A safety mechanism employed in gas systems, this device provides an extra layer of protection against uncontrolled gas flow. It consists of multiple valves working in tandem, ensuring that if one valve fails, another is available to shut off the gas supply. For example, in a high-pressure gas pipeline, two or more valves might be installed sequentially. If the primary valve malfunctions and remains open when it should be closed, the secondary valve immediately activates, preventing a potentially hazardous leak or over-pressurization.
The incorporation of these multi-valve arrangements significantly enhances system reliability and safety. The enhanced safety is vital in applications where the consequences of gas leakage or uncontrolled flow are severe, such as in power generation facilities, chemical processing plants, and nuclear reactors. Historically, single-valve systems were more common, but catastrophic failures led to the development and adoption of multi-valve systems as a standard safety practice to mitigate risk and improve operational integrity.
