PC Plumber Water & Drainage 2

Question 1

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

Accepted Answer

1/8 inch per foot

Answer

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

Question 2

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

Accepted Answer

No-hub coupling

Answer

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

Question 3

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

Accepted Answer

2 to 4 inches

Answer

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

Question 4

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

Accepted Answer

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

Answer

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

Question 5

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

Accepted Answer

Flush with or slightly below

Answer

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

(PC) Plumber Certification Practice Test