Valves can leak when dirt of grit infiltrates their fine-tuned core. Extra care should be taken when installing valves to prevent debris from entering the system. Over months and years, grit often accumulates with water flow?EUR??,,????'??+a fact that necessitates screen filters. ?EUR??,,????'??+ Photo courtesy of Rain Bird

The three main components of every automatic sprinkler system are the controller, station-control valves and sprinklers.

The controller is the brain of the system, telling the control valves when and how long to supply water to the sprinklers. The sprinklers direct and control the water applied to the lawn and plants.

A cutaway view of a modern valve helps explain how the devices operate. The solonoid (top) is an electrical switch that, when activated, lifts the plug-shaped stopper at center, allowing water to flow through the valve. When the solonoid switches the valve off, the stopper drops, interrupting water flow. ?EUR??,,????'??+ Photo courtesy of Rain Bird

Each valve controls a specific group of sprinklers called a watering station. The stations are generally laid out and installed according to the type of plant material to be watered, the location of the plant within the landscape and the maximum amount of water that can be supplied. Each valve is connected to a numbered terminal within the controller, identifying it as Station 1, Station 2, etc.

The controller operates the valves in order, one at a time. In other words, one station would water completely before another station would turn on. This is called a watering cycle. The information stored in the controller memory that determines when and how long the stations will water is called a program. ?EUR??,,????'??+ From www.toro.com

The JTVF-AVB valve also features a Buna-N diaphragm with self-cleaning 90-mesh pilot water filter and captive stainless steel spring for added durability. ?EUR??,,????'??+ Photo courtesy of Rain Bird

Valve Troubleshooting Tips

Q: What do I need to check when a closed valve continuously leaks water?

1.) The most common reason is called ?EUR??,,????'??low head drainage?EUR??,,????'?? this is when the lowest head on the zone drains the water from the lateral piping out through the sprinkler. This is actually not a leaking valve, but the effect of gravity on the water in the piping system. If you are experiencing low head drainage, it will stop after all the water has drained out of the pipes. A solution would be to install check valves, such as the HCV, in the sprinklers.

Some residential sprinkler systems use exterior valves attached directly to the home?EUR??,,????'???s water supply. The disadvantage of such a setup is its vulnerability to mowers, children, pets and winter freeze. Be sure to install each valve higher than the level of your highest sprinkler outlet to prevent backflow. ?EUR??,,????'??+ Photo courtesy of Toro

2.) If water is leaking through the valve, there is most likely debris in the valve that will not allow it to fully close. To fix this, you?EUR??,,????'???ll need to disassemble the valve, rinse all the parts with clean water and re-assemble the valve. (A check valve in the sprinkler will not fix this type of leak.)

A: Most irrigation valves are designed to close within 10 to 20 seconds of the solenoid deactivating. The most common reason why a valve would close slower is that there is a restriction in the valve metering port(s). Hunter valves incorporate the metering ports in the diaphragm assembly. In the plastic center of the diaphragm assembly, there are small holes that meter (restrict) the amount of water that can flow to the top of the valve. If debris clogs these holes, the flow is restricted too much and the valve can either close real slow or stay open indefinitely. To fix this, simply replace the diaphragm assembly.
?EUR??,,????'???From www.hunterindustries.com

All in-ground valve box protects the valves and their electrical connections from standing water with a permeable gravel bed that lets water quickly drain away. Avoiding water is critical for the health of valves?EUR??,,????'??? electrical switches. ?EUR??,,????'??+ Photo courtesy of Toro

Anti-siphon Valve Technology

One new valve on the market incorporates backflow prevention into the valve unit. The Jar Top Series Anti-Siphon Valve (JTVF-AVB) for residential and light commercial applications combines convenient, tool-free access with backflow prevention in one valve unit. Its threaded bonnet design allows for tool-free access and maintenance, eliminating the need to remove and replace multiple screws. Adding the anti-siphon function increases its versatility while reducing the number of parts contractors must install.

A solid brass valve like this offers superior durability and frost-resistance on commercial sites. Featuring a brass body and bonnet?EUR??,,????'??+built to handle up to 220 PSI?EUR??,,????'??+this Hunter IBV has a sturdy stainless steel flow control stem. ?EUR??,,????'??+ Photo courtesy of Hunter Industries

The Rain Bird unit features a double-filtered pilot flow for maximum reliability and a balanced-pressure diaphragm. The valve operates in low-flow and Xerigation applications when the RBY filter is installed upstream and it accepts a latching solenoid for use with battery-operated controllers.
?EUR??,,????'???From Rain Bird

12: Hours, the recommended length of time that water should be turned off when checking for irrigation valve leaks. Source: University of Nebraska-Lincoln Cooperative Extension Service