(a) 
The following table of fixture unit values shall be employed when the relative load factors of different kinds of plumbing, fixtures and in estimating the total load carried by soil and waste pipes.
Fixture
Fixture Unit Value
Lavatory with 1-1/4" trap
2
Bathtub with 1-1/2" waste
3
Bathtub with 2" waste
4
Shower stall with 2" waste
3
Shower stall with 3" waste
4
Water closet with 4" waste
6
Dental unit or cuspidor with 1-1/4" waste
1
Sink (glass or silver) with 1-1/2" waste
3
Sink (surgeon’s) with 1-1/2" waste
3
Kitchen sink (residence) with 1-1/2" waste
3
Sinks (3 compartments), cafe or eating establishment with 2" waste
4
Laundry tubs with 2" waste
4
Garbage disposal with 1-1/2" waste
3
Garbage grinder (salvagers) with 2" waste
4
Restaurant sink (single) 1-1/2" waste
2
Double scullery sink compartment 1-1/2" waste
4
Restaurant dishwashers up to 30 gal. water capacity 2" waste
2
Combination laundry tub and sink with 2" waste
4
Combination laundry tub-and-sink with 1-1/2" waste
3
Service sink (slop sink)
4
Service sink with flush valve
6
Drinking fountain
1/2
Urinal–stall and washout
5
Urinal–pedestal siphon jet and blowout
4
Floor drain with 4" outlet
6
Laundry tubs with 1-1/2" waste
3
Sterilizer (instrument) with 1-1/4" waste
1
Dish washing machine with 2" waste
4
Floor drain with 3" outlet
4
Floor drain with 2" outlet
3
Washing machines (domestic)
2
Dish washing machines (domestic)
3
Sink (bar or fountain) with 2" waste
3
Sink (factory wash-up) with 2" waste
4
Baptistery with 2" waste
4
Air conditioning unit with 2" waste
4
Acid sinks (laboratory) with 1-1/2" waste
4
Potato peeler with 2" waste
4
Single compartment scullery sink with 1-1/2" waste
3
1 double compartment sink
4
2 double compartment sinks with 2" waste
5
Restaurant dishwashers up to 100 gal. water capacity with 3" waste
6
(b) 
To assign fixture unit values for waste outlets for plumbing fixtures operating intermittently and for waste outlets other than those mentioned in the above table, the number of fixture units shall be computed by dividing the rate of discharge into the waste line in gallons per minute by 7-1/2.
(c) 
Fifty (50) fixture units shall be used for each twenty-five (25) gallons per minute pump capacity for a pump or sump ejector discharging into a sanitary drainage system.
(d) 
The maximum number of fixture units which may be connected to any given size of building drain, soil or waste line, or building sewer is given in table A of this section.
(e) 
No soil or waste stack shall be smaller than the largest horizontal branch connected thereto.
(f) 
A soil or waste line shall not be of less diameter than the trap of the fixture it serves. All horizontal kitchen sinks or urinal waste lines shall be not less than 2" size. No waste or vent pipe shall be smaller than 1-1/2" size; provided, however, that where 1-1/2" traps are used for lavatories, drinking fountains, or fountain cuspidors, such traps may be connected to waste or vent pipe at floor on wall with 1-1/4" pipe. See section 3.05.182 in regard to the use of 3" waste pipe for single and duplex dwellings.
TABLE A. DRAINAGE LINE SIZES
Maximum Number of Fixture Units Which May Be Connected to
Pipe size
(in)
Vertical soil and waste stack. Main stack to extend full size through roof.
Horizontal branch drains receiving discharge from one “branch interval”
House drains receiving discharge from more than one “branch interval”
 
Total
1/8" fall
1/4" fall
1/2" fall
1/8" fall
*1/4" fall
1/2" fall
1/16" fall
1-1/2
8
 
3
3
 
 
 
 
2
24
 
8
12
 
21
26
 
2-1/2
35
 
13
18
 
24
31
 
3
75
 
32
45
 
27
36
 
4
400
110
150
225
150
200
300
 
5
1000
250
350
490
360
500
700
250
6
2200
460
700
950
625
950
1300
500
8
6000
1400
2000
2800
1950
2800
3900
1200
10
12000
3600
5000
6500
5000
7000
9000
2400
12
18000
6300
8400
10500
9000
12000
15000
3600
15
 
 
 
