Donaldson Torit DFO 2-4 User manual

Model DFO 2-4 Model DFO 3-6
Installation
and Operation Manual
IOM 9603801
Revision 8
Downflo®Oval
DFO 2-4 and DFO 3-6
Throughout this manual
statements indicating
precautions necessary
to avoid equipment failure are
referenced in a Note. Statements
indicating potential hazards that
could result in personal injury or
property damage are referenced
in a Caution! box.
Installation,
Operation, and
Service Information
This manual is property of the owner. Leave with the unit when setup and
start-up are complete. Donaldson Company reserves the right to change design
and specifications without prior notice.
Patent Numbers:
6,387,162 6,090,173
6,488,746 5,562,746
6,364,921 6,368,388
Other Patents Pending

Donaldson Company, Inc.
2
CAUTION!
Application of Dust Control Equipment
• Combustible materials such as buffing lint, paper, wood, aluminum or steel dust, weld
fume, or flammable solvents represent fire or explosion hazards. Use special care when
selecting and operating all dust or fume collection equipment when combustible
materials are present to protect workers and property from damage due to fire and/or
explosion. Consult and comply with National and Local Codes relating to fire or
explosion and all other appropriate codes when determining the location and operation
of dust or fume collection equipment.
• When combustible materials are present, consult with an installer of fire extinguishing
systems familiar with these types of fire hazards and local fire codes for
recommendations and installation of fire extinguishing and explosion protection
systems. Donaldson Torit dust collection equipment is not equipped with fire
extinguishing or explosion protection systems.
• DO NOT allow sparks, cigarettes or other burning objects to enter the hood or duct of
any dust or fume control equipment as these may initiate a fire or explosion.
• For optimum collector performance, use only Donaldson Torit replacement parts.
Warning – Improper operation of a dust control system may contribute to conditions in the work
area or facility that could result in severe personal injury and product or property damage. Check
that all collection equipment is properly selected and sized for the intended use.

Downflo Oval, Model DFO 2-4 and DFO 3-6
3
Contents
Description ........................................................... 4
Purpose and Intended Use..................................... 4
Rating and Specification Information ................... 5
Operation ............................................................. 6
Inspection on Arrival ............................................ 7
Installation Codes and Procedures ........................ 7
Installation ........................................................... 7
Site Selection, Grade-Mounted Units .............. 7
Unit Location.................................................. 7
Electrical Wiring ................................................... 8
Rigging Instructions.............................................. 8
Hoisting Information ...................................... 8
Typical Installation ............................................... 9
Standard Equipment ........................................... 10
Hopper Assembly ......................................... 10
Leg Assembly ................................................ 11
Compressed Air Installation ......................... 12
Solid-State Timer Installation ............................. 14
Solenoid Connection ................................ 15
Timer and Solenoid Specifications ............ 15
Preliminary Start-Up Check ................................ 16
Service Information ............................................ 16
Operational Checklist ................................... 16
Filter Installation and Replacement .............. 18
Filter Removal .............................................. 18
Filter Replacement ........................................ 18
Dust Disposal ............................................... 18
Compressed Air Components ....................... 18
Optional Equipment ........................................... 20
Power Pack ................................................... 20
Side-Mount Power Pack ............................... 22
55-Gallon Drum Pack ................................... 23
5-Gallon Pail Pack ........................................ 24
Magnehelic®Gauge ...................................... 26
Photohelic®Gauge ........................................ 28
Delta P Control............................................. 30
Delta P Plus Control ..................................... 31
Damper Installation ...................................... 32
Exhaust Grid Installation .............................. 32
Plenum Silencer............................................. 33
Exhaust Silencer ........................................... 33
HEPA or ASHRAE Afterfilter Installation .... 34
Abrasion-Resistant Inlet Collar..................... 35
Cold Climate Kit........................................... 36
Explosion Vents ............................................ 37
Sprinkler Installation .................................... 37
Troubleshooting ................................................. 38
Service Notes ...................................................... 42
Warranty ............................................................ 44
This manual contains specific precautionary statements relative to worker safety. Read
thoroughly and comply as directed. Discuss the use and application of this equipment with a
Donaldson Torit representative. Instruct all personnel on safe use and maintenance
procedures.
Magnehelic®and Photohelic®are registered trademarks of Dwyer
Instruments, Inc.
Data Sheet
Model Number _______________________________ Serial Number ________________________________
Ship Date ____________________________________ Installation Date ______________________________
Customer Name ____________________________________________________________________________
Address ____________________________________________________________________________
____________________________________________________________________________
Filter Type ____________________________________________________________________________
Accessories ____________________________________________________________________________
Other ____________________________________________________________________________

