At what pressure is a fusible plug typically not required in boiler operations?

A fusible plug is a safety device used in boiler operations to prevent overheating of the boiler's water and to avert potential damage or failure due to low water conditions. It is designed to melt at a certain temperature, allowing for the release of steam and mitigating the risk of an explosion when the water level drops.

In general, at pressures below 200 psi, the risk of catastrophic failure from low water levels is lower, and the operational practices in place often include additional safety measures that make the use of fusible plugs less critical. Boilers operating under this threshold are generally regarded to have adequate safety systems to manage low-water conditions effectively without the added protective measure of a fusible plug.

Therefore, the indication that fusible plugs are not typically required under such pressure levels aligns with the safety protocols and regulations in the industry that dictate how boilers are operated at varying pressures. Above this pressure, additional measures and protections come into play, as the risks associated with boiler operations increase, necessitating more robust safety features.