Inlet Fittings

Most countries have their own Standards for cylinder valve connections. Some gases have there own unique connections, while some gases with similar properties may share the same connection type. One gas, or group of gases, may have several different connection specifications according to cylinder size or maximum cylinder fill pressure. Cylinder connections either seal metal-tometal, or by the use of a soft sealing washer, (some metal-to-metal connections types may allow the used of an o-ring seal). PTFE tape should not be used on cylinder valve outlet connections.

Regulator inlet connections are normally available in brass or stainless steel. Some fittings may not be available in brass depending on the properties on the gas they are intended to be used with. A good guideline is to following the cylinder valve material, (ie. if the cylinder valve is brass, brass or stainless regulators and fittings should be acceptable, if the cylinder valve is stainless steel brass regulators and fittings should not be used.).

With so many different internationally recognised gas cylinder valve connections being used, there is some inter-changeability of fittings between different counties. Advice from a reliable source should be sort before using fittings from one Standard on cylinder valves from another Standard. Most cylinder valve fittings are available for purchase as separate components, but a few types will only be sold as part of a complete regulator do to the “high risk” nature of the gas the fitting is intended to be used with.