What does the spring in the relief valve assembly of an RPZ do?

The role of the spring in the relief valve assembly of a Reduced Pressure Zone (RPZ) device is critical to its operation. The primary function of the spring is to maintain pressure balance and to force the relief valve open when the pressure differential reaches a certain point. This is essential for the RPZ to function properly and to provide adequate backflow prevention.

When the pressure in the system exceeds a predetermined level, typically due to back pressure conditions, the spring's tension is overcome, resulting in the relief valve opening. This action allows water to drain from the assembly, preventing any potential backflow of contaminating materials into the potable water supply.

By ensuring that the relief valve opens under these specific conditions, the spring plays a vital role in maintaining safe water quality. Understanding this function is critical for individuals responsible for the maintenance and recertification of backflow prevention devices, as it directly impacts the device's ability to protect against contamination.