As the ball valve usually rubber, nylon and Teflon as the seat ring material, so its temperature limits by the valve seat ring material. Cut-off valve function is * metal sphere in the medium under the action of compressed between the plastic seat to complete the (floating ball valve). Valve seat ring in a certain contact pressure under the action of elastic plastic deformation occurred in some areas. Can compensate for this deformed sphere of manufacturing accuracy and surface roughness of sealing performance guarantee. Also, because the ball valve seat rings are usually made of plastic, so in the choice of valve structure and performance, to consider the ball of fire and fire, especially in the petroleum, chemical, metallurgy, and other departments flammable, explosive media equipment and piping systems used in ball valve, should pay attention to fire and fire.
    Typically, the double regulation, strict sealing, slurry, wear, reduced access, opening and closing action quickly (1 / 4 turn open and close), high pressure cut-off (large pressure), low noise, there is the phenomenon of cavitation and gasification, a small amount of leakage to the atmosphere, the operation torque is small, fluid resistant piping systems, recommended ball valve.  
    Ball also applies to the light structure, low pressure cut-off (pressure difference), corrosive piping system. At low temperature (cryogenic) equipment and piping systems can also be used ball. Oxygen in the metallurgical industry pipeline systems, need to use the ball through the strict degreasing. In the pipeline and gas pipeline be laid in the head lines in the ground, the need to use full bore ball valve welded. Can regulate the performance of the requirements, the need to use V-shaped opening with a special structure of the ball. In the petroleum, petrochemical, chemical, power, urban construction, the working temperature above 200 ℃ piping system can use metal to metal sealing ball valve.