Veolia Water Technologies & Solutions

Flotrex Pleated Cartridge Filters

high efficiency cartridge filters with various microfiber media

The Flotrex pleated cartridge filter family features microfiber media. Flotrex filters combine precise micron ratings with exceptional solids-holding capacity and long service life. A wide variety of materials offer application flexibility. Flotrex pleated filters feature both nominal and absolute micron retention ratings (from 0.2 to 40 microns). 


hydrophobic "adverse to water" filters 

typically used for vent filtration or harsh chemical environments

Flotrex AP

Flotrex AP (absolute filter made of pure polypropylene microfibers) is constructed with layers of melt-blown polypropylene media to provide absolute particle retention. This filter has exceptional solids-holding capacities with precise micron-retention ratings and a long service life. 

  • Hydrophobic 
  • Meets FDA requirements for food and beverage contact 
  • Absolute rated for air, gas, and liquid filtration 
  • Low pressure-drop across the wide range of 0.6 to 40 microns. 
  • Wide chemical compatibility 
  • Sterilized by steam or autoclave or sanitized with compatible chemical agents 
  • Made in the USA


  • ISO 9001:2015 certified processes
  • For further details please see the product factsheet and/or product declaration.


Flotrex PN

Flotrex PN nominal pleated cartridge filters offer economical filtration solutions to protect final filters. The all-polypropylene construction of the Flotrex PN filter provides superior chemical compatibility. The layered thermally bonded polypropylene media has excellent dirt-holding capacities and reliable retention characteristics. Flotrex PN filters do not contain adhesives or additives as the sleeves and end caps are thermally bonded.

  • Economical solution
  • Wide chemical compatibility
  • Sterilized by steam or autoclave or sanitized with compatible chemical agents
  • Made in the USA


  • ISO 9001:2015 certified processes
  • For further details please see the product factsheet and/or product declaration.


Flotrex HR

Flotrex HR (HR stands for Halar) absolute pleated cartridge filters offer outstanding performance in extremely harsh chemical environments. Flotrex HR filters are made entirely from Halar (ECTFE) (Halar is a trademark of Ausimont.). Halar is an industrial-grade fluoropolymer with excellent solvent resistance. For this reason, Flotrex HR filters can withstand the harshest process conditions and provide wide chemical compatibility. Flotrex HR filters produce consistent, uniform process streams in the most demanding filtration applications.

Flotrex HR filters deliver high flow rates and high-purity results with absolute rated efficiencies (99.9% filtration efficiency at rated pore size based on ASTM F795 and F661 test methods) and retention characteristics that typically outperform polypropylene microfiber filters.

  • ​​​​Hydrophobic
  • Halar is Ethylene Chlorotrifluoroethylene (ECTFE)
  • Broad chemical compatibility: aromatics, halogenated solvents, organics, ozone (9,000 ppm/hrs)
  • Designed for both pre- and final filtration Sanitized with compatible chemical agents such as ozonated water. Must not be autoclaved or steam sterilized.
  • Made in the USA


  • US FDA 21 CFR compliant materials
  • ISO 9001:2015 certified processes
  • For further details please see the product factsheet and/or product declaration.


hydrophilic "affinity to water" filters 

used for aqueous (water-based) systems

Flotrex GF

Flotrex GF (glass microfiber) pleated filters are absolute-rated, glass microfiber media filters and do not leach any flavor-altering substances. Flotrex GF filters are ideal for final filtration applications and have the important International Bottled Water Association (IBWA) - recommended 1.0-micron absolute rating. 

  • Hydrophilic
  • Low pressure drop
  • Wide chemical compatibility
  • Sterilized by steam or autoclave or sanitized with compatible chemical agents
  • Made in the USA


  • ISO 9001:2015 certified processes
  • For further details please see the product factsheet and/or product declaration.



hydrophobic "adverse to water" filters

Flotrex AP


  • Pre-Filtration and Final Chemical Filtration – Broad Chemical Compatibility 
  • Pre-Filtration of Pharmaceuticals and Biological Fluids – Dependable Protection for Final Filters 
  • High Throughput for Beer Filtration 


Flotrex PN


  • Filtration of Liquid Polymers, Coatings, and Inks 
  • Filtration of Bulk Chemicals 
  • General Clarification and Prefiltration 
  • Filtration of Viscous Streams 
  • Beer Trap Filtration 
  • Post Carbon Bed and DI Bed Filtration 
  • Pre-Filtration to Protect Expensive Final Filters 


Flotrex HR


  • Filtration of Aggressive Chemicals, including Toluene and Xylene 
  • Filtration of Ozonated Water 
  • Beverage 


hydrophilic "affinity to water" filters 

Flotrex GF


  • Final Filtration for Bottled Water 
  • Pre-Filtration of Pharmaceuticals and Biologicals 
  • Cosmetic Oil, Gel, and Shampoo Filtration 
  • Beverage Clarification 
  • Paints and Coatings 
  • Ink 

Chemical Compatibility 

chemical compatibility 

Veolia manufactures a series of melt-blown polypropylene depth filters as well as pleated filters made from a variety of microfiber and polymeric membrane materials. This wide array of cartridge media and elastomer materials ensure the right filter and configuration for your application. Veolia filter cartridges are designed and manufactured for their resistance to a wide range of chemical solutions. 

