE. The specification of Section 7.2.0 was

used to purchase a device to be used in a field test program.

The "as built" measure was thoroughly inspected to determine

compliance with the specification. The measure was found to conform

to all specification requirements with the exception of having an

approximate neck inside diameter of 2.125" instead of the specified

2". The overall height of the measure is approximately 32 inches.

The prototype measure was judged to be acceptable. The general

description of the measure as indicated on the identification plates

i nc I udes

Delivers 5 Gallons to zero

Model M Special, Serial Number 18994

Stainless Steel type 304

Cubical coefficient of thermal expansion 26.5 X ICT^ per °F

Figure 24 is a photograph of the measure.

The measure was subjected to a gravimetric calibration employing

the NBS procedure discussed in section 4.0.

9.1 FIELD TEST PROGRAM . A test program was devised to check operating

gasoline dispensers with both a conventional 5-gallon field standard

and the prototype. The tests consisted of routine dispenser checks

with each dispenser being checked independently with both measures.

The tests were conducted by B. C. Keysar and D. J. Hine. The procedures used for the tests, following inspection and pretest determinations in accordance with NBS Handbook 112, were as follows:

- 96-
I r
Prototype Measure

1. The measure was placed adjacent to the dispenser to be

tested and adjusted to level condition. The position of

the 3 legs of the measure was marked for convenience in

returning after each draft.

2. The dispenser register was returned to zero and the indicator position noted if not zero.

3. The totalizer readings were noted and recorded.

4. The electrical switch was activated to energize the dispenser pump.

5. A 5-gal Ion draft was made to wet the measure with test

product.

6. The wet-down draft was returned to appropriate storage as

directed by the service station operator. A 10-second

drain following cessation of main flow was used.

7. A 5-gallon draft was made to the measure. If the dispenser

was equipped with an automatic nozzle, the fast-flow setting

was used. The draft was terminated with the register

indication as close as possible to 5.0 gallons.

8. The test measure neck scale indication was observed and

recorded

.

9. Dollar amount verified by manual price/gallon computation.

10. The product was returned to appropriate storage as in Step 6.

11. Repeat Steps 2, 4, 7, 8, and 6.

12. Repeat Steps 2 and 4 followed by a slow-flow 5-gallon draft

- 98 -
made into the standard. If the dispenser was equipped

with an automatic nozzle, the slow-flow setting was used;

otherwise slow flow was obtained manually. The draft

was terminated as close to 5.0 gallon registration as

poss i b le.

13. Repeat Steps 8, 6, and 3.

Conventional Measure . The test procedure employed with the

conventional measure was exactly the same as that with the

prototype with the following exceptions:

Step I. The measure was not leveled since it has no

adjustment.

Step 8. To obtain the measure liquid level indication,

the measure was held by the bail several feet off

the ground by one of the testers while the reading

was observed and recorded by the other tester.

Step 6. Emptying of the measure was accomplished by slowly

inverting the measure to allow the liquid to drain

into a funnel and subsequently to storage. The

time to drain the measure was maintained at 25 to

30 seconds followed by a 10 second drain after

cessation of the main flow.

9.1.1 ADDITIONAL FIELD TESTS . To further evaluate the prototype

measure, the two measures were transported to a weights and measures

office and with the assistance of three inspectors additional testing

was performed. This testing was limited to a relatively small sample

since the goal was to determine how the two measures would compare

- 99 -
when used by persons normally responsible for testing gasoline

di spensers.

9.2 F I ELD TEST DATA . When conducting the tests described in 9.1

and 9.1.1 the data was recorded on the form shown as Exhibit 6. A

summary of the data collected during the routine phase of the field

test program is shown in Exhibit 7. The results of the additional

field tests conducted on six dispensers is not included, however;

the results of those tests differed only in that the magnitude of

the difference between the two standards was greater. Comparison

of the data presented in Exhibit 7 reveals that in most tests the

results obtained with the conventional field standard were slightly

more positive (less negative) than indicated with the prototype standard .

9.3 CONCLUSIONS FROM FIELD TESTS . The field test program for testing

gasoline dispensers was very limited and was performed primarily to

verify the capability of the prototype measure. The tests did provide

evidence that the concept of the measure was extremely good.

Scale reading was greatly simplified for the width of 1/2 cubic inch

division was greater on the prototype than I cubic inch division

on a conventional measure. Additionally, the emptying procedure

was much easier since the prototype measure was drained through its

own hose and no funnel was required. Also, the drain time was not

influenced by any human factor. It was recognized that the process

of moving the standard from the dispenser to the storage tank fill

pipe was awkward for only one individual. This could easily be

- 100-
Data

=

S

=hee|

Date of Test Observer

API/NBS RESEARCH ASSOCIATE PROGRAM - RETAIL FUEL DISPENSER INVESTIGATION

Location

Dispenser manufactured by:

Manufacturer Model and/or Serial No.

Product Delivered: Premium Regular 3rd Grade

Last OFFICIAL inspection by: Date

Weather

Field Standard Identification

Sea I e Read i ng

Draft No.

Draft No.

Draft No.

Draft No.

1 ( norma I

)

2 ( norma I

)

3 (slow)

4 ( )

Remarks

Total Number of dispensers tested at this location

Exhibit 6. Field Test Data Sheet

101 -
SUMMARY

OF

DATA

-

SERVICE

STATION

FIELD

TESTS

in

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i_ • • • • i • • a) O CM no m O CM m CM NO in in p- NO — CM ><

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r- rm m p- p~ \ \ On ON \ \ p~ p~

m m m m wp- n- wp- r- o — o —m m m m p- p- p- \o o — mm mm wp- r- wp~ p^

p- p- p- r- Wp~ W W \N p~ r~ p" p- p~ p~

c

0

CM CM CM CM cm cm cm cm mm mm

Exh i b i t 7

- 102 -
SUMMARY

OF

DATA

-

SERVICE

STATION

FIELD

TESTS

in®

o

co

o in o o

m — mo

4- + It

ro in o • • • i r- oo — o

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in

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cm o• • in o

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L. i © o o m cm o o — CM (XI — — — — O CM ><

i i i i + + i i i i i i 1 1 i i + +

(0E in in in in in in

i_ cm in CM O C" in cm in r-~ in r- o o in o in o o

O

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CM

=*fc

i i i i 4- + i i i i i i i i i i + +

©

E in in in in

i_ cm in cm in in in r~ o in in in in cm in r- o o in O

zz — o m m cm o — O CM CM — M0 CM

=«fc + i i i + + 4- 1 i i i i i i i i + 4-

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in ZD ro © © © ro ro © © ro •— •— •— •— •— «

• — •

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l_ © i © i © 1 © 1 © 1 © 1 © 1 © 1 © 1 © CL CM CL CM CL CM CL CM CL CM Cl XI CL CM CL CM Cl CM O CO 00 CO CO CO CO CO 00 CO 00 CO 00 CO 00 U~) CO cr> co c CM CM CM CM CM CM CM CM CM © — 1 — 1 — 1 — 1 — 1 — 1 — 1 — 1 — 1 4- CL CO CL CO CL CO Q_ CO Q_ co CL CO CL CO Q_ CO CL CO

CO < L- < U- < Ll_ < L_ < l_L_ < Ll_ < L- C Ll_ < L_

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r-~ r~ r-~ r- r~ r- \ M X X X X X X X X CM CM CM CM CM CM CM CM m m

NX XX r~ i'' XX XX XX r* r-- r~ r~- r- r- c- r-~ \ x n- c- r- r-~ \ \ r- rc

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mm mm mm mm m- m

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Exhibit 7 Continued

- 103 -

7/13/73

API

Special

-17.5

-17.5+

-17.5

7/13/73

FS-282-5

-20.0

-20.0

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Exhibit 7 Continued

-104-

being

left

delivering

just

slightly

(I

to2

in^)

on

the

plus

side.
corrected by attaching a carrying handle to the measure or mounting

the measure on a wheeled cart.

From the limited tests it appears that it would be impossible

to predict within several cubic inches the result of a second normal

flow test based on the result of the first. The major problem here

would seem to be that under most conditions the history of the

dispenser just prior to the first test is generally unknown to the

person performing the inspections. It might well be a questionable

philosophy to accept a single normal-flow test as an indication of

the operating capability of the dispenser.

It is felt that the tests conducted by B. C. Keysar and D. J. Hine

represent a much more controlled and exact application of a conventional metal field standard than might be encountered in observing

a routine weights and measures inspector's procedure. The facilities

where dispensers are tested seldom include a means to allow

the measure to be suspended several feet off the ground to facilitate

leveling and reading of the graduated neck scale. The operation is

therefore dependent upon the island being relatively level so that

the measure can be placed on the island to allow the neck scale to

be more easily viewed. Conceding that the island is level, the proper

method to read the graduated neck scale will require the inspector

to be on his hands and knees!

- 105-
9.4 RECOMMENDED FIELD TEST PROCEDURE. For either a conventional

field test measure or a measure fabricated from the specification

of 7.2.0, a well-defined procedure is necessary.

In June 1973 the Office of Weights and Measures published NBS

Handbook 112, Examination Procedure Outlines for Commercial Weighing

and Measuring Devices. Exhibit 8 is a modified reprint of EPO No.

21 of that Handbook which covers single product motor fuel dispensers.

EPO No. 22 covers blended product motor fuel dispensers. The Examination Procedure Outline provides an excellent summary of appropriate

reference numbers to NBS Handbook 44. To supplement the EPO, an

Examination Checklist was prepared and is shown in Exhibit 9. This

checklist is intended to simplify the Device Inspection and PreTest Determinations and should be completed prior to actual performance testing.

To properly inspect a motor-fuel dispenser, a step-by-step

procedure must be followed. The procedure includes both visual and

manual inspection and should proceed as follows:

1. The dispenser panel covers are removed by authorized

personne I

2. With a checklist similar to Exhibit 9, complete all items

except I I and 1 6

3. Record the totalizer reading on the test report form.

4. Place the measure to be used adjacent to the dispenser

being tested and establish level condition for the measure.

5. Activate the switch to energize the dispenser pump.

6. Make a normal draft into the measure. During the draft

- 106-
Reprinted from

U.S. Department

of Commerce NBS

Handbook 112 (Mod i f i ed

)

Examination Procedure Outline for

RETAIL MOTOR-FUEL DISPENSERSSINGLE PRODUCT

It is recommended that this outline be followed for conventional, single-product, power-operated retail dispensers—"gasoline pumps."

H-44 General and

Liquid Measuring

Device Code

References

INSPECTION:

1. Indicating and recording

elements.

Design S.1.1. Readability G-S.5.. G-S.6.,

G-UR.3.2.

Unit Price and Product

Identity S.I.4.3., S. 1.4.4., UR.3.2. Advancementand Return

to Zero S.1.1.4., S. 1.4.2.. UR.3.1.

2. Measuring elements.

Air eliminator vent (if self-contained pump). . . Security seal on adjusting

S.2.1. mechanism G-UR.4.4., S.2.2.

3. Discharge hose S.3.4..UR.1.1..S.3.1.

4. Marking requirements G-S.1., S.4.I.,

G-UR.3.3.

5. General considerations.

Selection G-UR.1.1.

Maintenance G-UR.3.1..G-UR.4.1.

Installation G-UR.2.1., UR.2.1., UR.2.4. Accessibility G-UR.2.3.

Assistance G-UR.4.3.

PRE-TEST DETERMINATIONS:

1.

Tolerances.

Applicable requirements . . G-T.. T. 1

.

Basic values T.2.I., T.2.4.

TEST:

Allow 10-second drain period

each time test measure is emptied.

Todetermine proper operation

of totalizers, observe and re- cord the totalizer indications

before and after all test drafts.

1. Normal test— full flowbasic tolerance N.I., N.2., N.3.4.

N.4.1.

If first test is well within tol- erance. proceed to 2; otherwise. repeat this test.

2. Check computed price on

both sides of dispenser G-S.5.5.

(See Price Computation

Table.)

3. Special test—slow flow

basic tolerance N.4.2., N.4.2.2.

4. Check effectiveness of

zero-set-back interlock S.2.5.I., UR.3. 4. On equipment with re- mote pumping systems,

activate one dispenser

and check all others operated by the same pump

to make certain they will not operate without acti- vating the individual

starting levers.

5.

Check effectiveness of

anti-drain valve S.3.6.

6.

Elapsed time-test (if necessary) N.4.3.. T.2.4. Security seal—Apply leadand-wire seal to secure adjusting mechanism.

Note on the official report the

number of gallons of product

dispensed during test.

Exhibit 8

-107-
RETAIL MOTOR FUEL DISPENSER EXAMINATION CHECKLIST

(Reference: NBS Handbook 44 & NBS Handbook 112, EPO 21 & 22)

LOCATION

DISPENSER: Make & Model Serial No.

