UPVC butterfly valve is a new generation of butterfly valve which meets the market demand for various corrosive pipeline fluids. It is small in size, light in weight, simple in structure, compact and beautiful in appearance. It is easy to install compare with the gate valve. The average weight is reduced by about 30-50%. The butterfly plate can be opened and closed by rotating 90 degrees. Moreover, the butterfly plates on both sides of the rotating shaft are subject to the same medium force and the opposite torque, so the starting process can be realized. The closing torque is small.