Illinois Administrative Code › Title 77 - PUBLIC HEALTH › Part 890 - ILLINOIS PLUMBING CODE › Subpart J - DRAINAGE SYSTEM › Section 890.1320 - Drainage System Installation

Current through Register Vol. 48, No. 28, July 12, 2024
a)
				Drain - Underground. A building drainage system installed in the ground shall
				be of cast iron, copper Type "K", or non-metallic Schedule 40 or heavier.
				Drains shall be installed on a continuous bed of undisturbed earth or granular
				fill so as to support the pipe and fittings.
b) Existing Drain and Sewer Installation.
				Existing drain, waste, vent and sewer may be used in the renovation of the
				plumbing system of an existing structure if they are in serviceable condition
				and the materials comply with Appendix A.Table A (Approved Building
				Drainage/Vent Pipe and Approved Materials for Building Sewer).
c) Freezing. No soil or waste pipe shall be
				installed or permitted outside of a building or in an exterior wall unless the
				piping is protected from freezing. This does not prohibit a soil or waste pipe
				from extending from a manufactured or mobile home unit to an approved point of
				discharge, provided that the waste line is protected from freezing.
d) Dead Ends. Dead ends shall be avoided in a
				drainage system, except where necessary to extend the system to install a
				cleanout in an accessible location. A dead end intended for future connection
				(extension) that is more than 2 feet above a floor or more than 10 feet
				horizontally from the nearest vented connection shall have a vented connection
				to the outside atmosphere. (See Appendix J.Illustration A.)
e) Horizontal Drainage Piping. Horizontal
				drainage piping shall be installed at a uniform grade.
f) Small Piping. Horizontal drainage piping
				of 3 inches diameter or less shall be installed with a grade of at least
				¼-inch per foot.
g) Large
				Piping. Horizontal drainage piping larger than 3 inches but less than 8 inches
				in diameter shall be installed with a grade of at least 1/8-inch per foot. For
				piping 8 inches or larger in diameter, the grade is determined by the number of
				drainage fixture units connected to the drain pipe. (See Appendix A.Table
				G.)
h) Minimum Velocity. If
				conditions do not permit building drains to be installed with a grade as great
				as that specified in subsections (f) and (g), a lesser grade may be used,
				provided that the computed velocity will not be less than 2 feet per
				second.
i) Changes in Direction.
				Changes in direction shall be made in drainage piping by the use of 45 degree
				wyes, long sweeps, short sweeps, quarter, fifth, sixth, eighth, or sixteenth
				bends, or by a combination of these fittings. Single and double sanitary tees
				and short sweep quarter bends shall be used in drainage lines only where the
				direction of flow is from the horizontal to the vertical and may be used for
				making necessary vertical offsets between the ceiling and floor above. (See
				Appendix J.Illustrations B, C and D.) Exception: A short sweep drainage quarter
				bend of less than 3 inches diameter and placed in a horizontal to horizontal
				position for a stack vent arm may be used to receive graywater.
j) No fittings having a hub in the direction
				opposite to flow, or tee branch, shall be used as a drainage fitting. No
				running threads, bands or saddles shall be used in the drainage system. No
				drainage or vent pipe or fitting shall be drilled or tapped.
k) No fitting, connection, device or method
				of installation shall be used that obstructs or retards the flow of water,
				waste or air in the drainage or venting system by an amount greater than the
				normal frictional resistance to flow. The enlargement of a 3-inch closet bend
				or stub to 4 inches shall not be considered an obstruction if it is necessary
				to increase the bend or stub at the floor line to 4 inches in diameter to
				accommodate the water closet outlet.
l) Fixture Connections. Branch wastes and
				fittings for circuit-vented fixtures shall be installed so that the fixture
				drain enters the side of the branch drain. (See subsection (i) and Appendix
				J.Illustration E.)
m) Back-to-Back
				Fixtures. Back-to-back fixtures shall be installed with fittings that will
				prevent mixing of the discharge prior to a change in direction of flow of the
				discharge from each fixture, or shall be installed with fittings especially
				designed to eliminate throw-over or backflow of the discharge from one fixture
				to the other fixture.
n) Location
				of Drains. All building drains, branches of building drains, building sewers or
				any sanitary sewers shall be located at least 50 feet from a well or buried
				suction line, except that, when cast iron pipe with mechanical or compression
				joints or Schedule 40 PVC pipe with solvent weld and watertight joints is used
				for the building sewer, the drains shall be located at least 10 feet from a
				well or buried suction line.
o)
				Backwater valves may be installed in the building storm drain or the building
				drain to prevent backflow into the building, where backflow of storm water or
				sewage could occur. Backwater valves may be installed in the branches of the
				building drain that are below grade. Backwater valves, when fully opened, shall
				have a capacity of at least that of the pipes in which they are installed.
				Backwater valves shall be installed to be accessible. All backwater valves
				shall conform to ASME A112.14.1. All bearing parts of backwater valves shall be
				made of corrosion-resistant material.