What is the purpose of a fusible plug in a gas cylinder?

A fusible plug serves a critical safety function in gas cylinders by melting at a predetermined temperature, typically due to excessive heat. When the temperature rises beyond a safe limit—often in situations like a fire or exposure to extreme heat—the fusible plug will melt, allowing gas to escape safely from the cylinder rather than causing the cylinder to rupture or explode. This mechanism helps to prevent catastrophic failures by controlling the release of gas in emergencies, which can mitigate the risk of injury or damage.

The function of the fusible plug is specifically designed for safety and does not aim to cool the gas or enhance the flow of gas. While the type of gas contained in the cylinder may be indicated through labels or markings on the cylinder, the fusible plug itself does not serve that purpose. Instead, its key role is to act as a thermal safety device, protecting both the cylinder and surrounding environment from the dangers posed by high-temperature scenarios.