In any hydraulic system, proper filtration is essential for removing contaminants that could otherwise detract from the performance, reliability, and longevity of various hydraulic components. In addition to removing contamination entering the system from the outside, filters must also capture metallic particles generated by wear and tear on metal components within the system. This is where magnetic filtration can come in handy. If fluid analysis has shown that your oil contains a high percentage of ferromagnetic particles, you should definitely considering using a magnetic filter or filters in conjunction with standard filtration. This will be most effective in systems with low oil viscosity and low flow. Here are the probable advantages and disadvantages of adding magnetic filtration.
Reduced Costs: Magnetic filtration can help you save money on filter costs in two ways. First of all, they are reusable, so you never have to buy new ones. Secondly, they can help extend the life of your conventional filters, so you have to replace those filters less often.
Protection for Electrohydraulic Valves: If you have servovalves or solenoids in your system, any ferromagnetic particles floating around in your fluids can potentially interfere with the electromagnets inside these valves. By using magnetic filters to capture more magnetic particles, you can protect your electrohydraulic valves and get better performance and longevity from them.
Improved Particle Identification: Because magnetic filters tend to capture ferrous particles sooner than traditional filters, the particles have not been crushed and pulverized by repeated journeys through the system. This means they are easier to identify, which will help you determine which parts are giving off the particles.
Clumps: Perhaps the biggest risk of using magnetic filters is that a clump of particles could suddenly break off from the filter and drift off into other parts of the system. This clump would probably be larger than any contaminant that would otherwise be in the system. Plus, it could possibly be magnetized, causing it to adhere to some other metallic part and escape filtration forever. In either case you could be looking at significant damage from a rogue particle clump.
Cleaning: Depending on the type of magnetic filter you have, you may be able to simply wipe it clean to remove collected particles, or you may need to blast it with an air hose. The latter will entail special safety precautions.