DeVilbiss Plus SB-2-475-H Service Bulletin

Plus HIGH EFFICIENCY sPRAY GuN (suCtIoN/PREssuRE)
®
IMPORTANT: Before using this equipment,
read all safety precautions and instructions.
Keep for future use.

DESCRIPTION

The Plus spray gun is a general-purpose,
®
heavy-duty, high-production spray gun suit-
able for use with most types of materials.
It is available in one suction feed version or
in two pressure feed versions.
NOTE
These guns include 300 series
stainless steel fluid tips and
needles. Guns should not be used
with chlorinated solvent materials.
See page 2 for potential hazards.
Important: These guns may be used with
most common coating and finishing materi-
als. They are designed for use with mildly
corrosive and non-abrasive materials. If used
with other high corrosive or abrasive materi-
als, it must be expected that frequent and
thorough cleaning will be required and the
necessity 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.
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).
NOTE
Depending on hose length, larger
I.D. hose may be required. Do not
use more pressure than is neces-
sary to atomize the material being
applied. Excess pressure will create
additional overspray and reduce

transfer efficiency.

NOTE
If quick connects are required, use
only high flow quick connects ap-
proved for HVLP use such as DeV-
ilbiss HC-4419 and HC-4719. Other
types will not flow enough air for
proper gun operation.
NOTE
If an air adjusting valve is used at the
gun inlet, use DeVilbiss Model HAV-
500 or HAV-511. Some competitive
adjusting valves have significant
pressure drop that can adversely
affect spray performance. Models
HAV-500 and HAV-511 have minimal
pressure drop.
2. Attach the suction feed cup or
fluid hose to the material inlet.
NOTE
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.

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. Fill the suction or pressure feed cup
with the material. Do not overfill.
If using a suction cup, make sure that
the cup lid vent hole is clear.
2. Open the spreader adjustment valve
(10) (Fan) by turning the valve stem
counterclockwise.
3. Open fluid adjusting screw (17) by
turning counterclockwise.
4. Turn on air supply and set gun inlet
pressure to 40 psi. Some materials
can be sprayed at lower pressures,
improving transfer efficiency.
5. Turn on the supply air to the pressure
cup (if used).
6. Spray a test area.
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 mate-
rial 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
adjustment valve (10), either clockwise to
decrease the width or counterclockwise to
increase the width.
SERVICE BULLETIN
SB-2-475-H
Replaces SB-2-475-G
Repair Kit KK-5058-2
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
scratching or burring of the holes which will
cause a distorted spray pattern.
To clean fluid passages, remove excess
material from cup, then flush with a suit-
able solvent. Wipe gun exterior with a
solvent dampened cloth. Never completely
immerse in solvent as this is detrimental to
the lubricants and packings.
NOTE
When replacing the fluid tip or
fluid needle, replace both at the
same time. Using worn parts can
cause fluid leakage. See Chart 2.
Also, replace the needle packing
at this time. Lightly lubricate the
threads of the fluid tip before reas-
sembling. Torque to 15-20 ft.-lbs.
Do not overtighten the fluid tip.
To prevent damage to fluid tip
(5) or fluid needle (11), be sure to
either 1) pull the trigger and hold
while tightening or loosening
the fluid tip, or 2) remove fluid
needle adjusting screw (17) to
relieve spring pressure against
needle collar.
TRANSFER EFFICIENCY
The DeVilbiss PLUS
®
and pressure feed spray guns,
when tested under recommended
conditions with automotive
refinishing materials, have been
found to exceed 65% transfer
efficiency.
suction feed