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)