GPT Material Selection & Properties 4

Question 1

What is the primary reason galvanized steel pipe is NOT recommended for gas service inside buildings?

Accepted Answer

The zinc coating reacts with gas odorant to create corrosive compounds

Answer

The zinc coating on galvanized pipe reacts with sulfur compounds in gas odorant (mercaptans) to form zinc sulfide, which can flake off and clog equipment.

Question 2

A technician needs to select pipe for a high-pressure gas main operating at 100 psi. Which material is most appropriate?

Accepted Answer

Schedule 40 black steel

Answer

Schedule 40 black steel is appropriate for high-pressure gas mains at 100 psi; PE and CSST have lower pressure limitations for typical residential use.

Question 3

Which ASTM standard covers the thermoplastic pipe used for underground gas distribution?

Accepted Answer

ASTM D2513

Answer

ASTM D2513 is the standard specification for thermoplastic gas pressure pipe, tubing, and fittings used in underground gas distribution.

Question 4

What is the minimum burial depth for PE gas pipe installed under a roadway per NFPA 54?

Accepted Answer

36 inches

Answer

PE gas pipe under roadways must be buried at least 36 inches deep to protect against traffic loads and excavation damage.

Question 5

A gas service line transitions from underground PE to above-ground steel at the meter. What is this transition fitting called?

Accepted Answer

Anodeless riser

Answer

An anodeless riser is the factory-made transition fitting that connects underground PE pipe to above-ground metallic pipe at a meter set.

(GPT) Gas Pipe Technician Certification Practice Test

(GPT) Gas Pipe Technician Certification Practice Test

GPT Material Selection & Properties 4