×
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

Different thickness between pipe and Tee

Different thickness between pipe and Tee

Different thickness between pipe and Tee

(OP)
Dear All,
I have a question regarding pipeline with pigging system. The pipe thickness is caculated is lower than the thickness of equal Tee(half percent) For pigging the ID of pipe and Tee should be same, normally whats the solution? I guess increasing thickness of pipe(same as Tee) is not good one.
Please let me know your opinion

Thanks in Advance

RE: Different thickness between pipe and Tee

Farzam,
Please do not try to "over-engineer" something that has been working just fine for a hundred years or more.

RE: Different thickness between pipe and Tee

shazam.....

Some companies offer "flexable" or gell pigs...

All piping wall thicknesses are not the same, even though the pipe schedule is...

We are not building a precision watch here....

-MJC

   

RE: Different thickness between pipe and Tee

All cleaning or batching pigs can handle a pretty wide variation in wall thickness.  I once built a 20-inch line that used 6 different wall thickness of pipe (pipe was in short supply and I bought the odd lots that were in people's yards) with a pretty wide variation in ID.  We've been running turbo pigs in this line 1-2 times per week for 12 years with no problems at all.

I've also seen a 12-inch foam pig make it through a 3-inch vent (not in reusable condition, but without too many pieces missing).

If you are running a smart pig it is always best to run a dummy pig first to see if the smart pig will get stuck.  It is amazing how much variation even something that delicate can tolerate.  You didn't say what size line you are working with, but 0.5% variation in 10 inch is 0.05 inches.  In 36 inch it is 0.18 inches.  Neither number should be a problem.

David

RE: Different thickness between pipe and Tee

If you can weld the two wall thicknesses directly together and still be within the wall thickness difference allowed by code, then don't worry about pigs passing the weld points.

If you can't weld the pipe and fitting directly, then you need a transition piece, so don't worry about it in either case.

"Make everything as simple as possible, but not simpler." - Albert Einstein (1879-1955)
***************
http://virtualpipeline.spaces.live.com/

RE: Different thickness between pipe and Tee

(OP)
Dear David and BigInch,

Thanks a lot for your recommendations
Farzam

RE: Different thickness between pipe and Tee

Specify the Tee to be fabricated with the same ID as the pipe. Thickness of pipe and tee will not need to be the same as different design method and materials are used.

RE: Different thickness between pipe and Tee

...........I hope it is a barred Tee

RE: Different thickness between pipe and Tee

If you working under API code, it tells you the tollerances inc ovality, buckles and etc.
That is why you use gauge plate after hydro test. I think difference in diameter up to 5% of inside pipeline dia is acceptable so your is 0.5% that looks ok.

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