Donaldson Company, Inc.
4
Description
The Downflo Oval, Models DFO 2-4 and DFO 3-6
are continuous-duty dust collectors with oval,
cartridge-style filters. The downward airflow design
delivers high filtration efficiency while using less
energy. Continuous-duty means no downtime. The
filters are pulse-cleaned in sequence, one set
at a time, without turning the unit off. Model DFO
2-4 is two filters wide by two filters high by one
filter deep and Model DFO 3-6 is two filters wide by
three filters high by one filter deep.
Designed to increase the versatility of the unit,
standard options include top, front, and abrasion-
resistant inlets, HEPA and ASHRAE afterfilter
packs, Checker board control panel, and various
dust removal options.
Purpose and Intended Use
Downflo Oval collectors are widely used on
nuisance dust where the load to the collector is less
than 2 grains per cubic foot. Some typical
applications include abrasive blasting, grinding,
pharmaceuticals, powder paint applications, sand
handling, and welding. Each application is different
and selecting the correct filter cartridge for the
application and type of dust collected is important.
• For all ambient, extremely fine, and non-fibrous
dust, use Ultra Web®filter cartridges which offer
high efficiency and performance on fine
particulate.
• For fibrous dust, use a cartridge with an open-
pleat design, such as Fibra-Web®.
• Operations involving high temperature and high
humidity may require special attention.
Temperature, moisture content, and chemistry
issues may require custom collector design.
Appropriate cartridge options are available from
Donaldson Torit.
• Hygroscopic dust such as fertilizer, salt, and
sugar should be handled under a controlled, low
humidity environment. Contact Donaldson Torit
for filter cartridge selection.
• Flammable or explosive dust may require
custom collector design options and special
cartridges. Contact Donaldson Torit for design
assistance.
• Applications with high hydrocarbon or high oil
content may require special treatment or filter
media.
CAUTION!
• Misuse or modification of this
equipment may result in personal injury.
• Do not misuse or modify.

Downflo Oval, Model DFO 2-4 and DFO 3-6
5
Rating and Specification Information
All Units (per IBC 2003 Specifications):
Wind........................................ 90 MPH Exposure C
Seismic Spectral Acceleration, Ss.................................... 1.5 g
Seismic Spectral Acceleration, S1....................................... 0.6 g
Importance Factor, 1............................................ 1.0
Ground Snow Load ............................... Pg = 40 PSF
Compressed air, maximum psig ........................... 60
Housing rating, inches water gauge .................. +-20
Power, valves and controls ..........120-Volt 50/60 Hz
DFO 2-4 DFO 3-6 Side View
DFO 2-4 and DFO 3-6

Donaldson Company, Inc.
6
Operation
During normal operation, dust-laden air enters the
unit through the dirty-air inlet. Airflow is directed
downward through the collector and heavier
particulate falls directly into the hopper. The
cartridges remove fine particulate and clean, filtered
air passes through the cartridge to the clean-air
plenum and discharges through the clean-air outlet.
Filter cleaning is completed using pulse-jet
technology. A solenoid and air diaphragm valve
aligned to each filter provides the pulse cleaning.
The cleaning sequence starts at the top filter and
continues down through each filter. Remove,
inspect, or change the filter cartridges from outside
the unit by removing the filter access cover and
sliding the filter out.
Unit Operation
CAUTION!
• Combustible materials such as buffing
lint, paper, wood, aluminum or steel
dust, weld fume, and flammable
solvents represent fire or explosion
hazards.
• Use special care when selecting and
operating all collection equipment
when combustible materials are
present to protect workers and
property from damage due to fire
and/or explosion.
• Consult and comply with all National and Local
Codes relating to fire or explosion, and all other
appropriate codes when determining the location
and operation of dust collection equipment.
• Donaldson Torit equipment is not equipped with
fire extinguishing or explosion protection
systems.
filter
cleaning
system
diaphragm
valve
compressed-air
supply
hopper
Filter Cleaning Operation
dirty-air
inlet
clean-air
outlet
clean-air
outlet
filter cartridges
clean-air
plenum
Normal Operation
dirty-air
inlet
optional
clean-air
outlet
optional
clean-air
outlet

