ASME UG-136 (d)(2)

[kwal123]

Anyone out there have input on the new wording for hydrotest requirements in UG-136. Is the Secondary zone now classified as pressure bearing also? Must secondary pressure zone be hydrotested?

 

[gr2vessels]

UG-136(d)(3) remained the same as the 2007 edition. It still calls for compressed air test at minimum 30 psi (or other gas).
Cheers,
gr3vessels

 

[kwal123]

Any comments on 136(d)(2) hydrotest of the shell and the new wording about primary and secondary zones. Until this change the secondary zone was not considered to be pressure bearing. Or am I reading this wrong?

 

[Duwe6]

It is not a pressure bearing area, but Code still requires leak testing - indicates weld and material quality.

 

[vpl]

The pressure containing parts of each valve shall be hydrostatically tested at a pressure at least 1.5 times the design pressure of the parts.

a) Hydrostatic testing shall be performed on the pressure containing parts of the shell of each valve at a pressure at least 1.5 times the design pressure of the parts. The valve shell is defined as parts, such as the body, bonnet, and cap, which isolates primary or secondary pressure from atmosphere.

Disclaimer: I am not a Code expert and any interpretation should be done only by the Code committee.

I read it that the Code committee wanted to clarify that any vessel part which performs a pressure boundary (isolates an internal pressure from atmosphere) function is to be hydrostatically tested, no matter the "origin" of the pressure as a "primary" or a "secondary" pressure. I wouldn't say that secondary pressures were excluded in the 2007 version — it's more that it's being explicitely defined in the 2010 version.



Patricia Lougheed

******

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.

 

[gr2vessels]

Patricia is right.
Cheers,
gr2vessels