The origin of valves and the history of valves in China
The development of valves is closely related to the development of industrial production processes. In ancient times, large stones and trunks were used to impede or change the direction of the flow of rivers or creeks. And as early as the end of the Warring States Period, Li Bing, the governor of Qinshu County had already dug a salt well in the Chengdu Plain and used a bamboo-made valve for drawing brine.
The ancient Egyptians and Greeks invented several original valves for crop irrigation, etc. It is generally accepted that the ancient Romans invented and developed a rather complex crop irrigation system that used plug valves, plunger valves, and check valves to prevent water backflow.
During the Renaissance, in the design of the artist and inventor Da Vinci, valves were used in the canals, irrigation projects and other large hydraulic systems, and many of his technical solutions still exist. Subsequently, in Europe, the requirements for valves became gradually strict due to the development of technology and hydraulic machinery. Metal valves, like copper and aluminum plug valveswere created in this time.
The modern history of the valve industry is in parallel with the industrial revolution. In 1712, Thomas Newcomen invented the first practical steam engine which put control requirements on the operation of the steam engine. From 1763 to 1776, James Watt improved the engine and valves, including plug valves, safety valves, check valves and butterfly valves used on steam engines, officially entered the mechanical industry.
The valve manufacturing industry had gradually become an important part of the machinery industry.
In the 1960s, the economies of developed, industrialized countries went into a period of prosperity. Countries such as West Germany, Japan, Italy, France, and the United Kingdom were eager to find an international market so as to export their products, including complete sets of machinery and equipment, which drove the export of valves.
From the late 1960s to the early 1980s, many colonial countries were independent, for developing their industries, they imported large quantities of equipment, including valves. Besides, the oil crisis caused oil-producing countries to invest heavily in the highly profitable oil industry. These were reasons that the international valve production and trade were rapidly developing during that period of time.
China's valve industry production started from the 1960s, and mostly imitated the products from the former Soviet Union. Because of the backwardness of machinery industry and low accuracy of machining, valves made in China at that time had large leakage and could not meet the general control requirements of the industrial production process.
Since the 1970s, with the expansion of industrial production and the improvement of industrial process control requirements, some regulating valves were unable to meet the requirements of high pressure, high-pressure drop, low and high temperature, conveying corrosive media. Because of these, some large petrochemical enterprises imported equipment with control valves, like sleeve valves with balanced plug, eccentric rotary valves, etc. Those imported valves pointed out the development direction for domestic control valve manufacturers, and some of them began to model on those products.
Started from the 1980s, with the implementation of reform and opening up policy, China had organized major enterprises to import and learn from advanced technique, design and equipment from other countries, so the quality of valve and manufacturing technique had been rapidly improved. With the progress of industrial projects such as large power stations, various electro-hydraulic actuators, long-stroke actuators, etc. had been developed to meet the control requirements.
In the 1990s, China's regulating valve industry began to develop rapidly after introducing foreign advanced technologies, filling some blank space and shortening the gap with other countries. At present, many valves production enterprises in China have been able to design and manufacture various kinds of valves in accordance with ISO, DIN, AWWA and other standards, some of which have reached the international advanced level.
For outlining, valves are a kind of control components in pipeline transportation systems, including shut-off valves with the simplest structure and various valves used in extremely complex automatic control systems, such as ball valves, butterfly valves, gate valves, globe valves, check valves, safety valves, plug valves, etc. Valves can be used to control the flow of different kinds of fluids such as air, water, mud, oil, liquid metals, radioactive media, corrosive media. The distribution of the valve market is mainly based on the construction of engineering projects, industries, among which the biggest users are petrochemical, electric power, metallurgical, chemical and construction industries