The CUNO DuoFLO filter system is an advanced proven alternative to the use of standard bag filters. Developed
using CUNO's extensive depth filtration experience, the DuoFLO filter features a true graded-porosity media
structure and a 62 % increase in filter surface area. Compared to conventional felt filter bags, DuoFLO filters
provide:
up to 4 times or more the service life
+
superior contaminant removal efficiency
+
enhanced flow per filter element
+
reduced loses associated with frequent filter change-outs (production
+
downtime, disposal, and labor costs)
The DuoFLO filter will easily retrofit most existing bag filter housings. To
take advantage of the DuoFLO system in applications where bag filter
housings are currently in use, simply remove the existing bag support
basket, replace it with a DuoFLO support basket, and insert the DuoFLO
filter. For new installations, CUNO offers a full line of DuoFLO filter
housings (page 5).
The DuoFLO element is comprised of two cylinders bonded to a top plate and a
lower seal plate. As shown in Figure 1, the fluid enters the top of the filter
through flow channels located in the DuoFLO filter top plate. The fluid flows
between the inner and outer media cylinders, and then passes through the media
and support basket into the clean chamber of the filter housing.
Top P lat e
Flow Channels
The DuoFLO design incorporates an innovative new geometry of both filter
element and restrainer basket which provides 100% 3 dimensional support of
the DuoFLO media. This eliminates the potential for filter element rupture and
the resulting gross contamination of the downstream effluent with previously
Inner Media
Cylinder
Outer Media
Cylinder
removed particles. The design of the DuoFLO element also reduces filter
element hold-up fluid volume by 67% compared to conventional bags,
minimizing worker exposure to process fluids.
+
Filter design combining a
graded-porosity media with 62%
greater filter surface area
+
Hold-up volume reduced by
67% compared to conventional
bag filters.
+
100%, downstream support of
the filter element
+
Superior flow characteristics
+
Longer Service Life – up to 4 times or more that of conventional felt filter bags
Increased productivity - less down time for filter change-out
+
Reduced product loss & related disposal costs
+
Used element retains less fluid, making it lighter weight for easier removal
+
Eliminates displacement balloons and associated spillage during change-out
+
Eliminates filter rupture, contaminant bypass and unloading
+
Allows operation to higher differential pressures before filter change-out
+
Maximizes utilization of filter surface area and maintains low operating pressure drop
+
Reduces flow per unit area (flux) for improved effluent quality
Lower Seal
Plate
CUNO utilizes state-of-the-art technology to produce the DuoFLO filter element optimizing both performance and
filtrate quality to ensure customer satisfaction. DuoFLO filter elements are sized to replace conventional # 1and # 2
bag filters and are available in both polypropylene and polyester materials (including 21 CFR listed materials) with
nominal ratings from 1 to 200 micron.
1
Page 3
The DuoFLO filter design provides an increase in filter
surface area of 62% when compared to commonly used
#1 and #2 bag filters. This additional surface area
provides the following benefits
Lower flux (flow rate per unit area): Since filter
+
life is inversely proportional to flux, reducing the
flux by 50% can achieve up to a three-fold
increase in filter life. Additionally, lower flux
improves the retention efficiency of the element.
Lower initial pressure drop: This increases the
+
time before the recommended change-out
pressure is reached
DuoFLO filters are offered in a graded porosity filter
media where two media layers of different porosities are
combined. The result is superior contaminant holding
capacity. The added capacity is achieved by removing
the larger contaminants in the first layer and the finer
contaminants in the tighter, downstream layer (see
Figure 2). The configurations of each nominally rated
filter media have been optimized to achieve the longest
service life. Media Migration is eliminated by thermally
bonding the exterior surface of the downstream media
layer.
Extensive testing, supported by field results,
has demonstrated the superior life advantage
achieved by DuoFLO elements while obtaining
superior efficiencies. As shown in Graph 1,
DuoFLO elements provide for up to 4 times the
throughput compared to equivalently rated
conventional bag filters (the life of the filters
were measured to the same terminal differential
pressure).
