Graco RATIO BULLDOG 238-253 User manual

308–628
Rev. A

Model 238–257 Shown
INSTRUCTIONS-PARTS LIST
INSTRUCTIONS
This manual contains important
warnings and information.
READ AND KEEP FOR REFERENCE.
33:1 RA TIO BULLDOG  AND 68:1 RA TIO KINGCARBON STEEL
Cart-Mounted Airless Package
WITH DURA-FLO 750 DISPLACEMENT PUMP
33:1 RA TIO BULLDOG PUMPS
228 bar (3300 psi) Maximum Working Pressure
7 bar (100 psi) Maximum Air Inlet Pressure
Part No. 238–253, Series A
With High Pressure Fluid Filter
Part No. 238–257, Series A
With High Pressure Fluid Filter ,
hose and gun
Part No. 238–254, Series A
With High Pressure Surge T ank
68:1 RA TIO KINGPUMPS
422 bar (6120 psi) Maximum
Working Pressure
6.3 bar (90 psi) Maximum
Air Inlet Pressure
Part No. 238–265, Series A
With High Pressure Fluid Filter
Part No. 238–266, Series A
With High Pressure Fluid Filter ,
hose and gun
Refer to page 2 for T able of Contents.
GRACO INC. P.O. BOX 1441 MINNEAPOLIS, MN 55440–1441
COPYRIGHT 1995, GRACO INC.
Graco Inc. is registered to I.S. EN ISO 9001

 
Table of Contents
Warnings 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setup 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operation 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Data 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dimensions 19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Graco W arranty and Disclaimers 20. . . . . . . . . . . . . . . .
Toll-Free Graco Phone Numbers 20. . . . . . . . . . . . . . . .
Symbols
Warning Symbol
WARNING
This symbol alerts you to the possibility of serious
injury or death if you do not follow the instructions.
Caution Symbol
CAUTION
This symbol alerts you to the possibility of damage to
or destruction of equipment if you do not follow the
instructions.
WARNING
INSTRUCTIONS
EQUIPMENT MISUSE HAZARD
Equipment misuse can cause the equipment to rupture or malfunction and result in serious injury .

This equipment is for professional use only .

Read all instruction manuals, tags, and labels before operating the equipment.
 Use the equipment only for its intended purpose. If you are not sure, call your Graco distributor .

Do not alter or modify this equipment.
 Check equipment daily . Repair or replace worn or damaged parts immediately .
 Do not exceed the maximum working pressure of the lowest rated system component. Refer to the
T echnical Data on page 17 for the maximum working pressure of this equipment.
 Use fluids and solvents which are compatible with the equipment wetted parts. Refer to the Tech-
nical Data section of all equipment manuals. Read the fluid and solvent manufacturer ’ s warnings.
 Do not use hoses to pull equipment.
 Route hoses away from traffic areas, sharp edges, moving parts, and hot surfaces. Do not expose
Graco hoses to temperatures above 82  C (180  F) or below –40  C (–40 F).
W
ear hearing protection when operating this equipment.
 Do not lift pressurized equipment.
 Comply with all applicable local, state, and national fire, electrical, and safety regulations.

 
WARNING
INJECTION HAZARD
Spray from the gun, leaks or ruptured components can inject fluid into your body and cause extremely
serious injury, including the need for amputation. Fluid splashed in the eyes or on the skin can also
cause serious injury .

Fluid injected into the skin might look like just a cut, but it is a serious injury . Get immediate medi -
cal attention.

Do not point the gun at anyone or at any part of the body .

Do not put your hand or fingers over the spray tip.
 Do not stop or deflect leaks with your hand, body , glove or rag.
 Do not “blow back” fluid; this is not an air spray system.
 Always have the tip guard and the trigger guard on the gun when spraying.
 Check the gun dif fuser operation weekly . Refer to the gun manual.
 Be sure the gun trigger safety operates before spraying.
 Lock the gun trigger safety when you stop spraying.
 Follow the Pressure Relief Procedure on page 8 if the spray tip clogs and before cleaning,
checking or servicing the equipment.
T ighten all fluid connections before operating the equipment.
 Check the hoses, tubes, and couplings daily . Replace worn or damaged parts immediately.
Do not repair high pressure couplings; you must replace the entire hose.
MOVING P ARTS HAZARD
Moving parts, such as the air motor piston, can pinch or amputate your fingers.
 Keep clear of all moving parts when starting or operating the pump.
 Before servicing the equipment, follow the Pressure Relief Procedure on page 8 to prevent the
equipment from starting unexpectedly .

