What is the main function of the Master Valve in an irrigation system?

The primary function of the Master Valve in an irrigation system is to control the flow of water after the backflow prevention device. This valve plays a critical role in the overall operation of the irrigation system, as it serves to shut off the water supply to the entire system when it is not in use.

By controlling the flow after the backflow prevention device, the Master Valve helps to ensure that any water that might flow backward is effectively stopped, protecting the drinking water supply from contamination. When the irrigation system is activated, the Master Valve opens to allow water to flow to the various zones of the system. In addition, it usually operates in conjunction with the controller, which signals when to open or close the valve based on the irrigation schedule.

The other choices involve functions that are not typical roles of the Master Valve. Regulating system pressure, measuring water flow, and distributing water among zones are tasks usually assigned to other components within the irrigation system, such as pressure regulators, flow meters, and zone valves.