PRODUCT DISPENSED:

Yes No

1. Equipment suitable for application and properly installed

(G-UR.I.I, G-UR.2.1, & UR. 2.1)

2. Primary indicating and/or recording element (S.I.I)

3. Acceptable units and sub-division units (S. 1.1.2)

4. Convenient indicator scale graduations (S. 1.2.1. G-S.5 & G-S.6)

Clear interval between graduations 0.04" or more (S. I .2.3)

Graduation width 0.008" or more (S. I .2.2)

5. Indicator index symmetrical with graduations and no more than

0.06" clearance between the index and the graduations (S.1.3)

6. Functional Zero-Set-Back Interlock (S.2.5.1)

7. Proper return to zero function or operation (S.I.I. 4)

8. Meter equipped with a vented vapor eliminator (S.2.1)

9. Meter adjustment element properly sealed (G-UR.4.4 & S.2.2)

10. Automatic directional flow valves (G-UR.2.1 & S.2.3)

11. Piping prevents discharge of metered liquid- to other than the

delivery point (include leak check) (G-UR.4.1 & S.3.2)

12. Equipment does not facilitate perpetration of fraud (G-S.2)

13. Meter used for dispensing single product (S.4)

14. Meter used for dispensing blended product (S.4 & S. 1.4.3)

15. Tolerance for Tests (G-UR.4.1, G-T, T.l, & T.2):

i_n£ i_rv^ i Maintenance Acceptance Special

16. Antidrain Valve test performed and accepted

Date Inspector

Exh i b i t 9

- 108 -
observe the hose, nozzle, and visible piping for leaks.

If an automatic shut-off nozzle is used, use the fast

setting. Stop the indicator as close as possible to an

even incremental gallon. Deactivate the dispenser pump

and place the nozzle in its proper location. If the measure

is not wetted from a previous test proceed to Step 9.

7. Read the scale of the measure and record on the report.

Complete I tern II of checklist.

NOTE: The reading of the scale is an important function of

inspection. The eyes must be level with the liquid

meniscus as shown below to obtain an accurate scale reading

It might be necessary for the inspector to be on h i s hands

and knees to properly read the scale. An alternative would

be to have a means to suspend the measure from its bail

or handle.

8. Compare the recorded scale reading with the appropriate

tolerance. If the scale reading is we I I within the tolerance

the test is considered acceptable. If not, the test must

be repeated. Verify the accuracy of the Amount of Sale

display.

Meniscus

Metal Graduated Scale

Gage Glass

Li ne-of-S i qht

- 109 -
9 . Return the liquid in the measure to the appropriate storage

tank as directed by the service station operator. Care must

be exercised in the emptying process. The drain hose or

funnel must be grounded to the fill tube and contact with

the measure maintained during emptying. If the measure is

not equipped with a drain valve, slowly tilt the measure

and pour the liquid into a funnel inserted into the tank

fill tube. The elapsed time for emptying should be between

25 to 30 seconds followed by a 10-second drain following

cessation of the main flow.

NOTE: During emptying, the axis of the measure should be between 75 to 85 degrees from the horizontal.

10. If the normal test is to be repeated, repeat Steps 4,

return the indicators to zero, 5, 6, 7, 8, & 9. If not,

go to Step II. (A complete test should consist of 2 normal

flow tests and I slow flow test.)

11. Repeat Step 4, return the indicator to zero, and repeat

Step 5.

12. Make a slow draft into the measure. If an automatic

nozzle is used, use the slow setting. Fill rate should be

about 20 percent of normal rate. Stop the indicator as

close as possible to an even incremental gallon. Deactivate the dispenser pump and place the nozzle in its

proper position.

13. Repeat Steps 7 & 8.

-I 10-
14 . With the dispenser pump off, place the nozzle in the measure

and open the nozzle to check the antidrain valve. Only

a small quantity of liquid will drain and then stop if

the valve is functioning.

NOTE: Do not shake, elevate, or otherwise attempt to force

leaking. This will VOID the test.

15. Repeat Step 9. Caution: If this is the last dispenser

to be tested at this location, additional care must be

taken to completely drain the measure of f tamable liquid

before placing it in a vehicle.

16. Read and record the totalizer reading. Verify the gallons

dispensed during the test with the difference between

begin and end totalizer readings.

17. Complete the test report, affix a seal if appropriate, and

have the dispenser panels replaced by an authorized person.
10.0 TEST MEASURE EVALUATION SUMMARY. The examination of test

measure design and performance provided evidence to substantiate

the need for changes in the design of the features that contributed

most to non-uniform measurement. The two major sources of potential

error were found to be scale reading errors and emptying in a manner

other than that used when the measure was calibrated. The tentative

specification addresses itself to features that would greatly reduce

these error sources. One feature of the specification that could

require attention is the difficulty of cleaning and inspecting

through the 2" neck opening. It would require that care be taken

to protect the measure from an atmosphere that would promote rusting.

This requirement is no different than for existing measures.

Additionally, the small diameter neck may increase the foaming problems

found with some petroleum products. This condition, as with conventional measures, requires the inspector to maintain continual

surveillance during testing to avoid overflow which voids the test.

In addition to design change needs, it was also established

that there was a need for uniform acceptance/reject ion criteria for

use by all volume calibration agencies. With existing practices,

the only uniform criteria that might be exercised would be rejection

if the measure leaked or was completely erroded with rust. To

establish a rust level that would control the acceptance or rejection

of a given measure would be extremely difficult and would be perhaps

even more difficult to uniformly promote with all potential users.

However, it should be realized that rust corrosion and severe dirt

films are forms of equipment abuse. A measure that conforms to the

- 112 -
design specifications included in this report will not exhibit a

severe rust condition unless it has been improperly maintained.

A calibration report specifies a volume that is based upon the

measure being clean and reasonably free of corrosion damage. If

the measure does not meet these qualifications when inspected, the

calibration is nearly meaningless.

Damage to a test measure in the form of dents is a very sensitive

problem. If the calibration is performed on a dented or otherwise

damaged measure, it is impossible to establish, to everyone’s

satisfaction, that the damage existed prior to calibration. Some

calibrating agencies attempt to include a damage description on

the report of calibration but the success of this is questionable.

Any dent or damage to a test measure should be repaired so that it

isn’t externally visible and doesn't allow air or foreign material

entrapment. This must be done prior to submitting for calibration

or reca I i bration.

Since the procedure used in the calibration of a test measure

has been found to be important to achieving reproducible calibration

values, the importance of adapting the scale reading and emptying

portions of the laboratory calibration procedure to field applications

of the test measures cannot be overemphasized. This philosophy

must be promoted by all users if uniformity is to be realized.

Every person who performs calibration work with metal volume

standards should realize that they are working with a precision instrument. The reference to this equipment as buckets or cans promotes

a crude image and oftentimes results in crude treatment. These
devices are instruments which deserve and require careful treatment

both in handling applications and storage.

A clean, properly maintained and used test measure will promote

improved measurement.

- 114 -
I 1.0 INTRODUCTION TO LARGE VOLUME PROVER DESIGN & EVALUATION. During

the first two years of the API/NBS Research Associate Program, it

became evident that the program must be expanded beyond the study of

I, 5, and 10 gallon field standards. Representatives of the petroleum

industry and weights and measures jurisdictions were actively suggesting

that the research program be expanded to include larger volume provers

for application in truck- I oad i ng facility meter inspection and truckmounted meter inspections. Approvals were obtained from API and NBS

and the expansion was begun.
12.0 PROVER DESIGN STUDIES . The study of prover design had primarily

been completed when an attempt was made to locate existing field

standards design criteria in the very early stages of the Research

Associate Project. Further studies supported the earlier conclusion

that standard prover specifications were virtually non-existent.

A review of the angle evaluation liquid retention studies and

the reports on the engineering survey conducted by American Petroleum

Institute in the mid-l960 ? s resulted in certain design criteria that

would be considered.

Since the API survey had selected API Standard 1101, "Measurement

of Petroleum Liquid Hydrocarbons by Positive Displacement Meter",

this document was used as the base starting point in developing a

"Tentative Large Volume Prover Specification". The Specification

covered 4 Volumetric Provers (50, 100, 750 & 1500 gallon) mounted on

a single tra i I er

.

The specification was completed, reviewed by API Weights and

Measures Task Force Members and representat i ves of KJBS Office of

Weights and Measures, revised to reflect comments received during

review, and submitted to four known prover manufacturers for bid.

Following receipt of the bids from the manufacturers, the bids

were evaluated and a contract was awarded to the lowest bidder.
13.0 VOLUMETRIC PROVER FABRICATION . The manufacture of the provers

was initiated immediately following award of contract. Several

changes were made to the specifications at the request of the manufacturers. These changes included fabricating the 50 and 100 gallon

provers of stainless steel and epoxy coating the 750 and 1500 gallon

provers in lieu of terne-plate or galvanized coating. These changes

were approved and reflected no additional cost.

During fabrication, several visits were made to the manuf acturers

facility. These included a visit prior to final assembly and a visit

for a final checkout and calibration by water-meter method. Several

modifications were requested to the provers before final approval

for shipment could be given. The provers were approved for shipment

prior to receipt of the scale plates to avoid unnecessary delay in

shipping to NBS

.

13.1 EXAMINATION AND CALIBRATION . When the prover system was received

at National Bureau of Standards it was immediately subjected to a

thorough inspection. Several defects were noted i n -the provers that

required correction before the equipment could be calibrated. The

major problem was a weld seam on the bottom cone discovered by interior

inspection, that would deter proper draining of the large prover.

The seam was ground smooth and the epoxy coating was subsequently

patched. An excessive amount of welding slag, sand-blasting sand,

and fabrication debris resulting from the modifications required at

final checkout necessitated an extensive cleaning which included

complete disassembly of the main valve.
Following the repairs and thorough cleanup of the interior of

the provers and exterior of the trailer and provers, the provers were

subjected to a series of calibrations. The provers were received

without the scales installed and it was therefore necessary to conduct

an initial calibration to position the scales. After the scales had

been installed the provers were subjected to a check calibration.

An unacceptable difference was noted between the water-meter calibration

and the calibration against NBS standards. Due to lack of facilities

and time, the water meter was not verified for accuracy at the manufacturers’ facility. A water-meter "check" calibration should only be

accepted if previously checked against an approved standard. Due

to the unusual height of the two large provers mounted on the trailer,

a procedure was developed and modifications to the calibration facility

were made to permit calibration of the provers.

The provers were then subjected to a routine official calibration

by the Mass and Volume Section of the National Bureau of Standards.
14.0 PLANNED FIELD TEST PROGRAM . The field test program was devised

to verify the applicability of the large volume provers that had been

designed, fabricated, and calibrated under the auspices of the API/NBS

Research Associate Program. To accomplish this goal, it was considered

necessary to conduct a large number of tests on as many meters as

possible in an allotted period of time. Additionally, the concensus

was that tests should be conducted within as wide a range of products

and ambient temperatures as possible. For this reason, tests were

scheduled at two loading terminals in Milwaukee, Wisconsin and two

loading terminals in the Washington, D. C. area. Two series of tests

were scheduled for each terminal location so that tests could be

performed in both the cold winter months and the moderate to hot summer

months

.

A document was prepared describing the guidelines under which

the tests would be performed and was supplied to the terminal manager

prior- to initiating the test series. A copy of the document is included

as Exhibit 10.

-I 19-

F
THE AMERICAN PETROLEUM INSTITUTE IS CONDUCTING A SERIES OF TESTS

AT VARIOUS TANK TRUCK LOADING FACILITIES. THESE TESTS ARE PART OF

THE RESEARCH ASSOCIATE PROGRAM SPONSORED BY THE DIVISION OF MARKETING

IN COOPERATION WITH THE NATIONAL BUREAU OF STANDARDS. THE RESEARCH

ASSOCIATE PROGRAM INVOLVES THE DEVELOPMENT OF VOLUMETRIC STANDARDS

DESIGN AND CORRECT USE OR APPLICATION PROCEDURES.

FIELD PROVERS OF 50, 100, 750, AND 1500 GALLONS HAVE BEEN DESIGNED,

FABRICATED AND CALIBRATED IN PREPARATION FOR FIELD TEST INVESTIGATIONS.

THE MAJOR GOALS OF THE FIELD TESTING WILL BE TO ACHIEVE A UNIFORM

EQUIPMENT DESIGN SPECIFICATION AND UNIFORM METER TEST PROCEDURE

REQUIREMENTS FOR USE WITHIN THE PETROLEUM INDUSTRY AND WEIGHTS AND

MEASURES JURISDICTIONS.

ALL TESTS WILL BE CONDUCTED IN STRICT COMPLIANCE WITH INDIVIDUAL

LOADING TERMINAL OWNER SAFETY AND OPERATIONAL REQUIREMENTS AND NORMAL

OPERATION WILL HAVE PRECEDENCE OVER THE FIELD TEST REQUIREMENTS WHEN

NECESSARY.

THROUGHOUT THE TESTS, NO METER WILL BE ADJUSTED OR OTHERWISE

ALTERED BY THE TEST PERSONNEL. THE OFFICIAL TEST PERSONNEL WILL CONSIST

OF THE API RESEARCH ASSOCIATE, D. J. HINE; API SPECIAL REPRESENTATIVE,

W. A. KERLIN; AND NBS REPRESENTATIVE, B. C. KEYSAR. THESE MEN WILL

COORDINATE ALL TEST WORK WITH THE PLANT MANAGER OR A REPRESENTATIVE

DESIGNATED BY HIM.

THE TEST DATA WILL BE EVALUATED IN ACCORDANCE WITH METHODS USED

BY THE WEIGHTS AND MEASURES JURISDICTION HAVING AUTHORITY OVER THE

INSTALLATION AND/OR BY PLANT METHODS. A COPY OF ALL TEST DATA WILL

BE SUPPLIED TO THE PLANT MANAGER WHEN TESTING IS COMPLETED.

- 120-
THE FOLLOWING ’’FIELD TEST PROCEDURE OUTLINE" WILL BE USED THROUGHOUT

THE TESTS UNLESS MODIFIED BY MUTUAL AGREEMENT:

FIELD TEST PROCEDURE OUTLINE

1. INVESTIGATE EXISTING PLANT METER CALIBRATION PROCEDURES AND/OR

GUIDELINES.

