Air Transfer : The process of transferring air from one SCBA cylinder to another SCBA cylinder of the same rated pressure capacity by connecting them together with properly designed fittings and a high-pressure transfer line
NFPA 1500 Standard on Fire Department Occupational Safety and Health Program, 2007 ed. https://law.resource.org/pub/us/code/ibr/nfpa.1500 .2007.pdf, (Std: Fr Dept Occupn Sfty and Hlth Prog - Amer) {399 NFC}