Downflo Oval, Model DFO 2-4 and DFO 3-6
7
Inspection on Arrival
1. Inspect unit on delivery.
2. Report any damage to the delivery carrier.
3. Request a written inspection report from the
Claims Inspector to substantiate claim.
4. File claims with the delivery carrier.
5. Compare unit received with description of
product ordered.
6. Report incomplete shipments to the delivery
carrier and your Donaldson Torit representative.
7. Remove crates and shipping straps. Remove
loose components and accessory packages before
lifting unit from truck.
Installation Codes and Procedures
1. Safe and efficient operation of the unit depends
on proper installation.
2. Authorities with jurisdiction should be consulted
before installing to verify local codes and
installation procedures. In the absence of such
codes, install unit according to the National
Electric Code, NFPA No. 70-latest edition.
3. A qualified installation and service agent must
complete installation and service of this
equipment.
4. All shipping materials, including shipping covers,
must be removed from the unit prior to, or
during unit installation.
Note: Failure to remove shipping materials
from the unit will compromise unit
performance.
CAUTION!
OSHA may have requirements regarding
recirculating filtered air in your facility.
Consult with the appropriate local
authorities to ensure compliance with all
codes regarding recirculating filtered air.
Installation
Site Selection, Grade-Mounted Units
1. The unit can be located on a reinforced concrete
foundation or rooftop.
2. Wind, seismic zone, and other live-load
conditions must be considered when selecting
the location for rooftop-mounted units.
Reference the Rating and Specification
Information.
3. Provide clearance from heat sources and
interference with utilities when selecting the
location for suspended units. Reference the
Rating and Specification Information.
4. Portable units require no special installation
accommodations.
Unit Location
1. When hazardous conditions or materials are
present, consult with local authorities for the
proper location of the collector.
2. Foundation or roof support must be capable of
supporting the entire weight of the unit, plus the
weight of the collected material, piping, and
ductwork.
3. Prepare the foundation in the selected location.
Install anchor bolts to extend a minimum of
1 3/4-inches above foundation.
4. Locate the collector to ensure the shortest and
straightest inlet- and outlet-duct length, easy
access to electrical and compressed-air
connections, and routine maintenance.
CAUTION!
Donaldson Torit equipment is not
designed to support site-installed ducts,
interconnecting piping, or electrical
services. All ducts, piping, or electrical
services supplied by others must be
adequately supported to prevent severe
personal injury and/or property damage.

Donaldson Company, Inc.
8
Electrical Wiring Rigging Instructions
Suggested Tools & Equipment
Clevis Pins and Clamps Lifting Slings
Crane or Forklift Pipe Sealant
Drift Pins Pipe Wrenches
Drill and Drill Bits Screwdrivers
End Wrenches Socket Wrenches
Large Crescent Wrench Spreader Bars
Hoisting Information
1. Use all lifting points provided.
2. Use clevis connectors, not hooks, on lifting
slings.
3. Use spreader bars to prevent damage to unit’s
casing.
4. Check the Specification Control drawing for
weight and dimensions of the unit,
subassemblies, and components to ensure
adequate crane capacity.
5. Allow only qualified crane operators to lift the
equipment.
6. Refer to applicable OSHA regulations and local
codes when using cranes, forklifts, and other
lifting equipment.
7. Lift unit and accessories separately, and
assemble after unit is in place.
8. Use drift pins to align holes in section flanges
during assembly.
CAUTION!
• Electrical installation must be
performed by a qualified electrician
and comply with all applicable
national and local codes.
• Lock out electrical power sources
before performing service or
maintenance work.
• Do not install in classified hazardous
atmospheres without an enclosure
rated for the application.
CAUTION!
• Failure to lift the collector correctly
can result in severe personal injury or
property damage.
• Use appropriate lifting equipment and
adopt all safety precautions needed for
moving and handling the equipment.
• A crane or forklift is recommended for
unloading, assembly, and installation
of the collector.
• Location must be clear of all
obstructions, such as utility lines or
roof overhang.
1. All electrical wiring and connections, including
electrical grounding, should be made in
accordance with the National Electric Code,
NFPA No. 70-latest edition.
2. Check local ordinances for additional
requirements that apply.
3. The appropriate wiring schematic and electrical
rating must be used. See unit’s rating plate for
required voltage.
4. If the unit is not furnished with a factory-
mounted disconnect, an electric disconnect
switch having adequate amp capacity shall be
installed in accordance with Part J, Article 430
of the National Electrical Code, NFPA No. 70-
latest edition. Check unit’s rating plate for
voltage and amperage ratings.
5. Refer to the wiring diagram for the number of
wires required for main power wiring and
remote wiring.

