5.1 SEPARATE TRAPS FOR EACH FIXTURE
a. Plumbing fixtures shall be separately trapped by a water seal trap placed as close as possible to the fixture outlet.
b. The vertical distance from the fixture outlet to the trap weir shall not exceed 24 inches.
c. Fixtures shall not be double-trapped unless a relief vent is provided between the two traps.
d. Fixture designs having integral dual traps within the fixture shall be permitted.
EXCEPTIONS:
(1) Fixtures that have integral traps.
(2) A combination-plumbing fixture may be installed on one trap provided the waste outlets are not more than 30 inches apart.
(3) One trap may be installed for up to three (3) compartment sinks, laundry trays or lavatories that are immediately adjacent to each other in the same room, and where the trap is centrally located when three such fixtures are installed.
(4) No clothes washer or laundry tub shall be discharged to a trap serving a kitchen sink.
(5) As otherwise permitted by this Code.
5.2 SIZE OF FIXTURE TRAPS
Fixture trap size (nominal diameter) shall be sufficient to drain the fixture rapidly and in no case less than given in Table 5.2. No trap shall be larger than the drainage pipe into which it discharges. Integral traps shall conform to appropriate standards.
5.3 GENERAL REQUIREMENTS FOR TRAPS
5.3.1 Design of Traps
Fixture traps shall be self-scouring and shall have no interior partitions except where such traps are integral with the fixture or where corrosion resistant materials of plastic or glass are used. Solid connections, slip joints, or couplings may be used on the trap inlet, trap outlet, or within the trap seal. (See Section 7.4.6.)
5.3.2 Trap Seals
Each fixture trap shall have a liquid seal of not less than two inches and not more than four inches EXCEPTIONS:
(1) Interceptors in Chapter 6.
(2) Special conditions such as accessible fixtures, a deeper seal may be required by the Authority Having Jurisdiction.
5.3.3 Trap Setting and Protection
Traps shall be set level with respect to their water seals and, where necessary, shall be protected from
Chapter 5
(1) Separate trap required for wash tray and separate trap required for sink compartment with food waste grinder.
5.3.4 Building Traps
Building traps shall not be installed except where required by the Authority Having Jurisdiction. Each building trap when installed shall be provided with a cleanout and with a relieving vent or fresh air intake on the inlet side of the trap that shall be at least one-half the diameter of the drain to which it connects. Such relieving vent or fresh air intake shall be carried above grade and terminate in a screened outlet located outside the building.
5.3.5 Prohibited Traps
a. The following types of traps shall be prohibited:
1. Traps that depend upon moving parts to maintain their seal.
2. Bell traps.
Table 5.2
MINIMUM SIZE OF NON-INTEGRAL TRAPS
Plumbing Fixture Trap Size in
inches
Bathtub (with or without overhead shower) 1 ½
Bidet 1 ¼
Clothes washing machine standpipe 2 Combination sink and wash (laundry) sink with food waste grinder unit 1 ½ (1) Combination kitchen sink, domestic dishwasher, and food waste grinder 1 ½
Dental unit or cuspidor 1 ¼
Dental lavatory 1 ¼
Drinking fountain 1 ¼
Dishwasher, commercial 2
Dishwasher, domestic (non-integral trap) 1 ½
Floor drain 2
Food waste grinder, commercial use 2 Food waste grinder, domestic use 1 ½ Kitchen sink, domestic, with food waste grinder unit 1 ½
Kitchen sink, domestic 1 ½
Lavatory, common 1 ¼
Lavatory (barber shop, beauty parlor or surgeon's) 1 ½ Lavatory, multiple type (wash fountain or wash sink) 1 ½ Laundry tray (1 or 2 compartments) 1 ½ Shower stall or shower drain (single shower head) 1 ½ Shower stall or shower drain (multiple shower heads) 2
Sink (surgeon's) 1 ½
Sink (flushing rim type, flush valve supplied) 3 Sink (service type with floor outlet trap standard) 3
Sink (service type with P trap) 2
Sink, commercial (pot, scullery, or similar type) 2 Sink, commercial (with food grinder unit) 2
3. Crown vented traps.
4. Separate fixture traps that depend on interior partitions for their seal, except if made from plastic, glass or other corrosion resistant materials.
5. “S” traps, of uniform internal dimension.
