Graco Pneumatic PR70, Instructions Manual

Page: 13 / 34

Setup
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This ensures any air in the hoses will travel to the
dispense head.
7. Set the Stroke Adjust switch to the 2 in. mark.
8. Hold a waste container at the end of the dispense
head (102) then press and release the start device.
9. Repeat the previous step until no air comes out of
the dispense valve.
10. If phasing adjustments and ratio checking are not
required, use the following procedure to attach the
static mixer.
a. Attach the static mixer with the dispense head
pointed up.
b. Hold waste container at end of dispense
head (102) then press and release the start
device.
c. Repeat the previous steps until static mixer has
been purged of air.
11. Use a 4 mm hex key to loosen screws (102a) hold-
ing dispense head in place.
12. Rotate dispense head back to normal dispensing
position.
13. Use a 4 mm hex key to tighten the screws (102a)
holding the dispense head in place.
14. Adjust snuff back to proper setting for operation.
See Adjust Dispense Valve Snuff Back on
page 14.
Phasing Adjustment
When the machine executes a shot, materials from
Tank A and Tank B enter the static mixer where they are
mixed and then dispensed. In order for the materials to
mix at the desired ratio, both materials must enter the
static mixer at the same time. The timing of the materials
entering the static mixer is dependent on the adjustment
of the phase adjustment screw for each piston.
Prepare Machine
1. Place a waste container under the dispense valve to
catch dispensed material.
2. Remove static mixer from dispense valve.
3. Install ratio check nozzle onto dispense valve.
4. If necessary, place a stand under ratio check nozzle
to support waste container close to nozzle.
5. Set middle switch to SHOT and bottom switch to
AUTO.
Adjust Dispense Quantity
6. Press and release the start device to dispense a
very small amount of material.
7. Adjust the stroke if more than a couple drops of
either material was dispensed or if no material was
dispensed from both sides. See the Adjusting the
Shot Size section on page 11.
F
IG
. 5: Ratio Check Nozzle
Shorten the stroke until just a pulse of material dis-
penses. The pumps are in phase when the material
begins to flow from the nozzle outlets at exactly the
same time.
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