four times weld repair

[etrobal]

we required repairs on a 48-inch diameter stub-in weldment and the last repair passed the ndt. however, the system was put on line after the repairs passed the ndt so we can minimize generation losses.

what will be the effect of not stress relieving the joint with four repairs? will a leak or crack eventually occur? the design temperature is 214MPag (310psig) and 216degC (420degF).

thanks.

 

[0707]

If stress relieving (PWHT)is required by the material quality of your 48" pipe, and if your four repairs have not been submitted to stress relieving even if they have passed the ndts, the repair zones are stressed and maybe they present know great hardness, this situation can induce a premature cracking on the pipe.

 

[unclesyd]

Is this the same branch connection mentioned in thread404-237045?

A little more information concerning materials and thicknesses of all components along with some weld details would be nice and help you get a more specific answer.

 

[PAN]

Please recheck...
- 214 MPa is not equal to 310 psi.
- Refer to ISO 13703 - 2000 Edition, Para. 7.4.2, stub in connection is not recommended for branch connection.

 

[etrobal]

yessir, 214MPag is not equal to 310psig. that should have been a 2.14MPag, typo error sir. unfortunately, we don't have any iso 13703, what we use is asme/ansi b311, the power piping code. but i will research this iso and request that a copy be purchased for our reference.

thank you again.