Irrigation Equipment - Valves

Zone valves are the mechanical devices that turn the water on and off to the individual sections of the system. Water meters and water service lines cannot provide enough water to water an entire yard at once, so the system is typically broken up into several individual zones or stations.

The concept of "zones" also allows the professional irrigator to group areas based on watering need. Flower beds verses grass, sunny areas verses shady areas, etc. Valves are typically installed near the area they water. Sometimes valves can be installed above the ground and grouped in a "manifold" near a faucet or water source.

There are two basic types of valves being used today. Manual valves, that require a person to turn them on and off, and automatic or electric valves, that are operated by the electric controller.

Manual valves require very little discussion. They are simple: if you know where they are and have a wrench (or valve key) to turn them on, all you need is a watchful eye and a string around your finger to remember how long they should run. Systems with manual valves are seldom installed today. Existing manual valve systems can be easily upgraded to automatic control for reduced hassle and greater efficiency by a professional contractor.

Automatic valves are a bit more involved, but you would be amazed at the simplicity of the technology that operates these devices. Most modern systems installed today rely on automatic electric valves.

Most automatic valves operate on 24-volt electricity. Wires run in the ground along with the main line pipe to the valve and are connected to the controller. When the controller sends the 24 volt current to the valve, it opens. When the current is cut the valve closes. The control wires are connected to an electric solenoid on each valve that converts the energy of the current and mechanically operates the valve.

If you cut any of the control wires in a system, you must repair them with an approved waterproof connector designed for direct burial. Wire nuts, electrical tape, or just a twist of the wires is not enough to keep water from eventually corroding the connection and interrupting the normal flow of current. Locating and repairing bad wire splices can be time consuming and costly.

If you think you have cut your control wires, call your irrigation contractor to make the necessary repairs. Broken wires or damaged wire insulation will lead to further problems down the road. Remember, direct burial connectors are the only approved repair parts.

Zone valves are generally buried in a "valve box". This is usually a 6 inch round plastic box with a green lid. Boxes can be covered with grass or mulch, but it is a good idea to have a general idea of their location in case service is needed.