The Desilter Hydrocyclone (Hydraulic cyclone) is a device to classify, separate or sort particles in a liquid suspension based on the ratio of their centripetal force to fluid resistance. This ratio is high for dense (where separation by density is required) and coarse (where separation by size is required) particles, and low for light and fine particles. Hydrocyclones also find application in the separation of liquids of different densities. In solid control system, the desilter hydrocylones are spare parts for mud cleaner, desilter. So the common using size is 4 inch and 5 inch.