Downflo Oval, Model DFO 2-4 and DFO 3-6
9
Typical Installation
1. Lift cabinet.
2. Apply sealant to hopper flange.
3. Fasten hopper to cabinet.
4. Assemble legs and cross braces.
5. Lift unit and hopper into position
over legs and lower slowly.
6. Fasten legs to unit securely.
7. Lift assembled unit to location.
8. Support and level unit.
9. Tighten all fasteners.
10. Remove crane.
Do Not lift with
this orientation
angle not to
exceed 30°
from vertical
(min 60°
from horizontal)

Donaldson Company, Inc.
10
Standard Equipment
Standard equipment consists of a collector cabinet,
hopper, and legs. Basic assembly starts by attaching
the hopper to the cabinet, then attaching the legs. A
detailed instruction drawing, shipped with each
collector, provides specific assembly and lifting
instructions.
CAUTION!
• Failure to lift the collector correctly can
result in severe personal injury or
property damage.
• Use appropriate lifting equipment and
adopt all safety precautions needed for
moving and handling the equipment.
Hopper Assembly
Assemble the standard or the optional steep-sided
hopper following these instructions.
1. Stand the hopper on the discharge end.
2. Apply 1/4-in diameter rope-type sealant around
the top flange toward the inside edge
of the bolt pattern.
3. Lift the collector and position over the hopper
and lower slowly.
4. Use drift pins to align holes.
5. Secure collector to hopper using
3/8-16 x 1 1/4-in bolts, flat washers, and nuts.
Tighten all hardware securely. See Hopper
Installation below.
Hopper Installation
Note: Support or block unit to prevent
personal injury or property damage.
hopper
3/8-16 x 1 1/4-in bolt
3/8-in flat washer
3/8-in flat washer
3/8-in lock washer
3/8-16 hex nut
1/4-in rope-type sealant

Downflo Oval, Model DFO 2-4 and DFO 3-6
11
Leg Assembly
Leg sets are designed for standard height collectors
and are rated as shown in the Rating and
Specification Information. Reference the drawing
shown below and the leg assembly drawing shipped
with the leg set for proper location and assembly.
1. Position and assemble legs and cross braces as
shown in Leg and Cross Brace Assembly.
2. Lift the cabinet and hopper assembly into
position over the legs and lower slowly.
3. Use drift pins to align the holes in the collector
with the holes in the legs. Attach each leg as
shown using the hardware supplied.
Do not tighten hardware at this time.
Tighten all leg and cross brace hardware
before removing crane.
CAUTION
4. Recheck the position of the leg sets and cross
braces.
5. Using a crane, lift the assembled unit onto the
anchor bolts. Fasten each leg pad to the anchor
bolts using flat washers, lock washers, and hex
nuts provided by others. Do not tighten
hardware at this time.
6. Level unit. Tighten all hardware on legs, cross
braces, and foundation anchors.
Leg and Cross Brace Assembly
All Leg Bolt Details:
Hex Bolt
flat washer
lock washer
hex nut

