CNC Coolant Filter Housings and Filter Bags


Bag filter for machine tool coolant

Bag filter housings are used in this industry due to their relatively large surface area of filtration and because the non-sealless type pumps require fine filtration.  I spoke with one coolant manufacturer who noted that some pumps recommended filtration as fine as 25 microns, finer then some of the additives used to improve coolant performance! 


Our high pressure coolant pumps do not require the fine filtration which piston, plunger and centrifugal pumps do because we do not have cups, packing or mechanical seals.  Thus our pumps provide the advantage of reducing your filtration requirements in support of less expensive filter bags which are replaced less frequently.  When a clogged filter bag is thrown away it typically contains a few gallons of coolant, so replacing them less frequently reduces overhead costs.  When using our sealless coolant pumps, your filtration requirements will likely be dictated by other equipment in your system, such as rotary unions or the tooling itself.  In some cases when filter bags are not required at all we can replace the perforated support basket with a mesh lined basket.


Our bag filter housings are available with displacement balloons; an elliptically shaped hollow stainless steel cylinder designed to be placed within the center of your filter bag, thus reducing the volume of coolant held within the bag without reducing surface area.  Therefore when the bag is removed from the vessel there is less drainage time required and less coolant loss. We can also provide powerful 9300 gauss magnets suspended in the center of the filter bag to attract ferrous particles within the coolant.  These magnets significantly increase holding capacity while increasing efficiency of fine particle capture.

Displacement balloon reduces remaining fluid inside bag filter housingPositioner keeps filter bag expanded and enables insertion of magnets


We can provide bag filter housings in the common #1 - #4 sizes in alloy and non-alloy materials; we can also provide filter bags or mesh lined baskets to use in lieu of filter bags; our mesh lined baskets can be fabricated to retrofit your existing bag filter housing.


Our selection of filter bags are unmatched, globally we offer the broadest selection by far.  Filtration for machine tool coolant applications are typically satisfied with nominally rated, inexpensive filter bags made of polypropylene or polyester felt.  One of our cost saving designs utilizes recycled materials in support of "operating green".


 If you are installing a completely new coolant system and require a filter housing, we offer variety to choose from.  The FLOWLINE II bag filter housing is an example of an inexpensive #2 size bag filter that would be suitable for most coolant filtration applications.

Another filtration product designed cnc machining centers is the
FLOWASH portable filter cart that provides a convenient option for quickly emptying  machine tool coolant sumps, reducing both labor and coolant waste.