Isthese a safe way TO CARRY OUT PNEUMATIC TEST ON A PRESSURE VESSEL AT HIGH PRESSURES?

Question

we are making pressure vessels and we have been advise that it is safer to carry out hydro testing as compared to pnuematic testing. Hydro testing tkaes time but with pnumatic testing it is dangerous. and ideas

Answer 1

The concern with pneumatic testing is the amount of energy stored in the vessel as it is pressured up. Since water is almost incompressible, there is little pressure stored and should the vessel fail it is quickly and safely released.

With pneumatic testing a failure can result in a significant release of energy and may in fact be described as an explosion.

I would personally never test a vessel with air because it is just too dangerous. Also you normally test at a much lower pressure with air and do not really give the vessel a "good" test of its strength.

If you do a complete pneumatic test and bubble test all seams, welds and connections then you save very little time with a pneumatic test.

Answer 2

air density is much less than water and if your vessel should explode it could hurt somebody if not by the sound produced by the explosion, the rapid expansion of air.
Water has a limited compression so if ever your vessel your explode, water would not scatter around the testing area and could hurt somebody. If a vessel filled with water should explode their will be less sound and since water is uncompressible it will not explode upon explosion.
If there is a crack in the vessel, water can be much easier to be seen than air thereby you can hold the pressure test at once.

Answer 3

This is terribly miss-spelled, but true. The compressibility of air makes pneumatic testing much more dangerous then hydrostatic testing with water.