What does the relief valve do if the outlet shut-off valve leaks?

The relief valve plays a critical role in maintaining system pressure and function. If the outlet shut-off valve leaks, the relief valve may attempt to open to relieve any excess pressure in the system. This means that it is designed to respond to pressure changes that indicate a problem, such as pressure that exceeds the safe operating limits due to a leak.

However, it is important to note that while the relief valve may attempt to open, it might not succeed if the leak is substantial or if there is some malfunction within the relief valve itself. This characteristic underscores the importance of regular maintenance and testing of both the outlet shut-off valve and the relief valve to ensure they function correctly when called upon. Proper operation of these components is essential for preventing backflow incidents and maintaining a safe water system.