Definition: 

1.The device used to control the flow in the pipeline.

Applied disciplines: Electric power (a subject); Hydraulic construction (two subjects) Definition 2: Equipment installed in a pressure pipeline to control the flow of water. Applied sciences: Water conservancy science and technology (a subject); hydraulic construction (two subjects); gates and hoists (three subjects)

The valve is a control component in the fluid delivery system and has functions such as cut-off, regulation, diversion, reverse flow, pressure regulation, diversion, or pressure relief. Valves used in fluid control systems, ranging from the simplest shut-off valves to various valves used in highly sophisticated automatic control systems, are quite diverse in variety and size. Valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, slurries, oils, liquid metals, and radioactive media. Valves can also be divided into cast iron valves, cast steel valves, stainless steel valves, chrome-molybdenum steel valves, chrome-molybdenum vanadium steel valves, dual-phase steel valves, and plastic valves depending on the material.

The history of the valve dates back to 1800. Before ancient 1800s, the ancient Egyptians used a similar wooden cock to control the distribution of water in order to prevent the Nile from flooding. These are the prototypes of the valve. The extensive use of industrial valves began after Watt invented the steam engine. At the beginning of the 20th century, valves made of various materials such as cast iron, cast steel, forged steel, stainless steel, chromium molybdenum steel, brass, etc., have appeared. Used in various industries, all kinds of working conditions. There are not many domestic companies that have introduced foreign valve production technologies. After introducing foreign production technologies, they have made breakthroughs in domestic valve production technology, improved quality, and increased longevity.

The valve is a smaller functional device used in industrial and urban construction. Its function is to control the active state of the medium (liquid, gas, powder) in the piping and equipment. Valves are classified according to their role in management. Cross-industrial and civilian general-purpose valves can be divided into gate valves, globe valves, plug valves, ball valves, butterfly valves, and diaphragm valves. According to the “China Valve Industry Development Trends and Investment Prospects Forecast Report 2013-2017” released by Concept Research Institute, China’s valve industry began to rise in the middle of the last century. Due to the needs of industrial construction and urban construction, the valve industry’s production scale is Smaller and larger, and in the practice and the introduction of foreign technology, from the simple development of more than 600 varieties to the production of the main 12 categories of valves, more than 3,000 models of scale, to achieve significant progress in research and development and production.

After several decades of development in China, the valve has made great progress. The current valve industry uses its performance parameters ranging from vacuum valves to ultra-high pressure valves of 600 MPa. The temperature ranges from cryogenic -196°C to high temperatures. 570 °C. Use medium for water, steam, urea, ethylene, explosives and other media. Valves are products with low profit margins and the market is highly competitive. Valves are used in a large amount in the water treatment industry, mainly in low pressure valve products such as butterfly valves, gate valves, and check valves. It is understood that there are more than 2,000 valve companies with a certain scale on the market, most of which are located in Jiangsu, Zhejiang and Central Plains.