Manufacturing method of valve rod of high temperature and high pressure cut-off valve

Abstract

The invention discloses a manufacturing method of a valve rod of a high temperature and high pressure cut-off valve. The method comprises the following steps: (1) processing the diameter of the valve rod of the high temperature and high pressure cut-off valve to the required pitch diameter of thread; and (2) carrying out cold extruding, plastic shaping and roll calibrating on the valve rod obtained in the step (1) by a rolling mode to form a required external thread, wherein 3 rolling wheels, i.e. an extruding wheel, a shaping wheel and a calibrating wheel, are used for the rolling mode. The thread accuracy of the valve rod manufactured by the method of the invention can reach to or even exceed the technical level of the like valve of American SWAGELOK which is the first brand all over the world, thereby enhancing the competitive force of China in the high-end valve market.

Description

technical field [0001] The invention relates to a method for manufacturing a valve stem, in particular to a method for manufacturing a valve stem of a high-temperature and high-pressure stop valve. Background technique [0002] At present, high-temperature and high-pressure globe valves have become indispensable fluid control equipment in industries such as nuclear industry, thermal power, petroleum, chemical industry, pipeline, shipbuilding, aerospace, and marine oil production. Most of the process systems in the above-mentioned industries need to be equipped with special valves. In particular, some high-end valves, such as high-temperature and high-pressure globe valves with a temperature resistance above 600°C and a pressure resistance above 30Mpa, are generally located in key parts of the process system. It will affect the realization of the function of the process system, causing the load reduction or even shutdown of the above-mentioned system unit. Therefore, the qua...

AI Technical Summary

Problems solved by technology

[0007] It can be seen from the data in the above table that the K value of the valve stem thread processed by the turning method is generally above 0.175, which cannot reach the standard requirement of 0.125~0.1443

At the same time, it was found in actual processing that the turning tool head wears seriously and needs to be replaced frequently, which not only increases the production cost, but also requires a lot of operating time and low production efficiency

[0008] As for the grinding method, although its precision is high, it can generally meet the precision requirements and performance of the valve stem thread, but its processing technology is more complicated, the cost is higher, and the economy is not good.

Therefore, grinding is not the most suitable method for threading the valve stem.

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