Hydrotesting Existing Pressure Vessels Which Have Been Uprated

[ddm0]

Is there an AS1210 ruling associated with the requirement to hydro test an existing pressure vessel which has been re-rated (that is, calculations have been performed to demostrate that the nameplate design pressure and temperature can be increased). The higher design temperature or pressure means that the hydrostatic test pressure is higher than original, but does the existing vessel need to be hydro tested again at the higher test pressure?

 

[tickle]

Why wouldn't you? I would have to check the code to be sure.

But, pressure vessel need registration in Australia, therefore, I am not sure that you can just increase the desgin temperature.

Firstly, how big is the vessel? If it is small why not just rehydro.

As a consultant, I tend to specify vessels to the flange rating. If they are small there tends to be no significant impact on the cost.

AS1210 also allows you to do a pneumatic test, but should be avoided if possible. There are safety issues in doing pneumatic tests if there are cracks filled with liquid.

 

[metengr]

Out of curiosity - what is the in-service inspection, repair and alteration code for boilers and pressure vessels located in Australia? Is the AS more of a construction code versus an in-service repair code, like the NBIC.

I would think for a re-rating of a pressure vessel, you would need to hydrotest the vessel under the new design conditions because this is an alteration. Second, I would presume you need to have a paper trail (documentation and stamping) similar to what was used when the vessel was originally constructed and hydrotested?