Evaluating pipe damage 1

[IFRs]

I have a 36" pipe that was "bumped" and now has a clearly visible dent. The pipe is used in an above-ground in-plant petroleum storage terminal. The operating pressure is 100 psig. What forms of inspection are appropriate? What codes might help provide guidance on acceptability? ASME B31.3 offers limited help. Thanks!!

 

[unclesyd]

Generally nothing is done other that an MT or PT to see if there is any cracking. You could also do UT to very the thickness at the point if impact. This is because pipe is routinely mechanically bent for fabrication.

Can you comeback with the size of the dent?

What is the material and schedule of the pipe?

 

[SJones]

API 579-1, Part 12, after the NDT mentioned above.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdoweb/

 

[IFRs]

Thanks!! The pipe is API 5L X-42, 3/8" wall. I have not seen the dent but we have requested measurements and pictures. I plan to follow up with NDE to determine if there is any cracking or excessive strain. Does API 579 (fitness for service) give specific guidance for piping? I don't have a copy of that one yet.

 

[metengr]

Does API 579 (fitness for service) give specific guidance for piping?

You can use it for general guidance. The dents and gouges are more applicable for shells.

 

[jte]

A thin wall 36" pipe could easily pass for a "shell".

Although I would lean towards API-579 / ASME FFS-1, another resource for you would be B31.G.

jt

 

[LSThill]

TEAM MEMBERS

reference to Buckling of Piping Components (Part 1a) Buckling of Pressure Vessels Compnnents (Part 1b)
Tuesday, April 22, 2008

http://www.paulin.com

Code case 2286 Displacement Bifurcation Buckling Liner and Non Liner. Asme Section Viii Division 1 and ASME B31.3.

Request a copy of the Webiner.

L S THILL