A pneumatic test is done using a non-flammable gas like compressed air, nitrogen, Helium or Hydrogen to identify microscopic cracks and defects in pressure systems.
This test method involves measuring the change in pressure inside the system over a time period.
Pneumatic tests are potentially more dangerous than hydrostatic because of the higher level of potential energy. Experienced and qualified personals should only perform Pneumatic tests when at least one of the following conditions exists:
– When pressure systems are so designed that they cannot be filled with water.
– When pressure systems are to be used in services where traces of the testing medium cannot be tolerated.
– A pneumatic application may require the test medium be pneumatic enabling minute leaks and
– defects to be identified.
A pneumatic test is a form of strength test that is done when elevated pressure at some multiple greater than 1.0 of the system maximum allowable working pressure (MAWP) and held for some length of time. The pressure multiple and time duration vary considerably from one regulatory jurisdiction to another, from one code/standard document to another, and from one company to another.