A safety valve’s main purpose is to protect the property, those in or near the property as well as the environment. It acts as a failsafe when the pressure within the plumbing system exceeds an acceptable amount. In this case the valve is forced open, releasing the specific substance from the system. Once the pressure is back to an acceptable rate, the safety valve is designed to close again to prevent further substance loss. A pressure relief valve is an example of a safety valve.