Several standards organizations issue and maintain standards for face-to-face and end-to-end dimensions of control valves. (Face-to-face dimensions are listed for flanged valve bodies, while end-to-end dimensions are given for welded-end and screwed-end connections). Following is an overview of standards organizations and popular standards that address face-to-face and end-to-end dimensions.
ISA – Instrument Society of America. ISA Standard S75.03 specifies face-to-face dimensions for flanged, globe style valves through ANSI Class 600, and S75.16 lists dimensions for globe valves in ANSI Classes 900 through 2500. ISA Standard S75.04 specifies face-to-face dimensions for many flangeless, rotary-shaft valves. ISA Standard S75.12 lists end-to-end dimensions for socket weld and screwed end connections, and ISA Standard S75.15 lists end-to-end dimensions for ANSI Class 150 through Class 2500 butt-weld ends. The ISA standards are the most popular for control valves.
ANSI – American National Standards Institute. In the past, ANSI B16.10 was the primary standard for face-to-face and end-to-end dimensions for all control valve end connections; however, ANSI has relinquished responsibility for these dimensions to the ISA. Fewer and fewer references to ANSI B16.10 should be observed now that the transfer of dimensional standards to the ISA is complete.
MSS – Manufacturers Standardization Society of the Valves and Fittings Industry, Inc. MSS SP-67 lists face-to-face dimensions for conventional butterfly valve constructions while MSS SP-68 lists face-to-face dimensions for high performance (offset) butterfly valve constructions.
DIN – Deutsche Industrie Norme is a West German national standards organization. DIN face-to-face dimensions are unique.
IEC – International ElectroTechnical Commission. IEC Standard EC534-3-1 is taken directly from ISA S75.03, and IEC Standard EC534-3-2 is taken from ISA S75.04.
API – American Petroleum Institute. API standards relate primarily to pipeline equipment other than control valves; however, the face-to-face dimensions that are included in API-609 are identical to the dimensions in MSS SP-68.