3.5 Seal seat structure with elastic element (l) The elastic element is the seal seat of butterfly spring, as shown in Figure 3. Fig. 3 Seal seat with butterfly spring (2) The elastic element is the seal seat of spring, as shown in Fig. 4. Fig. 4 Seal seat with cylindrical coil spring Fig. 3 and Fig. 4 Seal seat with butterfly spring or cylindrical coil spring has been widely used in non corrosive medium pneumatic ball valve. However, because it is difficult to select elastic element materials that can resist strong corrosive media and have good elasticity, and the heat treatment process of such materials is relatively complex, such seal seat structures are not widely used in pneumatic ball valves with strong corrosive media. (3) Combined lip seal seat Figure 5 Combined lip seal seat with elastic expansion ring Figure 5 shows the combined seal seat with elastic expansion ring and PTFE lip seal seat. The elastic expansion ring can be made of 1Cr18Ni9Ti or 1Cr18Ni9 to be compatible with strong corrosive media. Figure 6 shows the structure of elastic expansion ring; Figure 7 shows the structural form of PTFE lip seal seat. It can be seen from Figures 6 and 7 that the design angle of the lip of the polytetrafluoroethylene lip type seal seat is 30, while that of the elastic expansion ring is 34. Fig. 6 Structure of seal seat with elastic expansion ring structure Fig. 7 Structure of PTFE lip type seal seat Under the medium pressure, the elastic force of the elastic expansion ring can compensate for the shortcomings of insufficient elastic and plastic deformation capacity of the seal seat with a single PTFE material, which improves the reliability and service life of the seal of pneumatic ball valve. Under the condition of low medium pressure, due to the angle difference between the lip of the elastic expansion ring and the lip of the polytetrafluoroethylene lip seal seat, and the strong elastic-plastic deformation ability of the metal expansion ring, the polytetrafluoroethylene lip seal seat, under the effect of the elastic force of the elastic expansion ring, forms an outward tension tendency and compresses the ball to produce a pre compression force, which compensates for the insufficient sealing specific pressure caused by the reduction of the medium pressure. As long as it is within the elastic force range of the elastic expansion ring, it can ensure the reliable sealing of the pneumatic ball valve under lower pressure conditions.

Manual/electric soft seal butterfly valve instruction manual/electric soft seal butterfly valve is applicable to pipelines with water, sea water or oil as the medium. It is mainly used as a stop valve to cut off the medium in order to protect the pipeline system. Manual/electric soft seal butterfly valve is mainly composed of butterfly valve body, manual device or electric device