Filter Housings and Filter Bags


Bag filter for machine tool coolant


Most CNC machining center coolant systems utilize one or more bag filter housings.  Bag filter housings are pressure vessels designed to hold disposable filter bags (sometimes referred to as filter socks).  The most common filter retentions fall within 1 to 200 microns (nominal) and are 7" diameter x 32" long (referred to as a #2 size).

The filter bags are most commonly made of polypropylene or polyester felt.  The longevity of the filter bag is directly related to its efficiency and thickness of the material used to make the filter bag.  Thinner filter bags made from recycled material are the least expensive, however are consumed at a rate of 2-3 times when compared with filter bags made from thicker material.

We offer a complete product line of filter bags, from the inexpensive to sub-micron 99.9% (ultra expensive) designs.

While we'd be happy to cross-reference your current filter bag and provide a proposal, what we really want to do is make sure your system is "optimized" as much as possible.

For example, we offer stainless steel "balloons" designed to fit within the filter bag.  Why?  Because it displaces the "wasted space" within the filter bag.  When the filter bag needs changing, it holds 4-5 gallons of coolant, which you need to get rid of by either draining it someplace or dumping the contents back into your sump.  When you use a displacement balloon there's very little coolant left in the bag, making it easier to lift from the vessel and dispose of; also reducing wasted coolant.
 We also offer powerful rare earth magnets (9300 gauss) that can be inserted into the filter bags; these enhance the efficiency of retaining ferrous particles while extending the filter bag life.

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

If you are installing a completely new coolant system and require a filter housing, we offer a large 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 specifically for manufacturers is the
FLOWASH portable filter cart.  It provides a convenient option for quickly emptying  machine tool coolant sumps, reducing both labor and coolant waste.