Description The OPW 61fSTOP-1000 Overfill Prevention Valve ("The Stopper") is designed to prevent overfilling of aboveground storage tanks by providing a positive shut-off during a pressurized-fill (pump-on fill) delivery. Key Features A special crossbar tank-inlet adaptor – is provided with each Stopper to provide for tight-fills and help prohibit open-fills. Mounting hardware, upper drop tube and 14" lower drop tube provided (longer-length drop tubes can be purchased or added). Completely Automatic Operation – No pre-checks to perform, no resets, and no overrides to be broken or abused. Direct or Remote-Fill Compatible – Fuel delivery couplers can be connected directly to the 61ƒSTOP, or steel pipe can be threaded into the top of the valve and piped to a remote location where the couplers are contained in a 211-RMOT Spill Container. Integral Anti-Siphon Valve – Drain vents on the 61ƒSTOP act as an anti-siphon, by introducing air/vapor into the fill line after the valve actuates, to help isolate the tank from a potential siphon due to a broken or leaking remote-fill pipe. 150 psi (10 bar) Pressure Rated* with Low Pressure Drop – To enable quick, safe delivery of fuel into the tank. 25 GPM (95 L/min) Minimum Flow Rate Required. UL and ULC Listed CARB Approved NOTE: OPW recommends the use of the 61ƒSTOP with clean product only. Debris and other products such as contaminated waste oil may cause improper operation of the valve. NOTE: The 61ƒSTOP can be used in gravity drop provided the minimum flow rate is maintained. A tight shut off is not achieved in the closed position. However with a minimum tank size of 1,000 gallons, the leak rate will provide a 30 minute warning before the tank is full.