Bag filters have many uses in coolant filtration. They are often used as a pre-filter to remove large solid contaminants that might cause pump problems. They are well suited applications with modest solids loading.


  • Broaching, Hobbing, Trepanning
  • Gear Hobbing
  • Boring, Drilling
  • Chucking, Milling
  • Turning, Lathes, Machining Centers


Chips and swarf that are porous can fill the bag, providing very efficient filter media use. Bags are a good pick on applications that require the contaminants to be packed in drums for disposal, as the bags collapse and pack easily.

Bag filters have a relatively small surface area, about 4 - 5 sq. ft. in the largest standard housings. Therefore, we do not recommend them where the solids form a thin impervious layer, blinding off coolant flow.

Design and Customization

Polytech can provide loose bag housings or complete systems. Speak to one of our engineers about your application's specific requirements.

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Dual housings piped for parallel operation. Pressure switch signals need to change filters.