Flanges
Flanges
(OP)
All,
Is it possible to have two side of flanges, one with Weld overlay (625 alloy) on the groove, the other with no weld overlay?
Both flsnges are typical F65 carboon steel. Previously, we plan to make-up both flanges with weld overlay, but for error during installation causes us to match with wrong flanges without overlay.
Rgds
Is it possible to have two side of flanges, one with Weld overlay (625 alloy) on the groove, the other with no weld overlay?
Both flsnges are typical F65 carboon steel. Previously, we plan to make-up both flanges with weld overlay, but for error during installation causes us to match with wrong flanges without overlay.
Rgds





RE: Flanges
RE: Flanges
thanks for the reply mate, really need it.
We are not in position to replace the flange with 625 cladding. However we do have the CP system in place, hopefully it can help control the corrosion.
Can this system survived, or will the corrosion damaged the flange after a while?
rgds
RE: Flanges
I don't know what sort of warranty you will have on this kit, but whatever it is the cost of repair once it goes subsea is so far beyond the cost of fixing it now it doesn't bear thinking about.
This sort of corrosion eats the ring groove and rather rapidly causes leaks around the ring gasket.
I really hope you think again and notify this to the right level so that the correct decision can be made rather than "hope". It might work as a political slogan, but it doesn't work subsea....
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Flanges
Thanks for the info. Did you mean, even if the cladding is only on the groove, the non-cladded flange will get corroded badly? Fyi, our content is a dey gas and no corrosion is expected. The reason cladding was proposed was to avoid corrosion due to water ingression.
Rgds
RE: Flanges
All depends on the amount and penetration of the water. Also no water, no impact of CP.
If this is topsides you might get away with it, subsea probably not.
Either way it is not a good idea to knowingly hide an manufacturing error without getting approval from the client about any mitigation. Sometimes you just need to hold your hands up and admit a mistake rather than compound it by "hoping" it will be ok. That is close to wilful negligence and all sorts of nasty things happen legally when that occurs... There is always an option to replace the flange - it might not be your favoured one and the client might let it go if it will completely stuff up his schedule, but that's his decision to make, not yours.
Sorry if it sounds a bit harsh, but I wasn't going to let that go without a comment - that's what this forum is all about
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Flanges
Thanks for the info. This flange is a spool flange, separating between zone 1 and zone 2 pipeline in subsea.
Our field engineer wrongly make-up the flange, hence the situation we're in now. I wanted to be clear, that with current clad to non-clad groove flange and CP system in place, corrosion will definitely happen before I take it to the next level.
BTW, are you talking about crevice corrosion? Pardon me, I have very limited knowledge in material and corrosion.
Rgds
RE: Flanges
For subsea applications where risk is often times high (high consequence and/or probability of failure) the customer may want this corrected. As LittleInch stated, the customer is the one that needs to evaluate this risk and determine how to proceed. You never want to hide a mistake like this.
RE: Flanges
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