CONCOA CGA Connection Reference Chart
A CGA fitting is the standardized system for the attachment of a compressed gas cylinder to the required regulator or transfer line. Examples of CGA fittings would be CGA-580 for Non-flammable, Non-oxidizing gasses such as Nitrogen, Argon, or Helium. CGA-326 is used for compressed air. There are approximately a dozen commonly used CGA-fittings, with others used for special purposes.