Plumber Water & Drainage Flashcards

What is the minimum slope required for a 4-inch horizontal drain pipe under the IPC?

Answer: 1/8 inch per foot

The IPC requires a minimum slope of 1/8 inch per foot for 4-inch horizontal drain pipes.

Which type of pipe joint is used to connect cast iron soil pipe using a rubber gasket and stainless steel clamp?

Answer: No-hub coupling

No-hub couplings use a neoprene rubber sleeve and stainless steel clamp to connect cast iron no-hub pipe.

A P-trap must have its water seal depth within which range?

Answer: 2 to 4 inches

P-trap water seals must be between 2 and 4 inches deep to prevent sewer gas entry while remaining self-cleaning.

What is the purpose of an air admittance valve (AAV) in a drainage system?

Answer: To allow air into the drain to equalize pressure without a traditional vent

An AAV opens under negative pressure to admit air into the drain system, eliminating the need for a traditional vent pipe through the roof.

When installing a shower drain, the drain flange must be set at what height relative to the finished floor?

Answer: Flush with or slightly below

The shower drain flange must be set flush with or slightly below the finished floor surface to ensure proper drainage.

What is the maximum distance a fixture trap can be from its vent under most plumbing codes?

Answer: 8 feet

For a 1.5-inch trap, most codes allow a maximum trap-to-vent distance of 8 feet to prevent siphoning.

Which drainage fitting must be used when changing direction from horizontal to vertical in a drain line?

Answer: Long sweep 1/4 bend

A long sweep 1/4 bend (long turn elbow) is required when transitioning from horizontal to vertical to maintain flow and prevent clogs.