Correction Of Spray Pattern; Spray Pattern Test; Retooling And Repairs; Replacement Of The Material Nozzle And The Air Cap - WALTHER PILOT PILOT I Instructions De Service

6.1 Correction of Spray Pattern Imperfections
The following table shows how to correct a defective spray pattern.
Desired Spray Pattern

Spray pattern test

Fault
Swollen centre
Swollen ends
Coarse pearl effect
Unduly thin paint
layer in centre
Split centre
Split centre
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Retooling and repairs

If a jet contour other than already described is desired, the spray gun has to be
retooled. The suitable material air control head, material nozzle and needle-combina-
tion form together a unit - the nozzle set. Always change the complete insert assmbly
to maintain the desired finish quality.
Warning
Prior to any retools or replairs: Make sure that the spray gun is in depressurized con-
dition, i.e. all air inputs must be shut off - if not, imminent Risk of Injury.
Note
In order to perform the following procedures, please refer to the exploded diagram in
the beginning of these operating instructions.
7.1

Replacement of the material nozzle and the air cap

1. Remove air cap (Item 1) from the gun body (item 4).
2. Remove material nozzle (Item 3) from gun body; using a Size 7 wrench.
Reassemble in reverse order.
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Necessary adjustment
• Spray jet should be flatter
• Spray jet should be rounder
• Increase atomising air pressure
• Decrease atomising air pressure
• Increase nozzle diameter
• Reduce atomising air pressure
• Increase atomising air pressure
7.2

Replacement of the material needle

1. Unscrew the spring retaining bush (Item 17) from the gun body.
2. Withdraw the valve spring (Item 16) and the valve (Item 11) with the integrated
needle.
3. Use a screwdriver to remove the valve cap screw (Item 15), located at the end
of the valve.
4. Remove the needle spring (Item 14) and the needle (Item 12).
5. The setting dimension for the needle-controlled initial air input is 81 mm, measu-
red between the point of the material needle and the face of the 1st needle
retaining nut (Item 13), with the 2nd nut serving as lock nut.
Reassemble in reverse order.
7.3

Replacement of the defective needle packing

1. Remove the material needle, see above.
2. After the remove of the material needle unsrew the needle packing gland
(Item 27), using a properly sized screwdriver. The needle seal packing (Item 26)
can now be removed from the gun body.
Reassemble in reverse order!
Notice
When using the wide/flat-jet air cap (Item 28), make sure that the material
nozzle (Item 29) and the material needle (Item 30) are properly installed.
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Cleaning and service

Caution
Never immerse the spray gun in solvent or any other cleaning solution. The functio-
nal reliability and efficiency of the gun can otherwise not be guaranteed. Do not use
any hard, sharp or pointed objects when cleaning the spray gun. WALTHER PILOT
is not responsible for any damage resulting from improper cleaning.
The gun does not need to be dismantled for cleaning.
1. Fill the cleaned gravity-feed cup with a cleaning fluid compatible with the sprayed
material.
2. Operate the spray gun.
3. Do not stop the spray gun until clear cleaning fluid emerges from the nozzle.
The entire system should then be depressurised until the gun is used again. Clean
the spray gun only with cleaning agents which have been recommended by the man-
ufacturer of the sprayed material and which do not contain the following constituents:
• halogenated hydrocarbons (e.g. 1,1,1-trichloroethane, methylene chloride, etc.)
• acids and acidic cleaning fluids
• regenerated solvents (so-called cleaning thinners)
• paint removers
The above-mentioned constituents cause chemical reactions on electroplated com-
ponents, resulting in corrosion damage.
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