IV.
OPERATING SYSTEMS
44
C. HYDRAULIC SYSTEM
SPRAY BOOMS–
Hydraulically folding the extensions of the 60/80/90 foot boom system and adjusting spray
valves essentially turns it into a 60 foot boom. (continue reading this section for more information) Manually
folding the outer extensions of the 60/80/90 foot system, adjusting spray valves and recalibrating the spray
console essentially turns it into an 80 foot boom (see the section on the spray system and the section on cali-
bration for more information on the console).
The spray booms are controlled by an electro-hydraulic system. This system consists of operator manipu-
lated switches located in the sprayer’s cab and hydraulic cylinders attached to the booms. It provides control of
lift, level, horizontal fold, and vertical fold.
All GST 20 spray booms are equipped with a hydraulic breakaway
circuit. When folded out as an 80 or 90 foot spray boom, a one-way
hydraulic circuit on the outer boom section provides outer boom
breakaway functions. The outer breakaway is self-resetting and will
return to normal operating position after it has cleared the hazard (fig.
4.44-1).
FIG. 4.44-1
60/80/90 foot boom system
with all extensions folded
out.
90 feet
60/80/90 foot system with
extensions folded over.
60 feet
F o r
i n s t r u c t i o n
o n
h y d r a u l i c a l l y
f o l d i n g
extensions over, see page
48.
60/80/90 foot boom system
wit h
out er
ex t ens ions
manually folded forward.
80 feet
For information on manually
folding
outer
extensions
forward, see page 49.
OPERATING SYSTEMS
