Correction Of Spray Pattern; Trouble Shooting; Retooling And Repairs - WALTHER PILOT PILOT Maxi-HD Betriebsanleitung

6.1 Correction of Spray Pattern Imperfections
The following table shows how to correct a defective spray pattern.
Spray pattern test Deviation
Swollen centre
Swollen ends
Coarse pearl effect
Unduly thin paint layer in
centre
Split centre
Crowned centre
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Trouble shooting

Warning
Prior to any retooling the spray gun should be depressurized state, i. e. atomising air
as well as the material pressure - risk of injury.
Fault Cause
The nozzle or needle are dirty or
damaged
Dripping from the
nozzle
The setting screw (pos. 18) is tur-
ned too far to the back
Not enough material in the tank
Cup is tilted too much
Pulsating or un-
Material nozzle loose or damaged
steady jet
Material too heavy for the suction
cup
The gun blows in Valve cone (pos. 11) or
off position valve stem (pos. 10) damaged
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desired spray pattern
Necessary adjustment
• Spray jet should be flatter
• Spray jet should be rounder
• Increase atomising air pressu-
re
• Decrease atomising air pres-
sure
• Increase nozzle diameter
• Reduce atomising air pressure
• Increase material pressure
• Decrease material pressure
• Increase atomising air pressure
Remedy
• Clean or replace
• Adjust by turning clockwise
• Top-up material level
• Keep it level
• Tighten or replace (pos. 5)
•Use pressure tanks or pumps
• Replace
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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 cap, material nozzle and needle-combination
form together a unit - the nozzle set. Always change the complete insert assmbly
to maintain the desired finish quality.
Warning
Prior to any repairs or replacements: Make sure that the spray gun is in depressu-
rized 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 refer to the exploded diagram
at the beginning of these operating instructions.
Replacement of the material nozzle and the air cap
1. Unscrew the air cap nut (pos. 1).
2. Remove the air cap (pos. 2).
3. Unscrew the material nozzle (pos. 3) from the gun body (use size 13 wrenth).
4. Remove the intermediate ring (pos. 4) from the material nozzle.
The installation of the new nozzle insert assembly and of the remaining parts in
reverse order.
Replacement of the material needle
1. Unscrew the adjusting screw (pos. 18).
2. Remove the needle spring (pos. 17).
3. Pull the material needle (pos. 16) out off the gun body.
Reassemble in reverse order. An initial air inlet is not necessary.
Replacement of the defective needle packing
1. Disassemble the material needle as described above.
2. Remove the knurled screw (pos. 32).
3. Remove the needle packing (pos. 33) including the O-ring (pos. 34).
Reassemble in reverse order.
Note
Never reinstall a used needle packing, as otherwise the functional sealing reliabili-
ty of the spray gun will not be guaranteed.
Note
All sliding and moveable parts must be lubricated with a non-acidic, non-resinoge-
nic grease prior to installation.
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