The invention discloses a
ball valve with all-welded valve bodies and a
welding method of the
ball valve. The
ball valve comprises a spherical valve spool, a
left valve body, a right valve body, a middle valve body, a
valve stem, a
valve seat, sealing rings, a press plate, a lining plate and the like. The ball valve is applicable to valve systems in gas and liquid delivery pipelines, and a high-frequency
welding process is adopted to produce sealed parts. The spherical valve spool is placed in a spherical cavity in the middle valve body together with the lining plate, a thrust plate, a sliding bearing and the like, the sealing rings are mounted on the left and right sides of the spherical valve spool, the
valve seat and a valve-seat support ring thereof are mounted on the inner walls of the valve bodies on the left and right sides together with an elastic mechanism, joint parts between the middle valve body and the left and right valve bodies are all sealed by
welding, and one end of the
valve stem penetrates the middle valve body and is connected with the internal valve spool. The
valve stem rotates to drive the spherical valve spool in the cavity to rotate, so that the valve is controlled to be turned off. The ball valve is simple in structure, good in sealing performance, stable in welding and sealing quality, high in production efficiency and applicable to pipeline delivery systems for
petroleum,
natural gas and the like, and the problem of leakage of conventional valves is solved.