Master Plumber Exam Drainage, Waste, and Venting 4

Question 1

What is the minimum trap seal depth required by the IPC for fixture traps?

Accepted Answer

2 inches

Answer

The IPC requires a minimum trap seal depth of 2 inches to prevent sewer gases from entering the building through the fixture drain.

Question 2

A stack vent differs from a vent stack in that a stack vent:

Accepted Answer

Is an extension of the drain stack above the highest branch connection

Answer

A stack vent is the upper portion of the soil or waste stack that extends above the highest horizontal branch and serves as the vent terminal.

Question 3

What is the term for the pressure condition created by rapid water flow past a branch connection that can siphon a trap?

Accepted Answer

Induced siphonage

Answer

Induced siphonage occurs when waste flowing down a stack creates negative pressure at a nearby branch connection, pulling water out of adjacent fixture traps.

Question 4

Under the IPC, what is the maximum height of a horizontal offset in a drainage stack that requires a relief vent?

Accepted Answer

More than 5 stories above the offset

Answer

The IPC requires a relief vent when a horizontal offset in a drainage stack has more than 5 stories of drainage stack above it.

Question 5

A grease interceptor is required to have a vented inlet. What is the reason for this requirement?

Accepted Answer

To prevent siphoning of the trap seal and allow gas escape

Answer

Venting the inlet of a grease interceptor prevents the trap seal from being siphoned and allows gases produced by decomposing grease to escape safely.

Master Plumber Exam Practice Test

Master Plumber Exam Practice Test

Master Plumber Exam Drainage, Waste, and Venting 4