Ming precision valve manufacturing process three major characteristics

Compared with other mechanical manufacturing processes, the valve manufacturing process has the following characteristics: â‘  manufacturing process of the valve blank and the inspection process are complicated. Valve casting blank is a structure called the complex thin-walled shell parts. The casting requirements of smooth surface, casting a clear, in particular, to have a dense defect. In order to meet the above requirements, a series of process measures should be taken during casting, such as the selection of high refractory molding material and the control of sand moisture, the molding should be layered to ensure real sand to ensure that the hardness, the use of a reasonable system and strict control pouring hat gate Pouring speed and temperature. Due to the high technical requirements, valve casting rough casting process is much more complex than the average castings. In addition, the valve blank in addition to check size, position accuracy and appearance, there are some for the microstructure, mechanical properties, corrosion resistance and non-destructive testing and other tests, so the valve inspection process is more complicated. â‘¡ machining difficult Due to the wide range of valve materials, in addition to a variety of cast iron, carbon steel, most of its high strength, corrosion resistance and high hardness of the cutting performance of materials are poor, it is difficult to make the parts meet the required processing accuracy And surface roughness. The valve sealing surface geometry and surface roughness of the high requirements, so more difficult to increase the valve machining. At the same time, poor cutting performance of the valve material, but also to the valve processing methods, cutting tool material, cutting dosage, technology and equipment has brought a lot of new problems. â‘¢ valve parts installed on the machine more difficult Valve main parts of the structure, the shape is more complex, some parts are thin wall, slender, poor rigidity. When machining on a machine tool, positioning and clamping are difficult and often require complicated valve parts with special clamps. The accuracy of the positioning base is lower, the surface roughness is higher, and even non-machined surfaces are sometimes used for positioning. The machined sealing surface and other parts of the precision and surface roughness are high, it is difficult to ensure the quality of processing. Therefore, to meet the needs of the process, it is often necessary to increase the accuracy of the positioning of the base surface and reduce the surface roughness, or the positioning of non-machined surface of the base surface, which increases the complexity of the valve manufacturing process.