Patent ID: 6945286

Claim:
For use with a liquid delivery system, a connection system for closed fluid transfer delivery, wherein the connection point is provided by a filling assembly having a filling valve for receiving a filling coupler to communication with the liquid dispensing source comprising: apparatus for selective connection to, and selective disconnection from, a liquid dispensing source having a delivery vessel for a deliverable liquid to receive liquid dispensed from the delivery vessel for transfer to liquid-receiving device, with return flow of vapor to the delivery vessel as fluid transfer takes place; said apparatus providing a first passage providing selective communication between the delivery vessel and the liquid receiving device, to allow liquid under pressure to be pumped to the liquid-receiving device; a second passage providing communication, simultaneously with the communication provided by the first vessel, between the liquid-receiving device and the delivery vessel for return flow of vapor as the liquid-receiving device receives liquid; the first and second communication being established by quick connect/disconnect at a single connection point at the liquid-receiving device; the connection point comprising a chamber having a relief valve mechanism for providing continuous, uninterrupted liquid flow at an increased liquid flow rate through the first passage with inhibited backflow of liquid through the second passage for continuous, uninterrupted vapor flow from the liquid-receiving device; the filling assembly including a housing for the relief valve; the relief valve mechanism comprises a valve seat spring, a valve seat disk, and a valve seat; the relief valve operation being such that if back pressure may rise to a relief pressure, as determined by a calibration specification of valve seat spring, pressure exceeding the calibration specification of valve seat spring 1 compresses the spring which lifts the valve seat to allow liquid to be relieved for flow into the vapor return line; the relief valve operation being such that such pressure relief operation normally will not occur.