Pilot connection A to Z1 is needed to ensure the pressure relief function A to B. Pump flow at port A can be unloaded by application of pilot pressure to port X. This pressure must be equal to the pressure setting of the unloader pilot stage to initiate unloading; the system pressurizes again when this pressure drops by approx. 20% or more.
Pressure Relief and Unloading with Electrical Selection of Venting:
Sizes 16 to 40
When it is required to unload the system independently of the system demands, this can be achieved by using the cover types U3 and selecting a suitable size 03 solenoid operated pilot valve. By using Eaton-Vickers model type DG4V-3-2AL for example, the system is unloaded when the solenoid is de-energized. When the solenoid is energized the unloader function operates (via pilot port X) as described above.