Broken Sprinkler Valves

Valve Function

• The primary role of a sprinkler valve is to control the flow of water from the main line to the individual zones. Each valve generally controls a single zone on the sprinkler system. Sprinkler systems can have an unlimited number of valves, but only one zone can work at a time due to limitations of water pressure and flow rates. Valves can be made out of plastic or metal, but they all do the same thing. Some major manufacturers of sprinkler valves include Hunter, Toro, Rain Bird and Orbit.

Solenoid

• The solenoid is the black cylinder that sits on the top of each valve. This device is what actually controls the valve. When the sprinkler timer sends an electric signal to the solenoid, it activates a small plunger that presses down on a diaphragm. This releases a vacuum inside the valve, releasing water into the system. When the electric signal stops, the plunger retracts and the water is cut off. Many times, a malfunction in a sprinkler system is more the result of a defective solenoid than the valve itself.

Protecting Valves

• The most common way that a sprinkler valve is broken or damaged is when water freezes inside it. Water expands when frozen, and the valves are watertight. That means expanding water can't escape the valve, which causes pressure to build inside the valve. The pressure can rupture the valve, causing cracks and subsequent leaks. To protect your valves, drain all of the water from the manifold at the end of each year.

Fixing leaks

• Some damage to sprinkler valves can be repaired. If a solenoid burns out, it can be unscrewed and replaced with a new, universal model. The diaphragm inside the valve can also be replaced with repair kits, which are available at most home-improvement stores. But if a valve is cracked or the body is broken, you must replace the valve with a new one. While there are many manufacturers of sprinkler valves, almost all valves are interchangeable.