4 308-628
WARNING
FIRE AND EXPLOSION HAZARD
Improper grounding, poor ventilation, open flames or sparks can cause a hazardous condition and
result in a fire or explosion and serious injury
.

Ground the equipment and the object being sprayed. Refer to Grounding on page 5.
 If there is any static sparking or you feel an electric shock while using this equipment, stop spray-
ing immediately . Do not use the equipment until you identify and correct the problem.
 Provide fresh air ventilation to avoid the buildup of flammable fumes from solvents or the fluid
being sprayed.
 Keep the spray area free of debris, including solvent, rags, and gasoline.
 Electrically disconnect all equipment in the spray area.
 Extinguish all open flames or pilot lights in the spray area.
 Do not smoke in the spray area.
 Do not turn on or of f any light switch in the spray area while operating or if fumes are present.
 Do not operate a gasoline engine in the spray area.
TOXIC FLUID HAZARD
Hazardous fluid or toxic fumes can cause serious injury or death if splashed in the eyes or on the skin,
inhaled, or swallowed.
 Know the specific hazards of the fluid you are using.
 Store hazardous fluid in an approved container . Dispose of hazardous fluid according to all local,
state and national guidelines.
 Always wear protective eyewear , gloves, clothing and respirator as recommended by the fluid and
solvent manufacturer .

308-628 5
Setup
General Information
NOTE: Reference numbers and letters in parentheses
in the text refer to the callouts in the figures and the
parts drawing.
NOTE: Always use Genuine Graco Parts and Acces -
sories, available from your Graco distributor . Refer to
the Product Data Sheet for the pump, Form No.
305–753 for Bulldog Pumps and Form No. 305–755 for
King Pumps. If you supply your own accessories, be
sure they are adequately sized and pressure rated for
your system.
Fig. 2 is only a guide for selecting and installing sys -
tem components and accessories. Contact your Graco
distributor for assistance in designing a system to suit
your particular needs.
Prepare the Operator
All persons who operate the equipment must be
trained in the safe, ef ficient operation of all system
components as well as the proper handling of all fluids.
All operators must thoroughly read all instruction
manuals, tags, and labels before operating the equip -
ment.
Prepare the Site
The Bulldog pumps require 2.8 m  /min (100 scfm) of
compressed air while operating at 7 bar (100 psi) air
pressure and 60 cycles per minute. Ensure that you
have an adequate compressed air supply .
The King pumps require 4.2 m  /min (150 scfm) of
compressed air while operating at 6.3 bar (90 psi) air
pressure and 60 cycles per minute. Ensure that you
have an adequate compressed air supply .
Refer to Fig. 2. Bring a compressed air supply line (A)
from the air compressor to the pump location. Be sure
all air hoses (A) are properly sized and pressure-rated
for your system. Use only electrically conductive
hoses. The air hose should have a 3/4 npt(m) thread.
Install a bleed-type shutoff valve (B) in the air line to
isolate the air line components for servicing. Install an
air line moisture trap and drain valve (C) to help re -
move moisture from the compressed air supply .
Keep the site clear of any obstacles or debris that
could interfere with the operator ’ s movement.
Have a grounded, metal pail available for use when
flushing the system or draining the fluid filter .
Grounding
WARNING
FIRE AND EXPLOSION HAZARD
Before operating the pump, ground the
system as explained below . Also read
the section FIRE OR EXPLOSION HAZ -
ARD
on page 4.
1. Pump: use the ground wire and clamp (supplied).
See Fig. 1. Loosen the grounding lug locknut (W)
and washer (X). Insert one end of the ground wire
(34) into the slot in lug (Z) and tighten the locknut
securely . Connect the other end of the wire to a
true earth ground.
Fig. 1
W
X
34
Z

