1、 Overview
The valve is an important product in the general machinery, which is installed on a variety of pipelines or devices to control the flow of the medium by changing the channel area in the valve. Its role is: turn on or cut off the medium, prevent the medium from countercurrent, adjust the medium pressure and flow parameters, change the flow direction of the medium, divide the medium or carry out overpressure protection on the pipeline and equipment.
There are many kinds of valve products, which are divided into gate valve, globe valve, check valve, ball valve, butterfly valve, plug valve, diaphragm valve, safety valve, regulating valve (control valve), throttle valve, reducing valve and trap valve according to the function and structure principle; According to the material, there are copper alloy, cast iron, carbon steel, alloy steel, austenitic steel, ferritic-austenitic biphase steel, nickel-based alloy, titanium alloy, engineering plastics and ceramic valves. In addition, there are ultra-high pressure valves, vacuum valves, power station valves, pipeline and pipeline valves, valves for the nuclear industry, valves for ships and low-temperature valves and other special valves. A wide range of valve parameters, nominal sizes from DN1 (in mm) to DN9750; Nominal pressure from 1×10-10mmHg (1mmHg=133.322Pa) ultra-vacuum to PN14600 (unit 105 Pa) ultra-high pressure; The operating temperature ranges from ultra-low temperature of -269℃ to ultra-high temperature of 1200℃.
Valve products are widely used in various sectors of the national economy, such as oil, natural gas, oil and gas refining and processing and pipeline transportation systems, chemical products, medicine and food production systems, hydropower, thermal power and nuclear power production systems; The water supply and drainage, heating and power supply systems of urban and industrial enterprises, metallurgical production systems, fluid systems of ships, vehicles, aircraft and various moving machinery, irrigation and drainage systems of farmland, etc., all use various types of valves in large numbers. In addition, in the field of new technologies such as defense and aerospace, a variety of valves with special performance are also used.
The proportion of valve products in mechanical products is larger, according to the statistics of foreign industrial developed countries, the output value of valve accounts for about 5% of the output value of the entire machinery industry. According to statistics, a traditional nuclear power plant consisting of two sets of million-kilowatt units shares about 28,000 valves, of which about 12,000 are nuclear island valves. A modern large-scale petrochemical complex needs more than 100,000 sets of various valves, and the investment for valves generally accounts for 8% to 10% of the total investment in equipment.
2、The general situation of the valve industry in old China
After the Opium War, old China was in a semi-feudal and semi-colonial society for a long time, and the industrial base was very weak, and the valve industry was especially backward. In the late 19th century, imperialist countries such as Britain and the United States dumped various valves to our country through comprador. At that time, the name of the Valve was unknown, and the commercial common name was called "Val" (the translation of valve). The common name of "Val" has become a well-known substitute name in our country. The "Glasses" brand, "Ostrich" brand and the "W" brand and "C" brand made in the United States have flooded the Chinese market. Until the eve of the founding of New China, our country has not yet got rid of this situation of relying entirely on imports of "Val".
01 The birthplace of China valve industry: Shanghai
In old China, Shanghai was the earliest place to manufacture valves. In 1902, Pan Shunji Copper Workshop, located in Wuchang Road, Hongkou District, Shanghai, began to manufacture small quantities of teapot taps by hand. Teapot taps are a kind of cast copper cock. Pan Shunji Copper Workshop is the earliest valve manufacturer known in China so far. In 1919, Deda (Shengji) Hardware Factory (predecessor of Shanghai Gearshift Machinery Factory), started from a small bicycle bed, opened the production of small-caliber copper cock, stop valve, gate valve and fire faucet. The manufacture of cast iron valves began in 1926, with a maximum nominal size of NPS6 (in, NPS1= DN25.4). During this period, Wang Yingchang, Dahua, Lao Demao and MAO Xu and other hardware factories have also opened to manufacture valves. Subsequently, due to the increase in demand for water heating valves on the market, there are a number of hardware factories, iron factories, foundry (casting) factories and machine factories have opened to manufacture valves. In Shanghai Hongkou District, Hongqiao, Hongqiao, Daiming Road and Changzhi Road area to form a valve manufacturing group. At that time, the best-selling in the domestic market have "horse head" brand, "three 8" brand, "three 9" brand, "double money" brand, "iron anchor" brand, "chicken ball" brand and "eagle ball" brand and other low-pressure casting copper, cast iron valve products, mainly used in building sanitation facilities with water heating valves, there are also a small number of cast iron valves for textile industry. These factories are very small, backward technology, simple plant equipment, valve output is very low, but it is the earliest birthplace of China's valve industry, and later the Shanghai building hardware Industry Association was established, these valve manufacturers have to join, become a member of the waterway group.
02 Two large valve manufacturers
At the beginning of 1930, Shanghai Shenhe Machinery Factory manufactured low pressure cast iron gate valves below NPS12 for waterworks. In 1935, the factory jointly built Daxin Iron Factory (predecessor of Shanghai Bicycle Factory) with Xiangfeng Iron Pipe Factory and shareholders of Xiangtai Iron No., which was completed and put into operation in 1936. With imported 2.6 zhang (1 zhang ≈3.33m) lathe and lifting equipment, the main production of industrial and mining accessories, cast iron pipes and cast iron valves, the nominal size of the valve is NPS6 ~ NPS18, and can design and supply complete sets of valves for waterworks, products are exported to Nanjing, Hangzhou and Beijing and other places. In 1937, after the "813" Japanese invaders occupied Shanghai, most of the plant equipment was destroyed by Japanese artillery fire, and the following year, although it had also made NPS14 ~ NPS36 cast iron gate valves for Shanghai Zhabei, Nanshi Water works and British and French commercial water works, but due to economic depression, slow business, austerity and layoffs, On the eve of the founding of the People's Republic of China, it still failed to recover. In 1935, by the national businessman Li Chenghai and other five shareholders joint venture to build Shenyang Chengfa iron factory (the predecessor of Tieling Valve Factory) in the twelve Wei Road in the southern district of Shenyang, started from three houses and three machine tools, began to engage in mechanical repair and manufacture valves. 1939 Moved the factory to Tiexi North Second road for expansion, new casting, machining two large workshops. By 1945, it developed to have 400 employees, the main products are: large full boiler, cast copper valves, nominal size of underground cast iron gate valves below DN800. Shenyang Chengfa Iron Factory is a valve manufacturer struggling to survive in old China.
03 The valve industry in the rear
During the War of Resistance, many enterprises in Shanghai and other places moved to the southwest, so the enterprises in Chongqing and other places in the rear area soared, and the industry began to develop. In 1943, Chongqing Hongtai Machinery Factory and Huachang Machinery Factory (both factories are the predecessor of Chongqing Valve Factory) began to repair and manufacture plumbing parts and low-pressure valves, which played a great role in the development of wartime production in the rear area and the solution of civilian valves. After the victory of the Anti-Japanese War, there were Lisheng Hardware Factory, revitalizing Industrial Society, Jinshun and hardware factory and Qiyi Hardware Factory successively opened to produce small valves, and these factories were incorporated into Chongqing Valve Factory after the establishment of New China. At that time, some valve manufacturers in Shanghai also went to Tianjin, Nanjing and Wuxi and other places to build factories to repair and manufacture valves. Some hardware factories, iron pipe factories, machine factories or shipyards in Beijing, Dalian, Changchun, Harbin, Anshan, Qingdao, Wuhan, Fuzhou and Guangzhou have also been engaged in repairing and manufacturing valves for water heating buildings.