hydrostatic test pressure

[prasit]

Dear all

I design a vessel using PVElite and feel like there is something not right. In Hydrostatic stress calculation, the test pressure shall be calculated from 1.3*MAWP*stress ratio according to UG-99b. In my case, a nozzle MAWP = 492 kPa while shell MAWP = 783 kPa and ellip head MAWP = 786 kPa. In my opinion the test pressure should be based on the value of 492 kPa. However, the program picked shell MAWP 783 kPa for test pressure calculation. Which value shall be used then?

Prasit

 

[SnTMan]

prasit, test pressure should be based on the LOWEST MAWP of all the various components. Don't forget to look at nozzle flange ratings as well.

Regards,

Mike