×
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

Weld Repair of ASME Nozzle
2

Weld Repair of ASME Nozzle

Weld Repair of ASME Nozzle

(OP)
Good afternoon all,

A LH2 pressure vessel that was manufactured about 20 years ago was recently opened and had an internal inspection performed.  During the inspection, it was discovered that there was incomplete penetration on the nozzle weld, and after referring to the ASME Code, the nozzle did not have to have RT performed at the time of construction.

Does this weld need to be repaired according to NBIC standards or another national standard?  What other options are available to ensure continued and safe operation?

Thank you very much

RE: Weld Repair of ASME Nozzle

Yes, this weld should be repaired after a visual inspection of an in-service vessel. Regardless of what was done earlier during construction, incomplete penetration can result in fatigue crack propagation in service or other potential failure because this is a crevice. Remember, ASME Code only provides minimum requirements for long term safe operation.

You can try to evaluate if service loads or conditions can result in crack propagation. This requires engineering analysis to justify. It would be much easier to grind out and weld repair to ensure complete penetration.
 

RE: Weld Repair of ASME Nozzle

(OP)
Thank you very much metengr!  I'm still getting the hang of ASME and PV engineering so I very much appreciate the feedback.

RE: Weld Repair of ASME Nozzle

Derek,

If you are referring to incomplete joint penetration it may not be a defect as this nozzle weld could have been designed that way. Nozzle welded only from one side is allowed per ASME sect.8 under some conditions. It is not be the best practice but it is allowed.

You should look for the design criteria for that joint from manufacturer drawings and data reports. Liquid hydrogen being non-corrosive, I would not worry to much about having a crevice on the inside unless there is considerable load cycling.    

If it was designed as a full penetration weld or fillet welded from both sides then it is a weld defect and repairs will be needed according to NBIC standard.

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