2 filter: the filter is to remove a small amount of solid particles in the liquid small equipment, can protect the normal operation of the equipment, but also the delivery medium pipeline is an indispensable device, can effectively filter out the size close to the contamination of the sensitive components of the key moving parts of the dynamic oil film thickness of the particulate contaminants. The removal rate of suspended solids in water can reach more than 95%, and has a certain removal effect on macromolecular organic matter, bacteria, viruses, colloids, iron and other debris. Usually installed in the pressure reducing valve, pressure relief valve, fixed water level valve or the inlet side of other equipment to protect the normal use of valves and equipment. When the fluid enters the filter cartridge with certain specifications, the impurities are blocked, and the clean filtrate is discharged from the filter outlet, when the need for cleaning, as long as the removable cartridge is removed, re-installed after processing can be, therefore, the use of maintenance is extremely convenient.