100
75
50
25
Throughput (Percent)
0
1 micron5 micron10 micron25 micron
CUNO DuoFLO Elements
Competitor F
* Polypropylene media
22
Competitor FEX
Competitor H
Competitor HEX
Page 4
®
DuoFLOFilter Elements
Simple Filter Removal - Simply
insert the CUNO removal tool
into the top plate and lift the
filter from the housing.
Easy Filter Installation -.The
DuoFLO filter element is a rigid
cylinder that easily slides into
the support basket
Graded Porosity Media DuoFLO media consists of
2 layers. The first layer or
upstream zone is “open” to
remove the larger contaminant
while the downstream zone is
“tighter” to remove the smaller
contaminant. This design
provides greater contaminant
holding capacity and longer life
than conventional single layer
media.
Reduced Hold-Up Volume A 67% reduction in hold-up
volume significantly decreases
lost product and disposal costs.
Superior Sealing Collar Constructed from molded
polypropylene or polyester
with an advanced sealing
lip that provides a dynamic
spring-like seal, the DuoFLO
design eliminates
contaminant bypass.
Size Hold-Up Volume (gallons)
#2DuoFLO1.4
#2Standard bag
Support Basket - Full Support
of the filter element ensures
filter integrity even under the
most demanding conditions by
eliminating the potential for
media stretching which can
open the pore structure and
allow larger particles to pass.
4.3
Increased Surface Area -The
unique design provides 62%
more area than typical bag filters
for longer life and fewer filter
change-outs.
SizeFilter Area(ft )
#2DuoFLO6.7
#2Standard Bags 4.1
Singed Media Surface - Many
filter bags release fibers that end
up in the filtered product. The
DuoFLO filter media is thermally
treated to eliminate loose fibers.
2
The unique DuoFLO element design - 62% greater area and a unique
graded-porosity media structure - provides a service life advantage of up to
4 times greater than conventional filter bags. Other features
media treatment, thermal seaming, ultrasonic bonding
ensure that the
DuoFLO filter is unsurpassed in quality and performance.
Thermal Side Seam - Using
advanced thermal sealing
processes, the DuoFLO seam
eliminates the problem of
contaminants passing through
large needle holes.
Integral Media to Plate Seal an integral seal between the
plastic components and the
filter media is ensured by using
state-of-the-art ultrasonic welding
techniques.
(sealing collar
of plastic parts to media)
Page 5
Each grade of DuoFLO filter is manufactured from high
)
(
performance fibers selected based on extensive media
performance testing. No adhesives, binders, or silicone
are used in the manufacturing process. The DuoFLO
filter element is available in all-polypropylene,
all-polyester, or polyester media with polypropylene
lower seal and top plate construction.
DuoFLO elements are available in sizes and ratings to
replace standard #1 and #2 filter bags as follows:
Nominal Removal Ratings (microns)1, 5, 10, 25, 50, 100, and 200*
Filter Diameter (inches/cm)7 / 17.8
Filter Length (inches/cm)14.3 / 36.327.8 / 70.6
Media Area (ft
Hold Up Volume per Filter
(Gallons/Liters)
* available in polyester only
Maximum Operating
Temperature (°F / °C) *
Maximum Recommended
Flow Rate (gpm / lpm)
Maximum Forward
Differential Pressure
Recommended Change-out
Differential Pressure
CFR CompliantAll component materials of the DuoFLO "PP"
* Maximum temperature ratings are dependent on the fluid being filtered -
2/m2
)3.4 / 0.326.7 / 0.62
0.7 / 2.61.4 / 6.2
180 / 82300 / 149
75
/ 284150 / 56875 / 284
35 psid @ 68°F (2.4 bar @ 20°C)
20 psid (1.4 bar)
polypropylene element and "FE" polyesterare
listed for food contact per 21 CFR 177.1520.
see Chemical Compatibility Table.
150 / 568
DuoFLO filter elements are compatible with wide range
of chemicals and process conditions. The thermal and
chemical resistance data presented is for guidance only.
