What holds the Relief Valve open?

The Relief Valve is held open primarily by the action of the relief valve spring. This spring is designed to exert a specific amount of pressure, which determines the operational threshold of the valve. When the pressure in the system exceeds the set point of the spring, the spring compresses, allowing the valve to open and release excess pressure. This mechanism is crucial for preventing backflow and ensuring that the system remains within safe operating parameters. Understanding the role of the relief valve spring is essential for recognizing how pressure regulation works in backflow prevention systems, ultimately leading to effective maintenance and management of plumbing systems.