2. INVESTIGATE EXISTING PLANT SAFETY PROCEDURES THAT MUST BE ADHERED

TO DURING METER CALIBRATION OR TRUCK LOADING OPERATIONS.

3. STUDY THE SYSTEM TO BE TESTED CONCERNING METER SIZE, LIQUID

TEMPERATURE AND PRESSURE MEASUREMENT AT OR NEAR THE METER, NORMAL

AND MAXIMUM AVAILABLE FLOW RATES, TEMPERATURE COMPENSATION,

FLUID GRAVITY, PROPER METER INSTALLATION, ETC.

4. CHECK METER ADJUSTING ELEMENT FOR APPROPRIATE SEAL AND RECORD

ON DATA SHEET. CHECK FOR COMPLIANCE WITH HANDBOOK 44 REQUIREMENTS.

5. POSITION THE TRAI LER-MOUNTED SYSTEM AT THE LOADING RACK DESIGNATED

BY THE PLANT PERSONNEL AND ESTABLISH LEVEL CONDITION WITH LEVELING

JACKS.

6. PLACE FIRE EXTINGUISHERS AND BARRICADE SIGNS IN APPROPRIATE

POSITIONS.

7. CONNECT GROUND WIRE TO APPROPRIATE PROVER GROUNDING LUG AND

AVAILABLE POSITION GROUND.

8. IF FACILITY HAS SET-STOP FEATURE, SET APPROPRIATE VOLUME FOR

PROVER BEING USED.

9. POSITION DRAIN LINE TO PROVER. DO NOT CONNECT.

10. IF THE METER BEING TESTED IS EQUIPPED WITH A TEMPERATURE COMPENSATOR (ATC) OR TEMPERATURE-GRAVITY COMPENSATOR (ATG), IT SHOULD

BE DE-ACTIVATED UNLESS THE METER IS EQUIPPED WITH BOTH NET AND

GROSS INDICATION.

11. PERFORM PROVER "WET-DOWN" AT NORMAL LOADING RATE OF THE INSTALLATION.

12. MAKE NOTATIONS ON DATA SHEET OF FLUID TEMPERATURES AT METER AND

PROVER, PRESSURE AT METER, AMBIENT TEMPERATURE AND WEATHER

DESCRIPTION, NECK SCALE READING, AND METER READING.. IF METER

SYSTEM IS EQUIPPED WITH A RECORDING ELEMENT, PRINT A TICKET

AFTER EACH TEST RUN. CHECK PROVER DRAIN VALVE FOR LEAK.
13. CONNECT DRAIN LINE TO PROVER AND DRAIN PROVER, AS DIRECTED BY

PLANT PERSONNEL, ALLOWING 30 SECOND DRAIN AFTER CESSATION OF FLOW.

14. CONDUCT A "NORMAL FLOW TEST" AT FULL FLOW AND PROMPTLY RECORD

ALL TEMPERATURES, PRESSURE, NECK SCALE READING, AND METER READING

OR PRINTOUT.

15. CONDUCT A "SLOW FLOW TEST" AT A MINIMUM DISCHARGE RATE OF 20

PERCENT OF THE MAXIMUM RATED FLOW OR AT THE MINIMUM DISCHARGE RATE

MARKED ON THE DEVICE, WHICHEVER IS LESS. RECORD ALL DATA AS IN

STEP 14.

16. CONDUCT A METER TEST AT AN INTERMEDIATE FLOW RATE AND RECORD ALL

DATA AS IN STEP 14.

17. REPEAT STEPS 7 THROUGH 16 USING THE LARGER OR SMALLER PROVER NOT

PREVIOUSLY USED.

- 122 -
15.0 INITIAL FIELD TESTS . Prior to beginning the first series of

field tests, the prover system was subjected to "shake-down" to

establish operating procedures and allow the personnel that would be

conducting the tests to become familiar with the equipment.

Prior to loading any petroleum product in either of the provers,

it was discovered that the inlet nozzle to which the bottom- loadadapter was flanged was 3 inch size rather than 4 inch. This defect

was discovered when the adapter was removed and had not been obvious

during the initial examination. The 3 inch nozzles were cut out and

replaced with a 4 inch nozzle. A calculation based on the theoretical

dimensions of the two nozzles was performed to determine the prover

volume change created by the modification. The epoxy coating was

repaired following the welding modification.

Following the modification to the nozzles, the provers were

subjected to a series of runs and were judged to be performing to

expectations. The system was considered to be ready to begin the

scheduled field test intinerary. The prover system was towed to

Milwaukee, Wisconsin for the first series of testing.

The metering systems to be tested were subjected to a visual

examination in accordance with pre-test determinations presented in

NBS Handbook 112. To simplify the visual examination, a Check-List

was prepared utilizing NBS Handbook 112. The Check-List is shown in

Exh i b i t II.

Following the pre-test examination, the tests were initiated.

It was immediately evident that the pump-back facility of the loading

terminal would prove to be a serious deterrent to the conduct of the

- 123 -
TRUCK LOADING FACILITY PRE-TEST METER EXAMINATION CHECK-LIST

(Reference: NBS Handbook 44 & NBS Handbook 112, EPO 25)

LOCATION PRODUCT METERED

METER: Size , Make & Model No. , Serial No.

Yes No

Equipment & installation suitable for application (G-UR. I . I & G-UR.2.1)

Primary indicating and/or recording element (S.I.I)

Acceptable units and sub-division units (S.I.I)

One (I) gallon or equivalent unit (S.I.I)

Convenient indicator scale graduations (G-S.5 & S.1.2)

0.008" or more graduation width

0.04" or more clear interval

Indicator index symetrical with graduations, no more than 0.04" between

index and graduation, 0.06" or less clearance between graduation and

index. (S.1.3)

Proper return to zero function or operation. (S.I.I. 4)

Meter equipped with a vapor eliminator. (S.2.1)

Meter adjustment mechanism properly sealed. (S.2.2 & G-UR. 4. 4)

Meter equipped with ATC and properly sealed (S.2.6 & S.2.6.3)

Can ATC be properly deactivated. (S.2.6. 2)

Is adequate thermowell provided for meter temperature (Special)

Automatic directional flow valves. (S.2.3)

Meter equipped with automatic set-stop mechanism. (S.2.4)

Piping prevents discharge of metered liquid to other than the delivery

point (include leak check) (S.3 & G-UR. 4.1)

System does not facilitate the perpetration of fraud. (G-S.2)

Is meter used for single product. (S.4 & G-S.l)

Legible markings and instructions. (G-S.6 & G-UR. 3)

Maintenance tolerance of 25 in^ plus 1/2 in^ per indicated gallon on Normal Tests,

I in^ per indicated gallon on Special Tests, and Acceptance tolerance of 12.5 d

I

us

1/4 in-3 p er indicated gallon. (G-UR. 4. I, G-T, T. I , & T.2.)

Exhibit II -124-

Inspector signature Date
tests. It oftentimes took several hours to prime the pump in order

to pump-off the test liquid. It was also noted that it was difficult

to determine when the prover was empty. A crewman had to stand on

top of the prover to watch the product level during unloading.

Representatives from the API Division of Marketing Weights and

Measures Task Force visited the test site to view the testing. In

addition to the pump-off problem and visual emptying determination,

concern was indicated over a small pool of liquid retained in the

bottom drain line of the provers at the junction of the screwed elbow

on the bottom of the prover to the sloped drain line leading to the

drain valve. The decision was made that the prover drain lines be

modified to correct the pool condition and provide visual indication

when the prover was empty. Also, a decision was made that a portable

pump and motor system be obtained to include with the test system to

eliminate the need to depend on plant facilities.

With these decisions, the drain lines of the two large provers

were removed and transported back to the National Bureau of Standards

for modifications. A pumping system was ordered as well as two 4 inch

sight flow indicators to incorporate in the modified drain lines.

The drain lines were subjected to several tests to determine the

amount of liquid retained i n the pool and it was discovered that the

pool in either drain line consisted of less than one-half cubic inch.

The decision to modify the drain lines was for aesthetic value as

well as visual acceptability by outside observers. The drain lines

were modified by welding a half screwed coupling to a weld elbow which

was in turn welded to a pipe nipple that was threaded on the end to

- 125 -
accept the drain valve. The s i ght-f low- i nd i cator was installed downstream of the drain valve in order to eliminate having this fixture

within the calibrated volume of the provers.

The volumes of the as-built drain lines and the modified drain

lines were determined by repeated water fillings and the calibrated

volumes of the provers were adjusted accordingly.

- 126-
16.0 FIELD TEST PROGRAM . The field test program was intended to provide a large number of meter tests in order to test the capability of

the provers. In addition to the planned large quantity of testing,

it was also necessary to observe and record a large number of test

parameters. These parameters included meter register indication,

flow rate, prover neck scale reading, meter pressure, nine or ten

temperature readings depending upon the system, prover pump-off time,

and drain-down times.

In order to help eliminate errors by omission of required data,

three sets of tasks were developed for the three persons usually in

attendance during the tests. The assignments were as follows:

Crewman #1: Responsible for the operation of the meter. This

assignment included having an appropriate ticket

in the register; determining by checking with the

other members of the crew when the test was ready

to begin; obtaining the flow rate during the run;

making the meter register reading; assist in reading

the I i qu i d- i n-g I ass thermometers; and timing the pumpoff and drain-down periods.

Crewman # 2

Responsible for the operation of the prover. This

assignment included all valve manipulations, assisting

with temperature determinations during the run, determining the liquid level on the neck scale, and assist

in reading liquid-in-glass thermometers.

Crewman #3: Responsible for the general conduct of the test. This

assignment included recording all data on the data

- 127 -
sheet, assisting with temperature determi nat ions

during the run, obtaining temperature determinations

from the electronic thermometer, making periodic

gravity determinations of the metered product, and

assisting other members of the test crew as required.

With this distribution of assignments it was found that each member

of the test group was well occupied and only during pump-back of the

product from the prover to storage was there any unused time.

During the conduct of these tests it was agreed that a sequence

for the tests must be formulated so that each meter would be examined

within the same guidelines. The test sequence decided upon was as

fo I lows

Preliminary Run - Meter system stability check to include: flow

rate check, set-stop function, and generally

inspect the meter operation. This run could

be eliminated if the prover was wet-down from

a previous run on a different meter and the

inspection could be performed while a tank-truck

was loading through the meter to be tested.

First Run - Normal Flow Rate - one meter operating - record

a I I data

Second Run - Normal Flow Rate - one meter operating - record

a I I data.

Third Run - Slow Flow Rate - one meter operating - record

a I I data

- 128-
Additional Runs - Additional runs were made to determine the

repeatability of the meter, influence on the

flow rate and repeatability of the meter when

two or more meters were operating with the same

test liquid, and an additional slow-flow run.

16.1 TESTING PROBLEMS . During the conduct of the field tests there

were a number of problems encountered that are worthy of discussion.

16.1. I Product Pump-Off . As discussed in Section 15.0, problems

were encountered with terminal facilities for returning metered product

to storage. In addition to the pump-back facilities being either nonexistent or inoperable, it was found that in some cases product could

not be returned to storage if that same product was being loaded

through another meter. This was caused by the return line being

connected to the supply line from storage which had a higher pressure

than could be obtained with the pump-back pump.

During slow periods in the terminal, testing would proceed

quite well; but during normal loading it resulted in test delay. This

same piping configuration presented another potential problem in that

during the slow loading periods the same product would be recycled

through the meter into the prover and through the pump into the supply

line. Recycling would continue until a truck arrived to load the same

product being tested.

A further problem in the product pump-off area is that at some

locations no means is provided at the loading position to return the

product to storage. During the field tests, one such location was

encountered and the problem was resolved by the terminal operator

- 129 -
furnishing a tank truck for pumping the metered product into. Even

this resulted in delays since the truck had to move to the pump-back

facility after each 7,000 to 8,000 gallons of testing. It is also

expensive to tie up a truck and driver for the test period. Every

truck loading facility should be equipped with convenient product

pump-back facilities. The design should promote meter inspection and/or

calibration without inconvenience to either terminal operation or

test i ng personne I

.

16.1.2 Product Temperature and Pressure Measurement . It was often

difficult or impossible to find a means to measure the metered product

temperature and pressure at or near the meter. To make these measurements it was necessary to find a pressure tap or other opening that

could accept a short nipple that was screwed to a pipe tee so that

both temperature and pressure could be measured. Since pressure and

temperature at the meter are important in evaluating terminal operating

equipment, the capability for making these measurements should be

included in every loading terminal design.

16.1.3 Flow-Control Valves . At several test locations the control

valves that are used to regulate meter flow-rate, starting stage,

stopping stage and meter shut-down were found to be overly sensitive

to adjustments or could not be adjusted due to faulty 0-Rings or

ruptured diaphragms. Several meters had to be bypassed during the

testing due to such difficulties. The flow rate has a decided effect

on meter performance and any auxiliary equipment that controls or

effects flow rate should be capable of proper adjustment with a minimum

of maintenance. It is also desirable that flow rate adjustment be

- 130 -
provided with a security seal to prevent unauthorized adjustments.

16.1.4 Flow Stra i ners . Most piping systems in loading terminals include

a flow strainer upstream of the meter to protect the metering element

against foreign debris. Although not every strainer baskeT was inspected during the field tests, of those that were inspected an

alarmingly high percentage had extensive damage. The experience of

the field tests indicates that an established routine inspection of

the strainer is needed.

