The valve series are especially applicable for the high/low-temperature conversion course in such fields as the ammonia water in coke ovens or the injection circulating system in coke plants. 1.The connection dimension of the valve is identical to that of the above-mentioned 3-way ball valve for convenient replacement. 2.The specially-designed seal ring made from strong polytetrafluoroethylene with much greater abrasion strength could obviously enhance the service life of the ring. 3.The special interior structure applied not only reduces the production cost but also simplifies the processing and maintenance work. 4.The lower-loading Stem with backward sealing construction not only prevents the handle form backing-out but also ensures the reliability of the scaling part of the handle. 5.With compact structure in configuration,the specially-designed 3-part feature makes the valve much more perfect.