Graco PrecisionMix ii, Instructions And Parts List

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Overview
Flow Control Overview
Flow Control is used to limit the flow of material to the
air spray gun to help avoid sags and runs in the finish
due to coatings being applied too thick or quickly and
to assure adequate coverage. Flow control can be
configured for use with a manual or automatic air spray
gun. Refer to
Flow Control Setup , page 8–16.
The flow control module uses flow meters, fluid regula-
tor, current to pressure (I/P) transducer, and the Preci-
sionMix II 3K controller to adjust and maintain the flow
of material to the air spray gun.
Flow control is an optional feature of the Preci-
sionMix 3K system. Your system must be
configured with flow control hardware and
software in order to use flow control. Detailed
information on using flow control is in other
sections of this manual.
Flow control is NOT for use with air-assisted or
airless spray guns.
Flow Control Features
Ability to control one manual or automatic air
spray gun
Programmable maximum flow setpoint
Programmable lower flow control start value for
manual gun
Delayed activation of flow control after the gun is
triggered
Manual flow rate reset function, which can be
initiated from the in-booth Flow Control Station
An indicator light on the Flow Control Station to
show when the flow rate is resetting for manual gun
operation.
System Requirements
The fluid feed system must have adequate volume and
pressure to supply the air spray gun. The Component
A, B and C fluid supply pressures need to be bal-
anced. The fluid feed hose, gun nozzle and needle
size and travel must be sized and adjusted properly to
keep the flow control operating at its maximum effi-
ciency.
General Operation Sequence
1. When the controller is first turned on, a pre-config-
ured pilot air pressure is applied to the fluid regula-
tor.
2. When the air spray gun is triggered, the controller
waits for the set delay time to elapse before it
starts monitoring the flow and making any neces-
sary adjustments. The delay time is user select-
able (typically 1–2 seconds) and helps assure the
fluid is moving at a normal rate before flow rate
adjustments occur.
3. When the fluid moves through the fluid lines, the
flow meter(s) monitors the flow and sends meter
pulses to the controller. These pulses are con-
verted into flow measurements and checked
against the set values in the controller.
4. If the fluid flow falls outside the set values, the
controller sends a signal to adjust the fluid regula-
tor to correct the flow. The flow is raised or low-
ered by the pilot air pressure from the current to
pressure (I/P) transducer. The greater the pilot air
pressure to the fluid regulator, the higher the fluid
pressure and the greater the fluid flow.
5. When the air spray gun is turned off, the flow
control holds the pilot air pressure value and does
not attempt to adjust fluid flow until the gun is
triggered again.
6. When the gun is triggered, the process of control-
ling the fluid flow continues.