Weld repair to pitting on API 5L X65 pipe flange 1

[AlbertaMecchie]

I have some weld repairs to make to an api 5l x65 pipe flange face, the flange faces is pitted.

Was thinking of using a 7018 rod to do weld metal buildup and then machine the flange face.

Are there any specific heat treatment requirements or pre-heat / interpass temp requirements ?

 

[BenMacier]

If this is an API flange, likely to API 6A, weld repairs would only be allowed on weld fabricated ones.
In your description this is not an acceptable weld repair, but should be considered a weld overlay to recharge the thickness of the flange face.


* Finding a solution is great * Knowing how to implement it is fantastic * Believing it is the only one and best is naive ?

 

[SJones]

What does your qualified welding procedure specification say?

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[M.CH]

Hi Jon Ives

API 5L is a reference for the technical specification of pipe in petroleum and natural gas transportation and has nothing to do with the flange.

at the first you shall refer to project/client specification, by reason of that flange body and face repair is not allowed in some of specification.

if there is not any project/client specification, manufacturing standard shall be consider such as ASTM A105,ASTM A694,ASTM A691,MSS-SP75,etc. (refer to flange certificate).

Repair length/thickness restriction stated in the code/std.

If repair allowed by client/code/std. low hydrogen electrode such as 7018 or GTAW rod such as 70S-X shall be used. pre heat is very important, for low alloy CS flange (50~100 oC) is Ok depend on the dimension of flange due to weld rapid cooling may be happened by reason of material heat sink.

Finally, you shall consider all welding technical details in usual repair/buildup WPS.

 

[LittleInch]

If you've got access to the face of the flange why not just cut the flange off and weld in a new one? Or throw it away into scrap and buy a new one?

The flange is likely to be ASTM A694 F65 to MSS Sp-44.

This sounds like a wholly bad idea to me - flanges are not really designed to be weld "repaired" like this.

Is this an old flange someone has found knocking around and wants to use it? how otherwise did the flange face get pitted?

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