Tri eccentric hard sealing butterfly valve overcomes the leakage problem in low temperature environment
With the rapid development of industrial technology, the valve industry has put forward more stringent requirements, especially for hard sealed butterfly valves operating in cryogenic medium environment, in addition to meeting the performance of general valves, more importantly, the reliability, flexibility and some other special requirements of cryogenic valve sealing.
Compact structure, small size, light weight, and the same size Gate valve In contrast, it can reduce the space by 50%~40%, with small fluid resistance and rapid opening and closing. However, in some Chinese low-temperature equipment such as natural combustion liquefaction equipment, air separation equipment, pressure swing adsorption equipment and other chemical industries, the valves are mostly globe valves or gate valves, and the number of hard sealed butterfly valves is very small. The main reasons are The sealing performance under low temperature conditions is inferior to that of other valves, and the structure is unreasonable, which leads to medium leakage. The leakage seriously affects the safety and normal operation of these low-temperature equipment, and cannot meet the requirements of low-temperature equipment.
With the continuous development of cryogenic equipment in China, the requirements for the application of valves in the field of low temperature are constantly increasing. In order to meet the needs of market economic development, the metal hard seal butterfly valve has made structural improvements, developed a three eccentric seal structure, improved the sealing performance of the metal hard seal butterfly valve, and made it operate well in both high and low temperature environments.
Series products are long-life, energy-saving butterfly valves. Its structure is designed based on the principle of three-dimensional core weaving, and the valve seat adopts a multi-level structure compatible with hard and soft sealing, with exquisite processing and advanced technology. This product consists of valve body, butterfly plate, multi-level valve seat Valve rod , transmission mechanism and other main components. Therefore, it is widely used in the pipeline of corrosive media such as metallurgy, electric power, petroleum, chemical industry, air, gas, combustible gas and water supply and drainage. Features of three eccentric multi-level hard sealing flange butterfly valve: Because the butterfly valve of this product is designed based on the three-dimensional eccentric principle, the space movement track of the sealing surface is idealized, the sealing surfaces are free of friction and interference, and the sealing materials are properly selected, so that the sealing, corrosion resistance, high temperature resistance and wear resistance of the butterfly valve are reliably guaranteed. Its main characteristics are as follows: 1. Small opening torque, flexible and convenient, labor saving and energy saving. 2. Three dimensional core structure makes the butterfly plate more and more tight, with reliable sealing performance and no leakage. 3. High pressure resistance, corrosion resistance, wear resistance, long service life, etc. Main technical parameters Nominal diameter DN (mm) 50 ～ 2000 Nominal pressure PN (MPa) 0.6 1.0 1.6 2.5 4.0 Test pressure Strength test 0.9 1.5 2.4 3.75 6.0 Sealing test 0.66 1.1 1.76 2.75 4.4 Air seal test 0.6 0.6 0.6 0.6 0.6 Leakage rate ＜ 0.1 × DNmm3/s (in accordance with GB/T13927-92 standard) Applicable temperature Carbon steel: - 29 ℃~425 ℃ Stainless steel - 40 ℃~600 ℃ Applicable media Air, water, steam, gas, oil, acid, alkali, salt with weak corrosive media, etc Drive type: worm gear drive, pneumatic drive, electric drive Material of main parts Part name Material Valve body cast iron, stainless steel, chrome molybdenum steel, alloy steel Butterfly plate cast steel, alloy steel, stainless steel, chrome molybdenum steel Seal ring stainless steel and high temperature resistant asbestos board are combined into multiple layers Valve rod 2Cr13, 1Cr13 stainless steel, chrome molybdenum steel Bearing austenitic stainless steel, 304 nitriding Filler flexible graphite Features and principles of three eccentric multi-level hard sealing flange butterfly valve: 1. Deviation from pipe center 2. Deviation from the center of sealing surface 3. Inclined cone When the valve is opened, the butterfly plate and the valve seat contact instantaneously when they are closed, and the eccentricity 1 and 2 of the butterfly plate are used to quickly disengage from the valve seat, reducing the wear of the sealing pair, with small friction torque and flexible opening. Eccentric cone surface 3 enables the butterfly plate to pass through the inner hole of the valve seat to achieve contact sealing when the valve is opened or closed. In addition, the rotating radius of the conical butterfly plate is greater than the rotating radius of the contact position of the sealing pair, so the butterfly plate will become tighter and tighter when the valve is closed, which can realize self-locking and prevent the butterfly plate from over positioning. Note: Flange standard: GB/T9113.1-2000 GB/T911.5.1-2000 Note to the user: H1, H2 and H3 dimensions in the table can be lengthened according to the user's needs (long rod butterfly valve). If special materials are required, they should be put forward when ordering. Note: Dd represents multi-level sealing structure
