Characteristics and concepts of valve opening degree

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The valve opening, also known as the valve’s “travel” or “lift”, refers to the distance or angle over which the valve moves from a fully closed state to a fully open state. The valve opening is one of the key parameters for controlling fluid flow; it directly affects the valve’s flow characteristics and control accuracy. Please follow Beigaoke Valves to learn about some basic concepts and characteristics of valve opening degree: Valve opening degree refers to the distance or angle that the valve core or valve disc moves from its closed position when the valve is in the open state. The opening degree of the valve determines the amount of fluid flowing through it. The ideal flow characteristic is the flow characteristic obtained under the assumption of a constant pressure difference before and after the valve, and it mainly depends on the shape of the valve core. For example, in valves with a linear flow characteristic, the relative flow is proportional to the relative opening degree; this means that if the opening degree is 50%, the flow rate is also 50%. Valves with a constant percentage flow characteristic exhibit a flow change resulting from changes in opening degree that is proportional to the flow rate at that point, making them suitable for precise control over wide range of conditions. 1. Definition of valve opening – Linear opening: For certain types of valves, such as globe valves, the valve opening is the straight-line distance from the closed position to the open position of the valve disc. - Rotation opening degree: For ball valves or butterfly valves, the valve opening degree is the angle by which the valve disc rotates around its axis. 2. Relationship between opening degree and flow rate – The opening degree of a valve is proportional to the fluid flow rate, but this relationship may vary depending on the type of valve and the flow characteristics. 3. Valve type and opening degree – Globe valve: Typically has a linear opening degree, with flow characteristics that can be linear or equal percentage. - Butterfly valve: Features a rotating opening; its flow characteristics are usually close to equal percentage. - Ball valve: Rotational opening; its flow characteristics are similar to those of a butterfly valve. 4. Measurement of opening degree – The valve’s opening degree can be measured in various ways, such as using limit switches, angle sensors, or position transmitters. 5. Opening degree control – In automated control systems, the valve opening degree can be precisely controlled through actuators and controllers. 6. Representation of opening degree – The valve’s opening degree is usually expressed as a percentage, with 0% indicating complete closure and 100% indicating complete opening. 7. Flow characteristics of valves – The flow characteristics of valves include linear, equal percentage, quick opening, and slow closing, among others; these characteristics affect the relationship between the valve’s opening degree and the flow rate. 8. Optimization of valve opening – By adjusting the valve opening, fluid flow can be optimized, pressure losses reduced, and system efficiency improved. 9. Safety considerations – In some applications, the valve opening must be operated within a safe range to avoid excessive pressure or flow. 10. Feedback on valve opening – In automatic control systems, the feedback signal regarding the valve’s opening is used for closed-loop control to ensure that the valve operates accurately according to instructions. In summary, understanding the valve opening degree and its relationship with flow control is crucial for designing and maintaining fluid control systems. Choosing Beigaoke valves and evaluating and selecting the appropriate valve grade from a professional perspective is key to ensuring the efficient and safe operation of industrial systems. Choosing a professional valve team to handle the task usually yields the best results. As a well-known domestic valve manufacturer, Beigaoke Valves adheres to standards of professional technical guidance, high-quality technical support, and comprehensive after-sales service, offering you a one-stop solution for all your purchasing needs.