GPT GPT Pressure Testing & System Commissioning

Question 1

What is the standard test pressure for a gas piping system before commissioning per NFPA 54?

Accepted Answer

1.5 times the maximum allowable operating pressure

Answer

NFPA 54 requires pressure tests at 1.5 times the maximum allowable operating pressure to verify system integrity.

Question 2

Which test medium is preferred for leak testing gas piping systems?

Accepted Answer

Air or inert gas

Answer

Air or inert gas is preferred for pressure testing to eliminate explosion risk if a leak is discovered during the test.

Question 3

How long must a gas piping system hold test pressure to pass a standard pressure test per NFPA 54?

Accepted Answer

15 minutes

Answer

NFPA 54 requires piping to maintain test pressure for a minimum of 15 minutes without any measurable pressure drop.

Question 4

What procedure must be performed after pressure testing before gas is introduced into a new system?

Accepted Answer

Purging with inert gas

Answer

Purging with inert gas displaces air and moisture from the piping to prevent combustible air-gas mixtures when gas is introduced.

Question 5

Before performing a pressure test, appliance connections must be:

Accepted Answer

Disconnected or capped

Answer

Appliance connections must be disconnected or capped to isolate the piping system so only the pipe is being tested.

(GPT) Gas Pipe Technician Certification Practice Test