Liquid Filtration is the process of removing solid particles from a liquid with a filter medium collecting the particles and allowing only the clean liquid to flow. The filters are characterized by the type, particle size, flow rate, pressure range, and inlet/outlet size. The particle sizes are 0.1µm, 0.21µm, 0.3µm, 0.5µm (absolute or nominal), 0.7µm, 0.8µm, 1µm, 1.8µm, 3µm, 4µm, 5µm (absolute or nominal), or 20µm.