Master Plumber Exam Plumbing Fixtures and Appliances 3

Question 1

Which appliance requires a dedicated CSST or rigid gas supply line with a union or quick-disconnect fitting for service purposes?

Accepted Answer

All of the above

Answer

All gas appliances that may require servicing or replacement should have an accessible shutoff and a union or quick-disconnect to allow disconnection without cutting pipe.

Question 2

The maximum distance allowed between the weir of a P-trap and the trap arm connection to the drain stack is governed by the trap-to-vent distance rule. For a 1½-inch trap arm, this distance is typically:

Accepted Answer

3.5 feet

Answer

For a 1½-inch trap arm, the maximum trap-to-vent distance is generally 3.5 feet per UPC and IPC tables to maintain the trap seal.

Question 3

A water softener drain must discharge through an air gap or air break to a:

Accepted Answer

Indirect waste receptor

Answer

Water softener backwash must discharge indirectly to an approved receptor to prevent backflow and cross-contamination of the potable supply.

Question 4

What is the purpose of a vacuum breaker on a faucet with a threaded hose connection (sillcock)?

Accepted Answer

To prevent backflow if a hose is submerged in contaminated water

Answer

A hose-connection vacuum breaker prevents back-siphonage in case a garden hose is left submerged in a pool, bucket, or chemical solution.

Question 5

When a dishwasher drain connects to a garbage disposal, the high loop or air gap is required to prevent:

Accepted Answer

Dirty water from siphoning back into the dishwasher

Answer

The high loop or air gap prevents dirty sink water from back-siphoning into the dishwasher tub when the disposal runs or the sink drains.

Master Plumber Exam Practice Test

Master Plumber Exam Practice Test

Master Plumber Exam Plumbing Fixtures and Appliances 3