Griswold Controls DWS-100 1" Normally Closed Solenoid Control Valve for maximum performance at an economical price, no other remote-control irrigation valve can compare to the self-cleaning Griswold DW Series valve. The DW Series valve is the sensible choice regardless of your water source. Even potable water will eventually clog the types of screens found in other “contamination proof” valves. This translates into more maintenance work and more long-term cost. The unique Griswold Design allows the bronze-body DW Series valve to serve dependably under the most adverse conditions. Sludge, algae, silt, and other contaminants have no effect on the valve action. There are no filters or screens to clean, and no vulnerable exterior tubing to be damaged or deteriorate. The entire diaphragm-control mechanism is contained within the valve itself. Each time the valve opens or closes the pilot orifice is wiped clean. A tapered metering pin controls the opening and closing speed of the valve eliminating any possibility of water hammer or chattering.