Application And Drive Mode Of Sanitary Butterfly Valve In Sanitary Field
Application and drive mode of Sanitary Butterfly Valve in the sanitary field
Sanitary butterfly valve is a kind of valve widely used in the sanitary field. The reason why it is called butterfly valve is not that its appearance looks like a butterfly, but because this type of valve has a simpler appearance structure, is more convenient to use, has a smaller appearance, and is flexible to open and close. Butterflies are also small and flexible insects, and there are many similarities, so this device is called a sanitary butterfly valve.
The drive mode of sanitary butterfly valve is divided into manual, pneumatic, electric, etc. Among them, pneumatic butterfly valve is the terminal element in process control, and people have a newer understanding of its importance than in the past. The quality of the product depends on the quality of the product itself, whether the user correctly installs, uses, and maintains it, and it is very important to calculate and select it correctly. Due to the selection error at the time of purchase, the system is opened and stopped, and some cannot even be put into use. Users and system designers must pay attention to the selection principles of pneumatic sanitary butterfly valves. The specific principles are as follows.
Due to the error in calculation and selection, the system is often started and stopped, and some systems cannot even be put into use. Therefore, users and system designers should recognize the importance of valves on site and pay enough attention to the selection of regulating valves. According to the process conditions, select the appropriate structure and material; according to the characteristics of the process object, select the flow characteristics of the pneumatic sanitary butterfly valve; according to the process operation parameters, select the appropriate pneumatic sanitary butterfly valve caliber size; according to the requirements of the process, select the required auxiliary devices; and reasonably select the actuator.
The use of pneumatic sanitary butterfly valves with the same diameter as the pipeline and valve trims with limited flow capacity is conducive to reducing the valve inlet pressure and outlet fluid flow rate. It is not necessary to install additional pipe fittings such as reducers, which is conducive to reducing costs. By replacing valve trims with large flow capacity, the flow capacity can be expanded. By selecting valve trims with limited flow capacity, the error of calculating too large a caliber can be corrected.
In the era of digital information, more intelligent valve positioners or digital controllers will be used to realize nonlinear laws and compensate for the nonlinearity of the controlled object. The flow characteristics of pneumatic sanitary butterfly valves will be less used to compensate for the nonlinearity of the controlled object. The material of the valve trim changes with temperature. Therefore, the influence of thermal expansion at different temperatures should be considered, as well as the change of pressure resistance at high temperature. The corrosion resistance and fatigue resistance of the material should also be considered.
As a component used to realize the on-off and flow control of the pipeline system, the electric sanitary butterfly valve has been widely used in many fields such as petroleum, chemical industry, metallurgy, hydropower, etc. In the known electric sanitary butterfly valve technology, its sealing form mostly adopts a sealing structure, and the sealing material is rubber, polytetrafluoroethylene, etc. Due to the limitation of structural characteristics, it is not suitable for high temperature resistance, high pressure resistance, corrosion resistance, wear resistance and other industries.
A relatively advanced electric sanitary butterfly valve is a three-eccentric metal hard seal sanitary butterfly valve. The valve body and valve seat are connected components, and the valve seat sealing surface layer is welded with heat-resistant and corrosion-resistant alloy materials. The multi-layer soft stacked sealing ring is fixed on the valve plate. Compared with the traditional sanitary butterfly valve, the electric sanitary butterfly valve has the advantages of high temperature resistance, easy operation, no friction when opening and closing, and the sealing is compensated as the torque of the transmission mechanism increases when closing, which improves the sealing performance of the electric sanitary butterfly valve and extends its service life. Since the multi-layer soft and hard stacked sealing ring is fixed on the valve plate, when the valve plate is normally open, the medium forms a positive scouring on its sealing surface. After the soft sealing belt in the metal sheet interlayer is scour, it directly affects the sealing performance.
Selection of electric sanitary butterfly valve
The electric sanitary butterfly valve looks very complicated to install. But from an analysis point of view, it is just a few parts. It is small in size, simple in structure, and light in weight. It is also very simple to open the electric sanitary butterfly valve. Just press the switch and rotate it at a right angle to open it. At the same time, the electric sanitary butterfly valve has very good streamline control. The electric sanitary butterfly valve has a simple structure. Therefore, the only resistance is the valve of the sanitary butterfly valve, because the pressure through some valves drops a lot. And the sanitary butterfly valve has two kinds of sealing discs. One is elastic and the other is metallic. Electric sanitary butterfly valves are like many industrial mechanical equipment. The use of metallic ones has many restrictions compared to elastic ones.
Temperature and sealing. But the service life of metallic ones is much higher than that of elastic ones. If you choose to use it in some large-scale industries. We still recommend that you choose a metallic sanitary butterfly valve. Of course, to choose an electric sanitary butterfly valve, you must choose the size and type of the electric sanitary butterfly valve correctly.
The commonly used electric sanitary butterfly valves mainly have two types of clamp-type and flange-type electric sanitary butterfly valves. Each of these two has its own characteristics. The choice depends on which industry you use it in.
1. Electric opening and closing, with arbitrary adjustment, check and cut-off functions. Easy to operate, safe and reliable.
2. This valve can continuously realize the action of slow opening, fast opening or fast closing, slow closing, and effectively prevent the backflow of the medium at the pump outlet and the generation of water hammer.
3. Energy-saving drive, the same drive motor as the ordinary sanitary butterfly valve can realize the functions of high speed and small torque in the fast closing section and large torque in the slow closing low section.
4. When installed at the pump outlet, this sanitary butterfly valve has the common functions of both check valve and gate valve, so one valve can replace two valves, saving installation space and saving pipeline network cost.
5. Small flow resistance. The flow resistance coefficient of this valve does not exceed 0.3 when it is fully opened, so it can save energy and reduce the operating cost of the pipeline.
6. When an accident or power outage occurs, the opening and closing of the sanitary butterfly valve can be controlled manually.
