Method for casting valve body of flat gate valve

Abstract

The invention discloses a method for casting a valve body of a flat gate valve, and belongs to the technical field of valve body casting processes. The method is technically characterized in that a valve body cavity is vertically formed between a sand mold and a sand core; a plurality of valve body heat preserving risers are uniformly arranged at the open end of the valve body through the sand mold; a flange heat preserving riser is arranged at the upper end of a flange plate on each of two sides; a first external chill is arranged at the lower end of each flange plate; a plurality of second external chills are uniformly arranged at the periphery of a valve belly below the middle line of a flange; a third external chill is arranged on the outer bottom surface of the blind end of a main body of the valve body; process supplementary ion is arranged in an inner hole of the flange plate on each of the two sides; a fourth external chill is arranged on each of two end surfaces of a valve seat table in an inner cavity of the valve body. Therefore, the probability of occurrence of casting impurities and pore defects is reduced by using a vertical pouring method, gravity feeding is easy to implement so as to be matched with the chilling action of each external chill, and castings can be fed in sequence, so that the internal quality of the castings is well improved.

Description

technical field [0001] The invention relates to the technical field of casting technology of a valve body, in particular to a casting method of a flat gate valve body. Background technique [0002] The main function of the flat gate valve is to control the on-off of the pipeline. It is mainly used in natural gas, petroleum, chemical, environmental protection, urban pipelines, gas pipelines and other transmission pipelines, venting systems and gas storage devices. With the rapid development of the world economy, there is an increasing demand for chemical equipment and facilities such as natural gas and petroleum. The demand for slab gate valves with advantages such as restrictions is also increasing. [0003] The structure of the flat gate valve body is relatively special, especially its inner cavity structure is more complicated than that of ordinary castings, so it is difficult to cast such castings. At present, the common method is to use the flat casting method, that is,...

AI Technical Summary

Problems solved by technology

However, due to the large wall thickness, the large inner cavity of the casting from the valve seat to the closed end, and the long length, this type of cast steel blank is very prone to slag inclusions and sand holes when the commonly used flat pouring method is adopted. , Shrinkage porosity, cracks, pores and shrinkage cavities and other casting defects, so it is difficult to meet the quality requirements of the flat gate valve body castings cast by the general flat casting method

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