What is a full-flow filter?
A full-flow filter is a device for filtering, removing solid contamination from lubricating oil. Full-flow filtration can be the ultimate in oil filtration in that all oil flowing directly to the bearings must first pass through the full-flow filter. However, because of the cost and size limitations, the full-flow filter is no more than a coarse strainer and must be built to guarantee against restricting the oil supply to the engine. The demands of the engine require that bypass valves be built into the system to ensure an oil supply to the bearings when the filter will not handle the required volume. These bypass valves bleed at 3 p.s.i. and open wide at 9 p.s.i. differential pressure across the filter. These pressures may be frequently exceeded on starting the engine and also during normal operation when the filter becomes restricted with contamination. When this occurs, unfiltered dirty oil bypasses the filtering material inside and flows directly to the bearings. Despite its practi
