Method for casting butterfly valve body

Abstract

The invention relates to a method for a casting butterfly valve body, comprising the steps of: 1, manufacturing an inner core: forming an annular inner core structure for later use by utilizing a plurality of fan-shaped inner core boxes; 2, manufacturing an outer core boxes according to the method in the step 1: forming an annular outer core structure for later use by utilizing a plurality of fan-shaped outer core boxes; 3, manufacturing a mould base for later use; 4, concentrically arranging the inner core and the outer core on the mould base; 5, reasonably adjusting the positions of the inner core and the outer core, planishing water-glass sand in the inner core and drying by utilizing carbon dioxide gas for later use; and 6, completing pouring molten steel within 1.5-2.5 minutes through a pouring opening on an sealing cover, holding the temperature for 7 hours and completing the casting. The method has the advantages of simple preparation process, reasonable design and short processing time, the production efficiency increased by more than 50%, guaranteed stability of the molded butterfly valve body, better roundness, no cracks on the surface and greatly enhanced tightness of the valve.

Description

[0001] technical field [0002] The invention relates to a casting method, in particular to a casting method of a butterfly valve body. Background technique [0003] At present, the butterfly valve body is widely used in the field of sealed pipelines in the petrochemical industry. As the diameter of the sealed pipeline increases, the diameter of the butterfly valve body gradually increases to more than 2 meters. We call the butterfly valve body with a diameter greater than 1.8 meters. Large valve body structure, there is no special casting equipment for large butterfly valve body, because theoretical analysis shows that: butterfly valve body 11 has a large diameter and flanges 12 at both ends, it is difficult to control the surface quality and roundness after molding, and casting In the process, it is difficult to guarantee the shrinkage ratio of molten steel, that is to say, it is difficult to control the shrinkage ratio of the flanged end and the flangeless end at the same...

AI Technical Summary

Problems solved by technology

[0003] At present, the butterfly valve body is widely used in the field of sealed pipelines in the petrochemical industry. As the diameter of the sealed pipeline increases, the diameter of the butterfly valve body gradually increases to more than 2 meters. We call the butterfly valve body with a diameter greater than 1.8 meters. Large valve body structure, there is no special casting equipment for large butterfly valve body, because theoretical analysis shows that: butterfly valve body 11 has a large diameter and flanges 12 at both ends, it is difficult to control the surface quality and roundness after molding, and casting In the process, it is difficult to guarantee the shrinkage ratio of molten steel, that is to say, it is difficult to control the shrinkage ratio of the flanged end and the flangeless end at the same temperature, so it is easy to appear out of round and cracks during the casting process. The large-scale butterfly valve bodies sold are all welded by steel plates. The welded butterfly valve bodies have the following disadvantages: low durability, poor corrosion resistance and stability, which seriously reduces the sealing performance of the valve. The valve company often has to shut down for maintenance

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