6. Drum traps.
b. Hair interceptors, precious metal interceptors and similar appurtenances shall be permitted as required.
5.3.6 Trap Seal Maintenance
a. Traps
that
could lose their seal due to evaporation because of infrequent use shall be equipped with a readily accessible means to replenish the trap seal or a trap primer conforming to ASSE 1018 or ASSE 1044b. In addition to the priming requirement above, the installation of a sealing component on the fixture drain outlet to reduce trap seal loss shall be permitted. Sealing devices shall be properly sized for the drain outlet on which they are installed. They shall permit the fixture to drain completely and shall not leave standing water or waste on or around the device.
5.4 DRAINAGE PIPE CLEANOUTS
5.4.1 Cleanout Spacing
a. Cleanouts in horizontal drainage lines shall be spaced at intervals not exceeding the following values:
4" pipe size or less: 75 feet 5" size and larger: 100 feet
b. The distance referred to in Sections 5.4.1a shall include the developed length of the cleanout pipe.
5.4.2 Building Sewer
Cleanouts, when installed on an underground building sewer, shall be extended vertically to or above the finished grade level.
5.4.3 Change of Direction
a. Cleanouts shall be installed at changes of direction in drainage piping made with 60°, 70° and 90° fittings.
EXCEPTION: Where there are multiple changes of direction, not more than one cleanout shall be required in 40 feet of run.
b. Cleanouts shall not be required where changes of direction are made with one or more 22 1/2° or 45°
fittings.
5.4.4 Cleanouts for Concealed Piping
Cleanouts for concealed piping shall be extended through and terminate flush with the finished wall or floor;
or pits or chases may be left in the wall or floor, provided they are of sufficient size to permit removal of the cleanout plug and proper cleaning of the system.
5.4.5 Base of Stacks
a. A cleanout shall be provided near the base of each vertical waste or soil stack and located 6 inches above the flood level rim of the lowest fixture on the lowest floor. If there are no fixtures installed on the lowest floor, the cleanout shall be installed at the base of the stack.
b. For buildings with a floor slab, a crawl space of less than 18 inches, or where a stack cleanout is not accessible, the cleanout shall be installed in the building drain or building sewer, not more than five feet outside the building wall.
c. Rain leaders and conductors connected to a building storm sewer shall have a cleanout installed at the base of the outside leader or inside conductor before it connects to the horizontal drain.
5.4.6 Building Drain and Building Sewer Junctions and the Property Line
a. There shall be a cleanout near the junction of a building drain and building sewer either inside or outside the building wall.
b. A cleanout shall be placed in the building sanitary sewer and building storm sewer at the property line and brought to the surface per the requirements of the Authority Having Jurisdiction.
5.4.7 Direction of Flow
Cleanouts shall be installed so that the cleanout opens in the direction of the flow of the drainage line or at right angles thereto.
5.4.8 Connections to Cleanouts Prohibited
a. Cleanout plug openings in other than drainage pattern fittings shall not be used for the installation of new fixtures or floor drains.
b. If a cleanout fitting or cleanout plug opening is removed from a drainage pattern fitting in order to extend the drain, another cleanout of equal access and capacity shall be provided in the same location.
5.4.9 Cleanout Size
Cleanout size shall conform with Table 5.4.9.
Table 5.4.9
(1) See Section 5.4.10 for sizes 12" or larger for building sewers.
(2) See Section 5.4.13 for cleanout equivalents.
5.4.10 Manholes for Large Pipes
a. Manholes shall be provided as cleanouts for building sewers 12" size and larger. Manholes shall be provided at every change of size, alignment, direction, grade, or elevation. The distance between manholes shall not exceed 300 feet.
b. Manholes may be provided in lieu of cleanouts in underground building sewers, building drains, and branches thereof, 8" size and larger.
c. Such manholes shall comply with the requirements of Section 5.4.10a.
d. If manholes are installed indoors, they shall have a bolted, gas-tight cover.
e. Manhole construction shall comply with the standards of the Authority Having Jurisdiction.
5.4.11 Cleanout Clearances
Cleanouts on 3" or larger pipes shall be so installed that there is a clearance of not less than 18" for the purpose of rodding. Cleanouts smaller than 3 inches shall be so installed that there is a 12" clearance for rodding.