Spray Adjustments - Graco 259079 Operation Manuals

Spraying
12. Open gun fluid inlet valves A and B.
Note
On impingement guns, never open
fluid manifold valves or trigger gun if
pressures are imbalanced.
13. Disengage gun piston safety lock.
14. Test spray onto cardboard. Adjust pressure and
temperature to get desired results.
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15. Equipment is ready to spray.

Spray Adjustments

Flow rate, atomization, and amount of overspray are
affected by four variables.
• Fluid pressure setting. Too little pressure results
in an uneven pattern, coarse droplet size, low
flow, and poor mixing. Too much pressure results
in excessive overspray, high flow rates, difficult
control, and excessive wear.
• Fluid temperature. Similar effects to fluid pressure
setting. The A and B temperatures can be offset to
help balance the fluid pressure.
• Mix chamber size. Choice of mix chamber is based
on desired flow rate and fluid viscosity.
• Clean-off air adjustment. Too little clean-off air
results in droplets building up on the front of the
nozzle, and no pattern containment to control
overspray. Too much clean-off air results in
air-assisted atomization and excessive overspray.
3A1705E