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Electronic Butterfly Valve The main connection methods are flange type and clamp type. It is an important execution unit in the field of industrial automation control. This valve is generally installed horizontally. Structure and Working Principle It is typically composed of an angular travel electric actuator (with a rotation range of 0~90°) and the butterfly valve, which are connected mechanically to each other; after installation and adjustment, they work together as a single unit. Based on the mode of operation, they are classified into on-off type and adjustable type. The switch-type type directly connects to the power supply (AC220V or other voltage levels) and completes the switching action by directing current in either direction through the switch. The regulating type uses an AC220V power supply as its power source, and receives signal values of 4~20mA (0~5 for low-voltage control) preset by the industrial automation control system in order to carry out the regulation process. Primary use: Control of flow rate, pressure, and temperature in pipelines for industrial automated production. For example: electricity, metallurgy, petrochemicals, environmental protection, energy management, fire protection systems, etc. Disadvantages of butterfly valves: 1. Narrow range of operating pressure and working temperature. 2. The sealing performance is poor. Butterfly valves can be classified by structure into offset plate type, vertical plate type, inclined plate type, and lever type. Based on the sealing type, they can be divided into the semi-sealed type and the hard-sealed type. Soft-sealed types generally use rubber rings for sealing, while hard-sealed types usually use metal rings for sealing. Based on the type of connection, they can be divided into flange connections and clamp connections ； Based on the transmission method, they can be classified into manual, gear-driven, pneumatic, hydraulic, and electric types. Installation and Maintenance of Butterfly Valves 1. During installation, the valve disc should be in the closed position. 2. The opening position should be determined based on the rotation angle of the butterfly valve disc. 3. For butterfly valves equipped with a bypass valve, the bypass valve should be opened first before opening the butterfly valve. 4. It should be installed in accordance with the manufacturer’s installation instructions; for butterfly valves with heavy weights, a solid foundation should be provided. Selection of butterfly valves The disc of a butterfly valve is installed in the diameter direction of the pipeline. Within the cylindrical passage of the butterfly valve body, the disc-shaped butterfly plate rotates around its axis by an angle ranging from 0° to 90°; when it reaches 90°, the valve is in its fully open position. Butterfly valves have a simple structure, are small in size and light in weight, consisting of only a few components. Moreover, it can be quickly opened and closed by simply rotating 90°, making the operation simple; at the same time, this valve boasts excellent fluid control properties. When the butterfly valve is in its fully open position, the thickness of the butterfly disc is the only resistance to the flow of the medium through the valve body; as a result, the pressure drop across this valve is very small, giving it excellent flow control characteristics. Butterfly valves come in two types of sealing: elastic sealing and metal sealing. Elastic-sealing valves, where the sealing ring can be embedded in the valve body or attached around the butterfly disc. Valves with metal seals generally have a longer lifespan than those with elastic seals, but it is difficult to achieve a perfect seal. Metal seals can withstand higher operating temperatures, while elastic seals have the drawback of being limited by temperature. If a butterfly valve is to be used for flow control, the key is to correctly select its size and type. The structural principle of butterfly valves makes them particularly suitable for manufacturing large-diameter valves. Butterfly valves are widely used not only in general industries such as petroleum, gas, chemicals, and water treatment, but also in the cooling water systems of thermal power plants. The commonly used butterfly valves are wafer-type butterfly valves and flanged butterfly valves. A wafer butterfly valve is connected between two pipe flanges using bolts, while a flanged butterfly valve has flanges on it, with the flanges at both ends of the valve being connected to the pipe flanges via bolts. Structure of butterfly valves and problems encountered during use At present, butterfly valves, as components used to control the on/off status and flow rate in pipeline systems, have been applied in many fields such as petroleum, chemicals, metallurgy, and hydropower. In the well-known butterfly valve technology, sealing is typically achieved through a sealing structure, with sealing materials such as rubber and polytetrafluoroethylene being used. Due to limitations in its structural properties, it is not suitable for applications requiring high temperature and pressure resistance, as well as corrosion and wear resistance. A relatively advanced type of butterfly valve is the triple-eccentric metal hard-seal butterfly valve, in which the valve body and the valve seat are integrated components, with the sealing surface of the valve seat being clad with heat-resistant and corrosion-resistant alloy materials. Multi-layer soft folded sealing rings are fixed on the valve plate; compared to traditional butterfly valves, this type of butterfly valve offers advantages such as high temperature resistance, easy operation, friction-free opening and closing. When closed, the sealing is enhanced as the torque applied by the actuation mechanism increases, which improves the sealing performance of the butterfly valve and extends its service life. However, this type of butterfly valve still has the following problems during use: First, since the multi-layered soft and hard gasket assembly is fixed on the valve disc, when the valve disc is in the open position, the medium exerts direct erosion on its sealing surface; as a result, the soft sealing strip located in the metal layer is damaged by this erosion, which directly affects the sealing performance. Key points for construction and installation: 1) The installation location, height, and direction of the inlets and outlets must meet the design requirements; ensure that the flow direction of the medium is consistent with the arrow indicated on the valve body, and that the connections are firm and secure. 2) Before installing the valve, an external inspection must be carried out; the valve’s nameplate shall comply with the provisions of the current standard **“Marking of General Valves” GB 12220. For valves with a working pressure greater than 1.0 MPa and those that serve to shut off flow in main pipelines, strength and tightness tests must be conducted before installation, and they may only be used after passing these tests. During the strength test, the test pressure shall be 1.5 times the nominal pressure, and the test shall last for no less than 5 minutes; the valve body and packing must show no leakage to be considered qualified. During the tightness test, the test pressure is 1.1 times the nominal pressure ； The duration of the test meets the requirements of GB 50243. Key features: 1. Small and lightweight, easy to assemble, disassemble, and maintain, and can be installed in any location. 2. It has a simple and compact structure, allowing for quick 90-degree rotation to open it. 3. Low operating torque, requiring less effort and being lightweight. 4. The flow characteristic tends to be linear, resulting in good control performance. 5. The sealing material is resistant to aging and corrosion, and can be used with a variety of media. It is used in the supply and drainage systems of water treatment plants, power plants, steel mills, paper mills, chemical industries, and food service sectors, for regulation and shut-off purposes.