Each fixture shall be separately trapped by a water seal trap placed
as near to the fixture as possible, except that a set of not more than two
or three laundry traps, one sink and tray combination or two-compartment sink
may be connected with a single trap, provided that the trap is not located
more than two feet developed length from the outlet of such fixture.
Each plumbing fixture, excepting those having integral traps and those
mentioned in the preceding section, shall be separately trapped, and such
trap shall be placed as close to the fixture as possible.
Every trap shall be of the same nominal size as the fixture drain to
which it is connected, except otherwise provided in this chapter. In cases
other than fixtures, the size of trap shall be the same as the size of the
discharge pipe connecting thereto.
All bath traps shall be of the drum-type pattern or the cast brass bath
trap with the swivel joint pattern.
The size (nominal diameter) of trap for a given fixture should be sufficient
to drain the fixture rapidly and shall not be less than specified in the following
table.
|
Fixture
|
Minimum Size of
Trap and Branches
(inches)
|
Minimum Size of
Fixture Drains
(inches)
|
|---|---|---|
|
Bathtub (trap drum type)
|
1 1/2
|
1 1/2
|
|
Combination sink and laundry tray
|
1 12
|
2
|
|
Drinking fountain
|
1 1/4
|
1 1/4
|
|
Dental unit
|
1 1/4
|
1 1/4
|
|
Floor drain
|
2
|
2
|
|
Laundry tray
|
1 1/2
|
1 1/2
|
|
Lavatory
|
1 1/4
|
1 1/4
|
|
Shower stall
|
2
|
2
|
|
Sink, residence
|
1 1/2
|
2
|
|
Sink, hotel or public
|
2
|
2
|
|
Sink, pantry or bar
|
1 1/2
|
2
|
|
Sink, dishwasher
|
1 1/2
|
2
|
|
Sink, service (trap standard)
|
3
|
3
|
|
Sink, service
|
2
|
2
|
|
Sink, pot or scullery
|
2
|
2
|
|
Urinal, stall
|
2
|
2
|
|
Urinal, wall
|
1 1/2
|
1 1/2
|
|
Note: This table does not apply to fixtures with integral traps.
| ||
The fixture drains for water closets and other fixtures with integral
traps shall not be smaller than the fixture outlet, except that in the case
of water closets and pedestal urinals, the drain connection shall not be less
than four inches.
Each fixture trap shall have a water seal of not less than two inches
and not more than four inches.
Each fixture trap, except those in combination with fixtures in which
the trap seal is readily accessible, shall have an accessible brass trap screw
of ample size, protected by the water seal, provided that when a portion of
the trap can be completely removed for cleaning purposes, no trap screw is
required.
All traps shall be set true with respect to their water seals and protected
from freezing.
Every trap shall be self-cleaning and water-sealed and have a scouring
action. Traps for lavatories, sinks and other similar fixtures shall be of
lead, brass, cast iron or galvanized malleable iron. Traps shall
have full-size bore, smooth interior waterway such that a solid ball 1/4
of an inch smaller in diameter than the specified diameter of the trap will
pass freely from the outlet and entirely through the seal of the trap.
No form of trap which depends for its seal upon the action of movable
parts shall be used. No form of traps with partitions, except in a trap integral
with a fixture, shall be used. It shall be unlawful to use a mason's trap
or catch basin inside of a building until approved by the Plumbing Inspector.
It shall be unlawful to double-trap fixtures.
No crown-vented trap shall be installed.
A dandy cleanout, easily accessible, shall be provided at or near the
foot of each vertical waste, soil stack or inside leader. A cleanout shall
be installed on all hand holes of running traps.
Cleanouts shall not be more than 30 feet apart in horizontal drainage
lines. Cleanouts shall be installed at each change of direction of the building
drain greater than a forty-five-degree angle.
The bodies of cleanout ferrules shall conform in thickness to that required
for pipe and fittings of the same metal, and the cap or plug shall be of heavy
brass. Heavy lead plugs may be used for repair work. It shall be unlawful
to use or discharge any drainage into a cleanout.
