hydro test pressure

[212197]

UG -99 of ASME SEC. VIII DIV 1 asks to consider lowest stress ratio while calculating hydro pressure.

NB- 6220 does not specify requirement to consider lowest stress ratio while calculating hydro pressure.

What is the rationale behind the difference in requirement of the two codes?

Is it that due to higher factor of safety, higher hydro pressure is permitted on SEC. VIII DIV 1 equipment?

 

[TGS4]

Two different committees with two different groups of engineers.

Under no circumstances should you look to find anything rational to explain the difference between two ASME Codes. And that goes double for two Codes that report to difference Board (Board on Pressure Technology Codes and Standards; Board on Nuclear Codes and Standards).