ASME P4 or P4a data report?

[JAYDEE23]

We often supply flow measurement piping components for HRSG units. Being unfamiliar with what happens in the field we generally take our direction from the customer regarding ASME data reports. We currently have a job with 1 component being listed BEP "S" stamp and the other "BP" "S" stamp. Our customer is requesting P4a for BEP and P4 BP units. Can anyone elaborate a bit as to why this is. Ive looked through section 1, and because of my unfamiliarity with the finished units and the field work in general i am not able to make clear distinctions between the two requirements. Any help is very much appreciated.

 

[JAYDEE23]

Someone school me.

 

[JAYDEE23]

Anyone?

 

[qaqceng]

JAYDEE23,
Your customer is correct. Section I, PG-112.2.6 says P-4A Forms are to be used for shop or field-welded boiler external piping. The words "Boiler External Piping" were added to that paragraph in the 2006 Addenda of the code. Prior to the 2006 Addenda, P-4A's could be used for both Boiler Proper and Boiler External Piping.

 

[JAYDEE23]

Got it. I will go look. now. Thanks!!