Factors such as duration, degree of concentration of a
substance in a fluid and temperature should also be
considered. Thermal and chemical resistance should
also be considered when choosing all materials exposed
to fluids. CUNO strongly recommends that
compatibility be tested prior to use.
Biological AgentsExcellentExcellent
Mineral AcidsExcellentGood
Organic AcidsExcellentExcellent
Flow vs. differential pressure for a DuoFLO #2 size
element and support basket in water is depicted in
Graph 2. A typical filter system is often sized for an
initial differential pressure of 0.5 to 1 psi (0.04 to 0.07
bar). A lower flow rate per element typically extends
the life of the filter system.
0.08
0.06
0.04
0.02
0
150
Differential Pressure (psid
1.2
1.0
0.8
0.6
0.4
0.2
1&5micron
10 & 25 micron
50, 100, & 200 micron
0
25
0
50
75
Flow (gpm)
100
125
bar)
Differential Pressure
*#2 Size Element and Support Basket Pressure Drop Only, housing pressure losses are
not included.
4
0
100
200
300
Flow (lpm)
400
500
Page 6
CUNO DuoFLO filter housings are designed and manufactured to economically meet
demanding applications. The housings are available for #1 and #2 size DuoFLO filters
and are constructed from 304 or 316L stainless steel. DuoFLO ASME code housings
are designed, fabricated, and "U" stamped in accordance with ASME Section VIII,
Division 1 for 150 psi @ 300°F*. For those applications not requiring AMSE code
housings, an economical "DFN" version is available. A variety of inlet/outlet
connection styles are available (see specification table below). In addition, custom
designs are available on request.
The DuoFLO filter housing allows the user to realize all of the benefits of the
DuoFLO filter element. A positive element sealing mechanism eliminates bypass of
unfiltered fluid into the effluent stream. Since the DuoFLO filter element has more
surface area and better flow characteristics, larger conventional bag housings can be
eliminated in favor of smaller DuoFLO housings - reducing up-front capital
expenditures and installation costs. In addition, the true “in-line” configuration of
the inlet and outlet connections allow for installation without the additional piping
and elbows required by conventional filter bag housings.
The flow configuration of the DuoFLO housing eliminates the “dirty chamber” that is common in bag filter
housings, thus eliminating the potential for cross contamination of dirty fluid into the clean effluent during filter
element change-out. DuoFLO housings incorporate a design that results in environmental, health, and safety
benefitse by allowing used DuoFLO filter element removal without the spillage of, or contact by the operator with,
the process fluid.
+ Positive element sealing
mechanism
+ No dirty fluid chamber
+
Inline piping configuration
+
Excellent flow characteristics
#1
304 or 316L
#2150 / 568100 lb/45.4 kg12 lb/5.4 kg
#1304 or 316L
#2150 / 56856 lb/25 kg12 lb/5.4 kg
S.S.
S.S.
2” ANSI or DIN Flange
2” NPT or 2" BSPTr
2" NPT75 / 284150 PSI @ 250°F
+ Ensures no bypass of unfiltered fluid into the
effluent stream.
+
Eliminates unfiltered fluid from contaminating the clean
effluent side of the housing during filter change-out
+
Reduces operator contact with the fluid
+
Significantly reduces installation time and costs
+
Ease of piping for series or parallel installation
+
Reduces capital investment since fewer filter elements
are required for a given flow rate
75 / 284
✦ Dependent upon the material of the gasket installed.
150 PSI @300°F
(10.4 bar @ 149°C)
(10.4 bar @ 121°C)
80 lb/36.3 kg8 lb/3.6 kg
44 lb/20 kg8 lb/3.6 kg
4 lb/ 1.8 kg
5
Page 7
®
DuoFLOASME Code Filter Housings
Minimized Dirty Fluid Chamber - the DuoFLO filter element
extends to the top of the housing cover to significantly reduce the
dirty fluid volume compared to conventional bag filter systems
¼” NPT Connection- for easy
vent valve or pressure gauge
3 Eye Nuts - eliminate the
need for special tools and
allows for quick and easy
filter element installation
and removal
Light weight cover - remains
attached to the housing and
pivots open to allow easy
access for filter change-out.
