✓ TradeExamPro

TradeExamPro › Plumbing & Gas › Gas fitting (natural gas and LP)

Piping practice questions

36 questions from the gas fitting (natural gas and lp) practice test.

Piping practice test

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

What this covers

Sample questions

Which of these materials is not permitted for fuel gas piping under the IFGC?

  1. Schedule 40 steel pipe
  2. Cast-iron pipe
  3. Corrugated stainless steel tubing
  4. Polyethylene pipe underground
Show the answer

B. Cast-iron pipe

Cast-iron pipe is specifically excluded from gas piping. Steel pipe, listed CSST and polyethylene (outdoors, underground) are all recognized materials.

Reference: IFGC 2021 Section 403; NFPA 54 Section 5.6.2

Where may polyethylene (PE) plastic gas pipe be installed?

  1. Indoors, where it is exposed
  2. Indoors, inside wall cavities
  3. Outdoors, above the ground
  4. Outdoors, below the ground
Show the answer

D. Outdoors, below the ground

PE gas pipe is limited to outdoor underground use, because sunlight, heat and physical damage can destroy it. It comes above ground only inside a listed riser.

Reference: IFGC 2021 Section 404.17; NFPA 54 Section 7.1.7

How is polyethylene gas pipe joined?

  1. By heat fusion or listed mechanical fittings
  2. By solvent cement made for plastic gas pipe
  3. By cutting tapered threads on the pipe ends
  4. By soldering with a low-temperature alloy
Show the answer

A. By heat fusion or listed mechanical fittings

PE is joined by heat fusion or by mechanical fittings listed for gas. Polyethylene cannot be solvent cemented the way PVC can, and it must never be threaded.

Reference: IFGC 2021 Section 403.9; NFPA 54 Section 5.6.9

Other topics