Lock Valves: MFG No. 409-04, Double Circuit, 20 GPM, Inlet/Outlet 1/2 in. NPT Ports, 3000 PSI

The double lock valves are designed to lock a cylinder or part of a circuit while a directional control valve is in the neutral position. designed for applications where directional control valve leakage could adversely affect the performance of the system. with the directional control valve in the neutral position, flow from both ends of a cylinder is blocked, locking the cylinder piston in position by the double lock valve. when the directional control valve is shifted to direct flow to one side of the cylinder, pressure opens the check ball and simultaneously moves the piston over to the opposite side of the valve opening this check ball allowing free flow return to the directional control valve. the 407 lock valve has two adjustable flow controls, and the 408 has one adjustable flow control which, by adjusting in or out, changes the pressure drop in the valves. this in most cases, smoothes our pulsations and eliminates valve chatter. single lock valves are also available. the 411 single lock is nonadjustable and the 412 single lock is adjustable.