TUBE AS 3014563 - Caterpillar

Illustration 1 g00636306
(1) Main relief valve. (2) Main control valve (three bank). (3) Main control valve (four bank).The main relief valve is located in the main control valve. The main relief valve is connected to the load sensing line.
Illustration 2 g00636336
Illustration 3 g00636398
(1) Main relief valve. (4) Pressure adjustment screw. (5) Spring. (6) Pilot valve. (7) Cavity. (8) Passage to hydraulic tank. (9) Pump oil passage. (10) Passage to hydraulic tank. (11) Orifice.The oil from pump oil passage (10) flows through orifice (11) into cavity (7). Spring (5) keeps relief valve (1) on the seat. Spring (5) keeps pilot valve (6) on the seat. When the pump oil pressure in passage (9) flows to approximately 33000 kPa (4800 psi), the pilot valve opens. The oil in cavity (7) flows out of passage (10) to the hydraulic tank. The oil pressure in passage (9) is now higher than the oil pressure in cavity (7). The oil pressure will open relief valve (1) against the force of spring (5). The pump oil will flow past relief valve (1) through passage (8) back to the hydraulic tank.The setting of the relief valve can be adjusted with pressure adjustment screw (4). Turn pressure adjustment screw (4) clockwise in order to increase the pressure setting. Turn pressure adjustment screw (4) counterclockwise in order to decrease the pressure setting.