Pneumatic Pressure Testing
Our pneumatic testing services can be applied directly after construction, or following a stage 1 soundness test, depending on the pressure regime of the pipeline, whilst assessing creep compensation, normally associated with testing polyethylene gas pipelines in the United Kingdom.
Pneumatic testing is widely used to achieve minimum down time and economy and convenience of testing as compared to hydrostatic tests. It is also useful to detect very fine leak paths which may not be found in Hydrostatic testing.
Pneumatic pressure testing of piping and vessels at moderate-to-high test pressures or at low test pressures with high volume is more hazardous than hydrostatic pressure testing because the stored energy is much greater with compressed gases. Air, however, (like all gases) is compressible and, as a result, much more energy has to be put into the gas to raise its pressure. In fact, at the pressure ranges normally used for testing water-piping systems 200 times more energy is stored in compressed gas compared to water at the same pressure and volume. So, should a joint, pipe, or any other component fail under test pressure when using compressed gas, the energy can be released with deadly force!
Hazards from loss of containment during pneumatic pressure testing include both blast overpressure and missiles. In applications where pressure testing with liquids is undesirable or non-industry standard such as piping systems and vessels with a lower maximum operating pressure, pneumatic pressure testing can only be justified when care in fabrication and in non-destructive examination of vessels and piping reduces the probability of loss of containment to such a small value that risk is acceptable.
Pneumatic pressure testing is most commonly used on gas pipelines with a maximum operating pressure of 2Bar with most or all of the pipeline buried.
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