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| Illustration 1 | g00437205 |
Control Valve (1) Detent. (2) Centering spring. (3) Passage to piston end of cylinder. (4) Outlet passage. (5) Passage to head end of cylinder. (6) Spool. (7) Relief valve. (8) Inlet passage. (9) Valve body. | |
The control valve is an open center directional valve. The control valve is classified as a four-way valve. The blade control lever directs the control valve in order to allow oil to flow to the blade cylinder .
The operator sets the position of the control valve by moving the blade control lever at the operator console. The control valve operates in the following four positions:
- RAISE
- HOLD
- LOWER
- FLOAT
Spool (6) is held in the HOLD position by centering spring (2). The control valve contains detent (1) which holds spool (6) in place when the control valve is set in the FLOAT position.
Relief valve (7) is located in the valve body (9). The relief valve has a screw adjustment in order to limit maximum pressure to 8618 ± 345 kPa (1250 ± 50 psi).
Oil from the metering pump enters valve body (9) at inlet passage (8). Passages (3) and (5) are connected to the blade cylinder. Return oil flows through outlet passage (4) to the charge circuit.