Index revision : I - November 2018
12
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7. Problems, Troubleshooting.
Symptoms
Causes
Remedies
The pneumovalve does not
open
(the operating indicator
does not remain in out posi-
tion at the rear of the pneu-
movalve).
The control air does not
arrive at the pneumovalve.
Check the control circuit
(control hose folded or dis-
connected).
The control pressure is less
than 5 bar (72,5 Psi).
Increase the network pres-
sure.
The needle control rod is
jammed. If there is a leak at
the gaskets, the paint may
dry if the gun is not used for
some time preventing the
needle rod from moving.
Check if any product has
flowed through the venting
hole.
If this is the case, replace the
pneumovalve.
The piston seal is damaged.
If this seal leaks, pressure
cannot build up in the con-
trol chamber.
Remove the pneumovalve.
Check that the needle can
recede by pushing the end
of it with a flat tool. If it does
not operate correctly,
replace the pneumovalve.
The pneumovalve does not
close.
The control air circuit
remains pressurized.
The control solenoid valve is
not operating correctly. The
air cannot be drained.
The return spring is broken.
After disassembling the
pneumovalve, exert a pres-
sure on the end of the nee-
dle. Lack of resistance is a
sign that the spring is worn. If
so, replace the pneumov-
alve.
The needle control rod is
jammed.
Check that the indicator
can move out by pressing
on the end of it with a flat
tool.
If it does not operate cor-
rectly, replace the pneumo-
valve.
The pneumovalve no longer
acts correctly as a valve.
If the pneumovalve cannot
be closed, the needle does
not exert enough pressure
on its seat, resulting in prod-
uct leakage.
See previous symptom.
The needle is faulty.
Remove the pneumovalve.
Check visually for scratches
or faults on the needle. If
faults can be seen, change
the needle.
Check for foreign matter on
the needle bearing.
Clean as necessary.