GSi InterSystems STP, Manual

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To adjust the relief valve setting, remove the protective cap-
nut and loosen the lock-nut on the valve stem. Use a 1/8" hex
key to turn the valve stem clockwise to increase pressure or
counter-clockwise to reduce pressure. Make valve
adjustments in small increments and observe the gauge while
doing so. When adjustment is complete, tighten the lock-nut
to maintain valve adjustment, then tightly rethread the cap-nut
onto the valve stem.
If no change in pressure is noted when making adjustments,
the relief valve may be sticking or the gauge may be
defective. If the gauge and relief valve have been eliminated
as the source of the problem, then the pump may be worn,
particularly if the problem is low pressure.
NOTE:
THE GAUGE WILL LAST LONGER IF IT IS NOT CONTINUOUSLY SUBJECTED TO PUMP
PRESSURE PULSATIONS. CLOSE GAUGE SHUT-OFF VALVE AFTER CHECKING & SETTING PRESSURE.
4.3.3 Boom Left/Right Flow Control Valves V-6, V-7
A pair of in-line flow control valves mounted at the rotational motor, meters the flow of hydraulic fluid out of the
rotational motor ports (reference figure 4-3). V-6 controls the speed of the boom swing to the left. V-7 controls the
speed of the boom swing to the right. The flow controls will need to be adjusted upon initial start-up. To adjust, first
loosen the small set screw on the metering screw. Turn clockwise to decrease boom swing speed and counter-
clockwise to increase boom swing speed. After desired speed is achieved, re-tighten the set screw to lock setting.
NOTE:
AVOID EXCESSIVE BOOM SWING SPEED, WHICH WILL RESULT IN UNCONTROLLABLE BOOM
POSITIONING, AND INCREASED WEAR AND TEAR ON THE TRUCK PROBE.
4.3.4 Hydraulic Cylinders
These double-acting, non-cushioned rod cylinders raise or lower, and extend or retract the boom. The up/down
cylinder is 3.00 bore x 24 stroke. The in/out cylinder is 1.50 bore x 48 stroke. The cylinders are attached at each
end to the boom with a pivot pin. Solenoid valve V-1 controls the up/down movement. Solenoid valve V-3 controls
the in/out movement.
4.3.5 Rotary Actuator (Compartmentalized Probe Only)
The actuator is essentially a double acting hydraulic cylinder that drives a rack and pinion unit, thus converting linear
motion into rotary motion. The actuator is coupled directly to the inner tube of the compartmentalized probe. The
rotary actuator opens the sampling ports to receive a sample. When the sampling ports are closed, the sample
dumps into the vacuum conveying chamber of the probe. Solenoid valve V-4 controls rotary actuator motions.
FIGURE 4-2, RELIEF VALVE