Download Veolia Chemical Compatibility Table

How to Use the Chemical Compatibility Table: 

R = Resistant. No significant change was observed in flow rate or bubble point of the membrane following 48 hours exposure to the test fluid at 77°F (25°C). 

LR = Limited Resistance. Moderate changes in physical properties or dimensions of membrane were observed. Filter may be suitable for short term, noncritical use. 

NR = Not Resistant. The membrane is basically unstable. Extensive shrinkage or swelling of the membrane may occur. The filter may gradually weaken or partially dissolve after extended exposure. 

O = Insufficient Data. Testing on your own solution is recommended. 

chemical resistance 

Veolia polypropylene cartridge filters are made of pure polypropylene, an inert material which is compatible with a wide range of chemicals. No resins, binders, antistatic agents, or other materials are added during the manufacturing process. Veolia polypropylene cartridge filters are manufactured with a proprietary melt-blown microfiber technology. This unique process thermally welds microscopic fibers of polypropylene into a compact matrix which resists fiber sloughing and particle unloading into the filtrate, even under extreme mechanical and chemical actions. The manufacturing operation is precisely controlled to yield cartridge filters with consistent micron ratings and true graded density for high particle retention and longer life. 

Download Veolia Chemical Resistance Guide

How to Use the Chemical Resistance Guide: 

R = Recommended for use. 

NR = Not recommended for use. 

NA = No available test data. User should run test prior to use. 


frequently asked questions 

what is the difference between the Flotrex and Memtrex series? 

Flotrex filters use a pleated microfiber filtration media, while the Memtrex series use polymer membrane filtration media. As such, the Flotrex filters are more economical, but the Memtrex filters have lower micron ratings and sharper retentions than the Flotrex filters. Memtrex filters are typically used as the final filtration step, while the Flotrex may be used as a prefilter or final filter in some applications. 

when should I use a pleated or depth filter? 

Depth filters are primarily nominally-rated with 0.5 µm – 200 µm ratings, while the pleated filters are primarily absolute-rated between 0.03 µm – 40 µm. Depth filters are typically cheaper and have higher dirt holding capacities. As such, they are often used as prefilters to the final pleated filters and are often used when feed waters have a wide particle size distribution and/or higher levels of suspended solids, such as RO pre-filtration, Oil & Gas, and chemical processing. 

Pleated filters, with their lower and more precise micron ratings are used when the particle size distribution is much narrower and for absolute removal of smaller particles, as is the case of pharmaceuticals, microelectronics, and vent filtration. Furthermore, pleated filters have lower pressure drops for comparable flow rates and micron ratings than depth filters due to their higher porosities and thinner media. 

what does absolute-rated mean? 

Absolute-rated has come to mean an efficiency level that is defined by a controlled laboratory test. While there is no official standard for absolute ratings, a manufacturer will make the efficiency data of these filters available. Veolia’s absolute filters have an efficiency level of 99% or greater. This means that at least 99% of particles with a diameter larger than the micron rating will be excluded by the filter. 

what does nominal-rated mean? 

Manufacturers do not typically document efficiency data for nominally-rated filters as they do for absolute filters. Nominal ratings are meant only as a guide and typically rank a cartridge filter’s efficiency compared to other cartridges in the same product line. For example, a 5-micron filter from a manufacturer will be more efficient than their 10-micron but less than the 1-micron cartridge. For more information on the distinction between absolute and nominal ratings, see the associated application bulletin in the Veolia library. 

how do I choose which pleated filter is right for my application? 

The greatest factors in choosing a pleated filter for your application are the hydrophobicity/hydrophilicity of the filter media, its chemical compatibility, and the micron rating. Hydrophobic (“water-hating”) filters are typically used for vent filtration or harsh chemical environments, while hydrophilic (“water-loving”) filters are used for aqueous (water-based) systems. Chemical compatibility is important to ensure that the filter does not become compromised during regular use. The micron rating indicates what size particles will be restricted from passing through the filter. Veolia has the technical expertise to help you find the right filter for your application to maximize lifetime and efficiency. Contact your sales representative or application engineer with any questions. 

Download Complete Pleated Filter FAQ Document