Page 708 - 2018_IRC

CHAPTER 32

TRAPS

User notes:
About this chapter: Chapter 32 regulates the design of fixture traps, methods for preventing evaporation of trap seals in traps, and the
required locations for interceptors and separators. The trap seal of a trap is an essential feature of a drainage system to prevent odors from
the drainage piping from entering the building. The discharge of various processes such as cooking and laundry create the need for equip-
ment to retain detrimental greases and solids from entering the drainage systems.
Code development reminder: Code change proposals to this chapter will be considered by the IRC—Mechanical/Plumbing Code Develop-
ment Committee during the 2018 (Group A) Code Development Cycle. See explanation on page iv.

SECTION P3201 P3201.2.1.4 Barrier-type trap seal protection device.
FIXTURE TRAPS A barrier-type trap seal protection device shall protect
P3201.1 Design of traps. Traps shall be of standard design, the floor drain trap seal from evaporation. Barrier-type
shall have smooth uniform internal waterways, shall be self- floor drain trap seal protection devices shall conform to
cleaning and shall not have interior partitions except where ASSE 1072. The devices shall be installed in accor-
integral with the fixture. Traps shall be constructed of lead, dance with the manufacturer’s instructions.
cast iron, copper or copper alloy or approved plastic. Copper P3201.3 Trap setting and protection. Traps shall be set
or copper-alloy traps shall be not less than No. 20 gage (0.8 level with respect to their water seals and shall be protected
mm) thickness. Solid connections, slip joints and couplings from freezing. Trap seals shall be protected from siphonage,
shall be permitted to be used on the trap inlet, trap outlet, or aspiration or back pressure by an approved system of venting
within the trap seal. Traps having slip-joint connections shall (see Section P3101).
comply with Section P2704.1. P3201.4 Building traps. Building traps shall be prohibited.
P3201.2 Trap seals. Each fixture trap shall have a liquid seal P3201.5 Prohibited trap designs. The following types of
of not less than 2 inches (51 mm) and not more than 4 inches traps are prohibited:
(102 mm).
1. Bell traps.
P3201.2.1 Trap seal protection. Traps seals of emer-
gency floor drain traps and traps subject to evaporation 2. Separate fixture traps with interior partitions, except
shall be protected by one of the methods in Sections those lavatory traps made of plastic, stainless steel or
P3201.2.1.1 through P3201.2.1.4. other corrosion-resistant material.
3. “S” traps.
P3201.2.1.1 Potable water-supplied trap seal primer
valve. A potable water-supplied trap seal primer valve 4. Drum traps.
shall supply water to the trap. Water-supplied trap seal 5. Trap designs with moving parts.
primer valves shall conform to ASSE 1018. The dis- P3201.6 Number of fixtures per trap. Each plumbing fix-
charge pipe from the trap seal primer valve shall connect ture shall be separately trapped by a water seal trap. The ver-
to the trap above the trap seal on the inlet side of the trap.
tical distance from the fixture outlet to the trap weir shall not
P3201.2.1.2 Reclaimed or gray-water-supplied trap exceed 24 inches (610 mm) and the horizontal distance shall
seal primer valve. A reclaimed or gray-water-supplied not exceed 30 inches (762 mm) measured from the centerline
trap seal primer valve shall supply water to the trap. of the fixture outlet to the centerline of the inlet of the trap.
Water-supplied trap seal primer valves shall conform to The height of a clothes washer standpipe above a trap shall
ASSE 1018. The quality of reclaimed or gray water conform to Section P2706.1.2. Fixtures shall not be double
supplied to trap seal primer valves shall be in accor- trapped.
dance with the requirements of the manufacturer of the Exceptions:
trap seal primer valve. The discharge pipe from the trap
seal primer valve shall connect to the trap above the 1. Fixtures that have integral traps.
trap seal on the inlet side of the trap. 2. A single trap shall be permitted to serve two or three
P3201.2.1.3 Wastewater-supplied trap primer like fixtures limited to kitchen sinks, laundry tubs
device. A wastewater-supplied trap primer device shall and lavatories. Such fixtures shall be adjacent to
supply water to the trap. Wastewater-supplied trap each other and located in the same room with a con-
primer devices shall conform to ASSE 1044. The dis- tinuous waste arrangement. The trap shall be
charge pipe from the trap seal primer device shall con- installed at the center fixture where three fixtures are
nect to the trap above the trap seal on the inlet side of installed. Common trapped fixture outlets shall be
the trap. not more than 30 inches (762 mm) apart.

2018 INTERNATIONAL RESIDENTIAL CODE ® 683
Copyrighted © 2017 by, or licensed to, ICC (ALL RIGHTS RESERVED); licensed to UL, LLC pursuant to License Agreement with ICC. No further reproductions authorized or distribution authorized.
ANY UNAUTHROIZED REPRODUCTION OR DISTRIBUTION IS A VIOLATION OF THE FEDERAL COPYRIGHT ACT AND THE LICENSE AGREEMENT; AND SUBJECT TO CIVIL AND CRIMINAL PENALTIES THEREUNDER.