PSV Outlet Flange mismatch
PSV Outlet Flange mismatch
(OP)
Dears
Find attached photograph for the PSV outlet mismatch. Your comments pls.
If the outlet is not matched with outlet piping, what are the issues we may face in future. Also if the inlet flange is not matched what are the issues we may face in future.
Your valuable comments are really appreciated.
Find attached photograph for the PSV outlet mismatch. Your comments pls.
If the outlet is not matched with outlet piping, what are the issues we may face in future. Also if the inlet flange is not matched what are the issues we may face in future.
Your valuable comments are really appreciated.





RE: PSV Outlet Flange mismatch
That is horrible, how any one has permitted that to happen is beyond comprehension. I don't even know how they have managed to do it as I can't see the nut on the far side.
Please advise size, and class rating of the two flanges.
The bore sizes probably won't match and what the bearing area for the gasket is I have no idea, but it won't be what it was designed for.
Flange sizes and ratings need to match each other otherwise you get incomplete sealing and stress developing which are not allowed for.
Where was the error here? piping size wrong, P & ID wrong, valve data sheet wrong?
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: PSV Outlet Flange mismatch
RE: PSV Outlet Flange mismatch
It's very odd, but you're drip feeding information here - please give us the full set of data, such as the valve data sheet, piping specs, whether my suspicions above is true, what the relief valve looks like with the piping off.
Turns out the diameter of the raised face bit is the same regardless of flange class, but clearly the number, size and PCD of the bolts is different.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: PSV Outlet Flange mismatch
Per ISO, only the term Safety Valve is used for all overpressure eventualities regardless of design.
RE: PSV Outlet Flange mismatch
If I were you, I'd issue a non-conformity note/report and request immediate actions.
Still, as LittleInch says, there is a lot of data missing here. Maybe the situation is not so bad (from the risk point of view), or maybe it is just a catastrophe waiting to happen. We can't say, based on the info provided so far.
Dejan IVANOVIC
Process Engineer, MSChE
RE: PSV Outlet Flange mismatch
Find attached reply from the PSV Manufacturer. Thanks a lot for your support
" This exceed is in accordance with API Standard 526, Section 2.4. Dimensions:"
“For some valve designs, the inlet raised face height may substantially exceed the nominal dimension specified in ASME / ANSI B16.5. Consult the manufacturer for exact dimension.”
RE: PSV Outlet Flange mismatch
However, it does not answer your fears. At the very least, check that the outlet of the SRV has the OD dimension I advised in my earlier comment. If it's larger so far so good, then check the OD of the mating outlet flange which MUST be that same dimension minimum. If you can, check the pipe/DN size also.
For whatever reason, you may have a very oversized SRV outlet flange and a "correct" mating flange.
Per ISO, only the term Safety Valve is used regardless of design.
RE: PSV Outlet Flange mismatch
BTW, where are the bolt holes on the RV exit flange?
RE: PSV Outlet Flange mismatch
The odd appearance is explained in the first paragraph of Leser's response. They're starting with a single casting, which is large enough for a range of different outlet flange classes, and then machining it for the specific desired connection (raised face and bolting pattern). Although it looks odd, it has no more effect on the performance than the color of the external paint.
RE: PSV Outlet Flange mismatch
One other thing though - maybe it's a trick of the camera, but those bolts don't look straight or at the same angle. A view of a flange with holes lines up to the holes in the PSV flange would be interesting and would tell you whether the holes are properly drilled.
By the look of it they've got a body which could pass for a #900 or #1500 3" flange (240 or 265mm OD), but you've got a #150 flange on it (190mm OD)
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: PSV Outlet Flange mismatch
RE: PSV Outlet Flange mismatch
RE: PSV Outlet Flange mismatch