Selection principle of valve blanks and machining allowance

First, the selection principle of valve blanks

Commonly used blanks for machining include castings, forgings, profiles and welded parts. Different types of blanks and the accuracy, roughness and hardness of the blanks have a direct impact on the machining process.

The following factors should be considered when selecting valve blanks.

①The material of the part and the organization and performance requirements of the material. The part material specified on the design drawing generally determines the type of blank. For example, if the part material is cast iron, the casting method must be used to make the blank. For steel parts, the mechanical properties of the material should be considered when selecting the blank. For example, the parts of high-pressure valves should generally be forged or welded to ensure that the material has good mechanical properties.

②The structural shape and external dimensions of the parts. The structural shape of the part is an important factor that affects the selection of the blank. For example, a valve body with a complex structure and shape can choose a casting. The valve body with a large size can be cast by sand casting; the valve body with a small size can be cast by investment casting.

③The size of the production program. The larger the production program of the parts, the better the economic effect of using high-precision and high-efficiency blank manufacturing methods.

④ Conditions for blank manufacturing. The blank should be selected according to the on-site equipment status and technological level, and the development prospects should be considered, and advanced blank manufacturing methods should be gradually adopted.