Fluid And Air Pressure Requirements; Flow Control Operation - Graco ProControl 1KS Operation

Fluid and Air Pressure
Requirements
The fluid input pressure to the fluid regulator must be
high enough to provide a 15-20 psi (0.1-0.14 MPa,
1.0-1.4 bar) pressure differential across the regulator at
the highest flow setting. For example, if the maximum
flow rate set point is 280 cc/min and 35 psi outlet pres-
sure is required to achieve that flow, the input pressure
must be 50-55 psi.
Required air pressure to the flow control module is
70-100 psi (0.35-0.7 MPa, 3.5-7.0 bar).
NOTE:
• For flow control modules 249849 and 24H989 used
with a 1:1 fluid regulator, the fluid outlet pressure
from the regulator must be between 5-75 psi
(0.034-0.52 MPa, 0.34-5.2 bar) for all flow set
points. Flow rate set points with pressures outside
this range are not achievable. There must be at
least 5 psi (0.034 MPa, 0.34 bar) fluid pressure at
the lowest flow rate.
• If flow control module 24H989 is used with a fluid
regulator at a ratio greater than 1:1, the relationship
of air pressure to fluid outlet pressure is very import-
ant. The lowest recommended air pressure from the
V/P is 5 psi (0.034 MPa, 0.34 bar). Back pressure
may be required to ensure minimal fluid pressure at
the lowest flow rate setpoint.
The turn down ratio of the typical fluid regulator is
approximately 3:1 or 4:1, depending on material type
and viscosity. For example, if the lowest flow rate
required is 100 cc/min, the top flow rate achievable may
be 300-400 cc/min.
NOTE: The top flow rate is not the maximum flow rate
range selected.
3A1080H

Flow Control Operation

See F . 83 for module 249849 and F
IG
24H989. The Flow Control System includes two infor-
mation loops:
• The pressure loop monitors fluid pressure with the
pressure sensor in the module. This allows the sys-
tem to react very quickly to set point changes.
While the gun is not triggered the system still drives to
the pressure determined from the data table from the
flow rate set point. This pressure drive will operate for
the amount of time set in the "GT-Off drive time" value in
the Advanced Screen. This screen can be accessed
and the setting modified while Flow Control is set to "On:
Setup" in Configure Screen 5, page 30.
The target pressure when the gun trigger is off can be
adjusted using the "GT-Off target rise" value in the
Advanced Setup Screen 7, page 38. This amount is
added to the value from the data table. This may com-
pensate for the immediate pressure drop at the gun
when the gun trigger is opened. Adjust for gun triggers
at the lowest flow rates.
• The flow loop monitors fluid flow through flow meter
pulses, ensuring accuracy. The gun must be trig-
gered during the flow loop.
The Flow Control System creates a data table that tar-
gets a desired flow rate based on the fluid pressure. It
then monitors the flow loop to maintain the flow rate.
The data table update performance can be modified
using the "Learn Strength" value in Advanced Setup
Screen 6, page 38. This determines how much of the
instantaneous flow error value is applied when updating
the table. High values make it learn more quickly, but
may lead to oscillation. Low values make it learn more
slowly, but may make adjustment times unacceptable.
Integrated Flow Control
. 84 for module
IG
79