Donaldson Company, Inc.
12
Compressed Air Installation
CAUTION!
• The compressed-air supply must be oil
and moisture free. Contamination in
the compressed air used to clean filters
will result in poor cleaning, cleaning
valve failure or poor collector
performance.
• Purge compressed-air lines to remove
debris before connecting to the unit’s
compressed-air manifold.
• Turn compressed-air supply OFF and
bleed lines before performing service
or maintenance work.
Manifold
CAUTION!
• 60-psig maximum operating pressure.
• Air regulator required.
Manifold
Note: 60-psig maximum supply pressure
pipe cap
manifold
diaphragm
valve
manifold
solenoid
valve
enclosure
Units Built Before November 2006
1. Remove the 1-in pipe cap from one of the unit’s
two air manifolds and connect the compressed-
air supply line. Use thread-sealing tape or pipe
sealant on all compressed-air connections.
2. Install a customer-supplied shut-off valve, bleed-
type regulator with gauge, filter, and automatic
condensate valve in the compressed-air supply
line.
Note: All compressed-air components must be
sized to meet the maximum system
requirements of 0.86 cu ft/pulse at 60-psi
supply pressure.
Do not increase supply pressure above
60-psi. Component damage can result.
manifold
solenoid
valve
enclosure
pipe cap
diaphragm
valve
Note: 60-psig maximum supply pressure
Units Built After November 2006

Downflo Oval, Model DFO 2-4 and DFO 3-6
13
Compressed-Air and Component Installation
compressed-air
supply line*
automatic
condensate
valve*
bleed-type
air filter*
regulator*
air supply
to manifold*
solenoid
electrical
connection*
manifold
solenoid
enclosure
diaphragm valve
hopper
blower fan
Magnehelic
gauge*
120-Volt blower
motor starter*
solid-state
timer
shut-off
valve*
Notes: 1. * Not included with standard unit.
2. Sprinkler taps not shown.
power supply
disconnect
switch*

Donaldson Company, Inc.
14
The solid-state timer requires a 105 to
135-Volt, customer-supplied power
supply.
CAUTION!
Solid-State Timer Wiring Diagram
Fan Starter Control Box
Disconnect
1FU
2FU
3FU
208-230V
60 Hz/3Ph
IL1
IL2
IL3
1M 1OL 1T1
1T2
1T3
230V
115V
H1 H2
H3 H4
X1 X2
stop
star
1M
1M
1TGS
fan
motor
OFF time ON time
program
pins program lug
pressure
switch
timing
logic
power
supply control
logic
4FU, 3A
105 to 135 V
50-60 Hz
solenoid
valves
L1 L2
COM
12
L1
L2
L3
Disconnect, fuses, low voltage blower starter, and 1TGS switch are customer-supplied.
Wiring by others
Wiring by factory
Solid-State Timer Installation
The solid-state timer is an electronic timer used to
control the filter cleaning system.
Note: Do not mount the solid-state timer on the
unit. Mechanical vibration can damage the
control.
1. Using the wiring diagram supplied, wire the
blower motor, blower-motor starter, solid-state
timer, and solenoid valves. Use appropriate wire
gauge for rated amp load as specified by local
codes.
2. Plug the program lug into the pin that
corresponds with the number of solenoid valves
controlled.
3. With power supply ON, check the operation of
the solenoid valves. The valves should open and
close sequentially at factory set 10-second
intervals.
4. If a Photohelic gauge or similar device is used to
control the solid-state timer and the jumper on
the pressure switch portion of the timer is
removed, the solenoid valves pulse only when
the differential pressure reaches the high-
pressure setpoint. The valves continue to pulse
until the low-pressure setpoint is reached.

