F Series excess flow valves are intended to close upon excessive discharge of vapor or liquid resulting from a break in the hose or piping system. They are used to protect cylinder, tank and piping systems, and are available in a large variety of sizes and body configurations.
When flow exceeds the valve’s setting, the valve closes and remains closed until the system equalizes. A built-in equalizing passage automatically opens the valve once pressure on both sides of the poppet is equal. Valves larger than 1/2-inch threaded NPT have a drill size No. 60. Valves with a 1/2-inch threaded NPT and smaller have a limited bypass to comply with NFPA 58