Method for controlling roundness of valve body during casting of butterfly valve body

Abstract

The invention discloses a method for controlling the roundness of a valve body during the casting of a butterfly valve body. The method comprises the following steps of: mounting an inner core and an outer core in an inner core groove and an outer core groove of a die base; arranging a round die cavity for casting an end flange of the butterfly valve body on two outer core boxes which are arranged oppositely in the outer core; taking a perpendicular line from the center of the round die cavity to a shaft lever as a reference line; moving inner core boxes and outer core boxes in the inner and the outer cores for 1.5 to 6 mm outwards respectively, which are positioned at the intersections of a diameter perpendicular to the reference line as well as the inner and the outer cores, and then fixing; keeping the inner core boxes and outer core boxes at the intersections of the inner and the outer cores unchanged; adjusting the positions of remaining inner and outer core boxes to ensue that the outer circumference of the inner core and the inner circumference of the outer core form smooth surfaces; closing; casting; and finishing. The roundness of the butterfly valve body cast by the method disclosed in the invention is accurate, the elliptic shapes or cracks are eliminated, the operating method is easy and low in cost, the production efficiency is increased, and the labor consumption is reduced.

Description

technical field [0001] The invention relates to a method for adjusting the roundness of a valve body, in particular to a method for adjusting the roundness of a butterfly valve body when casting the butterfly valve body. Background technique [0002] At present, the butterfly valve body is often used as on-off and flow control components of the pipeline system, mainly used in petroleum, chemical industry, metallurgy, hydropower and other fields, and has been widely used. 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. The butterfly valve body with a diameter greater than 1.8 meters is called a large valve. Body structure, the overall mold is usually used to cast the small butterfly valve body, and there is no specific casting equipment for the large butterfly valve body, because the valve...

AI Technical Summary

Problems solved by technology

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. The butterfly valve body with a diameter greater than 1.8 meters is called a large valve. Body structure, the overall mold is usually used to cast the small butterfly valve body, and there is no specific casting equipment for the large butterfly valve body, because the valve body has a large diameter and flanges at both ends, the flange exists during the casting process, resulting in molten steel The shrinkage ratio is difficult to determine, so that ellipse and cracks are prone to occur in the casting process. At present, the large butterfly valve bodies on the market are all welded by steel plates. The butterfly valve bodies formed by welding need subsequent finishing and are welded at the same time. The butterfly valve body has poor sealing effect, increased ellipticity, poor corrosion resistance, poor stability, and short service life, which is not conducive to use and promotion. Due to the need to stop for maintenance, it will increase production costs and reduce production efficiency.

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