Cleanouts shall be of the same size as the pipe up to four inches and
not less than four inches for larger pipes.
The openings of all underground cleanouts in a building shall be flush
with or above the floor. Exterior underground cleanouts shall be extended
to the surface or otherwise made accessible. Cleanouts concealed in walls,
floors or ceilings shall be extended to the surface or provided with access
doors.
Any floor or wall connection of fixture traps when bolted or screwed
to the floor or wall shall be regarded as a cleanout.
A grease interceptor and separator shall be installed in the waste line
leading from sinks, drains or other fixtures in the following establishments
when in the opinion of the administrative authority a hazard exists: restaurants,
hotel kitchens or bars, factory cafeteria or restaurants, clubs or other establishments
where grease can be introduced into the drainage system in quantities that
can effect line stoppage or hinder sewage disposal.
All interceptors shall be so designed that they will not become airbound.
They shall be vented and so located as to be readily accessible for cleaning.
An interceptor or separator shall be installed in the drainage system
of each establishment when in the opinion of the local authority a hazard
exists from the careless disposal of waste material, accidental spills or
overflow of grease-bearing, flammable, harmful or poisonous materials.
An oil separator shall be installed in the drainage system of the following
establishments when in the opinion of the administrative authority a hazard
exists: gasoline service station, garages where car washing and gasoline storage
is maintained, dry cleaners (using flammable solvents), chemical plants, gas
plants, aniline plants, tanneries, paint and varnish manufacturing plants,
printing ink plants, shoe polish plants, explosive plants, soap plants, cleaning
fluid manufacturing plants, testing laboratories and any place of manufacture
where volatile inflammable liquid is on hand for the use in progress and which
by accident or otherwise may be admitted to the drainage system.
Sand and similar interceptors shall be so designed and located as to
be readily accessible for cleaning and shall have a trap seal not less than
six inches.
Interceptors and separators shall be provided when required in the opinion
of the administrative authority.
The size and model of each oil interceptor shall be submitted for approval
of the administrative authority having jurisdiction before installation. Oil
interceptors shall be constructed so as to be oiltight and provided with inlet
and outlet connections and relief pipe of at least two inches from the top
of the separator to the open air. The separator shall be fitted with a tight
cover cleanout of manhole size and be watertight and gastight. All interceptors
shall be made of cast iron.
Garage floor drains, the minimum inlet or receiving basin, shall be
14 inches in diameter at the top and not less than 24 inches deep, and shall
be provided with a removable receptacle inside of basin, to receive the mud
as well as sand, silt and other material washed into the basin, for the purpose
of excluding same from the sewage system.
A.
Such basin must be provided with an air chamber in the
receiver, with a separate compartment constructed so that a separate discharge
of water and other material cannot come in contact with the fluid in the basin.
B.
The inlet of the receptacle in the basin must be protected
with a heavy guard having a solid top of sufficient size to entirely conceal
the opening of the receptacle when discharging water or other material into
the basin.
C.
Every air chamber compartment shall be provided with
at least two two-inch circulating vent pipes, the terminals of which shall
end in the atmosphere, and one terminal shall be at least one foot six inches
higher than the other to influence forced circulation. These terminals shall
not be less than 12 feet above grade level.
D.
All garage floor drains shall be vented and so located
as to be readily accessible for cleaning.
Garage floor drains shall be approved by the administrative authority
before installation is permitted, and the exact type, size or model of each
interceptor shall be submitted for approval.
Backwater valves shall have all bearing parts or balls of corrosion-resistant
material and be so constructed as to ensure a positive mechanical seal against
backflow except when discharging wastes.
Backwater valves shall be installed in drainage systems wherever such
drainage pipes are subject to backflow or back pressure. The administrative
authority may order the installation of backwater valves where same are necessary.
Where such a backwater valve is installed, it shall be so located as to be
readily accessible for inspection and cleaning and shall have a capacity of
not less than the pipe to which it is installed.
