Flange facing

[mowlin]

Does anyone know here i can get documentation on how much inches from a raised face on a WN flange can be removed while staying within code tolerances? I know the rule of thumb is 1/16"....

 

[TGS4]

I'd start with the "Code" itself. Which Code are you referring to?

 

[Cockroach]

Actually you are not permitted to remove material from the flange, at least by ASME B16.5-2003 or CSA Z245.12-05. Addition of material is permitted up to 1/16 inch, i.e. weld repair of the raised face, but taking away mass is strictly forbidden.

Think about it, would you not be changing the rating of the flange by reducing its mass?

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada

 

[Canadieng]

Actually,

According to ASME B16.5-2009:

6.3.2 Conversion.
A raised face may be removed from a raised face flange to convert it to a flat face flange, provided that the required dimension, tf, shown in Fig. 7 (Fig. II-7 of Mandatory Appendix II) is maintained.

 

[moltenmetal]

As CanadianEng correctly points out, you may remove the ENTIRE raised face in post-machining operations without affecting the flange rating- that's primarily what the raised face is there for! When you leave less than 1/16" of an inch of raised face, you risk affecting the way the gasket is engaged.