Most compressed gas cylinders require the installation of at least one cylinder valve. This valve allows the cylinder to contain gases and gas to be filled or emptied from the cylinder. The cylinder valve is the most vulnerable part of the compressed gas package and requires a thorough understanding to maximize its performance. There are four basic valve types: the pressure seal valve, the packed valve, the O ring valve, and the diaphragm valve. There are several versions or designs within each of the four basic types. This pamphlet will address the more common valves in today’s industry.
Pressure Seal valves
Pressure seal construction is adopted for Valves for high pressure service, typically in excess of above 170 bar. The unique feature about the pressure seal Bonnet is that the body-Bonnet joints seals improves as the internal pressure in the Valve increases, compared to other constructions where the increase in internal pressure tends to create leaks in the body-Bonnet joint.
A diaphragm is a flexible, pressure responsive element that transmits force to open, close or control a valve. Diaphragm valves are related to pinch valves, but use an elastomeric diaphragm, instead of an elastomeric liner in the valve body, to separate the flow stream from the closure element.
Working knowledge of cylinder valves
Working knowledge of cylinder valves can improve processes, save time and money, prevent problems, maintain the life and integrity of the valve, and improve the safety of your operation. This document must not be used as a valve modification or repair guide. No changes to valves are permitted, and any repairs shall only be made by or under the direction of the supplier.