SPED Pressure Testing & Commissioning 2

Question 1

During a hydrostatic pressure test, at what minimum hold time must the test pressure be maintained to verify integrity per ASME B31.3?

Accepted Answer

10 minutes

Answer

ASME B31.3 requires a minimum hold time of 10 minutes at test pressure for hydrostatic tests, though the examiner may require longer.

Question 2

Which fluid is preferred for hydrostatic testing of piping systems that will operate at cryogenic temperatures?

Accepted Answer

Water

Answer

Water is the preferred hydrostatic test medium even for cryogenic service because it is safe, incompressible, and readily available.

Question 3

What is the primary hazard associated with pneumatic pressure testing compared to hydrostatic testing?

Accepted Answer

Greater stored energy leading to more violent failure

Answer

Compressed gases store significantly more energy than liquids at the same pressure, making pneumatic test failures far more violent and hazardous.

Question 4

A piping system is pneumatically tested at 110 psig. What is the minimum preliminary test pressure used to check for leaks before full pressurization per ASME B31.3?

Accepted Answer

10 psig

Answer

ASME B31.3 requires a preliminary pneumatic test at no more than 10 psig before ramping to full test pressure to check for obvious leaks.

Question 5

When flushing a new piping system during commissioning, which criterion typically determines adequate flushing completion?

Accepted Answer

Flush fluid cleanliness meets system cleanliness class (e.g., NAS or ISO 4406)

Answer

Flushing is complete when the circulating flush fluid achieves the target cleanliness class, typically measured by particle count per ISO 4406 or NAS 1638.

(SPED) Society of Piping Engineers and Designers Certification Practice Test

(SPED) Society of Piping Engineers and Designers Certification Practice Test

SPED Pressure Testing & Commissioning 2