Temporary Repair Cracked Flange

[SIMONMAGSUCANG]

Dear all,

I have a few heat exchanger flanges found cracked possibly due to over-torqued and victim of hydrogen sulfide stress cracking, the operating temperature is between 45 to 129 deg C.

I can't shutdown the line for replacement, is there any ways to temporary repair these flanges and hold them for at least 1 year until next shutdown? Flange repair clamp sounds like a solution but I'm afraid it will further damage the flange during fastening..

Wish I can have more suggestions...

 

[DekDee]

brimstoner,
What does country of origin matter ? - if it is faulty it is faulty no matter where it is from.
And it may not even be faulty, it may just be the totally wrong material in the wrong environment.

simonmagsucang,
I have to agree with edstainless - you have major cracking and you have no idea of the full extent.
Is it only cracked from the outer edge to the bolt hole or has the crack propagated further into the internals of the connection ?
It appears the "bean counters" have said it can't be shut down for 12 months - you need to get someone a lot higher up the food chain than yourself involved (your companies Welding Engineer for a start).
You should not be looking for "fixes" on an internet forum - I am pretty sure there will be serious consequences if these flanges fail, just to save a few dollars in lost production.

Good luck with what you are trying to do but remember rule number 1 - CYA
Cheers,
DD

 

[SIMONMAGSUCANG]

Thanks for advise.

So far the cracks only be seen outside thw flange, the agenda is we might probably temporary shutdown the Glycol HX for a while in the next few days to have a full inspection, if it has cracks at the internal connection we will have to go for replacement of the flange which we have to go for higher authority to urge for pausing the production before worse thing happens.

If it doesn't crack at the internal connection, we might go for flange split repair clamp, and then find a suitable window to have it replaced in 3~6 months time rather than wait for the next shutdown (12 months).

I had repeatedly highlighting this issue to the production team and finally HSE and the facilities engineers will be conducting riSK assessment soon.

 

[selvas]

Replacing the flange will be better option for this scenario. Because the crack is worse and in time it goes cracking fast internally.

 

[engineerzRengineerz]

You can ask online sealing service providers or fermanite to provide a box clamp, and rely on it for few months, closely monitoring it on regular basis to make shure crack propagation doesn't leave the clamp.
Don't worry, it will survive, but they can't write down warranty, since the current situation is pretty bad, and any upset will jeopardise their warranty. You need to replace the flange and propbably whole manifold as soon as possible.