Bosch Rexroth R901374869

The isolator valve type Z2S is a releasable check valve in sandwich plate design. It is used for the leakage-free blocking of one or two actuator ports, also in case of longer standstill times. In direction A① to A② or B① to B②, there is a free flow; in the opposite direction, the flow is blocked. If, for example, there is a flow through the valve in direction A① to A②, the control spool (1) is moved in the direction of the B side, opens the ball seat valve (2) and then pushes the poppet (3) off its seat. Hydraulic fluid can now flow from B➁ to B➀. In order to allow the ball seat valve (2) to be safely closed, the control spool (1) must be hydraulically unloaded (see circuit example). Pre-opening

• Due to the pre-opening, there is a damped decompression of the pressurized liquid. Thus, possible switching shocks are avoided.

• The two-stage set-up with an increased control open ratio means even low pilot pressure can be unloaded securely.

Notice: In valves without pre-opening, sudden unloading of pent-up pressure volume may occur. Resulting switching shocks may lead to premature wear on installed components, as well as noise formation.

1	Control spool, area A2
2	Poppet, area A1
3	Stop

Type Z2S 6 A…SO40 Type Z2S 6 A…SO60

1	Control spool, area A2
2	Poppet, area A1
3	Stop
4	Control spool, area A4
5	Pre-opening, area A3

Type Z2S 6 -…SO55 (with pre-opening)