GPT Material Selection & Properties 2

Question 1

Which pipe material is prohibited for use with LP-gas service in most US codes?

Accepted Answer

Cast iron

Answer

Cast iron is prohibited for gas piping because it is brittle, prone to cracking, and cannot withstand vibration or soil movement.

Question 2

What is the minimum wall thickness designation required for steel pipe used in gas distribution systems per ASME B31.8?

Accepted Answer

Schedule 40

Answer

Schedule 40 is the minimum acceptable wall thickness for steel gas pipe under ASME B31.8 for most residential and commercial applications.

Question 3

A gas technician is installing pipe through a concrete floor slab. Which material requires a protective sleeve to prevent corrosion?

Accepted Answer

Black steel pipe

Answer

Black steel pipe must be sleeved when passing through concrete because the alkaline environment accelerates corrosion of uncoated steel.

Question 4

What property of polyethylene (PE) pipe makes it unsuitable for above-ground gas service?

Accepted Answer

It degrades when exposed to UV radiation

Answer

PE pipe degrades under UV radiation exposure, making it suitable only for buried underground applications.

Question 5

Which ASTM standard governs seamless and welded steel pipe commonly used in gas distribution?

Accepted Answer

ASTM A53

Answer

ASTM A53 covers seamless and welded black and hot-dipped galvanized steel pipe used in gas distribution systems.

(GPT) Gas Pipe Technician Certification Practice Test