The
butterfly valve has 90. Features such as rapid opening and closing of rotation, light weight, small structure size (especially wafer butterfly valve) and other advantages. However, its sealing reliability is relatively poor, so it is often used in medium and low pressure and medium and low temperature conditions in industrial production equipment. With the large-scale petrochemical production equipment, it is an inevitable trend to replace gate valves with butterfly valves. Due to the appearance of double eccentric high performance butterfly valve and triple eccentric metal hard seal butterfly valve, they better solve the problems of thermal expansion compensation and wear compensation. Therefore, butterfly valves have gradually begun to be used in more demanding media conditions.