GPT GPT Pressure Testing & System Commissioning 2

Question 1

What is the maximum allowable test pressure for plastic gas piping?

Accepted Answer

Manufacturer's rated pressure

Answer

Plastic gas piping must never be tested above the manufacturer's rated pressure to avoid material damage or failure.

Question 2

A manometer is used during pressure testing primarily to:

Accepted Answer

Detect pressure changes indicating a leak

Answer

A manometer measures pressure precisely, allowing technicians to detect even small pressure drops that signal a leak.

Question 3

Which type of pressure test is typically used for high-pressure gas transmission lines?

Accepted Answer

Hydrostatic test

Answer

Hydrostatic testing uses water to safely test high-pressure transmission lines at elevated pressures without explosion risk.

Question 4

When should a pressure test be performed on a gas piping system?

Accepted Answer

Before covering, concealing, or placing in service

Answer

Code requires pressure testing before covering or concealing piping so all connections remain accessible for visual inspection.

Question 5

What is the purpose of a regulator lock-up test during commissioning?

Accepted Answer

Verify the regulator maintains outlet pressure when there is no flow

Answer

A lock-up test confirms the regulator holds a stable outlet pressure when downstream flow stops, preventing over-pressurization.

(GPT) Gas Pipe Technician Certification Practice Test