Graco Alpha Plus AA Instructions-Parts List Manual page 10

Adjust the Spray Pattern
WARNING
INJECTION HAZARD
To reduce the risk of component rupture
and serious injury, including injection, do
not exceed the gun's maximum fluid
working pressure of 4000 psi (28 MPa, 280 bar) or
the maximum working pressure of the lowest rated
component in the system.
WARNING
COMPONENT RUPTURE HAZARD
Do not exceed the maximum fluid and
air pressure of this gun. Higher pressur-
es can cause parts to rupture and result in serious
injury.
1. Do not turn on the air supply yet. Set the fluid
pressure at a low starting pressure, approximately
600 psi (4.2 MPa, 42 bar). If a fluid pressure
regulator is installed, use it to make the adjust-
ments.
If your system does not have a fluid regulator, the
fluid pressure is controlled by the air regulator
supplying the pump, per the formula below:
Pump Ratio x Pump Air Regulator
Setting
2. Trigger the gun to check the atomization; do not be
concerned about the pattern shape yet.
3. Slowly increase the fluid pressure, just to the point
where a further increase in fluid pressure does not
significantly improve fluid atomization.
4. Close off the pattern adjustment air by turning the
knob (S, see Fig. 5) clockwise (in) all the way. This
sets the gun for its widest pattern.
10 309117
Operation
5. Set the atomizing air pressure at about 5 psi (0.35
NOTE: There is no fan adjustment when using AA
RAC tips and caps.
Fig. 5
= Fluid
Pressure
No Air
Fig. 6
bar, 35 kPa) when triggered. Check the spray
pattern, then slowly increase the air pressure until
the tails are completely atomized and pulled into
the spray pattern. See Fig. 6. Do not exceed 100
psi (0.7 MPa, 7 bar) air pressure to the gun.
For a narrower pattern, turn the pattern adjustment
valve knob (S, see Fig. 5) counterclockwise (out).
If the pattern is still not narrow enough, increase
the air pressure to the gun slightly or use a differ-
ent size tip.
S
In
(wider
pattern)
Too Little Air
S
Out
(narrower
pattern)
TI0396
Right Amount
of Air
0792