Downflo Oval, Model DFO 2-4 and DFO 3-6
15
Do not set compressed-air pressure above
60-psig. Component damage will occur.
CAUTION!
Solenoid Connection
The unit is equipped with 115-Volt solenoid valves
that control the pulse-cleaning valves, which clean
the filters.
One of three types of solenoid enclosures, the
weatherproof NEMA 4 with 1/8-in solenoid valves;
the gas-explosion proof NEMA 7 with 1/8-in
solenoid valves; or the dust-explosion proof NEMA 9
with 1/8-in solenoid valves, is mounted near or on
the unit’s compressed-air manifold.
Wire the solenoids to the solid-state timer following
the wiring diagram supplied with the unit. Filter life
and cleaning operation will be affected if not wired
correctly.
Timer and Solenoid Specifications
Power to the solid-state timer is supplied to
Terminals L1 and L2, which operate in parallel with
the blower starter’s low-voltage coil. On blower
start-up, power is supplied to the timer and the
preset OFF time is initiated. At the end of the OFF
time, the timer energizes the corresponding solenoid
valve to provide the ON time cleaning pulse for one
diaphragm valve and then steps to the next until all
filters have been cleaned.
To pulse when the blower is OFF, install a toggle
switch as shown on the Solid-State Timer Wiring
Diagram. When the toggle switch is ON, the timer
receives power and energizes the solenoid valves’
pulse-cleaning operation even though the blower is
turned OFF.
Input
105-135V/50-60Hz/1Ph
Output Solenoids
The load is carried and turned ON and OFF by the
200 watt maximum-load-per-output solid-state
switch.
Pulse ON Time
Factory set at 100-milliseconds, or 1/10-second.
Note: Do not adjust pulse ON time unless the
proper test equipment is available. Too much
or too little ON time can cause shortened
filter life.
Solenoid Valves
115-Volt at 19.7 watts each
Compressed-Air
Set compressed-air supply at 60-psig. The timer is
factory set to clean one filter or set of filters every
10-seconds.

Donaldson Company, Inc.
16
Preliminary Start-Up Check
1. Check all electrical connections for tightness and
contact.
2. Check for and remove all loose items in or near
the inlet and outlet of the unit.
3. Check that all remote controls are wired into the
control system and all service switches are in the
OFF position.
4. Check that all optional accessories are installed
properly and secured.
5. Check that hopper discharge is open and the
storage container is sealed, if equipped.
6. Turn power ON at source.
7. Turn the compressed-air supply ON. Adjust
pressure regulator for 60-psi.
8. Turn the fan motor ON then OFF to check for
proper rotation by referencing the rotation arrow
located on the motor’s mounting plate.
To reverse rotation, single-phase power supply:
Follow manufacturer’s instructions on the
motor’s nameplate.
To reverse rotation, three-phase power supply:
Turn electrical power OFF at source and switch
any two leads on the output-side of the fan-
motor starter.
9. Adjust the blower/fan for proper airflow by
adjusting the volume control damper on the
blower/fan discharge, if equipped.
Note: Excess airflow can shorten filter life, cause
electrical system failure, and blower motor
failure.
Service Information
Operational Checklist
1. Monitor overall performance of the collector.
2. Monitor exhaust.
3. Monitor pressure drop across filters.
4. Monitor dust disposal.

Downflo Oval, Model DFO 2-4 and DFO 3-6
17
This Page Intentionally Left Blank

Donaldson Company, Inc.
18
Filter Installation and Replacement
CAUTION!
• Use proper safety and protective
equipment when removing
contaminants and filters.
• Dirty filters may be heavier than they
appear.
• Use care when removing filters to avoid
personal injury.
• Do not drop filters.
Filter Removal
1. Turn power to unit OFF.
2. Start at the top access port.
3. Remove access cover. For units without Bag-In/
Bag-Out: remove access cover by lifting latch
handle and lifting cover to remove from yoke.
For units with Bag-In/Bag-Out: lift up access
cover handle and while pushing in on cover,
slide access cover to the side 1-inch to remove
access cover.
If the access cover clamp fails to operate
smoothly, apply WD-40®to the riveted pivot
points and to the clamp rod where it passes
through the outside of the cover. Wipe off
overspray.
4. Break the seal between the filter cartridge and
the sealing surface.
5. Slide the filter out the access port along the
suspension yoke and dispose of properly.
6. Clean the sealing surface with damp cloth.
Note: Clean dust from gasket sealing area to
ensure a positive filter gasket seal.
7. Check for an accumulation of dust in the storage
area and empty as necessary.
Filter Replacement
Note: Place filter part number label (supplied
with each replacement filter) over the
filter part number listed on the unit's
rating plate.
1. Slide the new filter cartridges onto each
suspension yoke.
Note: Insert the filter gasket end first.
2. Wipe cover gaskets clean and replace covers by
attaching cover to yoke hook and firmly latching
cover handle.
Note: Check that access covers are seated and
seal properly. Gaskets must be
compressed to ensure an airtight seal.
3. Turn electrical power and compressed air supply
ON before starting unit.
Dust Disposal
1. Turn unit OFF and empty dust container as
necessary to minimize dust in the hopper.
2. If the optional 55-gallon drum attachment is
used, empty when drum is 2/3 full.
3. If optional slide gate is used, close gate before
servicing drum.
4. Reinstall drum and open gate (if applicable).
Compressed Air Components
1. Periodically check the compressed air
components and replace compressed-air filter.
2. Drain moisture following the manufacturer’s
instructions.
3. With the compressed-air supply ON, check the
cleaning valves, solenoid valves, and tubing for
leaks. Replace as necessary.
CAUTION!
• The compressed-air supply must be oil
and moisture free. Contamination in
the compressed air used to clean filters
will result in poor cleaning, cleaning
valve failure or poor collector
performance.
• Purge compressed-air lines to remove
debris before connecting to the unit’s
compressed-air manifold.
• Turn compressed-air supply OFF and
bleed lines before performing service
or maintenance work.
WD-40®is a registered trademark of WD-40 Company.

