×
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

Tonge&Grove Flange face Evaluation

Tonge&Grove Flange face Evaluation

Tonge&Grove Flange face Evaluation

(OP)
Actually I'm evaluating a 36" flange (300#), I found some scratches on the flange face (tonge&grove), where should I look for some evaluating criteria?
This flange is part of an ASME Vessel.

RE: Tonge&Grove Flange face Evaluation

(OP)
Hello,

Begin with the National Board Inspection Code (ANSI - NB-23).  Also look at API Standard 510 (Inspection of Pressure Vessels).  You will have to decide what caused the damage and if the flange's structural integrity is challanged by it.

Look at the National Board's web site and especially this address:

http://www.nationalboard.org/Classics/articles.html

Regards, John.

RE: Tonge&Grove Flange face Evaluation

Check your flange spec. All dimensions, including surface finish, should be to the original spec. For B16.5 flanges (up to 24") the contact surface roughness for tongue and groove cannot exceed 125 microinches.

RE: Tonge&Grove Flange face Evaluation

B16.5 will also contain information pertaining to the extent of allowable imperfections in relation to the depth of the serrations.  

RE: Tonge&Grove Flange face Evaluation

I assume that by "scratches" you meant that the gasket surface had some mechanical marks but wasn't cracked (which would necessitate a whole different set of criteria for evaluation).  You need to evaluate several things in this case:  depth of scratches, orientation (radial or circumferential), length, type of gasket being used, and finally operating conditions (temperature & pressure) and service.  

If the scratches are radial, going from the bore of the flange to the OD of the gasket surface, you may have a problem, depending on the length and depth of the scratches.  If they are short and do not completely cross the gasket surface you might not need to do anything.  If they are long they may require machining to prevent a leak.  If they are circumferential and don't cross much of the gasket surface in a radial direction you might not have to do anything with them.  

If it is more of a gouge with displaced material at the edges than just a scratch, manual dressing with a flat file will remove the "humped up" metal.  If they are deep and you have concerns that the gasket won't "flow" into the void when bolted up you are probably looking at a machining job.  

If the service is such that any hint of a leak (even low ppm level leaks) is unacceptable, a machining job is required.  

If you have to do some machining to restore the gasket surface all is not lost as there are several companies around that can do machining in the field, including Furmanite, Koppl, and Team Industrial Services.  

Bottom line:  gasket surface irregularities don't automatically mean a field machining job is in order to obtain a good seal.  

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