FREE Journeyman Plumbers Water Supply and Distribution Questions and Answers

Question 1

A newly installed copper potable water distribution system in a commercial building must be tested for leaks.
According to most model plumbing codes, what is the minimum required hydrostatic test pressure?

Accepted Answer

1.5 times the working pressure, but not less than 100 psi

Answer

1.25 times the working pressure

Answer

100 psi or the working pressure, whichever is less

Answer

Equal to the street main pressure

Question 2

In a residential hot water supply system with a backflow preventer or check valve installed at the source, what device is essential to protect the water heater and piping from excessive pressure due to thermal expansion?

Accepted Answer

A potable water expansion tank

Answer

A pressure-reducing valve

Answer

A water hammer arrestor

Answer

A dielectric union

Question 3

A plumber is sizing a water service pipe for a single-family home using the Water Supply Fixture Unit (WSFU) method. The total WSFU load is 28, the developed length to the furthest fixture is 120 feet, and the static street pressure is 55 psi. Using a typical IPC/UPC sizing table, what is the minimum required size for the copper water service pipe?

Accepted Answer

1 inch

Answer

3/4 inch

Answer

1 1/4 inch

Answer

1 1/2 inch

Question 4

Which of the following locations would specifically require the installation of a water hammer arrestor according to most modern plumbing codes?

Accepted Answer

On the water supply lines for a clothes washing machine

Answer

At the connection to an outdoor hose bibb

Answer

On the hot water supply line to a kitchen sink

Answer

At the highest point in the water distribution system

Question 5

A plumber is performing a field test on a Reduced Pressure Principle (RP) backflow preventer (ASSE 1013). During the test of the relief valve, what is the minimum differential pressure at which the valve must begin to open and drip?

Accepted Answer

2.0 psid

Answer

0.5 psid

Answer

5.0 psid

Answer

1.0 psid

Question 6

When installing a water service line, what is the general code requirement for the minimum horizontal separation distance between the potable water line and a sanitary sewer line in the same trench?

Accepted Answer

The water line must be placed on a shelf 12 inches above the sewer line.

Answer

There is no minimum separation if the sewer pipe is cast iron.

Answer

The pipes must be separated by at least 5 feet of undisturbed earth.

Answer

A minimum of 18 inches is required, regardless of pipe material.

A newly installed copper potable water distribution system in a commercial building must be tested for leaks.According to most model plumbing codes, what is the minimum required hydrostatic test pressure?

A newly installed copper potable water distribution system in a commercial building must be tested for leaks.
According to most model plumbing codes, what is the minimum required hydrostatic test pressure?