beneath the filler cap (115). Its use is to filter spray fluid
(5) Secure parts with six washers (114) and
when the tank is loaded from the top.
screws (113).
b. Maintenance. Remove filler cap (115) and
(6) Attach safety chain from cap (115) to filler
flange, and screw cap onto filler flange.
inspect strainer and gaskets.
If strainer is dirty,
clogged, or damaged, or if gaskets are bad, remove
faulty parts for cleaning or replacement.
4-18.
Control Valve
c. Removal (fig. 4-9). Remove six screws (113)
a. General. The control valve assembly (47, fig.
and washers (114), and filler flange (116) from top of
tank.
Remove gasket (117), filler (118), and strainer
has three ports with connections to the pump outlet hose
assembly (119).
Detach cap chain from filler flange.
(14), spray boom inlet hose (42), and bypass valve (52).
d. Cleaning, Inspection and Repair.
Its use is to control spray fluid flow during spraying
operations. It is controlled by the valve lever (17, fig. 4-
WARNING
10). When the valve lever is in the VALVE CLOSED
Use air to maximum pressure of 25 psig.
position, fluid is directed to the bypass valve. When in
Avoid splashing insecticide fluid onto skin
the VALVE OPEN position, fluid is directed to the spray
or into eyes.
Observe precautions for
booms.
handling poisonous fluids by flushing
b. Maintenance and Adjustment.
Inspect
exposed areas with clean running water.
valve and connections for condition and security of
Wash hands thoroughly with soap and
attachment. Adjust flow control screw (40, fig. 8-1) for
water after handling and before eating or
back suction control.
To adjust, turn flow control
smoking.
screw fully in to shut off back suction. Back screw off 2
(1) Cleaning.
If spray fluid used in
to 21/2 turns for maximum back suction.
Set the valve
sprayer was water-base, clean the strainer by sloshing in
for maximum back suction.
clear water. If spray fluid used was oil-base, slosh in
Note:
mineral oil. Use a stiff bristle brush, or low-pressure air
The purpose of back suction is to draw fluid from
to dislodge particles which cling to wire mesh.
spray booms when the control valve is in closed
(2) Inspection.
Inspect all parts of strainer
position. This prevents nozzles from dripping.
and cap assemblies.
Check
for
condition
of
components, and replace defective or damaged parts.
4-19.
Bypass Valve
(3) Repair. Repair or replace any part which
a. General. The bypass valve (52, fig.
4-9) is
does not pass inspection.
Repair will consist mainly of
identical to the control valve (ref. para.
straightening filler metal components. Replace
torn
except for the end ports (fig. 8-1).
The bypass valve
gaskets or filler.
inlet port is attached to the control valve (47, fig. 4-9).
e. Installation. Install strainer in tank, using figure
The flanged outlet port is attached to the bottom of
the tank assembly (125). The other outlet port is
Note:
attached by hose to the pump inlet tube (28).
The
Line up all attachment holes as required when
bypass valve is set to either open or closed position prior
installing parts.
to flight. It is used to direct fluid from the control valve
(1) Place strainer assembly (119) in place,
back to the tank (closed position) or back through the
open end up.
pump (open position).
(2) Place filler (118) around outside edges of
b. Maintenance and Adjustment.
inspect
strainer top flange.
valve and connections for condition and security of
(3) Place gasket (117) over strainer top
attachment. Flow control screw (40, fig.
8-1) should
flange and filler.
be all the way in, as no back suction is required for the
(4) Place filler flange (116) over entire
bypass valve.
assembly of parts.
SECTION VII. MAINTENANCE OF BOOM SPRAY SYSTEM
attached to the top end of the tank assembly (fig.
4-
4-20.
Spray Booms
2). Fore and aft motions of the spray boom are
Two
spray
boom
restricted by front and rear boom cables (21 and 22, fig.
assemblies are installed on the insecticide sprayer.
Each boom has threaded holes for 30 spray nozzles.
rails of the tank support (fig. 4-2).
Vertical support of the spray boom is supplied by a boom
b. Maintenance and Adjustment.
support strut (15, fig.
4-22
