The Raised Face (RF) type is the most applied flange face,
and is easily to identify. It is referred to as a raised face
because the gasket surfaces are raised above the bolting circle
face.
Specifications covering the manufacture and dimensions of flanges:
ASTM SPECIFICATIONS
ASTM specifications regulate approved raw materials for which flanges can be made and specifications .
For stainless flanges are:
ASTM A.182 - Forged or Rolled Alloy Steel Pipe Flanges & Fittings for high temperature service.
ANSI AND MSS SPECIFICATIONS
The standards govern the dimensions and tolerances to which fitting are manufactured:
ANSI B. 16.5 - Steel Pipe
Flanges and Flanged Fittings (½ inch to 24 inch nominal diameter)
MSS SP.6 - Flange Facings
MSS SP.25 - Marking of flanges
MSS SP.39 - Bolts and Nuts for Flanges
MSS SP.44 - Large Diameter Pipeline Flanges. (Over 24 inch dia)
API-605 - Large Diameter Flanges for petroleum Usage. (Over 24 inch dia)
The ASME Code is not a standard as such but section VIII provides the procedure for calculating dimensions
For all pressurised vessels flanges.
The following are not flange specifications but they influence the manufacture of forged steel flange
ANSI B. 31.10 - Code for Pressure Piping
ANSI B. 31.3 - Petroleum Refinery Piping
ANSI B. 31.4 - Oil Transportation Piping
ANSI B. 31.5 - Refrigeration Piping Systems
ANSI B. 31.7 - Nuclear Power Piping
ANSI B. 31.8 - Gas Transmission and Distribution Piping systems
ANSI B. 36.10 - Standard for Wrought Steel pipe
ANSI B. 36.19 - Standard for Stainless Steel Pipe
ANSI B. 16.10 - Valve Dimensions Face & End
ANSI B. 16.11 - Forged Fittings Socket Weld & Threaded
