What necessary considerations should we pay attention to when selecting a valve positioner?

When it comes to valve positioners, many frontline instrumentation workers are likely familiar with them. As a core auxiliary component of control valves, they primarily improve the flow characteristics of control valves to enhance the positioning accuracy and reliability of the control valves. They are now widely used in numerous fields and occasions. There are many brands of valve positioners on the market, such as the Fisher positioner from the United States, the Siemens positioner from Germany, the ABB positioner from Switzerland, and the Yamatake positioner from Japan, all of which are globally recognized brands of valve positioners. Structurally, valve positioners can be divided into pneumatic valve positioners, electro-pneumatic valve positioners, and intelligent valve positioners. With so many brands and types available, it is essential to choose a valve positioner that suits our needs when making a purchase. Today, the technical editor will explainWhat necessary considerations should be noted when selecting a valve positioner?.
　　Note 1: Large Load
The accuracy of the valve positioner under ideal working conditions should correspond to a specific input signal, and the internal components of the control valve (Trim Parts, including the ball/valve core, valve rod, valve seat, etc.) should be accurately positioned at the required location each time, regardless of the direction of travel or the load borne by the internal components of the control valve.
　　Note 2: How stable are the zero point and range of the valve positioner?
If the zero point and range are prone to drift with changes in temperature, vibration, time, or input pressure, then the valve positioner will need to be recalibrated frequently to ensure the accuracy of the control valve's travel actions.
　　Note 3: Is it easy and convenient to calibrate the zero point and range of the positioner?
Can the zero point and range calibration be completed without opening the cover? However, it is worth noting that sometimes, to avoid incorrect (or unauthorized) operations, this kind of arbitrary calibration method needs to be prohibited.
　　Note 4: Can the valve positioner achieve 'Split Ranging'?
Can the valve positioner achieve 'Split Ranging'? Is it easy and convenient to implement 'Split Ranging'? Having the 'Split Ranging' function means that the valve positioner only responds to a certain range of input signals (e.g., 4-12mA or 0.02-0.06MPaG). Therefore, if 'Split Ranging' is possible, it allows for controlling two or more control valves sequentially with just one input signal based on actual needs.
The above content is what we want to discuss today.What necessary considerations should be noted when selecting a valve positioner?We hope that through today's explanation, we can help our vast number of instrumentation workers choose the right valve positioner, so that we can better meet the needs of our control valves and actual working conditions in the future. If you have more technical questions and product details regarding valve positioners, feel free toclick here..