Specifications

28. What are the components of
a pressure feed system?
A pressure feed system consists of:
a pressure feed spray gun, a pres-
sure feed tank, cup or pump, an air
filter/regulator, appropriate air and
fluid hoses, and an air com-pressor
(see figure 16).
Figure 16 - Pressure Feed System
Components
29. How is equipment hooked up
for pressure feed spraying?
Connect the air hose from the air
regulator to the air inlet on the gun.
Connect the mainline air hose to
the air inlet on the tank. CAUTION:
Do not exceed the container's
maximum working pressure.
Connect the fluid hose from the
fluid outlet on the tank to the fluid
inlet on the gun.
30. How is the pressure feed gun
adjusted for spraying?
Open spreader adjustment valve
for maximum pattern size (see
figure 8).
Open fluid adjustment screw until
the first thread is visible (see
figure 14).
31. How is the pressure feed
gun balanced for spraying?
1) Using control knob on fluid
regulator, set fluid pressure at
5 to 10 psi.
2) Using control knob on air
regulator, set air atomization
pressure at 25-35 psi.
3) Spray a test pattern (fast pass)
on a piece of paper, cardboard, or
wood. From that test pattern,
determine if the particle size is
small enough and relatively uniform
throughout the pattern to achieve
the required finish quality (see
figure 15). If particle size is too
large or is giving too much texture
in the finish, turn the atomization
pressure up in 3 to 5 psi
increments until particle size and
texture of finish is acceptable.
4) Spray a part with these settings.
If you are not able to keep up with
the production rate required or if
the finish is starved for material,
increase the fluid pressure with the
fluid regulator control knob in 2 to
4 psi increments until required wet
coverage is accomplished.
Note: A larger capacity fluid tip
may be required.
5) Remember, as you turn up the
fluid pressure the particle size will
increase. Once the coverage
required is obtained, it will be
necessary to re-adjust the
atomization pressure in 3 to 5 psi
increments as explained in step 3
to insure required particle size and
finish texture is achieved.
6) If using HVLP, using an “Air Cap
Test Kit”, verify that the air cap
pressure in not above 10 psi if
required by a regulatory agency.
Figure 17 – Air Cap Test Kit
After establishing the operating
pressures required for production
and finish quality, develop a
Pressure Standardization program
for your finish room to follow.
32. What is a Pressure
Standardization Program?
After establishing air and fluid
pressures that meet required qual-
ity and production, record the data
to be used for that application for
future reference. (see figure 18)
Figure 18 – Pressure
Standardization Chart
33. How should the spray gun be
held?
It should be held so the pattern is
perpendicular to the surface at all
times.
Keep the gun tip 8-10 inches (air
spray guns) or 6-8 inches (HVLP
guns) from the surface being
sprayed.
2. Air Atomizing Spray Guns (Cont’d)
10
Booth #: _______________
Material Sprayed ________
Application _____________
Viscosity _______________
Fluid Temperature ________
Spray Gun ______________
Air Cap ______ Fluid Tip ___
Air Pressure _____________
Fluid Pressure ____________