When two precision-bearing surfaces interact, they rely implicitly on a lubrication film devoid of particle or water presence to separateﾗand protectﾗthemselves from each other. The filter is designed to trap and extract any particles or moisture before these contaminants can enter the lubricated zone(s) and cause surface damage.
Almost exclusively in contamination control, filters incorporate a passive surface-attractant medium, designed to work in the direct-flow path of the lubricant and capture any dirt particles (contaminants) held in colloidal suspension as the lubricant, or lubricated air, flows through or across it. Depending on the working conditions, particle size, and fluid-flow rate, the porous filter media can be constructed of a variety of materials, including simple wire-mesh gauze, wire wool, pleated paper, cellulose, porous metal, fiberglass, diatomaceous earth, or felt. Due to higher fluid viscosity and line-delivery pressures, grease systems use heavy-gauge coiled wedge-wire or wire-mesh filters to attract large solid contaminants that may be introduced from a dirty grease-gun nozzle.
Enclosed, sealed gearboxes and reservoirs require breather devices to equalise pressure and control solid and moisture contamination. Old-style breathers constructed of wire wool can only prevent large solid contamination (40+ microns in size), and are now regularly replaced with newer-style breathers that employ desiccant-like silica gel hydrophilic media.
This media type allows the reservoir to breathe and prevent airborne particulates (3+ microns) from entering the reservoir. It also wicks and captures moisture from inside the reservoir, while preventing outside moisture from entering the reservoir or gearbox chamber.
Heavy water contamination usually enters a system as a result of maintenance or production personnel using oil that has been incorrectly stored in the outside elements, or through production-process-water spillage or high-pressure machine-cleaning (prevalent in food-manufacturing machinery).
Clean lubricants increase the life and performance of bearings and ensure the success of your operations.
If a machine has any form of replaceable/washable filter, screen, or breather as part of its fluid-management systemsﾗlubrication, hydraulic, and pneumatic-air systemsﾗwe can assume the OEM (original-equipment manufacturer) machine designer/engineer expected the equipment and its operators/maintainers to contend with and manage fluid- and air-borne contaminants. These built-in sacrificial filtration elements are specifically designed to provide an inexpensive method of managing and controlling potential contamination issuesﾗexternally and internallyﾗto protect delicate, close-tolerance, machine-bearing surfaces at work under a range of operating conditions.
In the majority of operating conditions, effective levels of contamination control and avoidance are achievable with minimum effort when the requirements and basic relationships of and between a machine, its operator(s), and maintainer(s) are understood.
The fact that a piece of equipment begins to run a process or make a product indicates the OEM has done its part: supplied a machine thatﾒs adaptable enough to work in an array of different operating environments or, if the end user is fortunate, one designed and built specifically for a unique operating environment. This means the machinery is fitted with a number of built-in contamination-control/filtration devices that are ultimately designed to fail in their own right. (They also require monitoring for condition and cleaning and/or replacement when their filter media is close to being exhausted.) These devices offer secondary protection through their ability to trap and control the ingress of contaminants into lubricating oil(s), grease(s), and air-flow systems.