Piston type swing check valve

The utility model relates to the technical field of check valves, in particular to a piston type swing check valve which comprises a valve body, a valve cover, a front flange and a rear flange, a rotating shaft is arranged on the inner side of the valve body, a rocker arm is rotatably connected to the outer side of the rotating shaft, a bolt is spirally connected to the inner side of the rocker arm, and the valve cover is arranged on the valve body. The check valve comprises a valve body, a bolt is fixedly connected to the inner side of the valve body, a check valve opening and closing block is spirally connected to the outer side of the bolt, a limiting piston is fixedly connected to the outer side of the check valve opening and closing block, and a guide plate is fixedly connected to the inner side of the valve body. According to the piston type swing check valve, the sealing effect of the check valve opening and closing block on the valve body is enhanced, the problem that a medium flows out due to insensi