16.1.5 S I ow-F I ow Contro. A problem was encountered during the field

tests in establishing a slow-flow rate. To obtain slow-flow through

a meter, a valve must be throttled that is normally open. In many

cases, the only available control is through the main shut-off valve

upstream of the meter. It was found that when gasolines are throttled

through a valve upstream of the meter, the disturbance may create a

vapor-liquid mixture that subsequently passes through the meter.

The difference in meter error between upstream and downstream throttling

is significant.

The best uniform solution to this problem would be the installation

of a control valve between the prover and the bottom- load adapter so

that flow could be throttled into the prover rather than into the

meter. This solution should improve the meter accuracy and promote

a uniform method for meter testing.

- 131 -
16.2

VAPOR RECOVERY SYSTEM TESTING . A logical extension to the

Field Test Program developed during the testing. Though more and

more loading terminals are installing vapor recovery or disposal

systems, few are being provided with appropriate proving standards.

It is generally agreed that every measuring device should be calibrated under nonmat operating conditions

.

16.2.1 TEST OBJECTIVE . The objective of the tests was to examine

neter performance when operating with a closed proving system as

compared to operating with an open proving system.

16.2.2 METHOD OF TESTS . The tests were conducted with the 1545.55

gallon volumetric prover designed specifically for bottom- I oad i ng

,

vapor recovery meter proving. The vapor recovery on this prover

was accomplished through a 4" elbow welded on the flanged top cover.

Removal of the top cover provided an open-to-atmosphere prover

similar to those used by both weight and measures jurisdictions

and the petroleum industry.

During the tests with the closed prover system, the pressure

inside the prover was periodically monitored. The pressure at

beginning of loading was approximately 0.5 psig but would drop to

about 0.3 psig and remain constant during the majority of the loading.

It is considered that this slight pressure deters evaporation. No

discernible change in flow rate between the open and closed system

tests could be detected.

16.2.3 TEST RESULTS . Approximately 150 tests were performed on

nine meters. Each meter was tested for about one-half day in both

- 132 -
the open and closed configurations. Results of the tests on each

meter were averaged and are shown in Figure 25.

The meter number versus the meter error is illustrated on

the graph of Figure 26. This graph indicates the definite offset

between the data points obtained by the two test methods. Going

still further. Figure 27 is a plot of meter number versus the

difference in meter error. The arithmetic average of these error

differences is represented by the solid line through the l.ll

gallon per 1 000 value.

16.2.4 DISCUSSION AND SUMMARY OF RESULTS . The data reflects a

serious error or bias in a measurement program. More importantly,

referring to NBS Handbook 44, Fourth Edition reveals that the

"allowable maintenance tolerance", listed in the Liquid Measuring

Device Code Table 3, is 525 cubic inches for a 1000 gallon draft.

The l.ll gallons or 256.4 cubic inch per 1000 gallons (average error

of Figure 27) is using 48.84 percent of the maximum allowable

maintenance tolerance.

Another serious problem worthy of discussion is the fact that

the comparison tests may well reflect conservative differences due

to the ideal physical character i st ics of the prover used for the

tests. This prover was designed for bottom loading and the penetration through the prover wall was made with a weld elbow extending

inside the prover. The elbow diverts the flow and promotes a very

gentle stirring action during the entire loading process. All of

the provers witnessed during the field tests have not had this

- 133 -
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Figure 25: METER TEST RESULTS - 134 -

DIFFERENCE

IN

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METER NUMBER VERSUS

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-136-
feature. The incoming stream on those provers would create a violent

boiling action during loading that assuredly would promote greater

vapor release and higher density vapor than experienced with the

prover used for the vapor recovery test series.

Still another important feature that has been indicated by the

field test program deals with the proving procedure. It was noted

that the first test on a meter should be discarded even though the

prover may be "wet-down" from a previous meter test. It is impossible

to predict the history of the meter system during the prior loading

and it is, therefore, necessary to make an initial run in order to

appropriately stabilize the system in preparing to perform the proving

operation.

From the comparison tests of vapor recovery, a cost analysis

was prepared to examine the "mi smeasurement" value. The analysis

includes several values that may not reflect any specific operation

as to monthly terminal gasoline throughput nor does it particularly

reflect a known "street value" for the product. The analysis does

reflect that the value of the measurement error is potentially very

I arge.

- 137 -
COST ANALYSIS

ITYPOTHETICAL TRUCK-LOADIfJG TERT1INAL WITH A MONTHLY GASOLINE THROUGHPUT

OF 215,000 BARRELS OR 9,030,000 GALLOfiS

IF AH INAPPROPRIATE PROVER IS USED TO CALIBRATE THE TERMINAL HETERS:

HISfEASURBElT = 9,030,000 x

6A

m

.oris life = 10,023 GALLONS

IF THESE RIISMlASURED GALLONS HAVE AN AVERAGE STREET VALUE OF $0.50;

MISMEASUREMEMT VALUE = 0.50 x 10,023 GALLONS PER MONTH = $5,011,50 PER MONTH

OR

ANNUAL MISMEASUREMEMT VALUE = $5,011,50 x 12 MONTHS = $50,138.00 PER YEAR

The results of the test series and the above analysis reflect

a very serious potential measurement error. The value is always

against the meter owner as the meter would be adjusted to deliver

more product than registered or "under-register". Such will be the

case if open volumetric provers are used in the calibration of

meters that normally operate as closed-fill systems.

- 138 -
16.3 FIELD TEST DATA ANALYSIS . The analysis of the data collected

during the field test program was done in two ways. First, following

completion of meter tests in a particular loading terminal, the recorded

data was reported to the terminal manager or superintendent on a

special form developed for that purpose. Exhibit 12 is a copy of

the report form. A report was prepared for each meter tested with

each prover and the information was furnished only to individuals

designated by the terminal superintendent. The information was

intended for use in comparing test data when the meters were subjected

to routine calibration check by terminal personnel. Second, upon

completion of the field tests, the completed data sheets were subjected to a comprehensive evaluation and data analysis process.

16.3.1 PROVER VOLUME VERIFICATION . Guarantee was needed that the

volumes of the provers, as previously determined by water calibration,

was valid. The provers were subjected to a routine volumetric calibration. The 60°F Volumes were determined to be 1545.55 gallons

and 758.181 gallons as shown on the Report of Calibrations in

Exhibit 13 and Exhibit 14. The values compare favorably with the

previously determined 1545.51 gallons and 758.257 gallons with the

smaller prover having the largest difference and that being only

0.01 percent of the total volume. The values used for statistical

data analysis were 1545.51 and 758.2 gallons respectively.

16.3.2 PRODUCT TEMPERATURE MEASUREMENTS . The temperature of the

product in the prover was determined at three depths in the prover

through liquid-filled thermowells installed in the prover shell.

- 139 -
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Exh i b i t 12

-140-
U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OE STANDARDS

WASHINGTON, O.C. 20234

REPORT OF CALIBRATION

Submitted by: American Petroleum Institute Test No. 232.09/332

Washington, D. C. Seal No. 4448

Item: 760 Gallon Vessel (Graduated Neck Type)

Maker: Kirkwood Tank Company (Maker #4090-1)

Material: Low Carbon Steel

Assumed Cubical Coefficient of Expansion:

0.0000186 per degree Fahrenheit

With the vessel described above in a standing position and a reference

attitude established by leveling the attached levels, and when drained

for 30 seconds after cessation of the main flow, the volume of water

delivered is as follows

Scale Volume Delivered Volume Delivered Estimated

Reading* at 60°F (U.S. Gal)** at 60°F (in 3

) Uncertainty (in 3

) 0 758.181 175140 ± 36.8

A scale division, between -160 and +180 as established by separate test,

is equivalent to 24.3 in 3

.

Position of the graduated scale was not changed as part of the calibration procedure.

*The scale reading is determined by the intersection of the horizontal

plane, tangent to the bottom of the gage meniscus, with the graduated

scale.

**The volume established is based on the density of water (reference

available on request). A U.S. gallon is equivalent to .003 785 412 m

3 or 231 in 3

.

ector

,

?aul E. Pontius, Chief

Mass and Volume Section

Optical Physics Division

Date: 13 June 1975

Exhibit 13

-141-
U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

WASHINGTON, D.C. 20234

REPORT OF CALIBRATION

Submitted by: American Petroleum Institute Test No. 232.09/332

Washington, D. C. Seal No. 4447

Item: 1500 Gallon Vessel (Graduated Neck Type)

Maker: Kirkwood Tank Company (Maker #4090-2)

Material: Low Carbon Steel

Assumed Cubical Coefficient of Expansion:

0.0000186 per degree Fahrenheit

With the vessel described above in a standing position and a reference

attitude established by leveling the attached levels, and when drained

for 30 seconds after cessation of the main flow, the volume of water

delivered is as follows:

Scale Volume Delivered Volume Delivered Estimated

Reading* at 60°F (U.S. Gal)** at 60°F (in 3

) Uncertainty (in 3

) 0 1545.55 357021 ± 71.3

A scale division, between -235 and +235 as established by separate test,

is equivalent to 25 in 3

.

The position of the graduated scale was not changed as part of the calibration procedure.

*The scale reading is determined by the intersection of the horizontal

plane, tangent to the bottom of the gage meniscus, with the graduated

scale

.

**The volume established is based on the density of water (reference

available on request). A U.S. gallon is equivalent to .003 785 412 m

3 or 231 in 3

.

Paul E. Pontius, Chief

Mass and Volume Section

Optical Physics Division

Date: 13 June 1975

Exh i b i t 14

-142-
Additionally, both commercial quality I iqu i d- i n-g I ass thermometers

and quartz-crystal temperature probes with electronic digital read-out

were used at each of the three measurement ooints.

The results of data examination for the liquid temperature

measurements indicate two conclusions. First, liquid-in-glass

thermometers, read to the nearest one-tenth degree and periodically

compared with a standard thermometer for accuracy, will provide

temperature measurements of sufficient accuracy and the accuracy

associated with the electronic device is not necessary for this

application. Second, the temperature of the product can be accurately

determined by a single thermowell located at the approximate centerheight of the prover. At no time for the tests conducted during

clear, cloudy, rain, sleet, or snow in both summer and winter was

a temperature gradient of significant proportions noted and recorded.

The only possible advantage to installing more than one thermowell

in a volumetric prover would be redundancy to reveal gross reading

error or to identify an erroneous indication created by a defective

thermometer or a thermowel I with insufficient I iquid fill.

16.3.3 STATISTICAL ANALYSIS -OF FIELD TEST DATA . The data sheets

completed during the field tests were screened to eliminate any meter

tests where an insufficient amount of data was taken or tests terminated because of equipment malfunction. The balance of the data

sheets were used in the analysis to evaluate the meter and prover

performance. Due to the extensive number of tests performed on each

meter, it was expedient to reduce the number of tests analyzed to

three norma I -flow tests and one s low-flow test. The tests were

- 143-
selected on the basis of being the first values appearing on the data

sheet rather than selecting what appeared to be the best or more

accurate tests. This was done to eliminate biased data selection.

16.3.3.1 ANALYSIS OF GROSS TEST DATA . The initial analysis was

performed by comparing the meter register indication against the prover

volume adjusted to include the neck scale reading. The results of

this analysis must be considered from the standpoint of statistical

significance. To simplify the statistical language, an approximate

assumption can be made that a "standard deviation" represents onethird of the "maximum uncertainty" of the normally distributed data set

being examined. With this definition, the percent of acceptable data

points at which the meter-prover system operated can be examined. For

a normal (Gaussian) probability distribution plus or minus one standard

deviation will include 68.26$ of the test data points, two standard

deviations include 95.46$, and three standard deviations include 99.73$.

For analysis the data was grouped by prover size. The averaged

results for the normal-flow tests yielded a calculated standard deviation

for the large prover of 2.135 gallons or 493 cubic inches which means

that 2 standard deviations (the 95$ limits) is 986 cubic inches. The

maintenance tolerance of H-44 for the 1545.51 gallon draft at normal

flow is 798 in 5

. The data then suggests that for the meters tested, 85

to 90 percent of the data points would be within H-44 tolerance. For

the smaller prover the calculated standard deviation was 1.038 gallons

or 240 cubic inches and 2 standard deviations is 480 cubic inches. The

maintenance tolerance from H-44 for this prover size is 404 in 5 . On the

- 144 -
basis of this standard deviation, approximately 90 percent of the

individual tests performed were within tolerance. Further, it was

noted that the percentage error of a single determination at normal

flow was the same for both provers.

The slow-flow test data yielded 3.117 gallons and 1.860 gallons

standard deviation for the large and small prover respectively, and

two standard deviations would be 1440 in^ for the large prover and

859 in^ for the small prover. The large prover special test tolerance

from H-44 is 1546 in^ and the small prover special test tolerance is

758 in-^. Thus, greater than 95 percent of the large prover tests were

within tolerance and approximately 90-93 percent of the small prover

tests were within tolerance.

16.3.3.2 TEMPERATURE EFFECTS ON TEST DATA . The observed and recorded

temperatures were used to correct the volumes in the provers and the

indicated volumes on the meter register.

