Small Bore Ball Valves
The body cavity space of the small bore ball valves
is narrow, so the usual structural design is no longer applicable. Therefore, the end of the valve stem is processed into a flat shape with a short axis. There are flat grooves and holes on the top and bottom of the sphere. The holes are used to connect the upper and lower valves to fix the sphere and limit degree of freedom of the sphere.
The small bore ball valves are widely used in the all kinds of industries such as petroleum, chemical, metallurgical, urban central heating industries and so on. But the ball valve made of PTFE macromolecule material can not be used at the situation which has the temperature of the transmission medium in the tiny particles. The bore ball valves with metal materials as sealing pairs will appear various situations when rotating the ball due to different structures. For example, it will appear sealing structure of the metal elastic seat, because there is no gap between the elastic seat and the sphere, so its friction is very large. The sealing structure of the metal floating seat is not easy to seal between the floating seat and the valve body. Composite ball open sealing structure increases the difficulty of processing and manufacturing costs for the sake of parts in a great deal and complex structure, especially for small bore ball valves, which is obviously not suitable. Q47H cam eccentric single seat fixed hard seal ball valve has been successfully developed by repeated analysis and testing , with the aid of the CAD aided design.