Other Applications
The principle of the fusible plug is also applied to the transport of liquefied petroleum gases, where fusible plugs (or small, exposed patches of the containers' lining membrane) are designed to melt or become porous if too high a temperature is reached: a controlled release, at a typical temperature of 250 °F (120 °C), is preferable to an explosive release (a "BLEVE") at a higher temperature. Corrosive gas containers, such as those used for liquid chlorine, are fitted with one or more fusible plugs with an operating temperature of about 158 to 165 °F (70–74 °C).
Fusible plugs are common in aircraft wheels, typically in larger or high-performance aircraft. The very large thermal loads imposed by abnormal landing and braking conditions (an RTO notably) can cause already high pressure in the tyres to rise to the point that the tyre might burst, so fusible plugs are used as a relief mechanism. The vented gas may be directed to cool the braking surfaces.
Fusible plugs are sometimes fitted to the receivers of air compressors as a precaution against the ignition of any lubricating oil vapour that might be present. Should the action of the compressor heat the air above a safe temperature the core will melt and release the pressure.
Automobile air conditioning systems were commonly fitted with fusible plugs, operating at 100–110 °C, but from concerns about the environmental effects of any released refrigerant gas this function has been taken over by an electrical switch.
A patented type of fireproof safe uses a fusible plug to douse its contents with water if the external temperature gets too high.
Read more about this topic: Fusible Plug