Abstract: Multi position flow check valves for both liquid and vapor filler conduits having essentially two positions, a closed position, and a wide open flow position to activate the latch, the valve being automatically closed from the flow position under hazardous conditions including equipment accidents and fires, and open only when manually opened for latching purpose in tank filling operations at bulk storage stations. One hazardous condition includes an appreciable stretch strain exerted on filler hoses connected between the storage supply tank and the mobile delivery tank sufficient when dangerous to close the valves and prevent serious escape of gases in event of hose rupture. Non-extendible elements providing the differential criteria also serve as remote shut-off controls, including manual, automatic and thermal for safety termination of a refilling operation.

Abstract: A high volume filler and automatic fill-limiting valve unit for customer LP Gas dispensing systems in which tandem backflow check valves are opened by incoming replenishing liquid. When a prescribed outage fill level is reached, the inner one of the valves is released from a mechanical restraint of a float control to convert and operate as an inflow check valve which is closed by the incoming flow pressure drop across it to arrest further inflow and permit the outer one of the valves to also close if it is mechanically free to do so. In either case after inflow shutoff the inner valve under spring pressure resumes its normal outflow check valve position to free the float mechanism and independently supplement the backflow check valve function of the outer valve.