The high-precision HPV-3 flow valve enables the transmission of control signals to the oil flow in the hydraulic section of hydropneumatic actuators. The devices are designed to meet the application requirements shown by the circuit symbols. A pneumatically pilot-controlled check valve is installed in series upstream from an adjustable flow valve. The oil flow is routed in the direction of operation to the element on Inlet 1; the load is connected to Outlet 2. In the home position the flow is blocked; when the actuating device is activated with a pneumatic signal (Port 12) the flow is set on the adjustable throttle.

It is also possible to install a check valve which blocks the flow in both directions. With this valve, the oil flow must be released in both directions by pneumatic control at Port 12. Combinations of several valves connected either in series or parallel offer a host of options for obtaining the required motion on the actuator.

With switching combinations, it is sometimes advantageous to dispense with one or more of the functions of this device. For this reason, elements are available in which the flow control is not included (HPV-3 CE), or in which the pilot-controlled check valve is omitted (HPV-3 R). A base plate with fitted check valve (GPRV) enables separation of the return flow from the valve functions.