Thread Content
Problems existing in the application of control valves: 1. There are a large variety of control valves, with numerous specifications and parameters. To meet the control requirements of different industrial production processes, such as those related to temperature, pressure, and the properties of the medium, there are nearly a thousand different types and specifications of control valves. This makes it difficult to select, maintain, and manage these valves. 2. Poor reliability of control valves: The characteristics of control valves at the time of manufacture differ significantly from those after they have been in operation for some time; for example, there is an increase in leakage, higher noise levels, and reduced repeatability of the valve’s performance, all of which pose difficulties for long-term stable operation. 3. The heavy weight of control valves makes their transportation, installation, and maintenance difficult. Typically, control valves are several times to hundreds of times heavier than ordinary instruments; for example, a DN200 control valve can weigh up to 700 kg. Transporting, installing, and maintaining such valves requires the use of mechanical equipment, which adds to the difficulties associated with their use. 4. Poor quality of the control system: The flow characteristics of the control valve do not match those of the process variable being controlled, which results in a decline in the quality of the control system. The ideal flow characteristic of the control valve is determined at the time of product manufacture. However, the characteristics of the processes to be controlled in industrial applications vary, and changes in the pressure reduction ratio prevent the operating flow characteristic of the control valve from matching those of the process, which in turn reduces the control quality of the control system. 5. Excessive noise from control valves: In industrial applications, the noise generated by control valves has become a major source of noise in industrial equipment. Therefore, reducing the noise level of control valves is an important research topic at present, and it has received attention from various countries. 6. Reducing energy consumption: Control valves are energy-consuming devices; in an era of increasingly scarce energy resources, it is even more important to employ energy-saving technologies to reduce the energy consumption of these control valves and improve energy utilization efficiency.