Flange Design Basis using Weld Ring Gaskets

[condesinc]

I am about to embark on an internal design guide/basis for flange design utilizing weld ring gaskets. So far I have found **zip** about relevant m and y to use. I suppose it could be argued that zero for both is applicable...and I have done this in the past on a few safe things, without getting whacked so far...but I would like to refer to anything out there first before getting general. Does anyone know of anything?

If interested, further complications not relevant to question above: These are fully jacketed vessels now under consideration, operated at near vacuum, 75 psi/FV jacket design, with the flange intimatly connected with both shell and jacket. Internal design pressure is sometimes 15, sometimes 20. The only real reason for an internal pressure is for hydrotesting (which I guess is bogus, since we could specify what we want), to keep vendor honest in all details, and give some rationale for flange design that will be able to handle without calcs other than pressure loads...external pressure really controls everything for shell. Previous gasketing methods was dual inner/outer spiral wound with center nitrogen purged. FEA proved that flanges could be much thinner than code due to the stiffening effect of the jacket, depending on how it related to both the flange and shell, and we did not care if inner ring leaked on hydro, only vacuum operation. Am planning to do the same thing here (FEA) with weld rings...but again, any conventional wisdom with "normal" flanges would be good to know...a few of those are also on the horizon.

Thanks
John

 

[SnTMan]

condesinc, if I understand, you plan to use a "gasket" that weld to both flanges in the pair. If so, you are not really seating a gasket with the bolting and the use of m=0, y=0 is probably justified.

I found a catalog page from Flexitallic. If this is what you have in mind contact them.

Regards,

Mike

 

[condesinc]

Thanks SnTMan. I guess I could try again, but last contacts with Flexitallic produced **shrug**.

The Germans invented this. I guess its a stretch to call it a gasket, but thats what it is, and done right will not leak period.

They also have rules for opening a vessel once a year for inspection, so they are actually at the point of having automatic lip weld removal tools etc... but so far I have found nothing on-line except a DIN standard for shapes/forms, and it was no help.

I have just found another German mfg, Kempchen, at

http://www.kempchen.de,

so will give them a shot. Thanks for reply

John

 

[SnTMan]

condesinc, that seems odd to me, I always have had good response from Flexitallic. Suggest you contact the Deer Park, TX facility and ask for an applications engineer.

Good luck

Mike