Historical
MSS SP-9-2018
Spot Facing for Bronze, Iron, and Steel Flanges
This MSS Standard Practice applies to the spot facing for U.S. customary (inch-series) bolting of pipe flanges in bronze, gray iron, ductile iron, or steel when cast integral with valves and fittings, as well as the companion flanges, when so required by the standard for the product.
Manufacturers Standardization Society of the Valve and Fittings Industry, Inc. [mss]