Setting The Atomization Fluid Pressure - Graco PRO AA5500SC Instructions And Parts List

Setting the Atomization Fluid Pressure

NOTE: Atomization fluid pressure will vary based on
the viscosity of the fluid, the flow rate desired, and oth-
er characteristics of your system.
Atomization Chart
Starting Fluid
Fluid Viscosity Pressure
40 or more 1500 psi
seconds in #2 (105 bar)
Zahn cup*
25–40 seconds 1000 psi
in #2 Zahn (70 bar)
cup**
25 or less 500 psi
seconds in #2 (35 bar)
Zahn cup***
* Includes fluids with 60% volume solids or greater.
Examples: high-build high-solids protective polyurethanes
and epoxies
** Includes fluids with 40 to 60% (medium) volume solids.
Examples: alkyd enamels, some protective polyurethanes
and epoxies
*** Includes fluids with 40% volume solids or less.
Examples: stains, lacquers, and decorative urethanes
1. Make sure the turbine air (electrostatics) and
atomization air are off.
2. Set the fluid pressure with the gun fluid regulator
for the type of fluid you are spraying, based on the
Starting Fluid Pressure in the Atomization Chart,
above.
Fig. 13
Operation
3. With the turbine air (electrostatics) off and the
Fluid Pressure
4. Increase the fluid pressure by the Fluid Pressure
Increments
200 psi
(14 bar)
5. Spray another test pattern across a piece of paper.
100 psi
6. Without being concerned about the presence of
(7 bar)
100 psi
(7 bar)
7. Continue to increase the fluid pressure by the
8. Turn on the atomization air and adjust the air pres-
NOTE: See Spray Pattern Troubleshooting on page
23 to correct spray pattern problems.
Gun Fluid
Regulator
01999A
Fig. 14
atomization air off, spray a test pattern across a
piece of paper, holding the gun 12 inches (305
mm) from the surface.
Without being concerned about the presence of
"tails", note the particle size.
Increment shown in the Atomization Chart for the
type of fluid you are spraying.
"tails", compare the particle size of the two test
patterns.
A decrease in particle size indicates improved at-
omization.
increments shown in the chart until the particle
size no longer reduces in size; do not exceed the
gun's Maximum Fluid Pressure of 3000 psi (207
bar).
When the particle size no longer reduces in size,
the pattern is atomized at the lowest possible fluid
pressure, but will still have tails.
sure until the tails are eliminated. See Fig. 14 .
Tails
No Air Too Little Air Right Amount
of Air