Ultrafiltering unit represents the water-treating system working through membrane technique that removes a vast number of water-borne contaminants. UF has pore size dimensions from 0.01 up to 0.1 micro and is considerably smaller than its corresponding micro-filtration-based unit. For this reason, it can extract quite a wide distribution of particles together with impurities found in the water, comprising of bacteria and viruses, together with other species of microorganism.

Units for UF generally have a pre-treatment system which removes larger particulate and debris material from the water; then membrane filtration removes smaller particles and impurities. Membrane filtration usually has hollow fiber or flat sheet membranes that remove impurities by both sieving and adsorption.

UF units are applied to drinking water treatment, wastewater treatment, and treatment of industrial process waters. UF is also applied in the food and beverage industry to purify raw materials and ingredients from impurities.

Commonly used materials for the construction of UF units include mild steel (MS), stainless steel (SS), and fiber-reinforced plastic (FRP). Material choice depends on various factors like the application, the operating conditions, and budget.

In summary, UF units are water treatment systems that utilize membrane technology to remove impurities and contaminants from water. They are commonly used in applications such as drinking water purification, wastewater treatment, and industrial process water treatment. UF units are usually made of materials like MS, SS, or FRP.