KOSO Valve positioner should be selected according to which aspects
KOSO valve positioner (also known as electric valve positioner) is the main accessory of the control valve, usually used in conjunction with the pneumatic control valve. It receives the output signal of the regulator, and then uses its output signal to control the pneumatic control valve. When the control valve acts, the displacement of the valve stem is fed back to the valve positioner through a mechanical device, and the valve position state is transmitted to the upper system through an electrical signal.
In many control applications, the KOSO valve positioner is one of the most important accessories for a control valve. Especially for a specific application, if you want to choose the most suitable valve positioner, you should pay attention to the following factors:
Can the valve positioner realize "split_ranging". Is it easy and convenient to realize "split_ranging"? Having the function of "split_ranging" means that the valve positioner only has a certain range of input signals (such as: 4 ~ 12mA or 0.02～0.06MPaG) has a response. Therefore, if it can be "split", it is possible to control two or more regulating valves successively with only one input signal according to actual needs.
Is the adjustment of the zero point and span of the positioner easy and convenient? Is it possible to complete the adjustment of the zero point and span without opening the box cover? But it is worth noting that sometimes in order to avoid incorrect (or illegal) operations, This kind of arbitrary adjustment needs to be prohibited.
How stable is the zero and span of the positioner? If the zero and span are prone to drift with changes in temperature, vibration, time or input pressure, the positioner needs to be recalibrated frequently to ensure adjustment The stroke action of the valve is accurate.
The accuracy of the KOSO valve positioner is under ideal conditions, corresponding to a certain input signal, the trim parts of the regulating valve (TrimParts, including ball/spool, valve stem, valve seat, etc.) should be accurately positioned at the required position each time. position, regardless of the direction of travel or the load on the trim of the regulating valve.
