PLATE 3625218 - Caterpillar

Illustration 1 g03588161
(1) Load Sensing Signal Relief Valve When the pressure at the inlet of the main control valve exceeds the pressure setting of the load sensing signal relief valve, the valve opens. The excess hydraulic oil then flows through the relief valve to the hydraulic tank.
Illustration 2 g03445537
The load sensing signal relief valve is a direct operated cartridge type valve. Implement system oil flows into inlet (2) which causes poppet (3) to unseat. The oil then drains back to the tank through outlet (8) .When the oil pressure of the circuit is greater than the relief valve setting, the oil pressure will overcome the force of the poppet spring. This process will cause poppet (3) to unseat. The oil will then flow out of outlet (8) and flow back to the hydraulic tank. Simultaneously, the oil will flow through a passageway in poppet (3) and into spring chamber (4) .The oil pressure in spring chamber (4) will stabilize poppet (3) during the operation of the relief valve.When the pressure of the oil in the circuit is less than the relief valve setting, the force of spring (5) keeps poppet (3) closed.The relief valve setting can be adjusted by changing the force of spring (5) which keeps poppet (3) closed. Loosen locknut (6) and turn plunger (7) clockwise in order to increase the relief valve setting. Turn plunger (7) counterclockwise in order to decrease the relief valve setting.