Since the ball valves are usually used as a seat seal material with rubber, nylon and PTFE, its use temperature is limited by the material of the valve seat seal ring. The cut-off effect of the ball valve is by the metal sphere in the media, in the plastic valve seat between each other tight to complete (floating ball valve). The seat seal ring under certain contact pressure, the local area occurrence elastic plastic deformation. This deformation can compensate the manufacturing precision and surface roughness of the sphere, and ensure the sealing performance of the ball valve.
Also because the valve seat seal ring is usually made of plastic. Therefore, in the choice of the structure and performance of the ball valve, to consider the fire and fire, especially in the oil, chemical, metallurgy and other departments, in flammable, explosive media equipment and piping system use ball valves, more attention should be fire and fire.
Usually, in double-position adjustment, strict sealing performance, mud, abrasion, shrinkage channel, and open and close movements (1/4), high pressure cut-off (pressure difference), low noise, cavitation and gasification phenomena, small leakage to the atmosphere, the operating torque, low fluid resistance in the pipeline system, the recommended use of ball valves.
Ball valves also apply to light structure, low pressure cut-off (low pressure), corrosive media piping system. Ball valves can also be selected in cryogenic (cryogenic) Installations and piping systems. In the metallurgical industry in the oxygen piping system, the use of a strictly degreasing ball valve. All diameter welded ball valves are required when the supervisor line in the oil pipeline and gas transmission line is buried underground. The ball valve with a special structure with V-shaped openings is required when regulating performance is required. In the petroleum, petrochemical, chemical, electric power, urban construction, operating temperature in more than 200 degrees of piping system can be selected metal sealed ball valves.