The plug valve is a commonly used fluid control valve, widely applied in industries such as oil, natural gas, and chemicals due to its high sealing performance and ease of operation. The valve features a simple design, where a rotating plug controls the flow direction of the fluid, ensuring safe operation in systems involving high pressure, high temperature, and hazardous media. 1. Working Principle The core structure of a plug valve is a cylindrical or conical plug with a through passage. When the plug rotates, the passage aligns or misaligns with the fluid pathway of the valve body, thus controlling the opening and closing of the valve. (1) Open Position When the passage on the plug valve aligns with the fluid pathway of the valve body, the fluid can flow directly through the valve, ensuring an unobstructed flow. This design minimizes pressure loss during fluid flow, making it suitable for applications where maintaining stable flow is essential. (2) Closed Position When the plug is rotated 90 degrees, the passage becomes perpendicular to the fluid pathway, completely cutting off the flow of fluid, achieving the closed position. The 90-degree rotation of the plug valve allows for a complete shutdown of the fluid flow, offering a quick response, making it ideal for emergency shut-off applications. 2. Structural Characteristics (1) Types of Plug Valves Plug valves typically come in two types: conical and cylindrical plugs. The conical plug provides better sealing performance but may require additional lubrication or material support at high temperatures, while the cylindrical plug operates smoothly and is suitable for applications requiring frequent on/off operation. (2) Sealing Materials The sealing design of plug valves typically uses PTFE (Polytetrafluoroethylene) or other non-metallic lining materials, which offer high corrosion resistance and flexibility, ensuring good sealing performance even under high pressure. Additionally, some high-end plug valves employ metal-to-metal sealing for extreme environments, preventing seal failure. (3) Wear and Corrosion Resistance The internal materials of plug valves are typically made of corrosion-resistant materials such as stainless steel or nickel-based alloys, preventing wear caused by medium corrosion. This makes them suitable for transporting acidic or corrosive media and is commonly used in the chemical industry and refining systems. (4) Simple Maintenance The internal structure of the plug valve is simple, with no complex springs or valve disc mechanisms, making disassembly and maintenance relatively easy. In high-temperature and high-pressure environments, specific materials and designs can be selected to extend the valve’s service life and reduce subsequent maintenance costs. 3. Application Scenarios The application of plug valves is commonly found in critical situations where leakage prevention is essential, as well as in systems requiring rapid opening and closing or fluid shut-off. Below are ...

A sleeved plug valve is a specific type of plug valve designed with a non-metallic sleeve or liner that surrounds the plug, creating a tight seal. This sleeve, often made from materials like PTFE (polytetrafluoroethylene), ensures a low-friction, corrosion-resistant seal, making the valve suitable for various applications where leakage prevention, durability, and chemical resistance are crucial. 1. How Sleeved Plug Valves Work In a sleeved plug valve, the plug rotates within a sleeve liner rather than directly against the metal body. This design reduces wear on the valve body and allows for smoother, more consistent operation. When the valve handle is turned, the plug rotates, opening or closing the flow path. The sleeve not only provides a tight seal but also allows for a self-lubricating effect, enhancing the valve’s longevity and performance. 2. Key Features and Advantages (1) Leakage Prevention The non-metallic sleeve acts as a reliable seal around the plug, minimizing the risk of external leakage. This feature is especially important in industries handling hazardous chemicals, as it prevents leaks and potential environmental contamination. (2) Corrosion and Chemical Resistance Sleeved plug valves are ideal for handling corrosive or abrasive fluids. The PTFE or other chemically resistant materials used for the sleeve make the valve suitable for environments where standard metal-on-metal contact would degrade over time. (3) Low Maintenance Due to their self-lubricating design, sleeved plug valves require less frequent maintenance compared to traditional plug valves. The sleeve also absorbs some wear, reducing the need for frequent replacements and improving overall valve durability. 3. Applications Industries such as chemical processing, water treatment, and oil and gas frequently use sleeved plug valves due to their reliability and ability to handle tough operating conditions. These valves perform well in systems that require minimal leakage, resistance to aggressive fluids, and easy maintenance.

1. Core Function of Gate Valves Gate valves are primarily used for on/off control in industrial pipelines, where the valve is either fully open or fully closed. This makes them particularly suited for applications that require an unobstructed flow path with minimal pressure drop. 2. Best for Straight-line Flow Systems One of the ideal applications for gate valves is in straight-line flow systems where flow restriction must be minimized. When fully open, the gate valve provides a clear, uninterrupted flow path, making it an excellent choice for such environments. 3. Widely Used in Isolation Services Gate valves excel in isolation services, where they are used to completely block or allow flow. This makes them essential for systems that require reliable shut-off, such as those in the oil, gas, and chemical industries. 4. Ideal for Large Diameter and High-Pressure Systems For large diameter pipelines and high-pressure applications, gate valves are highly effective. They are commonly used in industries where both large volumes of fluid and high pressure must be managed, thanks to their durability and reliable operation. 5. Limitations in Use However, gate valves are not recommended for throttling, frequent operation, or for use in systems with debris. These conditions can cause wear on the valve seat, potentially leading to reduced performance over time.