The Viking Flow Control Valve is a quick opening, differential diaphragm flood valve with a spring loaded floating clapper. The Flow Control Valve can be used to facilitate manual or automatic on/off control. It can also be used to control water pressure or flow rates. As an on/off control valve it is used on Deluge Systems, Sprinkler Systems or to automatically fill tanks or reservoirs. Video Model J-1 Flow Control Valve - Product Repair Video