Butterfly Vale

The disadvantage of rubber sealed butterfly valve is that when it is used as throttle, the improper use will cause cavitation, which will lead to rubber seat peeling and damage, so how to choose it correctly depends on the working conditions. The relationship between the opening of butterfly valve and the flow rate basically shows a linear proportional change. If it is used to control flow, its flow characteristics are closely related to the flow resistance of piping. For example, the caliber and form of valves installed in two pipes are identical, and the flow rate of valves varies greatly with different loss coefficients of pipes. If the valve is in a larger throttling range, the back of the valve plate is prone to cavitation, which may damage the valve, generally used outside 15 degrees. When the butterfly valve is in the middle opening, the shape of the opening formed by the valve body and the front end of the butterfly plate is centered on the valve shaft, and different states are formed on both sides. The front end of the butterfly plate on one side moves in the direction of downstream water and the other side moves in the direction of countercurrent water. Therefore, the valve body and the valve plate on one side form a nozzle-like opening and the other side is similar to a throttle orifice opening. The nozzle side is much faster than the throttle side, and the negative pressure under the throttle side valve often causes the rubber seal to fall off. The operating moment of butterfly valve varies with the opening and opening direction of the valve. Horizontal butterfly valve, especially large-caliber valve, can not be ignored because of the depth of water and the difference between the shaft and the head of the valve. In addition, when the elbow of the valve inlet side device forms a bias flow, the moment will increase. When the valve is in the middle opening, the operating mechanism needs self-locking due to the action of the hydrodynamic moment.
There are many valve industry chains in China, but they are not powerful countries in valve industry. Generally speaking, China has entered the ranks of the world's valve powers, but there is still a long gap between China and the world's valve powers in terms of product quality. The phenomena of low production concentration, low R&D capability of high-end products, low manufacturing technology level of the valve industry still exist, and the trade deficit between import and export continues to expand. There are absolutely not so many valve companies that can really survive in the market. However, the high-speed shocks in the valve industry will bring huge opportunities, and the results of the shocks will make the market operation more rational. The road to localization of high-end valves is unusually bumpy. Infrastructure has become a short-board restricting the development of high-end manufacturing industry in China. During the 12th Five-Year Plan period, the government will continue to intensify the localization of high-end equipment components. Here we select several key points mentioned in the Implementation Plan to develop representative valve industry for feasibility analysis of import substitution. From the analysis, it can be seen that the feasibility of valve import substitution varies greatly among various sub-industries, and high-end valves need more policy guidance and scientific research support urgently.
Valve industry, as an important part of equipment manufacturing industry, plays a very important role in the development of national economy. Because of the gap between domestic valve manufacturing level and international advanced level, many key valves with high parameters, high temperature, high pressure and high pound class originally depended on imports. For example, European OMAL brand has always been the main choice for domestic valve application industry. In order to promote the localization of valves, after the State Council issued "Several Opinions on Accelerating the Revitalization of Equipment Manufacturing Industry", the relevant departments of the State made a series of major deployments in accordance with the requirements of the nationalization of major equipment made by the State, led by the National Development and Reform Commission, the China Machinery Industry Federation and the China General Machinery Corporation. Together with the Association of Machinery Industry, it has deployed and formulated the localization scheme of valves for major equipment in relevant fields, and coordinated with relevant departments many times. Nowadays, the localization of valves has reached a consensus in the domestic valve industry. Actively adopt international standards for product design; absorb foreign excellent design structure (including patented technology); product testing and performance testing are strictly carried out in accordance with international standards; absorb foreign production process experience and attach importance to the research and application of new materials; clarify the technical parameters and working conditions of imported high-parameter valve products, etc. It is a way to speed up the localization process, promote the continuous renewal of valve products and realize the localization of valves in an all-round way. With the acceleration of the reorganization of the valve industry, the future industry will be the competition between product quality safety and product brands. The products will develop towards high technology, high parameters, strong corrosion resistance and long life. Only through continuous technological innovation, development of new products and technological transformation, can the technical water of products be gradually improved. Horizontal, to meet the domestic equipment supporting, fully realize the localization of valves. Under the huge demand environment, the valve manufacturing industry in China will show a better development prospects.
Working principle
Butterfly valve is a kind of valve that opens, closes or regulates the flow of medium by turning the disc opening and closing parts around 90 degrees. Butterfly valves are not only simple in structure, small in volume, light in weight, low in material consumption, small in installation size, small in driving moment, simple in operation and fast in operation, but also have good flow regulation function and sealing characteristics. They are one of the fastest growing valve varieties in recent decades. Butterfly valves are widely used. The variety and quantity of its use are still expanding, and it is developing towards high temperature, high pressure, large caliber, high sealing, long life, excellent regulation characteristics and multi-function of a valve. Its reliability and other performance indicators have reached a high level.
With the application of synthetic rubber to butterfly valves, the performance of butterfly valves has been improved. Because synthetic rubber has the characteristics of corrosion resistance, erosion resistance, dimensional stability, good resilience, easy forming and low cost, it can choose synthetic rubber with different properties according to different application requirements.