Rate of pressure raising during hydrotest

You can raise the pressure initialy to 2 bar g (you may convert to KSC)then hold it for 10 minutes. Check for any leak . If foound satisfactory you may go ahead 25% of your test pressureat a rste of 2 barg per minute. Once it achieve to 25% jhold it for 10 minutes and ensure no leak is observed.Continue the process in 4 stages till it reaches design pressure. at design pressure you have to carry out a leak check . I f you found satis factory you may raise the pressure to Test presure i,e 1.5 times of the DP. hold again for ten minutes and carry out final leak check. all the pressure must be recorded by using a recorder .

note, any hydrostatic pressure test must be done with zero air or other trapped gas inside. Any air left in there can cause a dangerous explosion if the vessel fails the test and the compressed air spreads the cracks and throws pieces around, like a bomb.

http://en.wikipedia.org/wiki/Hydrostatic_test

boiler with design opressure is 105 KSC. Please I am new. What is KSC?

hydrotest of boiler / pressure vessel is 1.5 times the design pressure.

kg/cm^2 the units of pressure

Really Thanks. Always aware with Kg/cm2 or Bar or Psig etc., but never KSC = kg/cm2 for this has never ever been used in my Country.

As they say "you learn something new eveyday".

I agree with posts #1 & #2, I was taught that if you raised the pressure to quickly, you ran the risk of an ingress of air. This air was then a risk to the people doing the inspection. If someone doing an inspection of say a crack and water under high pressure is released, then that can cause injury to that person if air in the system prolongs the discharge. My belief is that careful pressurisation is a safety issue for the personnel doing the inspection.

Regards JD.