Journeyman Plumbers Gas Piping Systems Questions and Answers

Question 1

A plumber is installing a new natural gas piping system that will operate at a standard pressure of 7 inches water column (approx. 0.25 psi). According to the International Fuel Gas Code (IFGC), what is the minimum required air pressure test for this new installation?

Accepted Answer

3 psig for a minimum of 10 minutes

Answer

According to IFGC section 406.4.1, for a gas system with a proposed maximum working pressure less than or equal to 0.5 psi, the test pressure must be no less than 1.5 times the working pressure, but not less than 3 psig. The test duration must be a minimum of 10 minutes.

Question 2

A plumber is installing a gas line to a new furnace. To protect the appliance's controls from particulate matter, a sediment trap is required. Based on model fuel gas codes, which of the following describes the correct installation of a sediment trap?

Accepted Answer

Downstream of the appliance shutoff valve and before the flexible appliance connector.

Answer

Fuel gas codes require a sediment trap to be installed downstream of the appliance's shutoff valve, as close to the inlet of the appliance as practical, and before any flexible connector. It must be configured with a tee fitting to force a 90-degree change in gas flow, allowing sediment to fall into the capped nipple.

Question 3

When installing Corrugated Stainless Steel Tubing (CSST) for a natural gas system, what specific safety measure is mandated by the manufacturer and fuel gas codes to protect against electrical hazards?

Accepted Answer

Bonding the CSST system directly to the building's electrical service grounding electrode system.

Answer

To mitigate the risk of damage from electrical arcing (such as from a nearby lightning strike), CSST systems must be bonded to the building's electrical service grounding electrode system. This is typically accomplished with a minimum 6 AWG copper wire and a proper bonding clamp attached to a rigid pipe component or CSST fitting.

Question 4

Which of the following locations is strictly prohibited for the installation of gas piping according to the International Fuel Gas Code?

Accepted Answer

Through a circulating air duct or chimney.

Answer

The IFGC explicitly prohibits the installation of gas piping in or through circulating air ducts, clothes chutes, chimneys, gas vents, dumbwaiters, or elevator shafts. A gas leak in these locations could quickly and dangerously spread throughout the building.

Question 5

A plumber is running an underground polyethylene (PE) gas line to an outdoor barbecue grill. According to the IFGC, how must the PE pipe be transitioned for the above-ground connection to the appliance?

Accepted Answer

The PE pipe must transition to an approved metallic pipe using a manufactured anodeless riser before it emerges from the ground.

Answer

Polyethylene (PE) plastic piping is not approved for above-ground use due to its susceptibility to UV degradation and physical damage. It must be terminated below grade and connected to an approved above-ground piping material, typically through a pre-manufactured anodeless riser or other approved transition fitting.

Journeyman Plumbers Exam Practice Test

Journeyman Plumbers Exam Practice Test

Journeyman Plumbers Gas Piping Systems Questions and Answers