Pressure Testing & Commissioning Flashcards
7 cards from real SPED practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Pressure Testing & Commissioning flashcards as text
During a hydrostatic pressure test, at what minimum hold time must the test pressure be maintained to verify integrity per ASME B31.3?
Answer: 10 minutes
ASME B31.3 requires a minimum hold time of 10 minutes at test pressure for hydrostatic tests, though the examiner may require longer.
Which fluid is preferred for hydrostatic testing of piping systems that will operate at cryogenic temperatures?
Answer: Water
Water is the preferred hydrostatic test medium even for cryogenic service because it is safe, incompressible, and readily available.
What is the primary hazard associated with pneumatic pressure testing compared to hydrostatic testing?
Answer: Greater stored energy leading to more violent failure
Compressed gases store significantly more energy than liquids at the same pressure, making pneumatic test failures far more violent and hazardous.
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?
Answer: 10 psig
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.
When flushing a new piping system during commissioning, which criterion typically determines adequate flushing completion?
Answer: Flush fluid cleanliness meets system cleanliness class (e.g., NAS or ISO 4406)
Flushing is complete when the circulating flush fluid achieves the target cleanliness class, typically measured by particle count per ISO 4406 or NAS 1638.
Which document is issued after all pre-commissioning checks are satisfied and authorizes introduction of process fluids into a piping system?
Answer: Mechanical Completion Certificate
A Mechanical Completion Certificate (MCC) formally confirms all construction and pre-commissioning activities are complete, authorizing process fluid introduction.
What action must be taken on spring-loaded safety valves during a hydrostatic pressure test of the connected piping?
Answer: Remove or block them to prevent premature opening
Safety/relief valves must be removed or isolated during hydrostatic tests to prevent them from opening at their set pressure, which is below the test pressure.