Butterfly Valve Butterfly valve, a main produt of poro valve, is widely used in various industries both in regular services and special medium such as sea water. It becomes more and more popular because of its low weight, cost effictive and advantage of techinical aspect such as low torque compared with traditional valve types like ggc valve, ball valve. And it replaces them in many fields more and more. According to the differnet working conditions and sizes&ratings, it is divided into two types: one is centered butterfly, another one is eccentric butterfly valve. They are as per api609, din 3202 design,covered 2”-24” &150lb-300lb with various materials such as cs,ss,alloy steel, dxss etc.