Low flow.
Inadequate air supply through the
I/P transducer.
Increase incoming air pressure.
Flow control no settling to setpoint.
Pressure or flow PID K-Factors
are not tuned.
See
For automatic operation, verify
the pressure switch electrical
connection. Check that the switch
closes when the gun fluid solenoid
is activated.
For manual operation, verify the air
flow switch electrical connection.
Check that the switch closes when
the gun trigger is activated.
Flow control over-driving to high
flow rates.
Gun Trigger signal not
synchronized with fluid flow
valve.
The flow control may activate
when the atomizing air is flowing
without any fluid flow.
• If this is because of a dusting
procedure, the flow control may
over-drive the fluid pressure
until it can converge.
• If this is because of system
startup, this is normal and the
flow control should eventually
react.
Check incoming system air
pressure. This should be at least
10 psi (0.7 bar) higher than the
target fluid pressure.
Check incoming fluid pressure
from pump. This should be at
least 10 psi (0.7 bar) higher than
the target fluid pressure. The
pump must be able to supply this
pressure at the target flow rate.
Check I/P pilot line output
pressure.
Higher fluid pressure cannot be
achieved.
Low fluid pressure after the fluid
regulator.
Check power output of the barrier
that powers the system. At 20 mA,
for 100 psi (6.9 bar), this should
be at least 13.5 volts.
Check for upwards settling of air
bubbles.
Check for downwards settling of
solids, such as metallics.
Unstable flow with Coriolis meter.
Presence of bubbles or sediment.
Consult the Coriolis Meter manaul
(see
Coriolis meter shows flow when
no fluid is flowing.
Low-flow cutoff may be set too low.
Increase the low-flow cutoff to just
above the highest false flow rate
that was observed.
Regulator pilot drives to high
pressure.
Inadequate fluid supply in pressure
control or flow control mode.
Check pressure and flow
capabilities of the fluid supply.
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