Overview
Valve is an important product in general machinery. It is installed on various pipes or devices to control the flow of medium by changing the channel area in the valve. Its functions are: connect or cut off the medium, prevent the medium from flowing back, adjust the parameters such as medium pressure and flow, change the flow direction of the medium, divide the medium or protect the pipelines and equipment from overpressure, etc.
There are many varieties 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, pressure reducing valve and Traps, etc.; According to the material, it is divided into copper alloy, cast iron, carbon steel, alloy steel, austenitic steel, ferritic-austenitic dual-phase steel, nickel-based alloy, titanium alloy, engineering plastics and ceramic valves, etc. In addition, there are special valves such as ultra-high pressure valves, vacuum valves, power station valves, valves for pipelines and pipelines, valves for nuclear industry, valves for ships and cryogenic valves. Wide range of valve parameters, nominal size from DN1 (unit in mm) to DN9750; nominal pressure from ultra-vacuum of 1 × 10-10 mmHg (1mmHg = 133.322Pa) to ultra-high pressure of PN14600 (unit of 105 Pa); The working temperature ranges from the ultra-low temperature of -269℃ to the 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, pharmaceutical and food production systems, hydropower, thermal power and nuclear power production systems; Various types of valves are widely used in heating and power supply systems, metallurgical production systems, fluid systems for ships, vehicles, aircraft and various sports machinery, and irrigation and drainage systems for farmland. In addition, in the fields of new technologies such as defense and aerospace, various valves with special properties are also used.
Valve products account for a large proportion of mechanical products. According to the statistics of foreign industrialized countries, the output value of valves accounts for about 5% of the output value of the entire machinery industry. According to statistics, a traditional nuclear power plant composed of two million kilowatt units has about 28,000 shared valves, of which about 12,000 are nuclear island valves. A modern large-scale petrochemical complex requires hundreds of thousands of various valves, and the investment in valves generally accounts for 8% to 10% of the total investment in equipment.
General situation of valve industry in old China
01 The birthplace of China’s valve industry: Shanghai
In old China, Shanghai was the first place to manufacture valves in China. In 1902, Pan Shunji Copper Workshop, located on Wuchang Road, Hongkou District, Shanghai, began to manufacture small batches of teapot faucets by hand. The teapot faucet is a kind of cast copper cock. It is the earliest valve manufacturer in China known so far. In 1919, Deda (Shengji) Hardware Factory (the predecessor of Shanghai Transmission Machinery Factory) started from a small bicycle and started to produce small-diameter copper cocks, globe valves, gate valves and fire hydrants. Manufacture of cast iron valves began in 1926, with a maximum nominal size of NPS6 (in inches, NPS1 = DN25.4). During this period, hardware factories such as Wang Yingqiang, Dahua, Lao Demao and Maoxu also opened to manufacture valves. Subsequently, due to the increase in the demand for plumbing valves in the market, another batch of hardware factories, iron factories, sand foundry (casting) factories and machine factories opened to manufacture valves one after another.
A valve manufacturing group is formed in the areas of Zhonghongqiao, Waihongqiao, Daming Road and Changzhi Road in Hongkou District, Shanghai. At that time, the best-selling brands in the domestic market were “Horse Head”, “Three 8″, “Three 9″, “Double Coin”, “Iron Anchor”, “Chicken Ball” and “Eagle Ball”. Low-pressure cast copper and cast iron valve products are mainly used for plumbing valves in building and sanitary facilities, and a small amount of cast iron valves are also used in the light textile industry sector. These factories are very small in scale, with backward technology, simple plant equipment and low valve output, but they are the earliest birthplace of China’s valve industry. Later, after the establishment of the Shanghai Construction Hardware Association, these valve manufacturers have joined the association one after another and become the waterway group. member.
02Two large-scale valve manufacturing plants
At the beginning of 1930, Shanghai Shenhe Machinery Factory manufactured low-pressure cast iron gate valves below NPS12 for water works. In 1935, the factory established a joint venture with Xiangfeng Iron Pipe Factory and Xiangtai Iron Co., Ltd. shareholders to build Daxin Iron Factory (the predecessor of Shanghai Bicycle Factory), in 1936 Completed and put into production, there are nearly 100 employees, with imported 2.6 zhang (1 zhang ≈ 3.33m) lathes and lifting equipment, mainly producing industrial and mining accessories, cast iron water pipes and cast iron valves, the nominal size of the valve is NPS6 ~ NPS18, and It can design and supply complete sets of valves for water plants, and the products are exported to Nanjing, Hangzhou and Beijing. After the “August 13″ Japanese invaders occupied Shanghai in 1937, most of the plant and equipment in the factory were destroyed by Japanese artillery fire. The following year increased capital and resumed work. NPS14 ~ NPS36 cast iron gate valves, but due to economic depression, sluggish business, and austerity layoffs, they have not been able to recover until the eve of the founding of New China.
In 1935, five shareholders including Li Chenghai, a national businessman, jointly established Shenyang Chengfa Iron Factory (the predecessor of Tieling Valve Factory) on Shishiwei Road, Nancheng District, Shenyang City. Repair and manufacture valves. In 1939, the factory was moved to Beierma Road, Tiexi District for expansion, and two large workshops for casting and machining were built. By 1945, it had grown to 400 employees, and its main products were: large-scale boilers, cast copper valves, and underground cast iron gate valves with a nominal size below DN800. Shenyang Chengfa Iron Factory is a valve manufacturer struggling to survive in old China.
03The valve industry in the rear
During the Anti-Japanese War, many enterprises in Shanghai and other places moved to the southwest, so the number of 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 were the predecessors of Chongqing Valve Factory) began to repair and manufacture plumbing parts and low-pressure valves, which played a great role in developing wartime production in the rear and solving civilian valves. After the victory of the Anti-Japanese War, Lisheng Hardware Factory, Zhenxing Industrial Society, Jinshunhe Hardware Factory and Qiyi Hardware Factory successively opened to produce small valves. After the founding of New China, these factories were merged into Chongqing Valve Factory.
At that time, some valve manufacturers in Shanghai also went to Tianjin, Nanjing and Wuxi to build factories to repair and manufacture valves. Some hardware factories, iron pipe factories, machinery factories or shipyards in Beijing, Dalian, Changchun, Harbin, Anshan, Qingdao, Wuhan, Fuzhou and Guangzhou have also been engaged in repairing and manufacturing some plumbing valves.
Post time: Jul-21-2022