An overview of the current valve in the two-piece metal-sealed ball valve, the valve body is mainly used to form the shape of the ball valve, the sealing structure is sealed with two separate seat. Because the seat and the valve body are used with clearance fit, and the bottom of the valve seat and the valve body must be sealed with a sealing material, so all the need to seal the site may have the phenomenon of leakage, and the gap around the valve seat It provides abrasion, corrosion and accumulation conditions for the transmission medium in the pipe. Ball valve in the process of switching movements. Sealing material at the bottom of the valve seat at each position of the degree of compaction will change, will cause some parts due to seepage into the medium caused by leakage, seriously affecting the normal operation of the valve for a long time so that the valve seat and the bottom of the premature seal structure damage. Due to more leakage points, the valve life is generally short, usually can not meet the user's requirements, only frequent replacement of the ball valve to maintain the operation of the system. Two improvements 2.1 Structure One-way metal seal ball valve (Figure 1) The main components of the left valve body (including the integrated valve seat), the right valve body, ball, right seat, elastic pad and stem, etc., Contact parts, surfacing Stellite or supersonic spraying of metal particles. Get a super-hard spray coating and make an integral seat sealing surface directly on it. Sphere also uses supersonic spray surface hardening technology. Right seat can not afford to seal, no need for surface hardening treatment. Elastic pad can be flexible graphite, disc springs can also be used. 2.2 How it works One-way metal seal ball valve is improved on the basis of ordinary two-piece metal seal ball valve (Figure 2). The left valve seat and the left valve body together to form an integrated valve seat. The ball and the left valve body form a sealing pair. Ball valve installation in the pipeline has a directional, the left end of the pipe connected to the downstream, the right end of the upstream pipe connection. Ball through the upstream pipeline medium pressure and from the bottom of the right seat spring pad preload thrust together, so that the ball is close to the integration of the valve body in the left valve body to form a seal to achieve the ball valve seal. The right seat only guides and preloads the ball. Due to the integrated valve seat, both the number of ball valve components is reduced and the leakage points between the seals are reduced. This integrated valve seat eliminates the leakage of the medium around the valve seat. Simple structure, superior sealing performance, can truly achieve zero leakage of the ball valve. The structure of the valve is very suitable for special conditions and solid particles or dust and other occasions. Three processing ball valve in the ball valve body and the integration of the valve seat seal, to be hardened. And must be paired grinding, making it an uninterrupted seal, so that the ball valve to achieve zero leakage. The right seat has no sealing requirements in the ball valve and low accuracy requirements, eliminating the need for paired grinding and eliminating the need for hardening. This product is easy to process. Very suitable for mass production. Four Conclusion One-way metal seal ball valve, compact structure, fewer parts, beautiful appearance, less leakage point, to achieve zero leakage, cost savings. Due to the elastic seat at the bottom of the right seat, the valve's switching torque is small and its service life is greatly increased. The product has obtained national patent (patent number: ZL.7). Products have been widely used in metallurgy, paper, steel and thermal power systems and other industries, good performance.