 
14000
20000
28000
4800
*Building (house) sewer laterals and mains only.
Note: Water closets shall not be connected to pipes of less than 4" diameter. No soil or waste stack shall be smaller than the largest horizontal branch connected thereto.
(1965 Code, sec. 15-138)
(a) 
Every building in which a water closet is installed shall have at least one 4" soil pipe waste and a vent stack extending through the roof at least 1'3", provided that 3" size waste and vent lines may be installed in a single-family and duplex dwelling. When 3" soil and waste lines are used, the waste line connecting the water closet to the 3" waste line shall have a developed length of not less than 14" and shall be constructed of 4" extra heavy lead pipe as specified in this article.
(b) 
For every branch of soil line serving a water closet at 25' or more in length, measured from fixture outlet to intersection of main house drain, the vent from same shall extend full size to main stack, or through the roof. Branches of less than 25' in length shall extend full size to the highest waste fitting on the branch. Fixtures on this branch shall be revented as provided in this article. When conditions require a larger drain or waste pipe within the building, then the same size vent pipe as the drain or waste pipe shall be extended through the roof unless the area of ventilation from the various vents extending through the roof is equal to or greater than that of the main waste line. All soil pipe waste lines in a building shall extend to a point 3' outside of building wall, shall be constructed of pipe not lighter than service weight cast iron pipe or Duriron pipe or other approved acid resisting material and shall extend up through building and out above roof as provided herein. When space between building, fences or property lines does not permit soil and waste line to extend 3' from the building then pipe as described for interior use shall be run under or along the side of the building until it passes in a direct line 3' from any building.
(c) 
All branches or change of direction of soil and waste lines shall be made with wyes and 1/8 bends or long sweep 1/4 bends. Cleanouts shall be provided and made accessible in change of direction. Tapped soil fittings shall not be used unless they are of the sanitary pattern. Waste pipe between tapped tee and water seal of trap shall be of galvanized steel, galvanized wrought iron, brass pipe I.P. size and weight or hard temper copper tube of weight not lighter than type L with cast brass sweat fittings. Such pipe shall be reamed and fittings shall be cast iron galvanized recess fittings.
(d) 
In buildings of six stories or more, not including basement, waste lines not buried in the ground may be of genuine wrought iron galvanized pipe known as “durham system.” This article shall apply the same to the wrought iron installation as it does to cast iron constructions. End of pipe shall be well reamed and screwed to shoulder fittings. All fittings used in wrought iron waste construction shall be cast iron galvanized recessed drainage fittings known as “durham” pattern and all branches or change of direction shall be made with wyes and long radius bends with cleanouts provided and made accessible as provided in a system of cast iron pipe. Installations shall be constructed with either soil pipe or genuine wrought iron galvanized pipe, but not with both.
(1965 Code, sec. 15-139)
(a) 
All horizontal soil and waste pipes shall be graded and given uniform fall, and shall be supported by piers built of brick or concrete or suspended from slabs, beams or joists every 5' apart for cast iron, or every 12' for wrought iron pipe. All hangers to be durable hangers of iron, steel or brass. Hangers on batteries of closets or urinals shall not be less than 3' apart. A horizontal line of lead work shall be supported under its full length with permanent supports in such manner as to prevent sagging of lead.
(b) 
Each vent, waste or supply stub run through a floor or wall shall be securely stayed in position and shall be at right angles with the floor or wall through which it extends, except when the sink waste opening is located behind the open area under the sink.
(c) 
All vertical lines shall be supported on every second floor, shall be plumb and permanently stayed in position just below roofline.
(1965 Code, sec. 15-141)
(a) 
No arms shall be permitted for kitchen sinks, urinals, slop sink, dish washing machine or garbage grinder disposal, but each shall waste into a vertical waste line independent of all other fixtures, except that two (2) compartment sinks in a residence may be connected together, and may waste through a 1-1/2" P trap. The waste shall be brought up through the floor or wall vertically and directly behind waste opening of fixture it serves.
(b) 
Washing machines in residences may connect to a continuous waste and vent serving a sink; providing, however, that a 2" P trap shall be used to trap waste opening. The seal of this trap shall be not more than 5' from the waste and the vertical inlet to this trap shall not exceed 4' developed length from the discharge waste opening to water seal in the trap. A cleanout shall be calked into the pipe hub at finished floor and may be reduced to receive the main waste outside of the building by placing a 3" x 2" or 4" x 2" Y in the mains waste either in front of the cleanout or in the riser of the cleanout. The 2" waste opening in this fitting shall be below finish ground grade and trapped with a 2" P trap. The trap inlet riser shall extend not less than 6" above finish grade. The waste from the machine shall discharge indirectly into this riser. All washing machines with fixed waste or water connection shall be connected to waste lines by one or the other of the above described methods.
(c) 
A dish washing machine installed in a residence which wastes into a soil or waste line below the overflow rim of the lowest fixture on the same floor level which is connected to the same soil or waste line, shall be protected by a floor drain installed without a backwater valve, connected to the waste line serving the dish washing machine or shall be protected by a 2" trapped safety waste opening to soil or waste line located outside the building. The inlet side of 2" safety waste shall be constructed, using return bend or bends on this riser, so that the discharge will be 6" above finished grade. Materials of this riser may be of galvanized steel pipe with galvanized malleable iron fittings.
(1965 Code, sec. 15-142)
(a) 
Establishments engaged in the storage, preparation, selling, serving, processing or otherwise handling of food shall have the wastes piping from all refrigerators, iceboxes and food handling equipment having waste connections connected indirectly into a fixture or drain which is trapped and vented.
(b) 
Indirect wastes connections shall be provided for drains, overflows or relief vents from the water supply system.
(c) 
Appliances, devices or apparatus such as stills, sterilizers and similar equipment requiring water and waste and used for sterile material shall be indirectly connected or provided with an air gap between the trap and the appliances.
(1965 Code, sec. 15-143)
The cleanout shall not be less than 2" and shall not be smaller than the waste line served. A cleanout shall be placed on the end of a house drain with wye branch where same connects with the house sewer and in all cases the cleanout shall be brought to the finish grade. A cleanout shall be placed at the base of each sink, stack. Sink waste cleanouts will be permitted under a building, only when the floor is more than 2' above the ground and the foundation wall has an access opening not less than 16" x 18" for entering, otherwise cleanouts as required shall be brought through outside wall of building into full view. All drain and waste pipes constructed under concrete floors shall be provided with cleanouts at the end of each branch, and in all cases they shall be accessible. It is definitely specified that no cleanout screw shall be installed in any position or in any location except where accessible for use. Base of all stacks shall be constructed with Y and 1/8 bends or long sweep 1/4 bends. In no case will a short 1/4 bend tee, or combination T Y be permitted at base of stack.
(1965 Code, sec. 15-144)