Fabrication method for a flange-type ball valve

Abstract

A fabrication method for an improved structure practical forged one-piece flange-type ball valve that consists of the forging the initial two blanks of the water inlet seat and the ball valve seat for a one-piece flange-type ball valve, based on the blueprints of conventional one-piece flange-type ball valves, with the water inlet seat having a left pipeline connection section already formed inside and the ball valve seat having a ball valve chamber, its contiguous water outlet port, and a right pipeline connection section already formed inside. To facilitate easier finishing, a shallower mating section is formed at the front end of the water inlet seat for contact with the ball valve chamber of the ball valve seat. A left water-tight gasket containment recess is then lathed in the mating section end surface of the water inlet seat and external threads are died along the outer sides of the mating section. Furthermore, internal threads are tapped in the connection hole at the front end of the ball valve chamber of the ball valve seat to enable the screw fastening of the external threads of the water inlet seat into the connection hole. A right water-tight casket containment recess is formed at the adjoining end surfaces between the water outlet port and the ball valve chamber and then a handle mounting hole is drilled. After the left and the right water-tight gaskets are inserted into the left and the right water-tight gasket containment recesses, the ball valve is placed inside the ball valve chamber. Then, the external threads of the water inlet seat mating section are coated with a thread locking agent and screw fastened to the internal threads in the connection hole of the ball valve seat which causes the left and the right water-tight gaskets to rest against the two spherical surfaces of the ball valve. As such, the ball valves fabricated according to the method of invention herein retain forged material strength, while avoiding the occurrence of pitting, reducing defect rates, allowing easier finishing, lessening material wastage, lowering production costs and, furthermore, minimizing component fabrication and shortening the manufacturing time.

Dependencies are inferred from the claim text.