The volume of the prover shell was corrected to the operating

temperature by the equation:

V

T| = V 6Q [I + 18.6 X I

0

—

6

( T |-60)U

where Vjj = Volume at Temperature Tj

Vgg = Volume at 60°F

Tj = Operating Temperature

The volume of the product in the prover was corrected for temperature by the equation:

Vj

2

= VT

[I + k (60-T2 )]

where T

2

= Product Temperature

- 145 -
Vj^ = Volume of Product Temperature

k = Volume Reduction Factor from ASTM D— 1 250 , Table 24

and the meter register volume was corrected for temperature by the

equation

:

Rj

3

= R Cl + k ( 6O-T3 )]

where T

3

= Product Temperature at Meter

Rj

3

= Corrected Volume for T

3

The analysis of data did not reveal any significant departure

from the comparative analysis of the "uncorrected" values. One factor

that did reveal itself was the problem of not being able to measure

the product temperature at or near the meter in a large number of

the meter systems tested. When the metered product temperature

could not be measured, the storage tank temperature posted in the

terminal was used. This temperature was often determined only once

per week and the posted tank temperatures and the temperature measured

in the prover were not always comparable.

16.3.3.3 SUMMER VERSUS WINTER TESTS . The data co I I ected dur i ng

each of the two distinct ambient temperature test periods were evaluated

by dividing the data for normal flows into two groups, under and over

60°F for one and under 40°F and over 70°F for the other. For the

norma I -flow tests there was no evidence of significant differences

between the low temperature and high temperature tests.

For slow-flow tests, significant differences in corrections to

the meter were found between high and low temperatures when the large

prover was used. The ambient temperature on the large prover became

statistically significant with the 13 to 14 minute test duration or

prover fill time.

- 146 -
16.3.4 SUMMARY OF TEST DATA ANALYSIS . Analysis and evaluation of

the Field Test Data provided evidence that the volumetric field

standards (provers) designed for these tests were sufficiently versatile and appropriate for the intended application. The equipment

was convenient to operate and was flexible enough to adapt to most

meter-proving situations encountered. The accuracy and repeatability

of the meter-prover were within normally acceptable limits and few

changes were required in the initial equipment specification to

develop the specification presented in Appendix A.

The meter error comparisons with existing H-44 tolerances were

within an acceptable range. The comparisons would have been improved

if the values of the calculated two standard deviations had more

closely coincided with the allowable tolerance. The data obtained,

though the number of meters tested was relatively small, reflects

that in normal meter testing the rejection or out-of-to I erance rate

would be in the order of 10 to 15 percent. This is possibly a small

amount higher than would be desired. The overall statistical analysis

for all meter systems suggests that the field test program was conducted

in a good state of system control if one uses a two standard deviation

criteria and in an excellent state of system control using the three

standard deviation theory.

- 147 -
17.0

VOLUMETRIC FIELD STANDARDS (PROVERS) DESIGN. The field tests

conducted with the equipment designed and fabricated for the Research

Associate Program provided an opportunity to evaluate the effectiveness of the equipment and appropriateness of the design.

From the information gathered and the experiences during the

tests, a specification was prepared to reflect the desired or required

criteria. Every attempt was made to produce a specification that would

promote uniformity in equipment and subsequent measurement. The

specification should establish equipment uniformity, regardless of

manufacturer, if complied with during fabrication.

The specification is included as Appendix A of this report.

17.1 FEATURES OF THE EQUIPMENT SPECIFICATION . Certain of the features

included in the specification require more discussion or clarification

than provided in a specification document. Those portions of the

specification that might conflict with previously accepted philosophy

or practice have been examined.

17.1. 1 NOMENCLATURE . The normally accepted designation for Volumetric

Field Standards varies with segments or individuals throughout the

entire user population. This report and the specification adopts

the use of p rover , standard or vol umetri c p rover as synonymous with

volumetric field standard.

17.1.2 ANT I -SWIRL PLATES . The anti -swirl plate or plates are considered to be necessary for all provers. The plates promote more

uniform draining and eliminates excessive air entrainment in the product leaving the prover.

- 148 -
17.1.3

BOTTOM LOADING ADAPTER. The adapter is defined as to type

and installation to promote uniformity and improve the operating

character i st i cs of the prover. The type of adapter is consistent with

the recommendation of the petroleum industry and proper instal lation

will reduce the turbulent action of the inlet stream with subsequent

reduction in evaporation loss or foaming.

17.1.4 THROTTLING VALVE FOR BOTTOM LOADING . A throttling valve is

required downstream of the meter to establish a s low-flow condition

for meter testing. Throttling upstream of the meter can produce a

liquid-vapor mixture that passes through the meter with resulting

measurement error.

17.1.5 SPECIAL MARKINGS . A conspicious information plate is required

to properly identify each specific prover and provide permanent documentation and i ndenti f i cation of the size, manuf acturer , material,

material character i st i cs , etc.

17.1.6 GROUNDING LUG . When liquid is introduced into a vessel

or tank static electricity is generated that must be dissipated to

ground. The grounding lug represents the point where a connection is

made to provide an electrical path, thus preventing "accidental discharge".

17.1.7 SCALE PLATES . The specification was prepared for Metric and

U. S. Customary systems of measurement. Recognizing that the equipment

may encounter dual applications, an allowance was made to provide

for an alternate graduated scale plate in addition to the plate graduated in incremental values consistent with the primary volume size

measurement system of the prover.

- 149 -
17.1.8 THERMOMETER WELL. Thermometer wells are considered to be more

desirable than encapsulated dial-type thermometers and can promote

more accurate temperature measurement if proper I i qu i d- i n-g I ass

thermometers are inserted into the thermowell which has a conducting

liquid inside.

The experience of the field tests indicated that a single temperature measurement at the vertical center of the prover is adequate.

At no time, during the field tests, was there any indication of

temperature stratification in the prover. The variation between

temperature measurements in the top one-third, center, or bottom

one-third was seldom greater than O.I°F.

A dial-type thermometer will be more susceptible to damage that

would require removal and replacement. Glass thermometers are expendable

and the thermowell is considered to be permanent.

Additional thermowells may be required at the discretion of the

purchaser and they are acceptable.

17.1.9 DRAIN LINE REQUIREMENTS . The drain line represents a conventional configuration with the exception of the sight-flow indicator.

The indicator is necessary to visually determine flow during draining

and time at which the prover is empty for beginning of 30-second drain

down. With closed-fill meter proving there is no visible access at

the prover top.

- 150 -
18.0 RECOMMENDED TEST PROCEDURE . In all device testing activities

it is important that uniform test procedures be employed by everyone

involved in the testing. To promote uniformity in meter testing it

is necessary to develop a detailed written procedure to present in

an orderly step-by-step manner. As with the tests conducted on motor

fuel dispensers, the basis for preparing the procedure was shown in

Exhibit 15 (2 pages) EPO No. 25. During the field tests of the

Research Associate Program experience and information was collected

to appropriately extend the EPO to yield the desired result. To

supplement the test procedure it is necessary to have a "Checklist"

similar to Exhibit 16.

The test procedure includes both visual and manual inspection and

should proceed as follows:

1. Perform pre-test meter examination and complete the checklist

provided.

2. Position the prover at the location to be tested. Level

the prover, verify that the prover drain valve is closed,

connect or position the loading adapter or delivery tube,

connect the vapor recovery nozzle to the prover making positive

that the interface valve between the recovery system and the

prover is open , connect appropriate ground and/or safety

interlock connections, and inspect the entire prover system

to determine that it is ready to receive product.

3. With the meter register at zero from pre-test check, cause

the set-stop to be set at one-half the volume of the prover

- 151 -
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Exh i b i

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( cont i nued

)

-153-

|
TRUCK LOADING FACILITY PRE-TEST METER EXAMINATION CHECK-LIST

(Reference: NBS Handbook 44 & NBS Handbook 112, EPO 25)

LOCATION PRODUCT METERED

METER: Size , Make & Model No. Serial No.

Yes No

Equipment & installaTion suitable for application (G-UR. I . I & G-UR.2.1)

Primary indicating and/or recording element (S.I.I)

Acceptable units and sub-division units (S.I.I)

One (I) gallon or equivalent unit (S.I.I)

Convenient indicator scale graduations (G-S.5 & S.1.2)

0.008" or more graduation width 0.04" or more clear interval

Indicator index symetricai with graduations, maximum 0.04" between index

and graduation, 0.06" or less between graduation and index. (S.1.3)

Proper return to zero function or operation. (S.I.I. 4)

Meter equipped with a vapor eliminator. (S.2.1)

Meter adjustment mechanism properly sealed. (S.2.2 & G-UR. 4. 4)

Meter equipped with ATC and properly sealed (S.2.6 & S.2.6.2)

Can ATC be properly deactivated. (S.2.6.2)

Is adequate thermowell provided for meter temperature (Special)

Automatic directional flow valves. (S.2.3)

Meter equipped with automatic set-stop mechanism. (S.2.4)

Piping prevents discharge of metered liquid to other than the delivery

point (include leak check) (S.3 & G-UR. 4.1)

System 'does not facilitate the perpetration of fraud. (G-S.2)

Is meter used for single product. (S.4 & G-S.l)

Legible markings and instructions. (G-S.6 & G-UR. 3)

Maintenance tolerance of 25 in^ plus 1/2 in^ per indicated gallon on Normal Tests,

I i n^ per indicated gallon on Special Tests, and 12.5 plus 1/4 in^ per indicated

gallon on Acceptance Tests. (G-UR. 4. I, G-T, T.l, & T.2)

Vapor Recovery Yes No

Inspector signature Date

Exhibit 16 -154-
if the meter system is so equipped. Read and record the

tota I i zer read i ng

.

4. Have a ticket inserted in the printing head.

5. Cause flow through the meter into the prover to begin.

6. With a stop watch, determine the rate at which the product

is being metered. Verify that the flow rate does not exceed

manufacturers rating.

7. Observe the system for leaks, proper set-stop operation,

and proper control valve function.

8. When the half-volume delivery is completed, cause the delivery

valve to be closed immediately.

9. If the meter system is equipped with a set-stop, verify

agreement between meter register and pre-set quantity.

0. Verify that the prover drain valve does not leak.

1. Repeat steps 3, 5, 6, 7, 8, 9, and 10.

2. Read the neck scale of the prover and the indicated volume

on the meter register. Compare these values but don't record

on the data sheet.

3. Connect the prover drain hose to the prover and pump-off

connection designated by terminal representative.

NOTE: Though not recommended, it may be necessary to move

the prover to another location for product pump-off.

4. Initiate prover pump-off or draining. Observe and time the

draining. When main flow ceases as observed in the sightflow- i nd i cator, time a 30-second drain-down before closing

the prover valve.

- 155 -
15 . Cause the register to be zeroed and the set-stop (if so

equipped) to be set at the nominal volume of the prover.

NOTE: It may be required or desirable to print a delivery

ticket for each prover test.

16. Repeat Steps 4 (if necessary) 5, 6, and 7.

17. When the delivery is completed, cause the delivery valve to

be closed immediately.

18. Read and record the prover neck scale level to an accuracy

of one tenth scale division.

19. Read and record the meter indication to the nearest one-tenth

division.

20. Determine and record on the data sheet the temperature of

the product in the prover to nearest 0.1 degree.

21 If the meter is non-temperature compensated or compensated

with both gross and net indication, the accuracy of the noncompensated or gross indication is determined by comparison

of data recorded in Steps 18 and 19. The meter tolerance

can be found in NBS Handbook 44 or calculated by the appropriate

equation as fol lows:

Acceptance Tolerance (in^) = (±) 12.5 + 0.25 (Prover Volume-gallons)

Maintenance Tolerance (in^) = (±) 25 + 0.5 (Prover Volume-gallons)

22. Determine the accuracy of the temperature compensated indication, if meter so equipped, by the method given in EPO

No. 25.

23. Repeat Step 13 (if necessary) and 14.

- 156-
24. If the test result is near or exceeds the allowable tolerance,

the test must be repeated. If well within tolerance,

proceed with the test.

25. A temperature compensated meter with both net and gross

volume indication can be verified by comparing the value of

the net indication with the corrected gross indication (correct

as in Step 22 substituting "gross reading" for "prover

readi ng")

.

26. Test the compensator of a temperature-compensated meter with

net indication only by deactivating the compensator and

repeating Steps 4, 15, 5, 6, 7, 17, 18, 19, 20, 21, 13, and 14.

27. Cause the "throttling valve" to be adjusted to achieve

approximately 20 percent of flow rate determined in normal

test or manufacturers recommended minimum flow rate. Minor

adjustment may be necessary as flow begins.

28. Repeat Steps 4 and 15.

29. Cause flow through the meter into the prover to begin.

30. With a stop watch, determine the rate at which the product

is being metered. Verify that the flow rate does not exceed

manufacturers rating.

3t>* Observe the system for leaks, proper set-stop operation,

and proper control valve function.

32. When the delivery is completed, cause the delivery valve to

be closed immediately.

33. Read and record the prover neck scale level to an accuracy

of one-tenth scale division.

- 157-
34. Read and record the meter indication to the nearest one-tenth

division.

35. Determine and record on the data sheet the temperature of

the product in the prover to nearest 0.1 degree.

36. If the meter is non-temperature compensated or compensated

with both gross and net indication, the accuracy of the noncompensated or gross indication is determined by comparison

of data recorded in Steps 18 and 19. The meter tolerance

can be found in NBS Handbook 44 or calculated by the appropriate equation as follows:

Special Test Tolerance (in^) = (±) | .0 (Prover Volume-gallons)

37. Determine the accuracy of the temperature compensated indication, if meter so equipped, by the method given in EPO

No. 25.

38. If the test result is near or exceeds the allowable tolerance,

the test must be repeated. If well within tolerance the meter

test is complete.

39. Repeat Steps 13 (if necessary) and 14.

40. Reactivate temperature compensator if deactivated, affix

security seals if appropriate, complete the report of test

(data sheet), and record final totalizer reading.

