×
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

WELDING A CUT OUT FLANGE

WELDING A CUT OUT FLANGE

WELDING A CUT OUT FLANGE

(OP)
All,

Please I will like to know if there is any code or specs on how many times you can cut out a flange and re-weld that same flange.

We have a 24'' X 900#. In modifying a pipe spool, we cut out the flange and we want to re-use it. is there a limit to the number of times we can re-weld a cut out flange.

Professionals, I really need your help.

Regards

Chitessy

RE: WELDING A CUT OUT FLANGE

This has been discussed many times and the best advice I can offer is to consider the action as a repair weld (albeit a complete repair weld(!)). This is normally limited to a single repair before you need to start again and completely remove the pipe and its HAZ and ditto that of the flange. I think most prudent engineers would only weld the same thing in the same place a maximum of three times before they start to get nervous. I don't believe it is specified in any code or standard as there are too many variables.

The issue is really one of material changes to the flange due to the heat input from the welding and its impact on the physical properties of the flange, in particular it's hardness, which varies by material, thickness, welding technique etc etc. Unfortunately some tests are destructive, hence a bit difficult to do unless you're trying to prove a point for many other similar fittings

You may be able to utilise the flange more times than twice, but it's really in the hands of the materials / welding engineer and the flange welding face may need to be tested for excessive hardness.

This is a response from the welding institute - http://www.twi-global.com/technical-knowledge/faqs...

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

RE: WELDING A CUT OUT FLANGE

At a certain point in time, the COST of two welder/fitters/grinders/labor working to cut/refit/regrind/refit/regrind the flange is ten times the price of a new flange with "good" metal.


You're wasting money and time and schedule trying to salvage a bad job repeated already twice. Field repairs are about 150.00 - 200.00 per hour per man. Your flange can come overnight.

RE: WELDING A CUT OUT FLANGE

(OP)
Thanks All for your responds, I sincerely appreciate.

Chitessy

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