Main Question or Discussion Point
Can somebody explain the the difference between Hydrostatic test and Air test. Instead of hydrotest can we test the pipelines with air pressure. The working pressure of pipeline is 16 bar.
What type of fluid is normally carried in the pipe? If contamination is not a concern (e.g. this is not a potable water line) then you may be able to use a glycol/water mixture for your hydro test. Again this assumes contamination is not a concern.Thank you Goest, My doubt is about the pipe test on board a tanker ship, actually as per specification the pipe should be checked with 16 bars (hydro) but the ambient temperature is below zero because of that they worried about freezing of water, so the maker is suggesting the pressure test with air. And practically if the air pressure is above 0.5 bar the leak finding with soap water is not recommended. And I would like to know about the other differences between the pressure test with water and air.
So per the code, a leak test using air may be performed if the system owner considers the hydrostatic test to be impractical.Prior to initial operation, and after completion of the applicable examinations required by para. 341, each piping system shall be tested to ensure tightness. The test shall be a hydrostatic leak test in accordance with para. 345.4 except as provided herein.
(b) Where the owner considers a hydrostatic leak test impractical, either a pneumatic test in accordance with para. 345.5 or a combined hydrostatic-pneumatic test in accordance with para. 345.6 may be substituted, recognizing the hazard of energy stored in compressed gas.