VALVE GP-MAIN CONTROL 2851536 - Caterpillar

Illustration 1 g01501784
One-way hydraulic circuit for the work tool (1) Main control valve (2) Main relief valve (3) Parallel passage (4) Return passage (5) Line relief valve (6) Attachment control valve (7) Line (8) Line for work tool (9) Ball valve assembly (10) Check and relief valve (11) Line for work tool (12) Return passage (13) Line relief valve (14) Line (15) Pilot line (16) Solenoid valve (proportional reducing valve) (17) Pilot line (18) Line (19) Main pump (20) Pilot pump (21) Pilot manifold (22) Pilot line (23) Hydraulic tank (24) Return line (25) Return line (26) Return lineThe single action hydraulic attachment circuit is for work tools that require one-way hydraulic flow. A hydraulic hammer is a good example.
Illustration 2 g01501785
Ball valve assembly (A) ONE-WAY flow (B) TWO-WAY flow (6) Attachment control valve (9) Ball valve assembly (10) Relief valve for work toolBall valve assembly (9) controls the front lines for the one-way hydraulic circuit and the two-way hydraulic circuit. With the lever in ONE-WAY position (A), the one-way hydraulic circuit is operational. With the lever in TWO-WAY position (B), the two-way hydraulic circuit is operational.Ball valve assembly (9) controls line relief valve (10) for the one-way hydraulic circuit. With the lever in OPEN position (A), line relief valve (10) for the one-way hydraulic circuit is functional. With the lever in CLOSED position (B), line relief valve (10) for the one-way hydraulic circuit is not functional. The CLOSED position is used for the two-way hydraulic circuit.Pilot pump (20) supplies oil to the pilot manifold (21). When the hydraulic activation lever is activated, pilot oil flows from pilot manifold (21) through pilot line (22) to solenoid valve (16). When the device for activation is pressed for one-way flow, pilot oil flows from solenoid valve (16) through pilot line (15) to attachment control valve (6). The pilot oil shifts the spool in the attachment control valve for one-way flow. Main pump (19) sends oil through line (18) to main control valve (1). The oil flows through parallel passage (3) and through attachment control valve (6). The main pump oil flows to the one-way hydraulic attachment through line (11). Supply oil is also sent to ball valve assembly (9). With ball valve assembly (9) in ONE-WAY position (A), pump oil flows to check and relief valve (10) .Relief valve (10) controls the operating pressure of the one-way hydraulic attachment. Because relief valve (10) is set lower than line relief valves (5) and (13) on attachment control valve (6), line relief valves (3) and (13) do not affect the one-way hydraulic attachment.The return oil from the attachment flows through line (14) to attachment control valve (6). The return oil then enters return passage (4) through line (24) to hydraulic tank (23). Return oil also flows to ball assembly (9). With ball valve assembly (9) in ONE-WAY position (A), the return oil drains through line (26) to hydraulic tank (23).