The floating pneumatic ball valve has simple structure and good sealing performance, but the load of the working medium borne by the ball is all transferred to the outlet seal ring. Therefore, it is necessary to consider whether the seal ring material can withstand the working load of the ball medium. This structure is widely used for medium and low pressure ball valves.

5. Classified by nominal diameter (1) Small diameter valves: valves with nominal diameter DN ≤ 40mm. (2) Medium diameter valve: valve with nominal diameter of 50~300mm. (3) Large diameter valve: the nominal valve DN is 350~1200mm. (4) Extra large diameter valve: valve with nominal diameter DN ≥ 1400mm.