Fuel oil purification is known to have a great impact on the service life extension of hydraulic equipment. Today, purification of industrial oil products is provided by different kinds of filters such as: (1) metal mesh; (2) paper filters; (3) synthetic fibers; (4) metal fibers; and (5) glass fiber filters. The degree of oil purification normally is related to the material the filter is made from. Nowadays, metal meshes are considered to be the most widespread filter for purification. This is due to the fact that the level of oil contamination in modern indutry the is very high and requires the filters to be made of durable material such as the metal mesh type filter. The filtration fineness of the metal mesh filter is between 10 and 20 microns. The disadvantages of these filters however, include the inability to retain particles with a size more than the nominal fineness of the mesh material in the filtering element. This is due to the fact that mesh has a certain space orientation and some impurities can easily pass through the mesh openings. Though the metal meshes are called ‘reusable’ meshes, it is very difficult to prepare them for service. Purification of meshes requires special conditions that include: (1) ultrasonic washing; (2) presence of chemicals; (3) heating; (4) pressure reduction; and (5) purging. All in all, filters are still requireed to be periodically changed since purification of filters doesn’t provide for original quality of filtration. Mesh filters with filtration fineness of between 10 to 25 microns are recommended to be used no more than 8 times before replacing. In the hi-tech market, there are also disposable mesh filters and they cost 5 times less than reusable filters. It is worth noting that reusable filters have been proved to be very efficient to purify dangerous and strong contaminated fluids. The sorbent material known as Fuller’s Earth is used for complete restoration of dielectric transformer oil’s performance characteristics. One of the most beneficial advantages of Fuller’s Earth is the possibility of multiple use and its cleanability. GlobeCore has developed a CMM-R unit that completely reactivates and resuses the sorbent after it is exhausted without removing the material from the oil regeneration columns. Additionally, this unit is designed to use other sorbents with the same performance characteristics as Fuller’s Earth.