Hydraulics for Excavators

They are suitable to be used on excavators machines.They are used to control the lowering of a load and the pilot pressure depends only from the spring preload and the piston area since they have no differential area.The pilot pressure is normally achieved simultaneously from the manipulators pressure to drive the main spool valve.For these valve it is not possible to determine a pilot ratio. They consist in a check valve that can be coaxial with the sealing plunger, a pilot piston and an auxiliary relief valve to cut off overload peaks.The sealing plunger is piloted by the pressure downloaded by the relief valve. The valve is not affected by any back pressure in the V2 line. In case of damage of the manipulators, the lowering of the load can be performed manually, operating on the proper manual pilot screw.Line T must be connected to the reservoir and without back pressure.