Abstract: A pressure vessel fitting which is non-metallic, thus, eliminating the need for the soldering, brazing or welding of the fitting which is necessary when conventional metallic fittings are used and, thus, eliminating the corrosion problems often encountered when metallic fittings are used. The pressure vessel fitting has a snap together design which eliminates the loosening problems under vibration which threaded connections are subject to, unless some type of retention or locking device is used. The non-metallic pressure vessel fitting generally comprises three components, namely, an internal fitting, a grommet and a snap retainer.