Selection Method For Regulating Valve
Jul 06, 2019| Selection method for regulating valve
Regulating valve, also known as control valve, in the field of industrial automation process control, by accepting the control signal output from the control unit, by means of power operation to change the final control element of the process parameters such as medium flow, pressure, temperature, liquid level.
As a terminal actuator for industrial process control, regulating valves have become the key equipment for industrial automation control with the continuous improvement of industrial automation. Whether the adjustment of the valve selection is appropriate is directly related to the quality of industrial control, and even to the safety of industrial production systems. Therefore, in the actual production process, it is necessary to select a suitable regulating valve according to the process conditions.
The choice of the structural form of the regulating valve: 1. Generally, it is more suitable to use a sleeve valve in the case of large vibration or high noise. For example, when the medium has viscosity or small particles, it is more suitable to select the eccentric rotary valve. Commonly used valves are straight through single seat valves, straight through double seat valves, angle valves, butterfly valves, ball valves, diaphragm valves, and the like. When selecting the structural form of the valve, it is also necessary to consider the process conditions and fluid characteristics of the conditioning medium.
The selection of the valve air opening/gas shutoff and the determination of the positive and negative action of the regulator, the selection of the valve air opening/gas shutoff must be determined in terms of process production requirements and safety requirements. The principle is that when the signal pressure is interrupted, the safety of the process equipment and production should be ensured, that is, the valve automatically enters a safe state when the regulating valve loses the signal pressure source. After selecting the valve opening or closing mode, the positive and negative effects of the regulator must be determined according to the form of the valve, so that the regulating valve and the regulator constitute a negative feedback control system.