Operation; Sequence Of Operation - Graco PD44 Operation & Maintenance Manual

Operation

Operation
The operation of the PD44 metering valve is controlled
by an external source. If a PD44 Control Box was pur-
chased, see the PD44 Control Box manual for operation
instructions. See Related Manuals on page 3.

Sequence of Operation

Step 1: Reload
• Spools shift to the right
• Material feed inlets are opened
• Materials are transferred into the metering cham-
bers by a pressurized feed system
• Outlet ports are blocked
• Metering rods are retracted to a precise position
determining the volume of each material
Step 2: Shift
• The balanced spool assemblies shift to the dis-
pense position
• Material path to the mixer inlet is opened
• Material feed inlet ports are blocked
• Metering rods remain in the retracted position
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Step 3: Dispense
• Metering rods extend
• A and B materials are simultaneously dispensed
from the metering chamber into the disposable
mixer
• A and B materials are dispensed at the predeter-
mined volume ratio.
Upon completion of the dispense stroke, the metering
rod and spool assemblies shift back to the reload posi-
tion.
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