2. Air and fluid hoses: use only electrically conductive
hoses.
3. Air compressor: follow manufacturer ’ s recommen -
dations.
4.
Spray gun: ground through connection to a prop -
erly grounded fluid hose and pump.
5. Fluid supply container: follow your local code.
6. Object being sprayed: follow your local code.
7. Solvent pails used when flushing: follow your local
code. Use only metal pails, which are conductive,
placed on a grounded surface. Do not place the
pail on a nonconductive surface, such as paper or
cardboard, which interrupts the grounding continu -
ity.
8.
T o maintain grounding continuity when flushing or
relieving pressure , hold a metal part of the spray
gun firmly to the side of a grounded metal pail,
then trigger the gun.

 
Setup
Supplied Components
Refer to Fig. 2.
WARNING
A red-handled bleed-type master air valve (35) and
a fluid drain valve (D) are supplied. These accesso -
ries help reduce the risk of serious injury , including
fluid injection and splashing of fluid in the eyes or
on the skin, and injury from moving parts if you are
adjusting or repairing the pump.
The bleed-type master air valve relieves air trapped
between this valve and the pump after the valve is
closed. T rapped air can cause the pump to cycle
unexpectedly . Locate the valve close to the pump.
The fluid drain valve assists in relieving fluid pres -
sure in the displacement pump, hose, and gun.
T riggering the gun to relieve pressure may not be
sufficient.
 The red-handled bleed-type master air valve
(35) is required in your system to relieve air trapped
between it and the air motor when the valve is
closed (see the
WARNING above). Be sure the
bleed valve is easily accessible from the pump, and
is located downstream from the air filter/regulator
(41).

With a wrench, loosen and remove the female air
line coupler (38). Screw it onto the main air hose
(A). Leave the mating coupler (37) attached to the
air filter/regulator (41).
The
air filter/regulator (41) controls pump speed
and outlet pressure by adjusting the air pressure to
the pump. It also removes harmful dirt and mois -
ture from the compressed air supply . Locate close
to the pump, but upstream from the bleed-type
master air valve (35).
The air manifold (47) provides ports for connect -
ing lines to air-powered accessories.
 The air relief valve (48) opens automatically to
prevent overpressurization of the pump.
 The air line lubricator (43) provides automatic air
motor lubrication.
The fluid filter (7) or surge tank includes a 60
mesh (250 micron) stainless steel element to filter
particles from the fluid as it leaves the pump. It
includes the fluid drain valve (D), which is re -
quired in your system to relieve fluid pressure in the
hose and gun (see the WARNING at left).
The suction hose (8) and tube (11) allow the
pump to draw fluid from a 19 liter (5 gallon) pail (E).
Two fluid shutoff valves (9) are supplied at the
fluid filter outlets. Attach the fluid hose (103) to one
of the valves. Keep the other valve capped and
closed at all times unless you are using a second
hose and gun.
Connect the Suction Hose
Apply thread sealant to the suction hose (8) and screw
it into the bushing (5) at the pump’ s fluid intake. Screw
the suction tube (1 1) onto the other end of the hose.
Connect the Fluid Hoses and Gun
NOTE: Models 238–257 and 238–266 include a Hose
and Gun Kit (101), which supplies fluid hoses, a spray
gun, and connecting parts (ref. nos. 102–106). If you
supply your own fluid hoses and gun, be sure they are
properly sized and pressure-rated for your system.
Use only electrically conductive hoses.
1. Connect the main fluid hose (103) to one fluid
shutof f valve (9) at the fluid filter (7) outlet.
2. Screw the coupling or nipple (105) onto the other
end of the main fluid hose (103).
3. Screw the short whip hose (104) onto the coupling
or nipple (105).
4. Screw the whip hose (104) onto the gun swivel
(106).
5.
Screw the gun swivel (106) onto the fluid inlet of
the spray gun (102).
Assemble Models 238–257 and 238–266
1. Assemble the fluid hoses and gun as explained in
the preceding paragraph.
2. Mark the date of assembly on the designation
plate (107) and install the plate as shown on its
separate instruction sheet.