- 158-
18.1 RULES FOR TESTING . During any testing process, certain rules

or guidelines must be established for the safety and protection of

personnel, equipment, and property. From the experience of the Research

Associate Program Field Tests certain rules have been identified that

are considered important in test i ng jpetro I eum product meters. These

rules include:

1. Notify appropriate plant personnel of your presence.

2. Be completely familiar with plant safety requirements and

comply with these requirements at all times.

3. Know plant emergency procedures.

4. Determine the location of plant safety equipment such as

fire extinguishers, water hose, etc.

5. Have plant representative verify proposed piping configurations

for testing, pump-off, etc.

6. Never manipulate, change or adjust plant valves, hoses,

switches, etc. without the express knowledge and approval

of the designated plant representati ve.

7. Maintain constant surveillance on the meter register, setstop, etc. during periods when product is flowing through

the meter into the prover. Set-stop malfunction is primary

cause for overf i I I i ng of a prover and can be eliminated by

the person watching the meter.

8. Be completely familiar with your test equipment.

9. Never attempt to pump-off or drain prover without appropriate

approval to do so.

- 159 -
Never leave the test equipment unattended during testing,

pump-off, etc.

Always leave the test site as you found it with respect to

hoses, valve positions, etc.

Never discuss the results of your testing with other than

designated or appropriate persons.

Always record a beginning and final totalizer reading to

avoid fouling plant inventory records.

- 160 -
19.0 SUMMARY OF THE API/NBS RESEARCH ASSOCIATE PROGRAM . The Research

Associate Program began on April 21, 1970. Two major areas of interest

were examined in detail. The first phase of the program dealt with

I, 5, and 10 gallon test measures or field standards. The investigations included design evaluation, calibration method examination,

and review of field test procedures. The results of the studies in

this phase of the program and which are contained in this report

include the following:

1. Development of a Recommended Inspection Procedure for all

field standard sizes,

2. Development of information on Hydrocarbon Liquid Retention for

certain geometric configuration,

3. Preparation of a specification for Improved Design Test

Measure, and

4. Development of a Field Test Procedure for testing petroleum

product retail dispensers with a field standard or test

measure.

The second phase of the program was directed to volumetric field

standards or provers normally used in testing truck-mounted meters

and tank-truck loading terminal meters. A tentative equipment specification was written and used in obtaining a trailer-mounted meter

proving system. The meter proving system was subjected to a series

of field tests to evaluate the design configurations and meter-prover

performance. The results of the large volume field standard phase

of the program and contained in this report include:

- 161 -
1. Preparation of an Equipment Specification for 200 to 5600

Cubic Decimeter (53 to 1480 U.S. Gallons) Volumetric Field

Standards,

2. Development of a field test procedure for testing meters in

liquid hydrocarbon service, and

3. Investigation of meter performance and calibration in meter

systems with vapor recovery.

The Research Associate Program was terminated on July 31, 1975

after a duration of 50 months. The results realized from the research

efforts are expected to make a significant contribution to a uniform

measurement process throughout the petroleum industry.

- 162 -
20.0 CONCLUSIONS AND RECOMMENDATIONS . The Research Associate Program

was not defined by any document when started in 1970. The first

assigned responsibility in the program was to develop a scope outline

for the subsequent research activity. From the initial outline,

annual program reviews extended the scope of intended research with

corresponding time extensions. What started as a two-year program

to evaluate I, 5, and 10 gallon measures evolved to over 5 years and

encompassed all sizes of volumetric field standards. The API Research Associate Program has become one of the longer duration projects

since the Research Associate Program was initiated at NBS in 1919.

A wide variety of subjects have been included in the activity of the

Research Associate Program. In many cases the studies on the various

segments associated with the program have resulted in solutions. In

other cases the problems were identified but solutions never reached.

The information developed within the project is expected to be

of considerable value to both weights and measures jurisdictions

and the petroleum industry. Prior to developing specifications for

test measures and provers, no uniform specification existed in the United

States. The same is true for the detailed test procedures that are

presented. They replace nothing equivalent in open literature.

Attempts early in the program to find specifications and/or detailed

procedures that might be in existence yielded very little useful

information. Implementation of the procedures and specifications will

greatly enhance meter calibration uniformity and should subsequently

contribute to advancing the state-of-the art for liquid hydrocarbon

- 163-
metering and meter calibration.

As previously mentioned, several problem areas were identified

but never subjected to research that might yield solutions. These

problems are presented for consideration of research that must be

completed in the future. They include:

1. Truck-mounted Meter Field Test Program . The equipment

,p rovers) to perform these tests was included in the tra i I er-mounted

p rover system designed and fabricated for the program. Extensive

tests will be required to evaluate the performance of the provers,

test procedures, and tolerances for the meter.

2. Tank-Truck Loading Terminal Design Recommendation . This

problem was clearly identified during the Field Test Program. A

number of design features were found to be necessary for a modern

loading terminal. The solution to the problem could be realized by

further evaluation of existing terminal facilities to establish

user requirements for facilitating proper operation and meter

ca I i brat ion

3. Vapor Return System Research . The tests conducted on

meters with vapor recovery during the program represented a relatively

small quantity of metering systems but did provide evidence of significant problems. Since virtually all loading terminals will be

equired to have vapor recovery or disposal systems within several

years, the meter performance in vapor recovery systems must be

extensively examined. Testing or calibrating of meters in vapor-recovery

- 164 -
systems with open provers cannot be predicted to have either credibi I i ty

or legal base.

4. Meter Tolerance Evaluation . The field tests conducted with

the volumetric provers provided only a very small sample for evaluating

meter performance. The tests were designed to evaluate the provers

rather than the meters. Additional testing would examine meter

accuracy, time and/or volume limits for meter test interval requirements, and meter repeatability.

5. Upstream Versus Downstream Throttling to Control Flow Rate .

To conduct s low-flow tests for meters it is necessary to use a valve

to throttle flow to the desired rate. Investigations during the

Field Test Program provided evidence that throttling flow through a

valve upstream of the meter could promote metering of a liquidvapor stream for some products. The findings prompted the recommended

throttling valve between the prover and bottom- I oad i ng adapter included

in the equipment specification.

The comparison between upstream and downstream throttling

effects needs additional investigation. The research could be included

with item 4 above.

6. Test Procedure Demonstration/Training Seminars . The single

best and most reliable means to implement a recommended procedure is

considered to be by demonstration to those individuals normally

expected to use the procedure in routine job performance.

It is proposed that a coast-to-coast itinerary be established

to conduct seminars at numerous convenient locations. The seminars

- 165 -
would acquaint weights and measures and petroleum industry personnel

with appropriate meter testing procedures. The conduct of the proposed

training seminars should be a combined effort by NBS Office of Weights

and Measures and API rep resentat i ves and should be planned to include

a maximum attendance at all seminars.

7. Liquid Retention of Volumetric Provers . Liquid retention

is a feature of volumetric provers that requires further investigation.

Due to limited facilities, the tests that were conducted were on

small volume devices and did not provide sufficient information to

allow extrapolation to large volumes.

The completion of the items listed above should bring the

research program to a logical conclusion and provide information

sufficient to evaluate existing or proposed meter installations.

- 166 -
21.0 ACKNOWLEDGEMENT . Appreciation is expressed to the American

Petroleum Institute for my appointment as a Research Associate at

the National Bureau of Standards. The support of API membership

and staff has been extremely gratifying.

I would also I i ke to express my sincere appreciation to the staff

of the Office of Weights and Measures for their enthusiastic support

and assistance in the project. Particular thanks go to Blayne C.

Keysar who, as project supervisor, provided valuable guidance and

assistance throughout the project.

The work at NBS has been greatly enhanced and made more pleasureable by the cooperative attitude encountered in contacts with employees

throughout NBS.

A special thanks goes to P. R. deBruyn of the Office of Industrial

Liaison, NBS. He has provided a great deal of moral support and

assistance from the beginning of the API Research Associate Project.

- 167 -
22.0 LIST OF REFERENCES

Cl] Keysar, Blayne C. , "Specifications and Tolerances for Metal Volumetric Field Standards", U.S. National Bureau of Standards Handbook

105-3, Superintendent of Documents, U.S. Government Printing Office,

Washington, D.C. 20402, 1971.

C2] Houser, John F., "Procedures for the Calibration of Volumetric

Test Measures", U.S. National Bureau of Standards NBS I R 73-287

(August 1973, Institute for Basic Standards, National Bureau of

Standards, Washington, D.C. 20234

C3] Bowman, Horace A. and Randall M. Schoonover, "Procedure for High

Precision Density Determination by Hydrostatic Weighing", Journal

of Research of the National Bureau of Standards - C. Engineering

and Instrumentation, Vol . 7IC, No. 3, July-August 1967, National

Bureau of Standards, Washington, D.C. 20234.

C4] Aimer, H. E., "Method of Calibrating Weights for Piston Gages",

National Bureau of Standards Technical Note 577, Superintendent

of Documents, U.S. Government Printing Office, Washington, D.C.

20402, May 1971.

C5] National Bureau of Standards, Technical News Bulletin, Volume 45,

No. 4, April 1961, U.S. National Bureau of Standards, Washington,

D.C. 20234.

[6] American Society for Testing and Materials, "Tentative Recommended

Practice for Use of the Terms Precision and Accuracy as Applied to

Measurement of a Property of a MaTerial", ASTM Designation E 1 77—

6IT, American Society for Testing and Materials, Philadelphia, Pa.,

1961 .

C7] Hughes, J. C. and Keysar, B. C., "Testing of Metal Volumetric

Standards", U.S. National Bureau of Standards Monograph 62,

Superintendent of Documents, U.S. Government Printing Office,

Washington, D.C. 20402, 1963.

E8] American Institute of Physics Handbook, Third Edition (1972)

McGraw-Hill Book Company, New York, New York.

C9] American Petroleum Institute, "Measurement of Petroleum Liquid

Hydrocarbons by Positive Displacement Meter", API Standard 1101,

American Petroleum Institute, 1801 K Street NW, Washington, D.C.,

20006, I960.

- 168 -
[10] National Bureau of Standards, Handbook 44 - 4th Edition,

"Specifications, Tolerances, and Other Technical Requirements for Commercial Weighing and Measuring Devices",

Superintendent of Documents, U.S. Government Printing

Office, Washington, D.C. 20402, 1971.

[11] Warn I of, Otto K., "Examination Procedure Outlines for

Commercial Weighing and Measuring Devices", U.S. National

Bureau of Standards Handbook 112, Super i ntencent of

Documents, U.S. Government Printing Office, Washington,

D.C. 20402, 1973.

- 169 -
23.0 BIBLIOGRAPHY

Allegheny Lud I um Steel Corporation, "Stainless STeel Handbook",

Allegheny Ludlum Steel Corporation, Pittsburgh, Pennsylvania, 1959.

American Petroleum Institute, "USA Standard for Mechanical Displacement Meter Provers", API Standard 2531, American Petroleum Institute,

1801 K Street NW, Washington, D.C. 20006, 1965.

Eisenhart, Churchill, "Expression of the Uncertainties of Final Results", Science, 14 June 1968, Volume 160, pp 1201-1204, American

Association for the Advancement of Science, c. 1968.

Fung, Y. C. and Sechler, E. E., "Instability of Thin Elastic Shells",

Proceedings of First Sympos i urr. on Naval Structural Mechanics, Perqamcn

Press, I960.

Kaplan, A. and Fung, Y. C., "A Nonlinear Theory of Bending and Buckling

in Thin Elastic Shallow Spherical Shells", National Advisory Committee

for Aeronautics Technical Note 3212, National Advisory Committee for

Aeronautics, Washington, D.C., 1965.

Roark, Raymond J., "Formulas for Stress and Strain", McGraw-Hill Book

Company, New York, New York, c. 1965.

Smith, Ralph W., "Testing of Measuring Equipment", U.S. National Bureau

of Standards Handbook 45, Superintendent of Documents, U.S. Government

Printing Office, Washington, D.C., 1951 (Out of Print).

Timoshenko, S., "Theory of Plates and Shells", First Edition, McGrawHill Book Company, New York, New York, 1940.

U.S. National Bureau of Standards, "Report of the Thirty-Eighth National

Conference on Weights and Measures", U.S. National Bureau of Standards

Miscellaneous Publication 209, Superintendent of Documents, U.S.

Government Printing Office, Washington, D.C., 1953

Metals Handbook Committee, "Metals Handbook", Eighth Edition,

American Society for Metals, Metals Park, Novelty, Ohio, 1961.

Schoonover, Randall M., "The Equivalence of Gravimetric and Volumetric

Test Measure Calibration", U.S. National Bureau of Standards NBS I

R

74-454 (February 1974), Institute of Basic Standards, National Bureau

of Standards, Washington, D.C. 20234.

- 170 -
APPENDIX A

VOLUMETRIC FIELD STANDARDS SPECIFICATIONS

SPECIFICATIONS FOR 200 TO 5600 CUBIC DECIMETER (53 TO 1480 U.S. GAL.)

VOLUMETRIC FIELD STANDARDS

EQUIPMENT SPECIFICATION

This specification is prepared for volumetric provers intended for:

1. Use in testing meters in low viscosity and low

vapor pressure liquid service, or

2. Use as field reference standards for water calibrations .

1 .0 FABRICATING VOLUMETRIC PROVERS .

1.1 SCOPE : This work shall consist of the fabricating of the volumetric provers herein described. The work shall include testing,

packaging, and shipping as specified.

