Patent ID: 8807530

Claim:
A bottom entry plastic ball valve comprising a valve stem cap ( 1 ), a valve stem ( 2 ), a valve stem sealing ring ( 3 ), a valve stem end surface sealing ring ( 4 ), a valve ball sealing ring ( 5 ), a supporting ring ( 6 ) for the valve ball sealing ring, a valve ball ( 7 ), a connecting pipe ( 8 ), and a valve body ( 9 ), wherein a hollow valve ball chamber ( 911 ) is provided inside the valve body ( 9 ), wherein the valve body ( 9 ) is provided with a valve cover hole ( 912 ) just below the valve ball chamber ( 911 ), the width of the valve cover hole ( 912 ) is larger than the diameter of the valve ball ( 7 ), the ball valve also comprises a valve cover ( 10 ) corresponding to the valve cover hole ( 912 ) so that a valve cover ( 10 ) can cover the valve cover hole ( 912 ) and can be fusion-bonded to the valve body ( 9 ), wherein the right end and the left end of the valve body ( 9 ) are respectively provided with a connecting pipe seat, the side of said each connecting pipe seat fusion-welded with the connecting pipe ( 8 ) is provided with an outer end surface ring ( 910 ) which is perpendicular to the axial line of the valve body ( 9 ), and the valve body ( 9 ) and the connecting pipe ( 8 ) are in end surface welding through the outer end surface rings ( 910 ) by hot melt, wherein two sides of the valve ball chamber ( 911 ) of the valve body ( 9 ) are respectively provided with a positioning end surface for the mounting ring for the valve ball sealing ring and a positioning end surface for the supporting ring for the valve ball sealing ring, and wherein the valve ball chamber ( 911 ) is an inner cylindrical surface coaxial with the valve body ( 9 ) and has an indentation at the valve cover hole ( 912 ), the valve cover ( 10 ) is provided with an inner cylindrical surface ( 101 ) of the valve ball chamber for supplementing the indentation, the valve body ( 9 ) is further provided with an inner cylindrical surface ( 92 ) fitted with the outer cylindrical surface of the valve ball sealing ring ( 5 ), the inner cylindrical surface ( 92 ) is in the shape of a circular ring concentric with the valve body ( 9 ), the inner cylindrical surface ( 92 ) has an indentation on the valve body ( 9 ), and the valve cover ( 10 ) is provided with an inner cylindrical surface ( 102 ) of the valve ball sealing ring for supplementing the indentation.