Pneumatic ball valve, with its well-known characteristics, is widely used in various pipeline systems for quick cut-off, changing the flow direction of media and automatic control. It can be driven manually, electrically or pneumatically. Figure 1 shows the typical structure of pneumatic ball valve (driving mode is not considered). Fig. 1 In the service performance of pneumatic ball valve, sealing is one of its main indicators. It can be seen from Figure 1 that the sealing structure of the pneumatic ball valve is mainly composed of three parts, one of which is the sealing between the main valve body and the auxiliary valve body, which is realized by the sealing adjusting gasket; The second is the seal between the main valve body and the valve stem, which is based on the standard; The outer sealing structure of the pneumatic ball valve is formed by means of the T-shaped packing or the 0-shaped sealing ring. The third is the seal between the ball and the main and auxiliary valve bodies, which is realized by the seal seat and forms the main sealing structure of the pneumatic ball valve. The tightness of the main sealing structure affects the working performance of the pneumatic ball valve, and is the key sealing structure in the design and manufacture of the pneumatic ball valve. This paper will focus on the non-metallic seal (also called soft seal) structure of the main seal of the pneumatic ball valve.

6. What is the basic content of measurement? The basic contents of the measurement method of electromagnetic flowmeter are: 1) the purpose of measurement legislation 2) the adjustment range 3) the measurement system unit 4) the management of measurement instruments 5) the measurement supervision 6) the measurement authorization 7) the measurement certification 8) the settlement of measurement disputes