Can be rotated for ideal pivot
orientation.
304 or 316L Construction -
provides compatibility with
a wide range of fluids. Shot
blast exterior finish improves
appearance and allows for
easy cleaning
installation
O-Ring Housing Seal - to
provide a positive seal between
the housing and the cover when
the system is in use
Double O-Ring Element Seal Seals the DuoFLO filter element
to the top of the stand pipe (inlet)
ensuring no by-pass
Support Basket - Full Support
of the filter element ensures
filter integrity even under the
most demanding conditions.
Eliminates media stretching
which can open the media
pores and allow larger
particles to pass.
ASME Code - meets local
and state design requirements
for pressure vessels
Inlet Stand Pipe - directs
fluid to the top of the filter
housing and inlet channels
of the DuoFLO filter element
Available Connections -
include 2” ANSI flange (shown),
2” NPT, 2” DIN flange, or
2” BSPTr to satisfy most common
piping requirements
Dished Bottom - drains the
clean liquid to the housing outlet
for better product recovery and
cleaner system operation
Optional Legs (shown below) -
Adjustable legs can accommodate an inlet/outlet centerline
height adjustment of up to
11 inches
In-line Bottom Inlet & Outlet - provides easy
and cost effective installation by reducing the
complexity of the piping scheme. Both the inlet
and outlet piping have ½” NPT connections for
drains, sample ports, or pressure gauge
installation.
Page 8
FlangeThreadMax.Min.Bolt Circle
anc
es
1DF135/8920/51
13/33.211 ½/29.215/38.14/10.210 ½ / 26.7
1DF263/16034/87
InchescmInchescmInchescmInchescm
1DFN129 1/274.940101.61230.5
512.7
1DFN243 3/4111.168 1/41731230.5
The inline bottom inlet and outlet connections offer tremendous flexibility in manifolding the housings for series or
parallel filtration. This concept allows for enhanced adaptability in achieving both short and long term flow and
process requirements. Manifold piping systems (with and without valves) are available for installing DuoFLO
housings in duplex, triplex, and quadplex configurations. Consult factory for more details.
Space Required to remove
element and support basket
Space Required to remove
element and support basket
B
A
CUNO
DuoFLO
C
E
5/16” diameter
hor hol
B
A
INLET
D
D
OUTLET
C
7
Page 9
DuoFLO®Filter System Accessories
The following accessories are available for use with the DuoFLO filter system:
DuoFLO Element
Installation Tool
DuoFLO Element
Removal Tool
Coatings
Industrial
Chemical
Petrochemicals
Food & Beverage
Pharmaceutical
Electronics
Water Treatment
Element Insertion Tool (Part # 60300-31): Constructed from 316
stainless steel, this tool facilitates insertion of DuoFLO elements into
DuoFLO Element
Hold Down Spring
the support basket. The tool is designed with curved ends to ensure no
damage is done when inserted into the element.
Element Removal Tool (Part # 74132-31): Constructed from 316
stainless steel, this tool facilitates removal of DuoFLO elements from
the support basket. The tool is designed with an easy-to grip handle
and locking tabs for proper support of element.
Element Hold Down Spring (Part # 64254-31): Constructed from
DuoFLO Magnet
316 stainless steel, this spring assembly ensures the DuoFLO element is
properly seated in side entry housings to prevent fluid bypass.
Magnet Assembly (Part # 60376-01): Constructed using 12,000 gauss
strength magnets inserted into a 304 / 304 L Stainless steel tube, this
magnet assembly provides for improved capture of metallic fines from
fluid streams. This assembly is designed for easy insertion and
removal and is fully supported when inserted into a DuoFLO element.
