Based on a number of serious incidents with valve threads not matching cylinder threads the CGA has developed a code for marking standard cylinder valve threads currently in the United States and Canada. This technical bulletin explains why a cylinder thread code is needed and also explains why both the cylinder and valve need to be so marked
CODE FOR INFORMATION INTERCHANGE (WITH ANSI X3.4-1977) (SUPERSEDING FIPS-PUB-1-1, FIPS-PUB-1-7, FIPS-PUB-1-15, FIPS-PUB-1-35, AND FIPS-PUB-1-36) (NO S/S DOCUMENT) (WITHDARWN 7/29/97)
INTERFACE BETWEEN DATA TERMINAL EQUIPMENT (DTE) AND DATA CIRCUIT-TERMINATING EQUIPMENT (DCE) FOR OPERATION WITH PACKET-SWITCHED DATA NETWORKS (PSDN), OR BETWEEN TWO DTES, BY DEDICATED CIRCUIT (ANSI X3.100)(NO S/S DOCUMENT)