Downflo Oval, Model DFO 2-4 and DFO 3-6
19
Filter Replacement
yoke
filter cartridge
access cover
cover handle
Optional and Bag-In/Bag-Out Filter Access Cover Removal (Top View)
Filter Access Cover
Removal (Side View)
latched unlatched removal
access
cover
yoke
latched
unlatched
yoke
access cover
hook
access
cover
Front of DFO
removal

Donaldson Company, Inc.
20
Optional Equipment
Power Pack
Radial Blade
The 3 through 10 horsepower power packs are
designed to fit on top or side of the unit.
1. The power packs are shipped assembled and
partial disassembly is required before installing.
2. Remove the blower housing fasteners and split
the blower halves. The motor side contains the
motor, half of the blower housing, and the
blower wheel. The inlet side consists of the inlet
half of the blower housing.
3. Mount the inlet side of the blower housing to
the collector using the supplied bolts, washers,
and nuts.
Note: For side mount blowers, install the bolt-
on adapter plate between the collector
and the inlet side of the blower assembly.
4. Apply sealant around the blower housing flange
and reassemble housing sections.
5. Rotate blower wheel manually to check
clearance.
6. Position the optional exhaust grid over the
power pack outlet, if equipped.
Note: See Damper Installation if an optional
damper control is used.
Backward Inclined
The 3 through 10 horsepower power packs are
designed to fit on top or side of the unit.
1. The power packs are shipped assembled and
partial disassembly is required before installing.
2. Remove eight motor-mount bracket fasteners
and remove the motor, motor-mount bracket,
and blower wheel as an assembly as shown.
3. Turn housing over and apply sealant toward the
outside edge of the bolt pattern on the blower
housing. Mount the blower housing to the
collector using the inlet cone fasteners.
Note: For a top-mounted TBI, install a spacer
ring between the fan housing and the
collector to provide the necessary
clearance for the damper installation.
For top-mount TBI with explosion vent,
install the spacer spool between the
blower housing and the collector to
provid e the necessary clearance for
explosion vent and weather dome.
Position of the blower fan housing should
not restrict explosion vent opening.
4. Apply sealant to the outside edge of the bolt
pattern on the blower housing. Reinstall the
motor, bracket, and blower wheel assembly.
Align the tab on the blower housing with the
slot in the motor-mount bracket.
5. Rotate blower wheel after installation to ensure
proper clearance between the inlet cone and the
blower wheel.
6. Position the optional exhaust grid over the
power pack outlet, if equipped.
Note: See Damper Installation if an optional
damper control is used.
CAUTION!
BEFORE INITIAL OPERATION:
• Tighten all set screws in fan wheel.*
• Tighten all set screws in bearings.*
• Repeat after 8 hours of operation.
• Repeat again after two weeks of
operation.
Reference Wheel Setscrew Torque Table
in the Side-Mount Power Pack section.