GSi InterSystems STP, Manual

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4.3.1.3 Boom LEFT/RIGHT Valve V-2
This solenoid-operated directional control valve alternately pressurizes opposing ports of the rotational motor to
swing the boom left and right. When the valve's "A" solenoid is energized, the valve spool shifts, pressurizing the
port that swings the boom to the left. When the "B" solenoid is energized, the valve spool shifts, pressurizing the port
that swings the boom to the right. Note, when neither "A" nor "B" solenoid is energized the valve is spring centered
so that all ports are blocked and movement is inhibited.
4.3.1.4 Boom IN/OUT Valve V-3
This solenoid-operated directional control valve alternately pressurizes the piston end and rod end of the double-
acting cylinder to extend and retract the boom. When the valve's "A" solenoid is energized, the valve spool shifts,
pressurizing the rod end of the cylinder, thus retracting the boom. When the "B" solenoid is energized, the valve
spool shifts, pressurizing the piston end of the cylinder, thus extending the boom. Note, when neither "A" nor "B"
solenoid is energized the valve is spring centered so that all ports are blocked and movement is inhibited.
4.3.1.5 Sample Ports OPEN/CLOSE Valve V-4 (Compartmentalized Probe Only)
This solenoid-operated directional control valve alternately pressurizes opposing ports of the rotary actuator to rotate
the sample ports to collect and dump samples. When the valve's "A" solenoid is energized, the valve spool shifts,
pressurizing the port of the actuator that opens the sample ports. When the "B" solenoid is energized, the valve
spool shifts, pressurizing the port of the actuator that closes the sample ports. Note, when neither "A" nor "B"
solenoid is energized the valve is spring centered so that all ports are blocked and movement is inhibited.
4.3.2 Relief Valve V-5
DANGER
EXCESSIVE SYSTEM PRESSURE MAY CAUSE HOSE OR COMPONENT BREAKAGE
RESULTING IN PROPERTY DAMAGE, BODILY INJURY AND/OR EVEN DEATH. SET RELIEF
VALVE TO PROPER SETTING.
The relief valve limits the hydraulic pressure produced by the
pump. Adjust the pressure to the recommended setting.
Check the hydraulic pressure. First open the gauge shut-off
valve. If the pump motor is running and the probe operates at
all, then the gauge should register some pressure. If it does
not, then the gauge may be defective. It is normal for the gauge needle to vibrate slightly. In order to view the relief
valve pressure setting on the gauge, a function must be dead headed momentarily to build pressure. Retract the
boom all the way in. Now activate the probes down function until the cylinder bottoms out. Continue activating the
solenoid momentarily while observing the pressure setting at which the relief valve is set on the pressure gauge.
Adjust the relief valve as necessary.
Hydraulic Power Unit
Horsepower
Relief Valve
Pressure Setting
3 HP TP Comp & Core 750
5 HP STP Comp & Core 1250