(1)
Except as provided in Sentences (2) to (5) and Article 7.4.5.2., fixtures shall be protected by a separate trap.
(2)
One trap is permitted to protect
(a)
all the trays or compartments of a 2- or 3- compartment sink,
(b)
a 2- or 3- compartment laundry tray, or
(c)
2 similar type single compartment fixtures located in the same room.
(3)
One trap is permitted to serve a group of floor drains and hub drains, a group of shower drains, a group of washing machines or a group of laboratory sinks if the fixtures
(a)
are in the same room, and
(b)
are not located where they can receive food or other organic matter.
(4)
Reserved.
(5)
An interceptor with an effective water seal of not less than 38 mm is permitted to serve as a trap. (See Note A-7.4.5.1.(5))
(6)
Where a domestic dishwashing machine equipped with a drainage pump discharges through a direct connection into the fixture outlet pipe of an adjacent kitchen sink or disposal unit, the pump discharge line shall rise as high as possible to just under the counter and connect
(a)
on the inlet side of the sink trap by means of a Y fitting, or
(b)
to the disposal unit.