Ball or half-ball valve with drain-proof mechanism

A ball or half-ball valve with drain-proof mechanism, comprising:

• a body;
• an inner side of the body being formed as an approximate round chamber and a through hole communicated to the chamber;
• a top of the body being formed with an upper penetrating hole and a bottom thereof being formed with a lower penetrating hole;
• a stem passing through the upper penetrating hole to the chamber;
• a top end of the stem being connected to an operating unit for driving the stem to rotate;
• an annular seat received in the through hole;
• a front end and a rear end of the annular seat having reduced stepped structures;
• a connecting ring having an inward reduced front end;
• the connecting ring enclosing a front end of the annular seat and being tightly engaged to an inner wall of the through hole of the body;
• a gap being formed between the stepped front end of the annular seat and an inner wall of the connecting ring so as to provide elasticity;
• a first drain-proof ring being an annular ring;
• a rear end of the first drain-proof ring being a V shape concave recess;
• in assembly, the first drain-proof ring enclosing an outer wall of the annular seat and a front side thereof resisting against a rear end of the connecting ring;
• a second drain-proof ring being an annular ring;
• a front end of the second drain-proof ring being formed as a convex V shape protrusion corresponding to the V shape concave recess of the first drain-proof ring;
• in assembly, the second drain-proof ring enclosing an outer wall of the annular seat and a front side thereof being engaged to the V shape concave recess of the first drain-proof ring;
• the second drain-proof ring being elastic;
• the connecting ring, the first and second drain-proof rings being made of elastic material;
• an elastic ring enclosing the stepped rear end of the annular seat and resisting against a rear end of the second drain-proof ring;
• a valve unit being installed to the inner side of the annular seat;
• the valve unit having an axial hole for receiving the stem;
• and
• a cover having a size corresponding to that of the through hole;
• and the cover being locked to an outer side of the through hole.