O'Brien PRO 301, Owner'S Manual

3

308–030

MOVING PARTS HAZARD

Moving parts can pinch or amputate your fingers or other body
parts. KEEP CLEAR of moving parts when starting or operat-
ing the sprayer. Follow the Pressure Relief Procedure on
page 2 before checking or servicing any part of the sprayer, to
prevent it from starting accidentally.

EQUIPMENT MISUSE HAZARD

General Safety

Any misuse of the spray equipment or accessories, such as
overpressurizing, modifying parts, using incompatible chemi-
cals and fluids, or using worn or damaged parts, can cause
them to rupture and result in fluid injection, splashing in the
eyes or on the skin, or other serious bodily injury, or fire, ex-
plosion or property damage.

NEVER alter or modify any part of this equipment; doing so
could cause it to malfunction.

CHECK all spray equipment regularly and repair or replace
worn or damaged parts immediately.

Always wear protective eyewear, gloves, clothing and respira-
tor as recommended by the fluid and solvent manufacturer.

System Pressure

This sprayer can develop 

2500 psi (175 bar) MAXIMUM

WORKING PRESSURE. Be sure all spray equipment and
accessories used are rated to withstand the this pressure. DO
NOT exceed the maximum working pressure of any compo-
nent or accessory used in the system.

Fluid and Solvent Compatibility

All chemicals used in the sprayer must be chemically compatible
with the wetted parts shown in the TECHNICAL DATA on page
31. Consult your chemical supplier to ensure compatibility.

Do not use 1,1,1-trichloroethane, methylene chloride, other
halogenated hydrocarbon solvents or fluids containing such
solvents in this equipment, which contains aluminum and/or
zinc parts. Such use could result in a serious chemical reac-
tion, with the possibility of explosion, which could cause death,
serious bodily injury and/or substantial property 
damage.

HOSE SAFETY

High pressure fluid in the hoses can be very dangerous. If the
hose develops a leak, split or rupture due to any kind of wear,
damage or misuse, the high pressure spray emitted from it
can cause a fluid injection injury or other serious bodily injury
or property damage.

ALL FLUID HOSES MUST HAVE STRAIN RELIEFS ON
BOTH ENDS! The strain reliefs help protect the hose from
kinks or bends at or close to the coupling which can result in
hose rupture.

TIGHTEN all fluid connections securely before each use. High
pressure fluid can dislodge a loose coupling or allow high
pressure spray to be emitted from the coupling.

NEVER use a damaged hose. Before each use, check the
entire hose for cuts, leaks, abrasion, bulging cover, or damage
or movement of the hose couplings. If any of these conditions
exist, replace the hose immediately. DO NOT try to recouple
high pressure hose or mend it with tape or any other device. A
repaired hose cannot contain the high pressure fluid.

HANDLE AND ROUTE HOSES CAREFULLY. Do not pull on
hoses to move equipment. Keep hoses clear of moving parts
and hot surfaces of the pump and gas engine. Do not use
fluids or solvents which are not compatible with the inner tube
and cover of the hose. DO NOT expose Graco hoses to tem-
peratures above 180

_

 F (82

_

 C) or below –40

_

 F (–40

_

 C).

Hose Grounding Continuity

Proper hose grounding continuity is essential to maintaining a
grounded spray system. Check the electrical resistance of
your fluid hoses at least once a week. If your hose does not
have a tag on it which specifies the maximum electrical resis-
tance, contact the hose supplier or manufacturer for the maxi-
mum resistance limits. Use a resistance meter in the appropri-
ate range for your hose to check the resistance. If the
resistance exceeds the recommended limits, replace it imme-
diately. An ungrounded or poorly grounded hose can make
your system hazardous. Also read FIRE OR EXPLOSION
HAZARD, below.

FIRE OR EXPLOSION HAZARD

Static electricity is created by the flow of fluid through the
pump and hose. If every part of the spray equipment is not
properly grounded, sparking may occur, and the system may
become hazardous. Sparking may also occur when plugging
in or unplugging a power supply cord or using a gasoline en-
gine. Sparks can ignite fumes from solvents and the fluid be-
ing sprayed, dust particles and other flammable substances,
whether you are spraying indoors or outdoors, and can cause
a fire or explosion and serious bodily injury and property dam-
age.  Always plug the sprayer into an outlet at least 20 feet (6
m) away from the sprayer and the spray area. Do not plug in
or unplug any power supply cords in the spray area when
there is any chance of igniting fumes still in the air.
If you experience any static sparking or even a slight shock
while using this equipment, STOP SPRAYING IMMEDIATELY.
Check the entire system for proper grounding. Do not use the
system again until the problem has been identified and cor-
rected.

Grounding

To reduce the risk of static sparking, ground the sprayer and
all other spray equipment used or located in the spray area.
CHECK your local electrical code for detailed grounding in-
structions for your area and type of equipment. BE SURE to
ground all of this spray equipment:
1. 

Sprayer: plug the power supply cord, or extension cord – each
equipped with an undamaged, three–prong plug, into a prop-
erly grounded outlet. Do not use an adapter. All extension
cords must have three wires and be rated for 15 Amps.

2.

Fluid hoses: use only grounded hoses with a maximum

f 500

ft (150 m) combined hose length to ensure grounding continu-
ity.  See Hose Grounding Continuity above.

3.

Spray gun: obtain grounding through connection to a properly
grounded fluid hose and sprayer.

4.

Object being sprayed: according to local code.

5.

Fluid supply container: according to local code.

6.

All solvent pails used when flushing, according to local code.
Use only metal pails, which are conductive. Do not place the
pail on a non–conductive surface, such as paper or card-
board, which interrupts the grounding continuity.

7.

To maintain grounding continuity when flushing or relieving
pressure, always hold a metal part of the gun firmly to the side
of a grounded metal pail, then trigger the gun.

Flushing Safety

Reduce the risk of fluid injection injury, static sparking, or
splashing by following the flushing procedure given on page
12 of this manual. Follow the PRESSURE RELIEF PROCE-
DURE on page 2, and remove the spray tip before flushing.
Hold a metal part of the gun firmly to the side of a grounded
metal pail and use the lowest possible fluid pressure during
flushing.

IMPORTANT

United States Government safety standards have been adopted under the Occupational Safety and Health Act. These standards
– particularly the General Standards, Part 1910, and the Construction Standards, Part 1926 – should be consulted.