Orbit watermaster 1-1/2-inch automatic reinforced valve with flow control-the 1-1/2-inch automatic valve with flow control is constructed of heavy-duty, glass-filled nylon. it is designed with full port characteristics to have the least amount of pressure loss possible. the flow-control feature allows users to increase or decrease the flow of water through the valve to meet their watering needs. the self-cleaning rubber diaphragm actively fights dirt, algae, debris and obstructing particles. this valve operates on a pressure range of 5 to 200 psi and flow rates of 5 to 200 gallons per minute.