×
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

Pad-type flange design

Pad-type flange design

Pad-type flange design

(OP)
The vessel in question is a 2003 U-2 stamped vessel with a 30" pad-type flange on the top head (for clarity, the nozzle configuration is as per Fig UG-40(a-2) in Div 1). This flange has been problematic during past maintenance activities and as a result some holes have been re-drilled larger and re-threaded.

With these holes drilled larger the question is being asked as to how large the holes and bolting can go and still remain Code compliant? The connecting flange is not the limiting component in terms of nut access - it is a modified flat cover designed in accordance with ADM so nut access is not a problem. I have not dealt with pad-type flanges in the past, and from what I can see opening reinforcement is required (AD-520) and the depth of the holes is limited (AD-740) - both references are from ASME VIII Div 2 2004.

So is there a limit on the bolt diameter? How are bolting requirements determined/checked with pad-type flanges?

RE: Pad-type flange design

You will need to satisfy AD-740. It sets a limit on the tapped hole depth based on the diameter.

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