Journeyman Plumbers Exam Gas Piping and Appliances 5

Question 1

A gas piping system operating at pressures above ½ psig but not exceeding 2 psig is classified as:

Accepted Answer

Medium pressure

Answer

NFPA 54 classifies gas piping at pressures above ½ psig (14 inches WC) up to 2 psig as a medium-pressure system, requiring different materials and joining methods.

Question 2

What must be installed where gas piping passes through a foundation wall or concrete floor slab?

Accepted Answer

A protective sleeve or casing

Answer

Gas pipe must be sleeved where it passes through masonry or concrete to protect it from corrosion, soil movement, and to allow for expansion.

Question 3

Under the International Fuel Gas Code, underground gas piping must have a minimum cover of:

Accepted Answer

18 inches

Answer

IFGC requires a minimum of 12 inches of cover for underground gas piping in residential applications, though 18 inches is common for areas with vehicular traffic.

Question 4

A pilot light that repeatedly goes out on a gas appliance most likely indicates a problem with:

Accepted Answer

The thermocouple or thermopile

Answer

The thermocouple generates a small voltage when heated by the pilot flame; if it fails or is positioned incorrectly, it causes the safety valve to close, extinguishing the pilot.

Question 5

Which of the following actions is required after replacing a gas appliance regulator?

Accepted Answer

Verify outlet pressure with a manometer at the rated flow condition

Answer

After regulator replacement, outlet pressure must be verified under load conditions with a manometer to ensure it is set to the correct operating pressure (typically 3.5 inches WC for natural gas).

Journeyman Plumbers Exam Practice Test

Journeyman Plumbers Exam Practice Test

Journeyman Plumbers Exam Gas Piping and Appliances 5