/ Published in Filter

What is the Difference Between Pleated, String Wound and Melt Blown Filter Cartridges?

Each type of filter cartridges is acceptable for pretreatment to RO membranes. Pleated filter cartridge is typically used in higher purity applications such as pharmaceuticals and microelectronics. String wound filter cartridge is just as they sound; material such as polypropylene in string form which is wound around a central core. The disadvantage of these filter cartridges is that they suffer form particle unloading at higher pressure drops and require a slower velocity through them than other types of filter cartridges. Typically 2-3 gpm per 10 inch equivalent rather than 5 gpm per 10 inch equivalent for pleated and melt blown filter cartridges. The melt blown variety is thermally bonded polypropylene microfibers and is typically denser near the core than at the outside.

Read more about Hydrodex different types of filter cartridge.

Sunday, 21 January 2018 / Published in

String Wound Filter Cartridge

  • Maximum dirt holding capacity
  • Long service life
  • Lower energy costs
  • Premium Polypropylene media offers wide chemical capability
  • High structural stability with no media


  • Diamond weave pattern provides highly engineered filtration capacity by subjecting particles to a graded pore structure and tortuous flow passage.
  • Maximum dirt holding capacity with low pressure drop.
  • Continuous wound to prevent media migration with no seams or binders.
  • Polypropylene media is devoid of “blooming” organic fillers or potentially poisonous binders.
  • 100% Polypropylene media with excellent chemical resistance to solvents, acids, bases and chlorides.
  • Full range of micron levels.
  • FDA compliant materials.


  • Micron Ratings: Nominal – 1, 3, 5, 10, 20, 50, 75, 150, & 200
  • Dimensions: 2 1/2” Outside Diameter
  • 1” Core Diameter
  • Length: 10, 20, 30, 40, 50, 60 & 70 inches
  • Effective Filtration Area: 30 Cubic inches per 10 inch equivalent


  • Inner polypropylene matrix core for with superior intrinsic strength. Stainless steel cores also available.
  • Filter media is polypropylene and devoid of “blooming” organic fillers or potentially poisonous binders.
  • 222 & 226 end caps available.
  • O-Ring options include – Silicone, NBR, Viton & Buna-N.


  • Quick order turn-around.
  • Exceptional customer service.
  • Leading industry knowledge.
  • Bring us your application and we will help you find the cartridge you need.


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Liquid Flow Rate vs. Pressure

Hydrodex String Wound Graph Pressure vs Flow Rate

Hydrodex String Wound Graph Pressure vs Flow Rate