(1)
Except as provided for in Sentence (2), traps shall
(a)
have a trap seal depth of not less than 38 mm,
(b)
be so designed that failure of the seal walls will cause exterior leakage, and
(c)
have a water seal that does not depend on the action of moving parts. (See Note A-7.2.3.1.(1) and (3))
(2)
The trap seal depth on fixtures draining to an acid waste system shall be a minimum of 50 mm.
(3)
Except for a floor-mounted service sink, every trap that serves a lavatory, a sink or a laundry tray shall
(a)
be provided with a cleanout plug located at the lowest point of the trap and of the same material as the trap, except that a cast iron trap shall be provided with a brass cleanout plug, or
(b)
be designed so that part of the trap can be removed for cleaning purposes. (See Note A-7.2.3.1.(1) and (3))
(4)
A bell trap shall not be installed in a drainage system.
(5)
A drum trap shall not be installed in a drainage system.
(6)
Except as permitted in Sentence (7), no bottle trap shall be used in a plumbing system.
(7)
A bottle trap may be used on a laboratory sink or other fixture equipped with corrosion resistant fittings.
(8)
No running trap shall be installed in a plumbing system unless an accessible handhole is provided for cleaning of the trap, and where the trap is too small to accommodate a handhole, a cleanout shall be provided.