KEY
SUPPLIED WITH ALL MODELS
1 Pump
2 Cart
5
Pump Intake Bushing
7 Fluid Filter (includes drain valve)
(surge tank on Model 238–254)
D Fluid Drain V alve (required)
8 Suction Hose
9 Fluid Shutof f V alves
11
Suction T ube
34
Ground Wire (required; see page 5
for installation instructions)
35 Red-Handled Bleed-T ype Master
Air V alve (required, for pump)
37 Air Line Male Coupler
38 Air Line Female Coupler
41 Pump Air Filter/Regulator
43 Air Line Lubricator
47 Air Manifold
48 Air Relief V alve (partially hidden)
SUPPLIED WITH MODELS 238–257 AND
238–266 ONL Y
102
Airless Spray Gun
103Electrically Conductive Fluid Supply Hose
104Electrically Conductive Fluid Whip Hose
105 Coupling (or Nipple)
106 Gun Swivel
COMPONENTS YOU MUST SUPPL Y
A
Electrically Conductive Air Supply Hose
B Bleed-T ype Master Air V alve
(for accessories)
C Air Line Moisture Trap and Drain V alve
E
Grounded 19 Liter (5 Gallon) Pail
05745
1
2
35
A
B
D
103
104
34
7
106
102
105
8
11
37
38
41
43
47
48
C
E
5
9
Detail of Air Line Connections
Fig. 2
Model 238–257 Shown
1Keep
this valve capped and closed unless
you are using a second hose and gun.
19
35
 
Setup

 
Operation
Pressure Relief Procedure
WARNING
INJECTION HAZARD
The system pressure must be manually
relieved to prevent the system from
starting or spraying accidentally . Fluid
under high pressure can be injected through the
skin and cause serious injury . T o reduce the risk of
an injury from injection, splashing fluid, or moving
parts, follow the Pressure Relief Procedure
whenever you:
 are instructed to relieve the pressure,
 stop spraying,
 check or service any of the system equipment,
 or install or clean the spray tips.
1. Lock the gun trigger safety .
2. Close the red-handled bleed-type master air valve
(35, required in your system).
3. Open the fluid shutof f valve (9).
4. Unlock the gun trigger safety .
5. Hold a metal part of the gun firmly to the side of a
grounded metal pail, and trigger the gun to relieve
pressure.
6.
Lock the gun trigger safety .
7. Open the drain valve (D, required in your system),
having a container ready to catch the drainage.
8. Leave the drain valve open until you are ready to
spray again.
If you suspect that the spray tip or hose is completely
clogged, or that pressure has not been fully relieved
after following the steps above, very slowly loosen the
tip guard retaining nut or hose end coupling and relieve
pressure gradually , then loosen completely . Now clear
the tip or hose.
Packing Nut/Wet-Cup
Before starting, fill the packing nut (F) 1/3 full with
Graco Throat Seal Liquid (TSL) or compatible solvent.
See Fig. 3.
WARNING
T o reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure at left.
The packing nut is torqued at the factory and is ready
for operation. If it becomes loose and there is leaking
from the throat packings, relieve pressure, then
torque the nut to 61–75 N.m (45–55 ft-lb) using the
supplied wrench. Do this whenever necessary . Do not
overtighten the packing nut.
Flush the Pump Before First Use
The pump is tested with lightweight oil, which is left in
to protect the pump parts. If the fluid you are using
may be contaminated by the oil, flush it out with a
compatible solvent. See Flushing on page 10.
Using the Airless Spray Gun
Before operating the equipment, read the instruction
manual supplied with the gun.
Spray some test patterns before doing any finished
work. Refer to the gun manual for detailed information
on correct spraying technique.

