RTJ Flanges - Minimum Dimensions when machining PCC-2 1

[digijtal]

Good day dear members,

I am having some trouble convincing myself that I am understanding ASME PCC-2 well for the repair by machining of RTJ flanges.

ASME PCC-2 305-3.1 states the following:

"Raised Face
Under-thickness of a raised face due to refinishing shall be acceptable, provided the minimum finished height of the raised face is 0.8 mm (0.031 in.)."

Does this also apply to the the raised portion of RTJ flanges?
My question really is whether the raised portion can be machined to minimum 8mm height and, subsequently, the bottom of the ring groove would now be below the level of the "flange thickness" so to speak, due to E having to remain the same?
Refer to below image for clarity.

Thanking you all in advance for your feedback.
Alan

 

[r6155]

See 305-4.5 Conversion of Flange Facing From Ring Type Joint to Raised Face.

Regards

 

[digijtal]

Hi There,

Thanks for your reply.

I have read section 305-4.5, but it seems that dimensions stated herein are relevant to RF flanges since they will be converted to such.

I wonder what the permissible geometries would be for pure RTFs

Best regards,
Alan

 

[r6155]

Not only can you modify the dimension, you also have to consider welding, PWHT, etc...etc.
I suggest you read article 305 in its entirety, it is very clear.

Regards