Master Plumber Exam Plumbing Fixtures and Appliances 2

Question 1

What is the minimum water closet compartment width required by most US plumbing codes when a wall-mounted toilet is installed?

Accepted Answer

30 inches

Answer

Most plumbing codes require a minimum 30-inch wide water closet compartment to allow proper access and use.

Question 2

A pressure-balancing valve in a shower is required to limit hot water outlet temperature to a maximum of:

Accepted Answer

120°F

Answer

Per ASSE 1016 and most plumbing codes, pressure-balancing valves must limit outlet temperature to a maximum of 120°F to prevent scalding.

Question 3

Which fixture requires a trap with a minimum 3-inch seal depth under most plumbing codes?

Accepted Answer

Floor drain subject to evaporation

Answer

Floor drains in infrequently used areas may require a 3-inch deep seal trap or a trap primer to prevent seal evaporation.

Question 4

An interceptor is required ahead of a kitchen sink when the sink serves:

Accepted Answer

A commercial kitchen in a food service establishment

Answer

Grease interceptors are required before drainage from commercial food service establishments to prevent grease from entering the public sewer.

Question 5

What type of flush valve mechanism is typically used in a flushometer-valve water closet?

Accepted Answer

Direct-flush valve with diaphragm or piston

Answer

Flushometer valves use a direct-pressure diaphragm or piston mechanism that opens directly to supply pressure, requiring no tank.

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