Method for casting valve body of heavy-calibre non-rising-stem flat valve

Abstract

The invention discloses a method for casting a valve body of a heavy-calibre non-rising-stem flat valve. In the method, ester-cured water-glass sand is used for modeling to make a sand core, two RND 300 neck-down heating heat-insulation dead heads (1) are arranged at the valve belly part of the valve body of the sand core, six shaped chills (4) which are 90mm thick are arranged at the bottom of the valve belly part at a distance of 30mm, eight shaped chills (3) which are 70mm thick are arranged at an edge flange of the valve body, and a Phi 200*50mm shaped chill (2) is installed at the tail part of the valve body; the neck-down heating heat-insulation dead heads (1) perform feeding on the valve belly part of the valve body, the shaped chills (4) perform feeding on the bottom of the valve belly part, and the neck-down heating heat-insulation dead heads (1) at the valve belly part perform feeding on the shaped chills (3) of the edge flange of the valve body, and the shaped chill (2) performs feeding on the tail part of the valve body. In the invention, the neck-down heating heat-insulation dead heads are used for feeding, convenience is brought for gas cutting, the casting yield is increased, casting defects, such as sand inclusion, shrinkage porosity, cracks, sand blowholes, slag blowholes and the like, are avoided, and technical demands of customers are met.

Description

technical field [0001] The invention relates to a casting method, in particular to a casting method for a valve body of a large-diameter concealed rod flat plate valve. Background technique [0002] Large-diameter hidden rod flat plate valves are mainly used in engineering aspects such as oil and natural gas wellhead equipment, choke and kill manifolds, and fluid control. With the rapid development of oil and natural gas drilling technology, the depth of oil and natural gas drilling is increasing; a large number of oil and gas reservoirs in deep, ultra-deep and complex formation conditions have been discovered, providing a rare development for high-performance hidden rod flat plate valves Opportunities, especially today when the status of oil as a strategic material is more obvious and the price of crude oil is high, countries all over the world are increasing the exploration and drilling of oil and natural gas, and the large-caliber hidden rod flat plate valve will have a b...

AI Technical Summary

Problems solved by technology

[0003] If the free forging blank is used for processing, the machining allowance is too large, the material utilization rate is low, and the product material cost and processing cost will increase; if the die forging blank is used for processing, the forging equipment must be replaced and expensive die forging dies must be purchased. This is neither economical nor realistic, and it is finally determined to use the cast steel blank

[0004] However, there are many problems in the steel castings of large-diameter dark rod flat plate valves: due to the large wall thickness of the valve body and the large mud core, it is easy to form casting defects such as sand inclusions, shrinkage porosity, shrinkage cavities, cracks, sand pores, and slag pores. The valve body of the large-diameter concealed rod flat plate valve cannot meet the required technical requirements

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