Situational Non-Flammable Control Valves for Oxygen Service

摘要

Past work has clearly demonstrated that numerous commonly used metallic materials will support burning in oxygen, especially at higher pressures. An approach to rectify this significant safety problem has been successfully developed and implemented by applying the concept of situational non-flammability. This approach essentially removes or breaks one leg of the conceptual fire triangle, a tool commonly used to define the three things that are required to support burning: a fuel, an ignition source, and an oxidiser. Because an oxidiser is always present in an oxygen system, as are ignition sources, the concept of situational non-flammability essentially removes the fuel leg of the fire triangle by only utilising materials that will not burn at the maximum pressure, for example, that the control valve is to be used in. The utilisation of this approach has lead to the development of a range of oxygen components that are practically unable to burn while in service at their design pressure, thus providing an unparalleled level of first safety while not compromising on the performance or endurance required in the function of these components. This paper describes the concept of situational non-flammability, how it was used to theoretically evaluate designs of components for oxygen service and the outcomes of the actual development, fabrication, and, finally, utilisation of these components in real oxygen systems in a range of flow-control devices.