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Plumbing Practice Test: Journeyman & Master Fundamentals

Plumbing math, drainage and venting, water supply, fixtures and materials, fuel gas and safety for journeyman and master plumber exams.

150 questions · 5 topics · free, no sign-up

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Mixed practice test

10 questions, graded as you go, with the reason for every answer. No sign-up.

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Sample questions

Under both the IPC and the UPC, the liquid seal of a standard fixture trap must fall within what range?

  1. 1 in. to 2 in.
  2. 2 in. to 4 in.
  3. 4 in. to 6 in.
  4. 6 in. to 8 in.
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B. 2 in. to 4 in.

Both model codes call for a seal of at least 2 in. and no more than 4 in. Less than 2 in. is too easily lost to pressure changes and evaporation; a much deeper seal slows flow and collects solids.

Reference: IPC 2021, Section 1002 (trap seals); UPC 2021, Section 1005

Under the Safe Drinking Water Act, solder and flux used on potable water piping may contain no more than what percentage of lead?

  1. 0.25 percent
  2. 0.2 percent
  3. 8 percent
  4. 50 percent
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B. 0.2 percent

The Act defines lead free for solder and flux as not more than 0.2 percent lead. 0.25 percent is the separate limit for wetted surfaces of pipe, fittings and fixtures, and 8 percent was the old limit for pipe and fittings before 2014.

Reference: Safe Drinking Water Act, Section 1417 (42 U.S.C. 300g-6)

Why is a propane leak in a basement or pit especially dangerous?

  1. Propane is lighter than air and collects at the ceiling
  2. Propane is heavier than air and collects in low areas
  3. Propane has no odorant and cannot be smelled
  4. Propane burns only when it is mixed with natural gas
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B. Propane is heavier than air and collects in low areas

Propane vapor has a specific gravity of about 1.5, so it flows downward and pools in basements, pits and trenches where it can reach an ignition source. Like natural gas, commercial propane is odorized so leaks can be noticed.

Reference: NFPA 58 (LP-gas properties); NFPA 54

A column of water about how tall produces a pressure of 1 psi at its base?

  1. 0.433 ft
  2. 27.7 ft
  3. 34 ft
  4. 2.31 ft
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D. 2.31 ft

Each foot of water gives 0.433 psi, so 1 psi takes 1 / 0.433 = 2.31 ft. 0.433 is the psi per foot, not feet per psi. 27.7 is the number of inches (not feet) of water column in 1 psi, and 34 ft is roughly the head equal to atmospheric pressure.

Reference: Hydrostatics: 0.433 psi per foot of head

A clothes washer's solenoid valves cause loud banging in the supply piping. Which correction is the recognized one?

  1. Install water hammer arresters near the valves
  2. Install a larger water meter and service line
  3. Install a backflow preventer at the washer box
  4. Install a vacuum relief valve on each supply
Show the answer

A. Install water hammer arresters near the valves

A water hammer arrester has a sealed air or gas cushion that absorbs the pressure wave, and it works best close to the quick-closing valve. Backflow preventers and vacuum relief valves deal with reverse flow and negative pressure, not shock.

Reference: IPC 2021, Section 604 (water hammer); UPC 2021, Section 609; ASSE 1010

Exams this helps with

ExamWho runs itWhere
Journeyman plumberState and local boardsUnited States (varies by state)
Master plumberState and local boardsUnited States (varies by state)
Apprentice / tradesman plumberState boardsUnited States (varies by state)

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