Function U - Unloading relief
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).