 
Operation
CAUTION
T o avoid tip-over , the cart must be on a flat and level
surface. Failure to follow this caution could result in
injury or equipment damage.
Prime the Pump
1. See Fig. 3. Remove the tip guard and spray tip
from the gun (102). See the gun instruction manu -
al.
2.
Close the air filter/regulator (41) and bleed-type air
valves (B, 35).
3. Close the fluid drain valve (D).
4. Engage the air line coupler (38) with the mating
coupler (37) attached to the air filter/regulator (41)
inlet and twist with a wrench to lock.
5. Check that all fittings throughout the system are
tightened securely .
6.
Place the suction tube (1 1) into the fluid supply
container.
7.
Open the fluid shutof f valve (9).
8. Open the bleed-type air valves (B, 35).
9. Hold a metal part of the gun (102) firmly to the side
of a grounded metal pail and hold the trigger open.
10. Slowly open the air filter/regulator (41) until the
pump starts.
11. Cycle the pump slowly until all air is pushed out
and the pump and hoses are fully primed.
12. Release the gun trigger and lock the trigger safety .
The pump should stall against pressure.
13. If the pump fails to prime properly , open the drain
valve (D). Use the drain valve as a priming valve
until the fluid flows from the valve. Close the valve.
NOTE: When changing fluid containers with the hose
and gun already primed, open the drain valve (D) to
help prime the pump and vent air before it enters the
hose. Close the drain valve when all air is eliminated.
Set the Air and Fluid Pressure
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 8.
1. Relieve the pressure. Install the tip guard and
spray tip in the gun, as explained in the gun manu -
al.
2.
Open the air filter/regulator (41) slowly . Use the
regulator to control pump speed and fluid pres -
sure. Always use the lowest air pressure neces -
sary to get the desired results. Higher pressures
cause premature tip and pump wear .
NOTE: T
o open the air filter/regulator , turn the
T -handle in (clockwise). T o close the regulator , turn the
handle counterclockwise. T o lock the regulator setting,
tighten the jam nut.
WARNING
COMPONENT RUPTURE HAZARD
T o reduce the risk of overpressurizing
your system, which could cause compo -
nent rupture and serious injury , never
exceed the specified Maximum Incoming Air Pres -
sure to the pump (see the T echnical Data, on
page 17).
3. With the pump and lines primed, and with ade -
quate air pressure and volume supplied, the pump
will start and stop as you open and close the gun.
CAUTION
Do not allow the pump to run dry . It will quickly
accelerate to a high speed, causing damage. If your
pump is running too fast, stop it immediately and
check the fluid supply . If the container is empty and
air has been pumped into the lines, refill the con -
tainer and prime the pump and the lines, or flush and
leave it filled with a compatible solvent. Eliminate all
air from the fluid system.

10 308-628
Operation
Shutdown and Care of the Pump
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 8.
For overnight shutdown, stop the pump at the bottom
of its stroke to prevent fluid from drying on the ex -
posed displacement rod and damaging the throat
packings. Relieve the pressure.
Always flush the pump before the fluid dries on the
displacement rod. See Flushing below .
Flushing
WARNING
FIRE AND EXPLOSION HAZARD
Before flushing, read the section FIRE
OR EXPLOSION HAZARD on page 4.
Be sure the entire system and flushing
pails are properly grounded. Refer to
Grounding on page 5.
Flush the pump:
 Before the first use
 When changing colors or fluids
 Before fluid can dry or settle out in a dormant pump
(check the pot life of catalyzed fluids)
 Before storing the pump.
Flush with a fluid that is compatible with the fluid you
are pumping and with the wetted parts in your system.
Check with your fluid manufacturer or supplier for
recommended flushing fluids and flushing frequency .
CAUTION
Never leave water or water-base fluid in the pump
overnight. If you are pumping water-base fluid, flush
with water first, then with a rust inhibitor such as
mineral spirits. Relieve the pressure, but leave the
rust inhibitor in the pump to protect the parts from
corrosion.
WARNING
T o reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 8.
1. Relieve the pressure.
2. Remove the tip guard and spray tip from the gun.
See the gun instruction manual.
3. Remove the filter element from the fluid filter (7) or
surge tank. Reinstall the filter or surge tank bowl.
4. Place the suction tube (1 1) in a container of sol -
vent.
5.
Hold a metal part of the gun firmly to the side of a
grounded metal pail.
6. Start the pump. Always use the lowest possible
fluid pressure when flushing.
7. T rigger the gun.
8. Flush the system until clear solvent flows from the
gun.
9.
Relieve the pressure.
10. Clean the tip guard, spray tip, and fluid filter ele -
ment separately , then reinstall them.
11. Clean the inside and outside of the suction tube
(11).