×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

API 661 Airfin - PWHT needed for new header nozzle?

API 661 Airfin - PWHT needed for new header nozzle?

API 661 Airfin - PWHT needed for new header nozzle?

(OP)
Greetings fellow engineers,
I am supporting a project in which we will be adding a nozzle to an existing airfin heat exchanger designed to API 661.

API 661, para 9.2.1 states "All carbon steel..headers shall be subjected to post weld heat treatment".

I would like to understand the intent of the PWHT requirement, and to understand if once the new nozzles are added to the header box if the header box must be PWHT'd.

I suspect that the concern is high stress concentrations near the corners of the square header box geometry, and perhaps concern with brittle fracture (although the CET should be +10degF for this service).  My feeling is that PWHT is not required for adding new nozzles, because residual stresses added during the welding process is minimal.  

Please note that the airfin in question is constructed from carbon steel (SA516-70 - norm) and that the service does not require PWHT.  Also, the maximum thickness of plate is 1-1/4", but the thickness of the area that the nozzles will be added is 3/4".

Any insight you can provide will be helpful.  Thanks!

x/0

RE: API 661 Airfin - PWHT needed for new header nozzle?

You are right, there is no code requirement for PWHT of the added nozzle.
Cheers,
gr2vessels

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources