Can someone advice me where I can find the norm (what norm?) for finish, flatness and waviness specifications, for mating surfaces of flanges.
Many thanks
koekoek
I went looking for the very same information today and could not find it. B16.5 and Taylor Forge- nothing about the surface flatness was mentioned. Anyone else??
Flatness of Girth flanges in a heat exchanger are delt with in API standard for refinery Heat exchangers. I am not sure whether it is API 660 or API 661. One of it is air fin exchanger the other is the exchanger for refinery service. This is tabulated against the diameter of the girth flange. 0.3mm for flange of dia 2500mm.
For Surface finish also refer B46.
Also you may Refer to TEMA this gives allowable defects in Raised face of Gasket face. Scratch marks, scoring etc are given here. you may use these as Norms.
It is API 660, which is more stringent than the TEMA flatness requirements. The same information is provided in ASME PCC-1, Guidelines for Pressure Boundary Bolted Flange Joint Assembly, so you may wish to get that document, which deals specifically with bolted joints, rather than the heat exchanger standard.