The evolutionary history of butterfly valves

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The original butterfly valve was a simple flap valve that did not seal tightly. It was typically used in water piping systems as a flow control valve and a damping valve. With the use of chemically resistant synthetic rubber in butterfly valves, their performance has been improved. Due to its corrosion resistance, erosion resistance, dimensional stability, good resilience, ease of molding, and low cost, synthetic rubber can be selected based on different performance requirements to meet the operating conditions of butterfly valves; for this reason, it is widely used in manufacturing the linings and elastic seat elements of butterfly valves. Due to its strong corrosion resistance, stable performance, low aging tendency, low friction coefficient, ease of molding, and dimensional stability, as well as the ability to improve its overall properties by filling it with appropriate materials to achieve greater strength and a lower friction coefficient, polytetrafluoroethylene (PTFE) overcomes some of the limitations of synthetic rubber. As a result, polymer materials such as PTFE and their modified versions through filling are widely used in butterfly valves, thereby further enhancing the performance of these valves; butterfly valves with a wider range of operating temperatures and pressures, as well as improved sealing performance and longer service life, have thus become available. To meet the requirements of industrial applications such as high and low temperatures, severe erosion, and long service life, metal-sealed butterfly valves have seen significant development over the past decade or so. With the use of alloy materials that are resistant to high and low temperatures, severe corrosion, and intense erosion, as well as those with high strength, in butterfly valves, metal-sealed butterfly valves have found wide application in industrial fields where extreme temperatures, severe erosion conditions, and long service life are required. Butterfly valves with large diameters (9750 mm), high pressures (2.2 kN/cm2), and a wide temperature range (-102 to 606°C) have been developed, pushing the technology of butterfly valves to a completely new level. Due to the wiping action of the butterfly valve disc, most butterfly valves can be used with media containing suspended solid particles; depending on the strength of the sealing elements, they can also be used with powdered and granular media. A butterfly valve is a type of valve that uses a disc-shaped closing element to rotate back and forth by about 90 degrees in order to open, close, and regulate the flow of fluid. Butterfly valves not only feature a simple structure, small size, light weight, reduced material consumption, and compact installation dimensions, but also require low driving torque; they are easy and quick to operate. Additionally, they offer excellent flow regulation capabilities as well as good sealing properties, making them one of the fastest-growing types of valves over the past decade or so. Especially in industrially developed countries such as the United States, Japan, Germany, France, and Italy, butterfly valves are widely used. The variety and quantity of these valves continue to increase, with developments focusing on higher temperatures, higher pressures, larger diameters, improved sealing performance, longer service life, better control characteristics, and multi-functional capabilities. Their reliability and other performance metrics are at a high level, and they have already begun to replace gate valves, ball valves, and other types of valves in some applications. With the advancement of butterfly valve technology. In the foreseeable future, especially in applications involving large and medium-sized diameters and medium to low pressures, butterfly valves will become the dominant type of valve. The application of Computer-Aided Design (CAD), Computer-Aided Manufacturing (CAM), and Flexible Manufacturing Systems (FMS) in the valve industry has raised the design and manufacturing of butterfly valves to a completely new level. It not only comprehensively revolutionized the design and calculation methods for valves, reducing the heavy amount of repetitive routine design work for technical professionals, thereby allowing them to devote more time to improving the technical performance of products and to the research and development of new products, but it also shortened development cycles and increased labor productivity. Especially in the field of metal-sealed butterfly valves, the application of CAD/CAM has led to the development of three-dimensional sealing pairs that are designed using CAD and manufactured through CNC machining; this prevents any squeezing, scratching, or wear on the sealing surfaces during the opening and closing process of the valve, thereby increasing its sealing performance and service life by orders of magnitude. When fully open, butterfly valves present low flow resistance; moreover, when opened at angles between approximately 15° and 70°, they allow for precise flow control. As a result, they are widely used in applications involving large-diameter piping systems, and they are set to gradually become the dominant type of valve.