What safety device is required on propane gas appliances?

The required safety device on propane gas appliances is the pressure relief valve. This component is vital for ensuring the safe operation of the appliance. The pressure relief valve functions to release excess pressure that may build up within the system, preventing potentially hazardous situations such as explosions or ruptures. In the event of a malfunction or over pressurization, the valve opens to allow gas to escape, effectively preventing damage to the appliance and the surrounding area.

While other devices like emergency shut-off valves and thermostats are important for operational efficiency and safety, they do not specifically address pressure control. A fire alarm is essential for detecting fires, but it does not play a direct role in the management of pressure within propane appliances. Thus, the pressure relief valve is specifically mandated as a critical safety component to protect against pressure-related incidents in propane systems.