Journeyman Plumbers Water Supply and Distribution Questions and Answers

Question 1

A newly installed potable water supply system within a commercial building must be tested for integrity. According to most plumbing codes, what is the minimum required hydrostatic test pressure?

Accepted Answer

1.5 times the working pressure, but not less than 150 psi, for 2 hours

Answer

100 psi for 15 minutes

Answer

The system's working pressure for 2 hours

Answer

50 psi for 4 hours

Question 2

A plumber is sizing the water distribution system for a single-family residence. The municipal water main provides a static pressure of 95 psi at the property line. Which of the following is required?

Accepted Answer

A pressure reducing valve (PRV)

Answer

A backflow preventer

Answer

A water hammer arrestor at the meter

Answer

A larger diameter service pipe

Question 3

To properly size a water supply system, a plumber uses the Water Supply Fixture Unit (WSFU) method. Which of the following best describes the principle behind this method?

Accepted Answer

It assigns a weight to each fixture based on its water consumption, duration of use, and frequency of use to determine the probable peak demand.

Answer

It calculates the peak water demand assuming all fixtures are used simultaneously.

Answer

It measures the static pressure required to operate the most demanding fixture in the system.

Answer

It determines the pipe size based solely on the total number of fixtures in the building, regardless of type.

Question 4

In a multi-story building, how does an increase in elevation affect the available water pressure at the fixtures on the upper floors?

Accepted Answer

Pressure decreases by approximately 0.433 psi for every foot of elevation gain.

Answer

Pressure increases by approximately 0.433 psi for every foot of elevation gain.

Answer

Pressure is not affected by changes in elevation.

Answer

Pressure decreases only if the pipe diameter is reduced.

Question 5

A plumber is installing water lines for a battery of washing machines in a laundromat. These machines have quick-closing solenoid valves. To prevent damage to the piping, which device is required?

Accepted Answer

Water hammer arrestors

Answer

A check valve on each supply line

Answer

An expansion tank

Answer

A tempering valve

Question 6

What is the primary purpose of flushing a new potable water line before it is put into service?

Accepted Answer

To remove any dirt, debris, or contaminants introduced during construction.

Answer

To test the system for leaks at maximum velocity.

Answer

To pre-stretch the piping material before applying test pressure.

Answer

To measure the maximum flow rate in gallons per minute (GPM).

A newly installed potable water supply system within a commercial building must be tested for integrity.According to most plumbing codes, what is the minimum required hydrostatic test pressure?

A newly installed potable water supply system within a commercial building must be tested for integrity.
According to most plumbing codes, what is the minimum required hydrostatic test pressure?