Small caliber Ball Valve Product Knowledge

An Overview
Ball in the petroleum, chemical, metallurgical and urban central heating and other industries has been widely used. But the sealing of PTFE polymer material of the ball, can not be used for temperature greater than 280 ℃ or transport medium was small granular condition. The materials for the sealing of metal hard seal ball valve, ball rotation will result in different structures of circumstances. Resilient sealing structure such as a metal seat, the elastic valve seat and does not form a gap between the spheres, so its great friction. Metal floating seat seal structure between its floating seat and valve seal is not easy. Combination ball softened sealing structure, because spare parts and more complex structure, increasing the difficulty of processing and manufacturing costs, especially small diameter seal valve, this structure is clearly not applicable. After repeated analysis and testing, and the help of CAD, successfully developed Q47H cam eccentric single seal valve seat fixed.
2 Work
Single eccentric cam ball seat valve center line offset with respect to the center line a, b, the valve seat sealing surface eccentric b. When the valve stem clockwise about O 90 °, then the sphere also rotates 90 °, and in close agreement with the valve seat sealing surface when the friction between the sealing filler stem between torque and friction torque is greater than the medium pressure forming torque, the valve will reach a reliable cable marker ties. As the valve seal with eccentric cam structure, when the valve is opened, the ball quickly from the valve seat sealing surface. When the valve is closed, the ball and seat sealing surface anastomosis quickly. So as to achieve the opening torque is small, close tightly purposes.
Three structural features
Small-diameter valve body cavity narrow space, the usual structural design is not applicable. Therefore, the stem ends with a short axis and processed into flat, spherical tank and the upper and lower holes are flat, the hole for connecting the upper and lower stem play a fixed sphere, limiting the role of freedom sphere, while balance the body cavity with the pipeline between media pressure. And stem with flat groove, the torque transmitted from the handle.
4 manufacturing and processing
Sphere two hole concentricity and ball valve centerline relative to the centerline of the eccentric dimensional tolerances more stringent requirements, generally require boring or CNC machining. Before assembly seat sealing surface and the ball should be equipped with a decent research, and then placed in the closed position of the sphere, installing left valve, adjusting pads, tighten the screws, the static pressure irrigation does not leak, this valve can be guaranteed in a sealed test under plastic security seal .
5 Conclusion
Seal small diameter ball valve structure in accordance with the length of existing home and abroad, connection type and dimensions related standards, the valve is not only suitable for conveying gaseous or liquid-phase medium, but also for medium and a liquid-liquid mixed slurry mixed media. The valve is used in metallurgy, textile and oil industries, to good effect.