There are 2 types of directional control valves:Terminal box type&Plug-in Connector Type.DSG valves are solenoid operated directional control valvs.They control the start, stop and direction of flow.
The directional control valves consist of housing (1), one or two solenoids (2), the control spool (3), and one or two retun springs.
In the de-energised condition the control spool (3) is held in the neutral or initial position by means of return springs (4) (except for impulse spools). The control spool (3) is actuated via wet pin solenoids (2).
To guarantee satisfactory operation care should be taken to ensure that the solenoid pressure chamber is filled with oil.
The control spool(3) is moved to the expected position by solenoid(2) and pushing rod(5). This gives free-flow from P to A and B to T or P to B and A to T.
When solenoid (2) is de-energised, the control spool (3) is returned to its initial position by means of the return springs (4).
The solenoids may also control the control spool (3) by an optional override button(6) under the de-energised condition.