The valve type Z2FS is a throttle check valve in sandwich plate design. It is used for the flow limitation of one or two actuator ports.
Two symmetrically arranged throttle check valves limit flows (by adjustable throttle spools) in one direction and allow free return flow in the opposite direction.
In case of supply throttling, the hydraulic fluid is directed through channel A➀ via throttling point (1) to actuator A➁. The throttle spool (2.1) can be axially adjusted via the spindle (3) for adjustment of the throttling point (1).
Simultaneously, the hydraulic fluid in channel A➀ is directed via the bore (4) to the piston side (5). The active pressure and the spring force retain the throttle spool (2.1) in throttle position.
The hydraulic fluid return flow from actuator B➁ displaces the throttle spool (2.2) and enables the unobstructed flow as check valve. Depending on the version ("S" or "S2"), the throttling effect may occur in supply or discharge.
Flow limitation
For actuator velocity adjustment, the throttle check valve is installed between the directional valve and the subplate.
Supply throttling