DuoFLO®Filter Applications
ElectrodepositionPaper CoatingsPrinting Ink
Trade Paint
Can CoatingsAutomotive PaintCoil Coatings
DispersionsArchitectural Paint
Parts WashingGround WaterLubricants
Pulp & PaperWaste WaterMachine Tool Coolants
Cooling WaterHydraulic FluidsTransformer Oil
AcidsFuelsSilicones
ChemicalsCatalyst RecoveryAerosol Products
Process WaterResinsMineral Oil
AlcoholsAlkalinesWaxes
GlycolsEstersSolvents
Fuel AdditivesDistillationFuels
GlycolsEnhanced Oil RecoveryInjection Fluids
Lube OilsAmines
Vegetable OilFruit JuiceLiquid Sugar
SyrupsBeerBottled Water
Edible OilsHoneyGelatin
Soft DrinksHigh Fructose Corn SyrupReady to Drink Tea
WineVinegarSports Drinks
Spirits
Catalyst RecoverySolventsWater Systems
Vitamin ExtractsActive Pharmaceutical IngredientsOpthalmics
Bulk Pharmaceutical ChemicalsCarbon RemovalLotions
OTC Solutions
Etching BathsCD’s / DVD’sSolvents
Process Water / RO PrefiltrationPhotochemicalsPrinted Circuit Manufacturing
Cooling WaterWell WaterWaste Water
Process WaterGround WaterRO Prefiltration
AdhesivesResins
8
Page 10
CUNO offers a complete line of DuoFLO 316 stainless steel support baskets (many available in
316 L S.S.) for use in existing bag filter housings or in the DuoFLO filter housing. The
DuoFLO element utilizes a basket for proper element support. The DuoFLO filter
basket has two concentric stainless steel cylinders to support both the inner and
outer filter element sleeves. This design ensures media integrity and consistent
effluent quality. DuoFLO baskets include the optimum combination of strength
and open area to provide proper media support, excellent flow characteristics, and
minimal pressure drop.
The DuoFLO filter support basket ordering guide (below) cross references the
competitive filter bag housing manufacturer and model to the correct DuoFLO
support basket needed to upgrade to the DuoFLO filter element.
TEV60339-31GD60340-31GDTEV60334-39442
*** Hold down Spring (Part # 64254-31) required for all side entry one bag housings
**** Seal Ring & FSI installation tool (Part # 74132-31) required
CUNO MAKES NO WARRANTIES, EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE. Since a variety of factors can affect the use and performance of a CUNO product in a particular application, some of which are uniquely within the user’s knowledge and control, user is responsible
for determining whether or not the CUNO product is fit for a particular purpose and suitable for user’s method of application
.
If the CUNO product is proved to be defective, THE EXCLUSIVE REMEDY, AT CUNO’S OPTION, SHALL BE TO REFUND THE PURCHASE PRICE OR TO REPAIR OR REPLACE THE
DEFECTIVE PRODUCT. CUNO shall not otherwise be liable for loss or damages, whether direct, indirect, special, incidental or consequential, regardless of the legal theory asserted, including, but not limited
to, contract, negligence, warranty or strict liability.
WARRANTY
Seller warrants its equipment against defects in workmanship and material for a period of 12 months from date of shipment from the factory under normal use and service and
otherwise when such equipment is used in accordance with instructions furnished by Seller and for purposes disclosed in writing at the time of purchase, if any. Any
unauthorized alteration or modification of the equipment by Buyer will void this warranty. Seller's liability under this warranty shall be limited to the replacement or repair,
F.O.B. point of manufacture, of any defective equipment or part which, having been returned to the factory, transportation charges prepaid, has been inspected and determined by
the Seller to be defective. THIS WARRANTY IS IN LIEU OF ANY OTHER WARRANTY, EITHER EXPRESSED OR IMPLIED, AS TO DESCRIPTION, QUALITY,
MERCHANTABILITY, FITNESS FOR ANY PARTICULAR PURPOSE OR USE, OR ANY OTHER MATTER. Under no circumstances shall Seller be liable to Buyer or any
third party for any loss of profits or other direct or indirect costs, expenses, losses or consequential damages arising out of or as a result of any defects in or failure of its products
or any part or parts thereof or arising out of or as a result of parts or components incorporated in Seller's equipment but not supplied by the Seller.