1.2 MATER I ALS : The material used in the fabrication of the provers

must be impervious to the liquids for which the prover will be

used. The material of all wetted surfaces (excluding the gage

glass and other removable hardware) must be identical throughout

the prover. The piping of the prover shall conform to the latest

revision of API Standard 5L or equal. Materia-I selection for

the prover shall be one of the following:

1. Stainless steel, 300 series,

2. Low-carbon steel, painted exterior, epoxy coating

on interior,

3. Low-carbon steel, terne or galvanized, painted

exterior, or

4. Low-carbon steel, painted exterior, interior coati

of material certified compatible with intended

I i qu i d serv i ce

.
1.3 MANUFACTURING METHODS:

A. STORAGE : Storage shall protect the material from rust, dirt,

and all other potential physical and chemical damage during

fabrication.

B. WORKMANSHIP AND FINISH : The workmanship and finish shall

be that which can be produced by skilled workmen using modern

tools in a modern fabrication shop.

C. WELDING :

(1) General: Welding shall be done according to the best

modern practices, by qualified welding operators. All welding

shall be performed in accordance with American Welding

Society, "Welding Handbook".

The same materials, processes, and type of equipment as

required for the execution of the fabrication shall be used

in qua I i fy i ng, we I ders and welding operators. If a fabrication

shop prequalifies its metal-arG welding operators according

to the standard qualification procedure of the American

Welding Society and certifies to the purchaser that an operator

has been prequalified within 12 months prior to the beginning

of work on the subject structures, the purchaser may consider

such operator qualified.

(2) Preparation of Material for Welding: Surfaces to be

welded shall be smooth, uniform, and free from fins, tears,

and other defects which would adversely affect the quality

of the weld. The surfaces to be welded shall also be free

A-2
from loose scale, slag, rust, grease, or other foreign

matter that would affect proper welding. Mill scale that

withstands vigorous w i re-brush i ng or a light film of drying

oil or rust i nh i b i t i ve coatings may remain. Oxygen cutting

shall, wherever possible, be done by machine oxygen cutting.

Machine cut edges shall be substantially as smooth and

regular as those produced by edge planing and shal I be free

of slag. Manual oxygen cutting shall be permitted only

where machine oxygen cutting is not practicable, and only

with approval of the purchaser. The edges resulting from

manual oxygen cutting shall be inspected and smoothed with

care. All re-entrant corners shall be filleted to a radius

of at least 20 millimeters (0.75 inch). The cut lines shall

not extend beyond the fillet, and all cutting shall follow

closely the lines prescribed.

(3) Assembly for Welding: Abutting parts to be joined by

butt welds shall be carefully aligned. The parts are to be

effectively restrained against bending, a maximum offset of

10 percent of the thickness of the thinner part joined, but

in no case more than 3.5 millimeters (0.125 inch), may be

permitted as a departure from the theoretical alignment.

Measurement of offset shall be based on centerline of parts

unless shown on plans.

Tack welds that are to be incorporated in the final welds

shall be subject to the same quality requirements as the

A-3
final welds. Such tack welds shall be as small as practicable and where encountered in the final welding, shall be

cleaned and fused thoroughly with the final weld. Multiplepass tack welds shall have cascaded ends. Defective, cracked,

or broken tack welds shall be removed prior to the final

welding.

(4) Procedure for Manual Shield Metal Arc Welding: The work

shall be positioned for flat welding wherever practicable.

The classification and size of electrode, arc length, voltage,

and amperage shall be suited to the thickness of the metal,

type of groove, positions of work, and other circumstances

attending the work.

When welding in the vertical position, the progression of

all passes shall be in the up direction.

Before welding over previously deposited metal, the slag

shall be removed and the weld and adjacent base metal shall

be brushed clean. This requirement shall apply not only to

successive layers but also to successive beads and to the

crater area when welding is resumed after any interruption,

it shall not, however, restrict the making of plug and slot

welds.

All butt welds, except when produced with the aid of backing,

shall have the root of the initial weld gouged, chipped, or

otherwise cleaned to sound metal before the welding is

started from the second side. Butt welds made with the use

of backing of the same material as the base metal shall

A-4
have the weld metal thoroughly fused with the backing.

Butt welds sha I I be extended beyond the edges of the parts

to be joined by means of extensions providing a similar

joint preparation and having a width not less than the thickness of the thicker part nor less than 25 mi I I imeters (I inch).

Each weld pass shall be terminated at least 19 mi II imeters

(0.75 inch) from the edge of the parts to be joined.

Extensions shall be removed upon completion and cooling of

the weld and the ends of the weld made smooth and flush

with the edges of the abutting parts.

(5) Dimensional Tolerances in Welding: The dimensions of

welded structural members shall be within the tolerances

permitted by the general specifications governing the work.

(6) Quality of Welds: Weld metal shall be sound throughout. There shall be no porosity or cracks on the surface

of any weld or weld pass. There shall be complete fusion

between the weld metal and the base metal and between successive

passes throughout the joint. Welds shall be free from overlap and the base metal free from undercutting.

(7) Cleaning and Protective Coating of Welds: Welded joints

that are to be painted shall not be painted until the welding

has been accepted. Welds that are to be galvanized or otherwise coated with metal shall be treated to remove every

particle of slag.

D. FORMING OR SHAPING : A I I formed sections must be smooth

continuous surfaces. Pockets, dents, or crevices that could

A-5
entrap air, liquid, or contaminents shall not be considered

acceptable. The vertical section (barrel) must also be

free from any dents or irregularities.

1.4 I NSPECT I ON : Inspection shall be performed in compliance with

American Petroleum Institute "Guide for Inspection of Refinery

Equipment, Appendix for Inspection of Welding", second edition,

1971 or latest edition.

1.5 TEST I NG : The prover and piping shall be tested by the hydrostatic

test procedure published by the American Society of Mechanical

Engineers' Steel Pipe, Flanges, and Flanged Fittings, USAS BI6.5-

1968.

The purchaser reserves the right to observe testing. The seller

shall furnish all covers, gaskets, bolts, and test equipment.

Gaskets to be shipped with the prover shall not be used for any

hydrostatic testing.

1.6 INTERIOR EPOXY COATING : If the interior of the prover is to be

coated with epoxy, such epoxy shall be certified by the manufacturer

to be impervious to liquid hydrocarbons and solvents. The epoxy

shall be applied in compliance with the recommendations of the

manufacturer. This shall include consideration of the surface

preparation prior to coating.

1.7 METHOD OF ACCEPTANCE : Acceptance shall be based on the satisfactory

completion of the job herein described. Satisfactory completion

shall include calibration traceable to National Bureau of Standards

and performed by a competent agency, and verification of the

operating character i st i cs of the prover.

A-6
2.0

PAINTING

2.1 SCOPE : This work shall consist of painting of prover and piping

fabricated of other than stainless steel.

2.2 MATER I ALS : All materials shall be of high quality and manufactured

by a company known to the purchaser. The paint materials must

be intended for application to the surfaces of the fabricated

prover and be relatively impervious to petroleum products.

2.3 PAINTING METHODS :

A. SCHEDULE OF PAINT COATS : The prover shall be painted with

three coats of paint as specified below. The paint for each

coat shall be as specified in 2.2.

( 1 ) Primer Coat

(2) Fi rst Coat

(3) Second Coat

B. PREPARATION OF METAL SURFACES FOR PAINTING : Preparation of

surfaces for painting shall comply with the standards as

given in U.S. Department of Transportation, Federal Highway

Administration, Bureau of Public Roads, "Standard Specification for Construction of Roads and Bridges on Federal

Highway Projects", FP-69, 1969. Available from Superintendent

of Documents, Washington, D.C.

C. PAINTING PROCEDURES : Painting shall comply with the standards

set forth for painting metal surfaces as given in U.S. Department of Transportation specifications cited in 2.3 B.

2.4 INSPECTION: Inspection shall be made by the purchaser. Inspection

shall be with consideration of the painting methods specified in

A-7
Section 2.3.

2.5 TEST I NG : Testing shall consist of random tests on the painted

surface with a dry film thickness gage of the electro-magnetic

type. The required dry film thickness shall be as follows:

Primer Coat . . . 0.051 + 0.006 millimeters (.002 ± .00025 inch)

Finish Coats . . . 0.102 + 0.010 millimeters (.004 + .0005 inch)

Total Dry Film . 0.153 + 0.015 millimeters (.006 ± .0006 inch)

2.6 METHOD OF ACCEPTANCE : Acceptance shall be the satisfactory

completion of the painting herein described.

3.0 EQUIPMENT DESCRIPTION

3.1 SCOPE : This section describes the type and design of volumetric

provers covered by Sections 1.0 and 2.0.

3.2 GENERAL DESCRIPTION : The volumetric prover is a vessel which

has a barrel of uniform circular cross-section with a cone-shaped

top which has attached to its apex a smal I diameter neck of

uniform cross-section with an appropriate liquid level gage.

The bottom of the prover is a cone-shaped sect-ion with a drain

pipe affixed to the apex. The prover must be provided with adequate means of support. AdzquaXz me.ani shall consist of, but not

be limited to, an external bottom reinforcing band and/or legs.

Level change between the empty and full prover must be prevented.

3.2.1 CAPAC I T I ES : The capacity of the prover shall be as indicated

on Table I or 2.

3.2.1. 1 ANT I -SWIRL PLATE : An anti-swirl plate or plates must be

attached to the bottom cone of the prover to minimize liquid

swirl during emptying. Refer to Figure I or Figure 2.

A8
3. 2. 1.2 BOTTOM LOADING ADAFTER : A bottom loading adapter may be

required by the purchaser. This adapter shall be attached

to the lower portion of the vertical section (barrel) of the

prover, just above the bottom conical section. The vertical

dimension, above grade, of the adapter should not exceed 122

centimeters (48 inches). Penetration of the vessel should

be accomplished with a weld elbow as shown in Figure 2.

The elbow shal I direct the flow around the periphery of the

prover and slightly downward. A small diameter bleed hole,

3 millimeters (0.128 inch) shall be drilled in the top of

the elbow (inside of prover) to eliminate trapping of air

when adapter is not used for loading. The bottom loading

adapter must comply with API RP 1004, "Bottom Loading and

Vapor Recovery for MC-306 Tank Motor Vehicles", Third Edition,

1975 or latest edition.

3. 2. 1.3 THROTTLING VALVE FOR BOTTOM LOADING : A th rott I i ng va I ve to

achieve reduced flow rate for a SZaO-FlotV Tz,6t may be required

by p urchaser. This valve, if required, shal I be of the

wafer-type and be installed between the flange of the Bottom

Load Adapter and the flange on the elbow attached to the

barrel. The valve shall be of the butter-fly type with a 12

millimeter (0.5 inch) hole drilled in the gate to prevent

blocking total flow if closed. The valve handle shall be

provided with a notched, indexing mechanism to mechanically

hold the valve In the selected open position.

A-9
3. 2.

1.4

REINFORCING BANDS : External reinforcing bands, at least

equal to the barrel thickness, shall be attached to the barrel

for strength and/or to prevent vessel distortion. A top

reinforcing band shall be provided which extends D/2 (see

Figures I and 2) above the barrel to top cone joint. Drain

provision for trapped liquid is required.

3.2. 1.5 LIFTING BAILS OR LUGS : Lifting bails or lugs shall be provided

such that the empty prover may be moved with a crane or hoist.

The bails or lugs (three required), located on the top reinforcing band, must be spaced to prevent prover distortion

during lifting and promote uniform bail or lug loading.

3.2. 1.6 SPECIAL MARKINGS : Each prover shall bear a permanent, conspicious plate upon which the following information appears:

1 . Name of Manufacturer

2. Address of Manufacturer

3. Material Identification (ASTM No. and Grade).

4. Material Thickness

5. Manuf acturers Model Number

6. Non-repet i t i ve Serial or Identification Number

7. Cubic Coefficient of Thermal Expansion of Material

per degree C (F)

8. Nominal Volume at Zero Level on the Neck Scale

9. Drain Time After Flow Cessation: 30 Seconds (unless

a different time value is requested by purchaser).

3.2. 1.7 SPIRIT LEVELS : Each prover shall be equipped with two shielded

style, ground vial levels, similar to Starrett #98. The top

surface of the prover neck or flange must be a reinforced

ground surface that will provide an indication of prover

level to facilitate installation of the levels and/or replacement in the event of damage to levels. The levels should be

mounted on the top cone at 90° to each other and approximately

A- 10
half-way between the outer edge of the prover and neck.

3. 2. 1.8 VAPOR RETURN TUBE : For provers sized from Table 2 and when

required by purchaser, a 4" (maximum) vapor return tube shall

enter just below the reinforced top of the neck and extend,

tangent to the prover surface, to a point in the same approximate horizontal plane as the bottom load adapter. The tube

shall terminate with a threaded tee to allow installation of

a proper vapor return fitting and a valve to serve as a vacuum

breaker during unloading. The tube must be attached to the

prover shell as required for rigidity. NOTE : The vapoA.

sietuAn tine i>ize tf> not standardized. A size smatieA. than

4" may be fiequified by the purchase*. ifi adequate &o*. this

intended appticatton.

3.2. 1.9 GROUNDING LUG : A grounding lug to protect against accidental

discharge of static electricity is required. The lug shali

be a threaded lug securely attached to the skirt of the prover

and on the same side of the prover as the vapor return line

and bottom load adapter.

3.2.1.10 LADDER AND PLATFORM : A ladder, when required to read gage

scale, reaching from the base of the prover to the top cone,

shall be fabricated of I" pipe or equal,. A level platform

of expanded metal (mesh) shall be provided, if necessary,

to a I I ow reading of the liquid level. The ladder shall be

securely attached to the prover for safety and on the same

side as the liquid level gage. See Figure 3.

