In industrial pipeline systems and many civilian fluid transportation fields, valves play a key role in accurately controlling flow, cutting off or regulating medium transmission, and flange butterfly valves have become widely used products due to their unique advantages. To ensure its continuous and efficient operation, it is essential to have a deep understanding of its structure, functions, and maintenance points.

Structural analysis of flange butterfly valve

1. Valve body: As the "skeleton" of the valve, it is usually made of materials such as cast iron, cast steel, stainless steel, etc., selected based on factors such as corrosiveness and pressure rating of the operating environment. Cast iron has a low cost and is suitable for scenarios such as general water supply and drainage where material requirements are not extremely strict; Cast steel has excellent comprehensive mechanical properties and can withstand high pressures, commonly used in industrial fluid pipelines; Stainless steel exhibits excellent corrosion resistance in working conditions with strong corrosive media, such as chemical acid and alkali solution pipelines, ensuring long-term stability of the valve body and preventing erosion and damage. Its shape design meets the requirements of pipeline connection, with standard flange plates, making it easy to tightly fix with the pipeline through bolts, forming a stable sealed connection, and ensuring that the medium transitions between the pipeline and the valve body without leakage.

2. Butterfly plate: The core component of butterfly valves, similar to the shape of butterfly wings, is mostly a circular metal plate, made of materials that are compatible with the valve body or slightly strengthened, such as butterfly plates that use surface hardening technology in wear-resistant scenarios. The butterfly plate is connected to the actuator through the valve stem and is located at the center of the valve body cavity, serving as the direct "executor" for cutting off and regulating flow. When working, rotate around the axis of the valve stem, from fully opening to allow the medium to flow smoothly, to gradually closing and cutting off or limiting the flow rate as needed, with flexible and efficient actions.

3. Valve stem: the "link" that transmits power, connecting the butterfly plate with external actuators (manual wrench, electric actuator, pneumatic actuator, etc.). It is necessary to ensure sufficient strength and rigidity to support the stable movement of the butterfly plate, without bending deformation affecting sealing and operation, and to have good wear resistance and corrosion resistance. Some parts are also designed with sealing sleeves to prevent the medium from leaking out along the valve stem, ensuring the overall sealing performance of the valve and extending its service life.

4. Sealing structure: it is a key design related to valve leakage. Rubber sealing rings are often embedded in the corresponding sealing grooves of the valve body or butterfly plate. Relying on rubber elasticity and preload, the butterfly plate is closely fitted when closed to achieve a two-way sealing effect, effectively blocking fluid leakage through the valve. High quality rubber seals can adapt to different temperatures and media, have excellent anti-aging performance, and maintain sealing integrity for a long time.

Features fully demonstrate advantages

1. Quick cut-off and regulation: In emergency situations, the flow of the medium needs to be immediately cut off. For example, if the fire water supply pipeline needs to stop water operation in response to a sudden fire, rotating the butterfly plate can achieve full open to full open switching in a short time (compared to traditional valves such as gate valves and globe valves that act more quickly), cutting off the water flow; In daily operation, the butterfly opening angle is fine tuned according to the flow demand, and the flow is precisely controlled. For example, the urban water supply system adjusts the water volume in different areas in different time periods, which can flexibly handle and ensure stable pressure and balanced water use in the pipeline network.

2. Low flow resistance characteristics: When the butterfly plate is opened, it has minimal obstruction to the flow of the medium, similar to the natural diameter state of the pipeline. The fluid can pass smoothly, reducing the overall energy loss of the pipeline system and saving energy and efficiency. Especially when transporting low viscosity media such as water and gas through large-diameter pipelines, compared to valves with complex flow channels and large valve core obstacles, it can significantly reduce pump energy consumption and improve transportation efficiency, which is in line with modern energy-saving and consumption reducing industrial concepts.

3. Bi directional sealing and wide applicability: Good sealing design enables it to withstand pressure in both directions and achieve excellent sealing effect. Regardless of whether the medium flows forward or backward, as long as it is in the closed state, it can effectively prevent leakage. And it can adapt to various fluid media, from common water supply and drainage media such as clean water and sewage, to various acid-base salt solutions and gases (natural gas, steam, etc.) in petroleum and chemical industries. With the advantages of diverse materials and reliable sealing, it is widely used in different industrial categories and civil facilities.

Maintenance points, guarding durability

1. Regular inspection of seals: Rubber seals are prone to aging, deformation, and loss of elasticity due to long-term exposure to media erosion, temperature changes, and pressure compression, leading to seal failure. According to the operating time and severity of the working conditions, regularly disassemble the valve (with a small diameter for easy operation) to check the wear and aging of the sealing components, and replace the problematic parts in a timely manner. It is recommended to check the conventional water supply and drainage valves every 1-2 years, and shorten the harsh working conditions in the chemical industry to about six months.

2. Cleaning and lubricating the valve stem: Frequent movement of the valve stem and contamination with medium dirt and dust can exacerbate wear, hinder flexible rotation, and even damage the sealing sleeve, causing leakage. Regularly wipe the valve stem and apply an appropriate amount of specialized lubricating grease (suitable for corresponding working conditions) to ensure smooth operation. Lubricate at least once a month to increase frequency in harsh environments and ensure stable and efficient power transmission.

3. Calibration and maintenance of actuators: Electric and pneumatic actuators are related to the accuracy and reliability of valve automatic control. Regularly check the electrical circuit connections and the sealing of the gas source pipeline, calibrate the actuator stroke and torque parameters, ensure that the butterfly plate opens and closes properly and with appropriate force, and avoid excessive force damaging the valve or inadequate sealing; According to the equipment manual requirements, oil and dust removal maintenance should be carried out on core components such as motors and cylinders to maintain good working conditions of the actuator, ensure accurate remote and automatic control of valves, and extend the overall service life. Generally, quarterly minor inspections and annual deep maintenance should be carried out.

The flange butterfly valve achieves multiple functions with its exquisite structure. As long as it follows the scientific maintenance method and strictly adheres to the key points of each link during use, it can firmly maintain the key nodes of the pipeline system for a long time, continuously and efficiently control the medium flow, and become a reliable and durable "flow guardian" in industrial and civilian fields, providing protection for various fluid transportation.