Louisiana Administrative Code › Title 51 - PUBLIC HEALTH-SANITARY CODE › Part XIV - Plumbing › Chapter 7 - Sanitary Drainage › Section XIV-725 - Drainage System Sizing

Current through Register Vol. 50, No. 6, June 20, 2024
A.
				Maximum Fixture Unit Load. The maximum number of fixture units that may be
				connected to a given size of building sewer, building drain, or horizontal
				branch of the building drain shall be determined using Table 725.A.1 of this
				code below. The maximum number of fixture units that may be connected to a
				given size vertical soil or waste stack, or a horizontal branch connecting to a
				vertical soil or waste stack, is given in Table 725.A.2 of this code.
Table 725.A.1
Building Drains and Sewers
Maximum Number of Fixture-Units that may be
							 Connected to Any Portion of the Building Drain or the Building Sewer
(Includes branches of the building drain. The
							 minimum size of any building drain serving a water closet shall be 3". No
							 building sewer shall be less than 4 inches in size)
Diameter of Pipe (in.)
Fall in Inches Per Foot
1/16
1/8
1/4
1/2
2
-
-
21
26
3
-
20
(not over two water closets)
27
(not over two water closets)
36
(not over two water closets)
4
-
180
216
250
5
-
390
480
575
6
-
700
840
1,000
8
1,400
1,600
1,920
2,300
10
2,500
2,900
3,500
4,200
12
3,900
4,600
5,600
6,700
15
7,000
8,300
10,000
2,000
Table 725.A.2
Horizontal Fixture Branches and Stacks
Maximum Number of Fixture Units that May be
							 Connected to:
Diameter of Pipe (in.)
(The minimum size of any branch or stack serving a
							 water closet shall be 3")
Any Horizontal Fixture Branch
(Does not include branches of the building drain. 50
							 percent less for battery vented fixture branches, no size reduction permitted
							 for battery vented branches throughout the entire branch length.)
One Stack of 3 Stories or 3 Intervals Maximum
More Than 3 Stories in Height
Total for Stack
Total at One Story or Branch Interval
1 1/4
1
2
2
1
1 1/2
3
4
8
2
2
6
10
24
6
3
20
(not over two water closets)
30
(not over six water closets)
60
(not over six water closets)
16
(not over two water closets)
4
160
240
500
90
5
360
540
1100
200
6
620
960
1900
350
8
1400
2200
3600
600
10
2500
3800
5600
1000
12
3900
6000
8400
1500
15
7000
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B.
				Minimum Size of Soil and Waste Stacks. No soil or waste stack shall be smaller
				than the largest horizontal branch connected thereto except that a 4x3 water
				closet connection shall not be considered as a reduction in pipe size. The soil
				or waste stack shall run undiminished in size from its connection to the
				building drain to its connection to the stack vent.
C. Future Fixtures. When provision is made
				for the future installation of fixtures, those provided for shall be considered
				in determining the required sizes of drain pipes. Construction to provide for
				such future installation shall be terminated with a plugged fitting or fittings
				at the stack so as to form no dead end.
D. Underground Drainage Piping. Any portion
				of the drainage system installed underground or below a basement or cellar
				shall not be less than 2-inch diameter. In addition, any portion of the
				drainage system installed underground which is located upstream from a grease
				trap or grease interceptor as well as the underground horizontal branch
				receiving the discharge there from shall not be less than 3-inch
				diameter.
AUTHORITY NOTE:
				  Promulgated in accordance with
				  R.S.
				  40:4(A)(7) and
				  R.S.
				  40:5(2)(3)(7)(9)(16)(17)(20).