Technical Information · issue 15 of 2006

New STIHL SG 20 Sprayer

IssueTI 15/2006

Full text

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STIH)

Technical Information 15.2006

New STIHL SG 20 Sprayer – Series 4247

Contents
1. Technical Description
2. Specifications
3. Accessories
4. Operating Instructions
5. Servicing Accessories and Special Servicing Tools
6. Service Notes
7. Troubleshooting

The SG 20 backpack manual sprayer is a further
addition to the STIHL product range and is suitable
for spraying fungicides, pesticides and herbicides.
Typical areas of application are:
. Tree nurseries and plantations
. Fruit and vegetable growing
. Crops
. Gardens
. Professional lawn care

The SG 20 sprayer features a one year limited
warranty for both professional and occasional use.

TI_15_2006_30_01_01.fm englisch / English USA
)m~ge 2 Technical Information 15.2006

1. Technical Description 2. Specifications

1.1 Pressure System

3
a

2
1

408TI003 KN
b
408TI001 KN

The pump piston (1) pumps the spray mixture from Discharge rate: 61 cu.in/min
the container (2) into the pressure chamber (3). (1000 cc/min)
The pressurized spray solution is stored temporarily a = 31 in (0.8 m)
in the pressure chamber (3) and then flows via the b = 40 in (1 m)
hose and pipe system to the nozzle.
Pressure: 2.8 bar
40 PSI (+/- 10%)

1.2 Nozzle
Container capacity: 4.76 gal (18 l)

Weight (dry): 11.5 lbs (5.2 kg)
408TI002 KN

The spray pattern can be adjusted by rotating the
nozzle.

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Technical Information 15.2006 Page 3

3. Accessories

3.1 Control Valve 3.3 Spraying Bell

408TI006 KN
408TI004 KN Spraying bell 4247 500 5800
Prevents dripping and guarantees a constant spray
pressure. Valve closes if pressure in cylinder drops
below rated value.
For detailed spraying of herbicides. Confines spray
so that it is shielded from the wind.
Available for different pressures:
Includes two exchangeable nozzles for spraying
Part No. Color Rated pressure herbicides at discharge rates of 104 cu.in/min
bar PSI (1700 cc/min) and 33 cu.in/min (535 cc/min)
respectively.
4247 500 7400 yellow 1 15
4247 500 7401 red 1.5 21
4247 500 7402 blue 2 29
3.4 Nozzle for Herbicides
4247 500 7403 green 3 43.5

1
3.2 Telescopic Wand

408TI008 KN

Nozzle 4247 502 1001 (1)
408TI005 KN

Telescopic wand 4247 500 2100 Fan jet nozzle (1) specially designed for spraying
herbicides at a discharge rate of 24 cu.in/min
(400 cc/min).

Length of spray wand adjusts for access to difficult-
to-reach areas. Extends reach by up to 39 inches
(one meter).

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4. Operating Instructions 5. Servicing Accessories and
. Lubricate the pump piston at regular intervals Special Servicing Tools
and before starting work – any light duty oil is No additional servicing accessories or special tools
suitable, including vegetable oil are required.
. The gasket in the cap must keep kept well
lubricated at all times – re-lubricate with grease
at regular intervals.
6. Service Notes
. After finishing work, drain and thoroughly clean
the sprayer – fill the container with about 5 litres . Before performing repairs, spray until the unit is
of clean water, pump and spray until the empty and completely depressurized. If
container and hose system are empty and pressure is not fully released, spray mixture may
completely depressurized. Do not store the unit escape unexpectedly and uncontrollably when
under pressure or filled with spray mixture. working on the hose and pressure system.
. After finishing repairs, perform a test run with
clean water.

7. Troubleshooting
Condition Cause Remedy
Water accumulates in the Liquid has been stored in the Remove the piston from the pump and
piston container for too long lubricate the pump with oil. Rinse with
clean water after every use.

Liquid leaks from top of pump Worn O-ring on piston Fit new O-ring on piston.
when pumping

No spray mixture comes out of Blockage in hose and pipe Clean all parts of the hose and pipe
nozzle system system (gun, filter in gun, wand, hose).

Pumping action produces no No suction Fit new O-ring on piston. Check that balls
pressure in the pump housing (4247 700 4000) are
properly seated and not sticking.

The lever falls down under its The check ball (intake side) is Remove hose from bottom of the pump
own weight sticking housing (4247 700 4000) and take out the
ball. Clean the ball and make sure it
moves freely.

The lever moves upwards of The check ball (delivery side) is Open the screw plug in the pump housing
its own accord sticking or missing (4247 700 4000) and take out the ball.
Replace or clean the ball and make sure it
moves freely.

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