A- I I
3.2.1. I I PROVER COVER : AM provers shall be provided with a hinged.

vapor-tight cover.

Provers sized from Table I shall have a 2" half-coupling welded

on the hinged cover or in the top of the neck just below the

cover to accommodate vapor recovery applications. The cover

shall have a sealing gasket.

Provers sized from Table 2 shall have a cover which consists

of an outer ring flange bolted to the prover neck and an

inner hinged cover for the 25 centimeter (10 inch) inside

diameter opening of the ring flange. The ring flange and

hinged cover shall have sealing gaskets. A gasketed clamping

ring may be substituted for bolting of ring flange. A

Pressure Activated Fill (PAF) Manhole Cover as used on tank

trucks is highly acceptable for the hinged cover and will

eliminate the need for a pressure rupture disc.

3,2.1.12 GAGE ASSEMBLY : The prover shall be provided with a gage

assembly that consists of 16 millimeter I .D. (0.625 inch)

clear borosilicate glass tube, holding brackets, adjusting

rods, 0-ring seals, and scale plates graduated above and below

zero. The assembly shall penetrate the top cone near the neck

and terminate with entry into the neck near the top. The

top fitting shall have a removable plug to facilitate cleaning

of the gage glass with a brush. The assembly must be rigid

and must be provided with means of affixing a I ead-and-wi re

sea I .

A- 1

2
3.2. 1.12. 1 Scale Plates: Corrosion resistant scale plates shall

mounted approximately on a tangent to the front of or

directly behind the gage glass. In either mounting, the

scale plate shall not be more than 6 millimeters (0.25

inch) from the gage glass. If the scale plate is mounted

behind the gage glass, protection of the glass in the form

of a shield is required. The protective shield must allow

removal of the gage glass for cleaning or replacement

without any difficulty.

The basic scale on all volumetric provers shall be cubic

centimeters or cubic inches. A single scale shall have

only one measurement system markings, e.g. cubic centimeters, decimal cub i c dec imeters cubic inches, or decimal

gallons. Dual scales are permitted only by providing two

scales and will be possible only when the scales are

mounted tangent to the front of the gage glass. The primary

scale must always be mounted on the left side of the gage

g I ass

.

3.2.1. 12.1. 1 Scale Plate Markings: Special requirements govern the

markings on all scale plates. These requirements include,

but are not limited to, the following:

1. All scale markings must be of a color contrasting

to that of the plate.

2. Scale plates shall be graduated above and below zero. The volume indicated by the markings, either above

or below zero, shall not be less than one and onehalf times the meter maximum acceptance tolerance

as determined by the prover size.

A- 1 3
3. Convenient major division lines, consistent to the

measurement system used, shall be longer than subdivision lines and be numbered for volume indication.

4. Graduation lines shall be of uniform width and not

more than 0.6 mm (.025 inch) or less than 0.38 mm (.015 i nch ) wide.

5. Scale plates mounted tangent to the front of the gage

glass shall have the length of the major graduations

(numbered) no less than 6.5 mm (.25 inch) and intermediate graduations length no less than 3 mm (.125

inch). All lines shall extend to the edge of the

scale plate nearest the gage glass.

6. Scale plates mounted behind the gage glass shall

have major graduations at least 19 mm (.75 inch)

and sub-division lines at least 12 mm (.5 inch)

in length.

7. The zero line of all scale plates shall extend across

the entire width of the plate and be clearly identified.

8. The minimum distance between any graduation lines

shall be 1.6 mm (0.0625 inch).

3.2.1.13 THERMOMETER WELL : A thermowell (length shown in Figure I

or 2) shal I be i nsta I led in the prover. The wel I is to point

inward and downward at an angle of approximately 15°. The

end of the thermowell inside the prover should be at the

approximate center of the cylindrical section height.

3.2.1.14 PRESSURE RELIEF PROTECTION : All provers built with vaporrecovery provisions must be equipped with a pressure relief

fitting (minimum 2 inch pipe size) of 20-35 kPa (3-5 psig)

rating and a rupture disc of 35 kPa (5 psig) burst rating.

(See 3.2. I . II )

3.2.1.15 VACUUM RELIEF PROTECTION : All provers built with vapor-recovery

provisions must be equipped with protection against vacuum

during unloading. This protection may be the valve in the vaporA- 14
return line plus a 2-inch vacuum relief fitting or by a checkvalve (not spring loaded) in the tee at the termination of

the vapor return line plus a rupture disc of 20 kPa (3 psig)

vacuum rating.

3.2. 1 . 16 DRAIN LINE REQUIREMENTS : The dra i n line, welded to the bottom

cone, shall have a downward slope of 7° (nominal). The drain

line shall consist of a length of pipe, a fast-acting valve

(butterfly or equal), a s i ght-f I ow- i nd i cator, and a fitting

to connect the drain hose. For provers less than 2000 dm^

(528 GAL.), the drain line should be 2-inch pipe (minimum).

For provers 2000 dm^ (528 gal.) and larger, the drain line

should be 4-inch pipe. The s i ght-f I ow- i nd i cator should have

a moving element to allow verification of flow. Adequate

i support of the drain line shall be provided.

3.2.1.17 DIMENSIONS AND DESIGN DETAILS : The dimensions and design details shall comply with the appropriate values of Figure I and

Table I or Figure 2 and Table 2 and any additional details

furnished by the purchaser.

3.2.1.18 OPERATING CONDITIONS: The Volumetric Provers described in

, specification are intended for. but not necessarily limited

the following 1 i qu i ds :

1 . Gasol i ne 5. A 1 coho 1

2. Jet Fuel 6. Water

3. Keros i ne or Stove Oi

7. Commercial Solvents

4. Diesel Oi 1

A- 1 5
3.2. 1.19 SUBMERGED FILL TUBE : One or more submerged fill tubes may

be required by the purchaser. The size requirements for the

tube/s/ will normally be for a 4-inch submerged pipe to extend

from the top of the prover neck, through the cone, to within

10 to 15 cm (4 to 6 inch) of the bottom cone. The tube may

be installed inside the prover neck or adjacent to the neck

depending on space limitations. If the submerged fill tube

i s i nsta I I ed adj acent to the prover neck it will not nullify

the requirements of 3.2. I . 12. I . I

.

Submerged fill tubes for

provers of less than 2000 cubic decimeter (528 gal.) volume may

be sized less than 4-inch.

3.2.1.20 SPECIAL ACCESSORIES : Special applications and/or installation

of the provers covered by this specification may require

that certain other features be added. Such requirements are

beyond the scope of this specification and must be supplied

to the manufacturer by the purchaser.

4.0 PREPARATION FOR SHIPMENT : The prover, valves, piping, etc. shall

be free of slag, scale, weld spatter, grit, dirt, water, and any

other foreign matter before shipment.

Prover shall be adequately supported and braced to prevent damage

during transit.

Stud bolts and threaded connection plugs or caps shall be thoroughly

lubricated with a graphite impregnated paste before installation.

Exposed flange faces shall be protected with securely fastened

wood cover plales and threaded connections with pipe plugs or caps.

A- 1

6
All hinged covers, gage assembly, valves, etc. shall be properly

installed and provided with adequate protection for shipment.

D. J. Hine, API Research Associate

USCOMM-NBS-DC

A- 1 7
<L

FIGURE

A- 1 8
TABLE 1

ITEM SYMBOL

REFER FIG. 1 UNIT VALUE

NOMINAL CAPACITY CUBIC 200 500 1000

DECIMETER (53) (132) (264)

(Gallon)

MAX. ALLOWABLE ERROR — cm^ 100 245 490

(Nominal Versus Calibrated (i n

3

) (6) (15) (30)

Capacity)

PROVER-INSIDE DIAMETER F mm 762 914 1270

(in.) (30) (36) (50)

PROVER-TOTAL HEIGHT B mm 1041 1443 1552

(in.) (41) (56.8) (61)

NECK-INSIDE DIAMETER G mm 152 203 254

(in.) (6) (8) (10)

NECK-HEIGHT A mm 460 508 508

(in.) (18) (20) (20)

PROVER-THICKNESS — mm 2.65 2.65 3.5

(Nominal) (in.) (.1046) (.1046) (.1345)

NECK-THICKNESS — mm 3.4 4.2 6.4

(Nominal) (in.) (.135) (.164) (.250)

HEIGHT OF BARREL C mm 336 635 620

(in.) (13.25) (25.0) (24.4)

TOP BAND WIDTH D mm 100 100 125

(in.) (4) (4) (5)

LOWER BAND WIDTH E mm 125 125 150

( in.

)

(5) (5) (6)

TOP CQNE ANGLE J Degrees 25 25 25

BOTTOM CONE ANGLE K Degrees 20 20 20

DRAIN LINE ANGLE - Degrees 7 7 7

SUBMERGED TUBE I.D. H mm - - - (in.) (3) (3) (3)

SCALE GRADUATIONS _ cm 3 75 150 150

( i n^) (5) (10) (10)

NOMINAL + AND - SCALE cm 3 2500 4650 8300

READING (

i n^>) (150) (275) (525)

A- I 9
FIGURE 2 .

A-20
TABLE 2

ITEM SYMBOL

REFER FIG.

UNIT

94. VALUE

NOMINAL CAPACITY — CUBIC 2000 2800 5600

DECIMETER (528) (740) (1480)

(Gallon)

MAX. ALLOWABLE ERROR

(Nominal Versus Calibrated cm^ 1000 1400 2800

Capacity) (in 3

) (62.5) (87.5) (175)

P ROVER- INS IDE DIAMETER F mm 1830 2235 2415

(in.) (72) (88) (95)

PROVER-TOTAL HEIGHT C mm 1780 2040 2415

(in.) (70) (80) (104)

NECK-INSIDE DIAMETER G mm 336 336 387

(in.) (13.25) (13.25) (15.25)

NECK-HEIGHT A mm 660 864 915

(in.) (26) (34) (36)

PROVER-THICKNESS - mm 4 5 5 (Nominal) ( in.

)

(.165) (.1875) (.1875)

NECK-THICKNESS - mm 9.5 9.5 9.5

(Nominal) ( in.

)

(.250) (.250) (.250)

HEIGHT OF BARREL B mm 520 416 902

(in.) (20.5) (16.4) (35.5)

TOP BAND WIDTH D mm 150 150 150

( in.

)

(6) (6) (6)

LOWER BAND WIDTH D mm 150 150 150

(in.) (6) (6) (6)

TOP CONE ANGLE J Degrees 25 25 25

BOTTOM CONE ANGLE K Degrees 20 20 20

DRAIN LINE ANGLE L Deqrees 7 7 7

DRAIN LINE ELEVATION E mm 100 130 150

(in.) (4) (5) (6)

SCALE GRADUATIONS _ cm3 400 400 400

( i n 3) (25) (25) (25)

NOMINAL + AND - SCALE _ cm^ 15600 22800 46000

READING (in 3 ) (950) (1400) (2600)

RING FLANGE OPENING H

cm5 25 25 25

( in 3

) (10) (10) (10)

A-2 I
LADDER & PLATFORM DETAILS

A-22
NBS-1 14A (REV. 7-73)

I

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLIC ATT ON OR REPORT NO. 2. Gov’t Accession

No.

3. Recipient*

4. 1 1 1 LL-. AND SUBTITLE —

Evaluation of Metal Volumetric Standards Used in the Measurement of Liquid Hydrocarbons. A report of a U.S. National

Bureau of Standards and American Petroleum Institute Research

Associate Project.

5. Publication Date June 1977

6. Performing Organizing

7. AUTHOR(S)

8. Performing Organ. Re|

V. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unr

11. Contract/Grant No.

12. Sponsoring Organization Name and Complete Address (Street, City, State, ZIP)

American Petroleum Institute

21C1 L Street, Northwest

Washington, D.C. 20037

13. Type of Report & Period Covered Final - 4/70 to 7/75

14. Sponsoring Agency Code*

15. SUPPLEMENTARY NOTES

16. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant bibliography or literature survey, mention it here.) Weights and measures jurisdictions and the petroleum industry have, for many years,

used metal volumetric standards in the measurement of petroleum liquid hydrocarbons.

As a result of several surveys, it was learned that a need existed to establish

uniform application procedures and investigate measurement accuracy. To answer this

need, a joint project under the Research Associate Program of the U.S. National

Bureau of Standards was established with the American Petroleum Institute as the

sponsoring agency. Equipment and techniques were evaluated and the program resultec

in an equipment specification, a recommended procedure for inspection, and a recommended procedure for the calibration of metal volumetric standards used by

weights and measures jurisdictions and the petroleum industry.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name; separated by semicolons) Accuracy , design analysis; equipment specification; field

standard; gravimetric calibration; liquid retention or clingage tests; precision; prove

Research Associate Program; standards inspection procedure; test measure; test measure

evaluation; temperature correction; "to contain; to deliver"; volumetric calibration

18. AVAILABILITY [X Unlimited 19. SECURITY CLASS 21. NO. OF PAGE'-

(THIS REPORT)

[j For Official Distribution. Do Not Release to NTIS 203

UNCLASSIFIED

1 1 Order From Sup. of Doc., U.S. Government Printing Office 20. SECURITY CLASS 22. Price Washington, D.C!. 20402. SD Cat. No. C M (THIS PAGE)

[x Order From National Technical Information Service (NTIS)

Springfield, Virginia 22151 UNCLASSIFIED $7.75

USCOMM-DC 29042-P74

*U.S. GOVERNMENT PRINTING OFFICE: 1977 240-S43/246 1-3





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