Hello All, I'm testing hydrostatic 2

[PatKop]

Hello All,
I'm testing hydrostatic vessel up to 600 bar (8700 psi) and just wondering what if some air will stay inside? Could be a problem to achieve 600 bar or it will be impossible to test such item. And the main problem if can be that pressure inside vessel will be higher then gauge is showing (I think not but I received such idea)?
Thanks in advance for answer
PatKop

 

[JR97]

PatKop,

Your main concern should be safety. Compressing any significant amount of air to that pressure can have horrendous effects if the component should fail. This is how people are killed !!!

Air in the unit will not affect your ability to reach pressure nor will it produce erroneous pressure readings.

JR97

 

[ButchCWIPSCI]

"Can be that pressure inside vessel will be higher then gauge is showing"

With the pressure you have stated I would make sure all gauges have been calibrated with in 30 days of the test if there is a concern set up a test rig with multiple gauges to see the accuracy this may give you a piece of mind and as stated earlier please be careful with trapped air in the system as JR97 said this is how people get killed!!

 

[gr2vessels]

PatKop,
The pressure vessel you mentioned has a very high design pressure and conversely a very high hydro test pressure. If it is a small piece of equipment, it might not be a big deal to perform the test, provided you have the testing equipment and expertise to conduct a such test.
However, for any larger equipment than you can lift with your hands, the test conditions are governed by the design code, say ASME Section VIII Division 2 or 3 or other equivalent. This test is suppose to be controlled by a detailed specification/ procedure, reviewed and accepted by the inspector/inspection agency, the Client and perhaps, in some cases, by the local goverment or its local office. It should not be allowed to be conducted by someone with limited experience and/or limited understanding of the consequences of the test gone wrong. Take my advice, stop before you'll cause a major problem, including destruction of the vessel, damage to the property and loss of personnel life. Only experienced people in conducting this kind of hydro test know how to prevent the entrapment of the air inside the vessels, the procedure for the pressure rise, stages of maintenance and checking the stressed components, water temperature, composition, etc. If you think that now you need help, ask before the test. Get a good testing procedure from an experienced fabricator, read the code requirements and speak to the inspector, who's suppose to witness the test anyway, check the test water requirements and the environmental issues related to the disposal of testing water. And many more other issues you have to address responsively before the test....
Best regards,
gr2vessels