You may find the guidelines in this AWS publication:- https://pubs.aws.org/Download_PDFS/D10.10-D10.10M-....
Thanks.

Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
ca.linkedin.com/pub/pradip-goswami/5/985/299

It depends on the code of construction. For example, Section I for Power Boilers exempts PWHT for application of non-load bearing studs - see below for General note 5 from table PW-39-4.

(5) for welds attaching nonload‐carrying studs or insulation attachment pins not exceeding 1/2 in. (13 mm) in diameter when using an automatic arc stud welding or automatic resistance stud welding process

thank you for your fast and beneficial answers.

Quote (metengr)

It depends on the code of construction. For example, Section I for Power Boilers exempts PWHT for application of non-load bearing studs - see below for General note 5 from table PW-39-4.

(5) for welds attaching nonload‐carrying studs or insulation attachment pins not exceeding 1/2 in. (13 mm) in diameter when using an automatic arc stud welding or automatic resistance stud welding process

and metengr is there any code that recommends pwht?
I found 2001 version of section I for power boilers and there is a limitation of 4" on that one.

there is a link for screen image of 2001 edition

• http://files.engineering.com/getfile.aspx?folder=0bab3bad-1c20-44c3-a6d4-bd

For tubing, most ASME Codes and Standards will exempt PWHT for non-load bearing studs provided the process is by arc or resistance welding and the heat affected zone from the stud does not encroach on the minimum wall thickness of the tube, by design.