Smithco Spray Star 2005/2005D Operator Manual - Manual (Page 25)

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Spraying Procedures
PARTS MANUALS AVAILABLE ONLINE AT smithco.com
HOSE & HANDGUN SPRAYING
A handgun (hand-nozzle or hand-lance) is used to control and direct the spray pattern to the ground, shrub or
tree. They must be constructed of long lasting and noncorrosive materials such as brass, stainless or aluminum.
The handgun fits to a hose of any length from the sprayer allowing operator mobility. The hose should be as
short as possible while still permitting operator mobility.
Liquid looses pressure due to friction as it travels through the hose, 1-3 psi (0.07-0.21 bar) for each foot (30 cm)
of hose. For most operations
1 /
2
" (1.25 cm) inside diameter hose is adequate. Trees over 40 ft (12 m) high re-
quire 3 /
4
" (2 cm) inside diameter hose and a sprayer pump capable of delivering a volume of at least 20 gpm (75
lpm) and a pressure of at least 400 psi (28 bar).
TROUBLE SHOOTING NOZZLE VALVES
Plugged nozzle valves can be classified in two categories:
Plunger blockage.
Plunger stuck.
Plunger blockage results when larger debris catches between the orifice and plunger seal. This is the smallest
flow passage within the nozzle valve.
Stuck plungers result when smaller debris collects around the barrel of the plunger and binds the plunger in
place.
Symptoms of a blocked or stuck plunger are:
Constant spray.
Dripping when nozzle is shut off.
Pinched or split o-rings will also cause nozzles to drip.
Operating a plugged nozzle valve for extended periods may result in nozzle valve coil failure. Clean
plugged nozzle valves immediately.
If plugged nozzles are a frequent problem in a particular boom section, inspect the machines boom
filter screens for plugged or damaged screens. An 80 mesh screen is recommended to prevent
nozzles from plugging. Check the mesh size of the strainers and replace if they are too coarse.
Nozzle valve component identification.
1. O-ring 30-168-18P
2. O-ring 30-168-20P
3. Valve Body 30-168-26P
4. Flynut 30-168-25P
5. Plunger 30-168-17P
6. O-ring 30-168-19P
7. Coil 30-168-21P
This covers the principles of what must be known to
prepare a sprayer for operation.