Based on MSS SP-6-2007 standard, we design and machine the ASTM flange contact finishes for steel flange of ANSI B6.5.
Stock Finish:
The most widely used of any gasket finish, because, practically, is suitable for all ordinary service conditions. This is a continuous spiral groove. Flanges sizes 12″(304.8mm) and smaller, are produced with a 1/16″ round-nosed tool at a feed of 1/32″ per revolution. For size 14″(355.6mm) and larger, the finish is made with 1/8″ round-nosed tool at a feed of 3/64″ per revolution.
Spiral Serrated or Hponographic:
This finish is produced by using a 90 degree round nosed tool.
Concentric Serrated:
This finish a produced by using a 90 degree round noise tool.
Smooth Finish:
The cutting tool employed shall have an approximate 0.06″ radius.
The resultant surface finish shall have a 125u inch to 250u inch (ANSI B 16.5 para 6.5;4.1).
1. Raised Face, and Large Male and Female:
Either a serrated concentric or serrated spiral finish having from 34 to 64 grooves per inch is used.
The cutting tool employed has an approximate 0.06 in radius. The resultant surface finish shall have a 125u inch(3.2um) to 500u inch(12.5um) approximate roughness.
2. Tongue and Groove, and Small Make and Female:
The gasket contact surface does not exceed 125u in (3.2um) roughness.
3. Ring Joint:
The inside wall surface of gasket groove does not exceed 63u in (1.6u m) roughness.
4. Blind:
Blind flanges need not be faced in the center if, when this center if, when this center part is raised, its diameter is at least 1 in. smaller than the inside diameter of fittings of the corresponding pressure class. When the center part is depressed, its diameter is not greater than the inside diameter of the corresponding pressure class fittings. Machining of the depressed center is not required.