Abstract: The troubles encountered in the operation of the pressure filter system of the plant involve fluctuation of oil pressure in hydraulic system, sluggish action of valve elements, plugging of oil circuit and short oil changing period. For tackling these problems, the FMD-A180 double-cylinder oil filtering machine is fitted for realizing on-line oil filtration. Practice shows the addition of the oil filtering machine can ensure oil purity, prolonged lubrication oil period, and increased utilization rate and service life of equipment.