Ring Joint Flange to RF Flange

[Jmoore1]

All, is there any standard that references bolting blanking (RF Flanges) to ring joint flanges using a full face gasket? ASME or otherwise, I can do a calc using a reduced effective area for a gasket although I am not sure whether ASME allows this.
Any information would be greatly appreciated.

 

[vesselfab]

I would never ever mix faces like that

 

[Jmoore1]

That was my initial answer to the field workers. However this is a standard practice used in the field for 40+ years and would cost several hundrend thousand dollars in replacement of all blanking equipment.

 

[donf]

Check page 26 in this link:

http://www.flexitallic.com/files/brochures/broSpiralWound.pdf

I agree with vesselfab, don't mix if you don't have to, but I've used this style gasket with RTJ and RF flanges when I needed a replacement valve in a hurry and RTJ valves were not available.

donf

 

[SnTMan]

Jmoore1, why do you need to do any calcs in the first place?

Regards,

Mike

 

[Jmoore1]

The owners engineers for the unit are telling the construction planners that they are not safe to use, I am looking at using codecalc to apply mating flange loads to find an MAWP of the system based off of a 6" 600# RJ to RF flange, alternatively I have found gasket suppliers that supply a gasket to mate the two flange faces.
Im realy looking for a basis as to the strength of this mating face.

 

[SnTMan]

Jmoore1, there is a good possibility that your ASME B16.5 flanges will not make for an Appendix 2 design, regardless of facing used. This has been discussed previously, search for more info.

Regards,

Mike

 

[C2it]

Mixing faces will land you in the faeces.

 

[rneill]

You might want to look at the Pikotek VCS gasket. This gasket is designed to be used with either RF or RTJ flanges and can be used to mate RF to RTJ.

The sealing element sits on the flange face inside of the ring groove so the groove becomes a redundant feature. The VCS is not fire safe but they have another version called the VCFS which is fire tested and has a secondary backup seal. This version can only be used on larger sizes of RTJ flanges.

I believe they have design reports available and third party test and certification data to validate acceptability to ASME Codes.