DeVilbiss EXL-620G User Manual

IMPORTANT: Before using this equipment,
read all safety precautions and instructions.
Keep for future use.
DESCRIPTION
The complaint high volume low pressure
gravity feed EXL guns are designed to apply
a wide variety of finishing materials. These
guns were manufactured to provide a maxi-
mum transfer efficiency by limiting air cap
pressure to 10 psi (complies with rules
issued by SCAQMD and other air quality
authorities).
These guns will produce approximately
10 psi air cap pressure at 30 psi gun inlet
pressure. Air cap test kits are available (see
Accessories) which can be utilized to set the
exact air cap pressure. Air consumption for
the EXL-620G (#2000 cap) is 15.5 SCFM at
10 psi air cap presssure.
This gun should not be used with
chlorinated solvent materials.
Halogenated hydrocarbon solvents
(for example: methylene chloride
and 1, 1, 1, - Trichloroethane)
are not chemically compatible
with the aluminum that might be
used in many system components.
The chemical reaction caused
by these solvents reacting with
aluminum can become violent
and lead to equipment explosion.
See page 2 for potential hazards.
Important: This gun may be used with most
common coating and finishing materials. It
is designed for use with mildly corrosive
and non-abrasive materials. If used with
other high corrosive or abrasive materials,
it must be expected that frequent and thor-
ough cleaning will be required and the ne-
cessity for replacement of parts will be
increased.
INSTALLATION
For maximum transfer efficiency, do not
use more pressure than is necessary to
atomize the material being applied.
EXL-620G HIGH VOLUME LOW PRESSURE
GRAVITY FEED SPRAY GUNS
1. Connect the gun to a clean, moisture and
oil free air supply using a hose size of at
least 5/16" I.D. hose. Do not use 1/4" I.D.
hose (25' x 1/4" hose at 18 CFM has a
pressure loss of 25 psi. 25' x 5/16" hose at
18 CFM has a pressure loss of 8 psi).
Depending on hose length, larger
I.D. hose may be required. Install an
HAV-501 air gauge at the gun handle
and air cap test kit over tip. When
gun is triggered on, adjust regulated
pressure to desired setting to pro-
vide a maximum of 10 psi at the air
cap. Do not use more pressure than
is necessary to atomize the material
being applied. Excess pressure will
create additional overspray and re-
duce transfer efficiency.
If quick connects are required, use
only high flow quick connects
approved for HVLP use such as
DeVilbiss HC-4419 and HC-4699.
Other types will not flow enough
air for proper gun operation.
If an air adjusting valve is used at the
gun inlet, use DeVilbiss Model HAV-
500 or HAV-501. Some competitive
adjusting valves have significant
pressure drop that can adversely
affect spray performance. Models
HAV-500
minimal pressure drop, which is
important for HVLP spraying.
2 . Attach the gravity feed cup to the
material inlet.
Protective coating and rust inhibi-
tors have been used to keep the
gun in good condition prior to
shipment. Before using the gun,
flush it with solvents so that these
materials will be removed from
fluid passages.
NOTE
NOTE
NOTE
and HAV-501 have
NOTE
SERVICE BULLETIN
SB-2-202-B
Replaces SB-2-202-A
Repair Kit KK-5058-2
OPERATION
Mix, prepare and strain the material to be
sprayed according to the paint maufacturer's
instructions.
Strain material through a 60 or 90 mesh
screen.
1. If used, install paint liner into cup. (See
instructions included with cup.)
2. Fill the gravity feed cup with the mate-
rial. Do not overfill. Make sure that the
cup lid vent hole is clear.
3. Open the spreader adjustment valve
(10) (Fan) by turning the valve stem
counterclockwise.
4. Close the fluid needle adjusting screw
(17) by turning clockwise.
5 . Turn on air supply and set gun inlet
pressure to lowest recommended pres-
sure for material being sprayed. Best
atomization will occur with 10 psig air
cap pressure. However, some materi-
als can be sprayed at lower pressures,
improving transfer efficiency.
6 . Spray a test area by turning fluid
needle adjusting
counterclockwise until a full coat is
obtained.
If the finish is too sandy and dry, the
material flow may be too low for the
atomization air pressure being used.
If the finish sags, there is too much material
flowing for the atomization air pressure
being used.
Both of the above can be corrected by
increasing or decreasing the atomization air
pressure or the material flow. Pattern width
can be altered by turning spreader adjust-
ment valve (10), either clockwise to de-
crease the width or counterclockwise to
increase the width.
See Spray Gun Guide, SB-2-001 latest
revision, for details concerning setup of
spray guns.
PREVENTIVE MAINTENANCE
To clean air cap and fluid tip, brush exterior
with a stiff bristle brush. If necessary to clean
cap holes, use a broom straw or toothpick if
possible. If a wire or hard instrument is used,
extreme care must be used to prevent scratch-
ing or burring of the holes which will cause
a distorted spray pattern.
screw (17)