Difference between API flanges & ASME Flanges

[irfan08]

We use ASME slip on/Socket weld flanges on our pump skids that deals with mostly water or glycol. We have a project where the medium is petroleum. My project engineer mentioned we can only use weld neck since they operate on higher pressure, but still unsure. Is there any data (tried API couldn't find it, may be looking in the wrong place) to back up our design

Thanks

 

[JLSeagull]

Within the refinery and petrochemical business most clients require ASME B16.5 flanges with a strong preference for weld neck raised face connections. Socket weld flanges are acceptable too. I do not know that any code prohibits the use of slip on flanges but many operating company specifications require other connections. Some serious chemical applications may use stub ends other flanged connections due to material issues.

API (6A?) flanges are often used upstream near the wellhead and perhaps related oil field or production areas. API flanges are not common within the gas processing or oil refining business. Checking my extensive list of PDF's I may not have a copy of the API flange specification or at least don't find it.

 

[dcasto]

since water/glycol are not a covered fluid in ASME, use what ever you want.

 

[gr2vessels]

irfan08,
The previous replies are mostly correct;- the flange rating should match the process requirements, for as long as there is a standard flange, matching the Client's piping specification. Most likely your standard ASME B16.5 Slip-On and Socket weld flanges are acceptable to your Client. You could try to match the Client's spares inventory (the type of flange mostly used on the mentioned plant). I'm sure the Client will appreciate your effort to satisfy their needs.
Cheers,
gr2vessels

 

[irfan08]

thanks everybody

 

[carthago]

..I believe that they are also diferences in outside diameter between B16.5 flanges and API 6A flanges

The rating designation is also different ( 3000 psi, 5000 psi, 10 000 psi and more )

The level of inspection is also different , API 6A is with level PSL1 , PSL2 ,...

 

[StressGuy]

Honestly,irfan08, the client's purchase specification should have addressed what kind of connections are expected at the interface and would possibly include the full pipe specification that the off skid piping is being designed by for your reference.

I'd request that from the client if you don't find it in the purchase specification.

Edward L. Klein
Pipe Stress Engineer
Houston, Texas

"All the world is a Spring"

All opinions expressed here are my own and not my company's.

 

[irfan08]

stressguy:

We know we have to use APi flanges, question was asked forore for my education.

 

[Vinzzzz]

Hi to all i need an help to verify if is possible coupling an oval gasket with an octagonal ring joint flange. this is due to the vendor that instead product the octagonal flange he have produced oval gaskets. I use for flange ASME B16.5 and for Gasket ASME B16.20 satndards.

thanks for all and best regards to everyone!!!

 

[hazel]

Dear Vinzzzz,
I have read an article said the octagonal ring joint flange is suitable for oval and octagnoal ring.
But oval ring joing flang is only for oval type ring.
I am not sure it is corrcet.
Because my plant only has octagnoal type flange, we use both oval and octagnoal ring. until now every flange is OK.