weld neck flange face hot dip galvanized

[jassin]

we have fire water system which is designed at 16 bar. the galvanized spools we received at site have coating of zinc on serreated face of raised face flange. As per design we have used flat face gasket.these spools were also hydro tested at shop and no leakage was found. but client is insisting for serration on face. Do ASME code allow to use these flanges. If not then suggest me an alternative.

 

[mk3223]

I don't believe there is a Code with a statement like what you just said.
IMO, it may not be an issue of the flange with galvanized face to be used in the water service. However, without a agreement before the HDG procedure, your client has a right to ask for a clean serrated face of flange on the galvanized piping system according to the ASME B16.5 code.
One possible option is to machine off the galvanized layer on the flange face.