PC Plumber Water & Drainage 3

Question 1

What is the minimum size of a building sewer that serves a single-family home under the IPC?

Accepted Answer

4 inches

Answer

The IPC requires a minimum 4-inch diameter building sewer for a residential structure.

Question 2

What is the term for negative pressure in a drain system that pulls water out of fixture traps?

Accepted Answer

Siphonage

Answer

Siphonage is the negative pressure (vacuum) that pulls trap water seals out, allowing sewer gases to enter the building.

Question 3

A plumber installs a dishwasher drain. Where must the drain hose be routed before connecting to the drain or disposal?

Accepted Answer

In a high loop or through an air gap above the flood level rim of the sink

Answer

A dishwasher drain must be looped high under the counter or use an air gap to prevent back-siphonage of contaminated water into the dishwasher.

Question 4

What type of vent serves as both a drain and a vent for the same fixture?

Accepted Answer

Wet vent

Answer

A wet vent serves simultaneously as a vent for one fixture and a drain for another fixture connected above it.

Question 5

Under the IPC, what is the minimum water pressure required at the point of use for a residential fixture?

Accepted Answer

20 psi

Answer

The IPC requires a minimum of 20 psi at the point of delivery for any plumbing fixture.

(PC) Plumber Certification Practice Test