The Most Influential Design in Industrial Air Filtration History

The Donaldson Torit Downflo® II cartridge dust and fume collector revolutionized dust collection in the 1980’s with a proprietary downward airflow design that delivers high filtration efficiency. DFT has ledgeless construction, so is often chosen for agglomerative applications.​

Downflo II Dust Collectors

290_Downflo_II_DFT_CollectorsEngineered for reliable performance

The long-standing, most influential cartridge collector in industrial air filtration history, the Donaldson® Torit® Downflo® II (DFT), delivers optimum performance and is one of the best values available in today’s marketplace. A leader in the industry for over 20 years with thousands of successful installations in place, DFT dust collectors ensure steadfast, trouble-free operation. The DFT advantages can be found in the collector’s proprietary design and components.

Now featuring a ledgeless design in combination with proprietary Ultra-Web® filter media and proprietary cleaning technology, the DFT continues its strong performance in traditional applications such as metalworking. It also generates interest and respect in process applications where ledgeless construction is often a requirement. Providing higher efficiency and smaller footprints than any baghouse collector or even other cartridge collectors, DFT adds up to long-term savings and improved performance in many applications.

Product Literature
Downflo® II Dust Collectors Brochure

Downflo II DFT 2-4 and DFT 3-6 After July 2003

Downflo II DFT 2-8 to 4-128 After July 2003


Ledgeless Construction

​Eliminates dust build-up and accommodates wash down environments.

Compact Design

Minimizes floor space.

Powerful Performance

Proprietary ExtraLife™ Filter Cleaning System provides 30% more cleaning energy.

Cost Savings

Fewer filter changeouts, reduced filter disposal costs, less energy usage.


Exceptional results for over 20 years and counting.

Easy System Setup

Easy Maintenance

10-Year Warranty

DFT Standard Operating Conditions 
Seismic Rating (zone)4
Wind Load Rating100
House Rating ("wg)​+15 / -20
Valves and Controls50/60 KHz

Pulse Cleaning Technology

ExtraLife Filter Cleaning System uses proprietary, computer-modeled pulse cleaning technology to easily “pulse off” dust from the surface of the filter, improving filtration efficiency and prolonging filter life. The red lines in the illustration show the increased pressure at the front of the Downflo filter generated by the ExtraLife system. The blue line shows the pulse signature of a standard cartridge collector.

Pulse gradients produced by the standard Downflo during pulse cleaning compared to gradients produced by a Downflo with the ExtraLife Cleaning System (red).


Collector Design​StandardOptional
Mild Steel Construction 
ExtraLife Filter Cleaning System 
Ledge-Free Hopper 
Sprinkler Taps 
Stainless Steel Construction 
High Temperature Construction 
Direct Drive Fans 
Chamber and Exhaust Silencers 
Abrasion Resistant (AR) Inlet 
Air Management Modules 
Extended Dirty Air Plenum 
Steep-Sided Hopper 
2-Mod Hopper 
Explosion Relief Vents 
Sprinkler Heads 
Service Platform (OSHA compliant) 
Damper Pack 
Drum Sentry Drum-Full Indicator 
Lined Clean Air Plenum 
Bag-Out Kit (Filter & Discharge) 
Bag-In/Bag-0ut Kit (Filter & Discharge) 
Cartridge FiltersStandardOptional
Ultra-Web (MERV* 15) 

Ultra-Tek (MERV 12)
Thermo-Web (MERV 14)
Fibra-Web (MERV 14)
Ultra-Web SB (MERV 15)

Ultra-Web AS (MERV 15)
Torit-Tex (MERV 16)

HEPA/ASHRAE Afterfilters 
Paint SystemStandardOptional
Prime Coated Interior 
Textured Multi-Coat Paint Finish with 2,000-Hour Salt Spray Performance 
Custom Color 
Premium Duty Finish 
Epoxy Coating 
Hopper DischargeStandardOptional
Drum Cover and Hose 
Slide Gates 
Rotary Valves and Transitions 
Screw Conveyors 
Electrical Controls, Gauges, and EnclosuresStandardOptional
Solid State Timer in NEMA 4 Enclosure 
Magnehelic** Gauge 
Delta P Control, Delta P Plus Control 
Custom Panels 
Photohelic** Gauge Standard & Weatherproof 
Basic Cold Climate Kit 
Heavy-Duty Cold Climate Kit 
Solenoid Enclosure (NEMA 7 & 9) 
10-Year Warranty 

*The Minimum Efficiency Reporting Value (MERV) of this filter cartridge has been determined through independent laboratory testing using ASHRAE 52.2 (2007) test standards. The MERV rating was determined at a face velocity of 118 feet per minute and loading up to four inches water gauge. Actual efficiency of any filter cartridge will vary according to the specific application parameters. Dust concentration, airflow, particle characteristics, and pulse cleaning methods all affect filtration efficiency.
** Magnehelic and Photohelic are registered trademarks of Dwyer Instruments, Inc.​​

Ultra-Web Technology Provides Filters that Deliver

Proven and proprietary Ultra-Web® technology delivers longer filter life, cleaner air and greater cost savings.