Hello

Is it allowable to design pressure vessels without combustion process acc. to ASME Section IV requirements with H-2 form?

In preamble of Section IV we can read that this section is for boilers "directly fired" with fuel. Shall it be interprated that combustion process need to be within the veseel?

By unfired pressure vessels i mean units like economizers which are used to preheat feeding water for a boiler using flue gases from a boiler which are normally wasted.

Currently we are designing some of our economizers under Section VIII with U stamp and some acc. to ASME Section IV with "H part" stamp as a "part of a boiler"

We need to confirm this for one of our clients who is insisting that we can use H-2 form for economizer instead of H-4 form.

Thank you for your help.

Best Regards

Lukasz

An economizer can be part of section IV. In this case it would be fired by flue gases, the combustion should not be in the vessel itself to be in the scope of section IV.
I see no problem to use the H-2 form for an economizer.