Spray Pattern Adjustments; Retooling Of Spray Gun - Walther PILOT WA 900 Instructions De Service

Warning
Make sure that nobody is present in the spraying zone when the gun is started
- imminent Risk of Injury.
1. Start the gun to produce a spray pattern sample (see 5.2. Starting/Stopping
Requirements).
2. Inspect the sample and readjust the settings of the gun as may be required (see

5.4 Spray Pattern Adjustments).

5.4 Spray Pattern Adjustments
The spray pattern of the of the series PILOT WA 900 can be adjusted as follows:
Adjusting the jet pattern
A
F
With internal control:
An optimum spray pattern can be regulated by using
adjustment screws 'F' (Fan air) and 'A' (Atomizing air).
The adjustment screw 'F' regulates the wide jet, the
adjustment screw 'A' regulates the round jet.
Without internal control:
The spray pattern is adjusted by a ressure regulator in the
plant (see operating instructions of plant systems manuf-
acturer).
The connection 'F' is for the wide jet,
A
the connection 'A' is for the round jet.
F
Adjustment of the material flow rate
Turn cap (1) from the standard position
1
(= notch mark on the piston housing).
2
• to the inside in order to decrease the material flow
rate.
• to the outside in order to increase the material flow
rate.
The material flow through the nozzle can be perfor-
med without using atomizing air, when the drawbar
(2).
Adjustment of the Material Pressure
This adjustment can only be made at the pump or the material pressure tank. Please
comply with the operating instructions and safety warnings issued by the manufac-
turers concerned.
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Adjustment of the Air Pressure
The air pressure is adjusted at the air pressure reducing valve of the compressor
system. Please comply with the operating instructions and safety warnings issued by
the manufacturer.
If you wish to change the spraying pattern beyond the adjustments outlined so far,
you must retool the spray gun (See 5.5 Retooling of Spray Gun).
WALTHER offers a great variety of air cap-/ material nozzle-/needle combinations for
this purpose.
Correcting of Spray Pattern Imperfections
The following table shows what to do to correct a spray pattern:
Spray pattern Fault
test
Swollen centre
Swollen ends
Coarse pearl effect
Unduly thin paint layer
in centre
Spray pattern is split in
the centre
Spray pattern is very
spherical
5.5

Retooling of Spray Gun

Combinations of air cap, material nozzle and needle, designed to match specific
spraying media tpyes and grades, form a unit - namely the nozzle insert assembly.
In order maintain the desired spray-finish quality standard always replace the
complete nozzle insert assembly.
Warning
Prior to retooling: Make sure that the spray gun is in unpressurized condition, i.e. all
air and material inputs must be shut off - if not, imminent risk of injury.
Note
In order to perform the following procedures please use the drawing at the beginning
of these operating instructions.
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desired spray result
Necessary adjustment
• Spray jet should be flatter
• Spray jet should be rounder
• Increase wide jet air pressure
• Decrease wide jet air pressure
• Increase nozzle diameter
• Reduce atomising air pressure
• Increase material pressure
• Decrease material pressure
• Increase atomising air pressure