Characteristics:      1. Provided with outstanding chemical steadiness and cold temperature resistance,PTFE covers a wide range of temperature(-180~C~250~C). The extremely small abrasion coefficient and sound lubrication performance may lower the abrasion between seals and shorten operating moment of valve, thus to lengthen the service life of product.    2. The eccentric design of body and disc enables the sealing face of disc functioning on seat sealing face by the means of cam, so that the seals between disc and seat can be ensured zero leakage. When valve is started, sealing faces will be separated quickly to greatly smooth then the friction of sealing faces and to reduce the torque when starting valve.    3. The specially designed PTFE seat may meet the requirement of bi-directional pressure bearing.