The 9200 Series coupler allows zero pressure connection and disconnection while either or both the coupler and nipple are under pressure. A lever operated cam, locks both coupler and niipple valve in the open or closed position. "Closed", the flow is shut off at the coupler, allowing easy, zero pressure connect and disconnect. Valves in the "open" position are locked in place and unaffected by the hydraulic surges. Valves will automatically close if the coupling is accidentally disconnected.