The internal thread connection ball valve and the butt welding connection ball valve are divided into an integral type, a two-stage type and a three-stage type. The valve body casting adopts the advanced technology introduced by Taiwan, China, with reasonable structure and beautiful appearance. The valve seat adopts elastic sealing structure, which is reliable in sealing and easy to open and close. The valve stem adopts a bottom-loaded structure with an inverted seal, and the valve stem is not impacted when the valve cavity is abnormally boosted. The 90° switch positioning mechanism can be set and locked as needed to prevent misoperation. Internal thread connection is not suitable for valve and butt welding ball valve for PN1.0～4.0MPa, working temperature -29～180°C (sealing ring is reinforced PTFE) or -29～300°C (sealing ring is para-polybenzene) On various pipelines, it is used to cut off or connect the medium in the pipeline. Different materials can be used for water, steam, oil, nitric acid, acetic acid, ammonia brine, neutralized water and other media.