How does a master valve differ from zone valves in terms of control?

• A. A master valve controls the main supply to all zones; zone valves control individual zones.
• B. A master valve controls individual zones; zone valves control the main supply.
• C. Master valve is for filtration; zone valves regulate flow.
• D. Master valve controls timing; zone valves operate automatically.

Answer: (B)

The main idea is how control is distributed between the main line and the branch lines. A master valve sits on the main supply and acts as the overall shutoff for the entire irrigation system, so you can stop water to all zones at once. Zone valves are placed at the start of each individual zone’s branch line and control water to that specific zone, allowing you to water only where needed. This setup makes maintenance and leaks safer and more efficient, since you can shut off the whole system or just one zone without affecting others. The other descriptions don’t fit because the master valve’s role isn’t to govern an individual zone, zone valves don’t control the main supply, and filtration or timing functions aren’t what these valves do.