Casting and forming of general needle valve body

General needle valve body casting molding.

Most of the stop needle valve bodies are made of cast steel. Only in the Federal Republic of Germany has developed the high-pressure stop needle valve bodies made of forgings. In the low-pressure range, the stop needle valve bodies are made of steel plate forged or molded shell welded together.

The valve body of high-pressure cast steel stop needle valve can be directly welded on the pipeline in Europe and the United States except for the United States, because the safety coefficient of steel pipe and cast steel is the same. The body of the cast steel stop needle valve is supplied in Germany with two transition sections to match the size and material of the pipe.

The structure with a casting intermediate piece, the upper neck is processed by the forged cylinder, the intermediate piece can also be a die forging or a forged steel ingot drawn to form another structure of the forged valve body, wherein the intermediate piece including the neck is an integral part

If the nominal diameter and nominal pressure are different and the manufacturing method is different, it depends on the problems of economy and manufacturing technology. In recent years, the seamless forged stop needle valve body provided for nuclear power plants in the United States and Japan is perforated on the heavy three-way forging press and forged to the required shape.

All forged body seat rings are later inserted. The cast steel valve body and the valve seat of the cast steel intermediate piece can be cast into shape, and hardfacing is directly on them. Most valve body structures with high pressure use seal welded seat rings.