Imported Nitrile O-ring one, import O-ring as a result of different materials, product performance are different. 1) Material NBR nitrile rubber O-rings made of imported, and strong performance of its airtight, there is a very good oil resistance and abrasion resistance, NBR is the most widely used, the price of the cheapest products. It is also commonly known as NBR NBR seals. 2) One of Viton (FKM or VITON) making the import-ring seal is the most widely used products. Because fluorine rubber with a variety of excellent performance, and is widely used in petroleum, chemical, aviation, aerospace and other sectors. Fluorine rubber high temperature resistance, can be used in -40 ℃ ~ 240 ℃ environment. VITON fluorine rubber resistant to strong oxidants, oil, acid, and fluorine rubber can be high vacuum and high-altitude environments, but also suitable for oil environment. Often been called or FKM VITON fluorine rubber seals. 3) the advantages of silicone rubber is 250 degrees high temperature, low temperature -60 degrees, silicone seal products are widely used in food, home appliances, lighting, medical equipment and other related industries seal imports silicone O-ring, also known as import SIL rubber O-ring. 4) EPDM has excellent ozone resistance, heat resistance and chemical resistance, and EPDM O-ring also has good electrical insulation properties and hot water. However, EPDM is not oil. NBR main purposes: used in the production of various types of oil-molded products, such as O-rings, seals, diaphragms, valves, bellows, but also for the production of plastic sheet and wear parts production of oil products, such as oil pipe, tape, NBR rubber o-rings and a large diaphragm capsule and other oils. Second, the advantages NBR: 1) performance, long life, work life dynamic pressure seal 5-10 times higher than conventional rubber seal products, up to a few times, under certain conditions, with the seal matrix with life . 2) friction is small, dynamic and static friction equal to "0" shaped rubber ring. 3) strong wear resistance, sealing surface wear and tear with automatic elastic compensation. 4) NBR good self-lubricating properties. Can be used for oil-free seal.