The standardization of pressure control valves is manifested in the following aspects

The standardization of control valves is manifested in the following aspects.

¢Ù In order to achieve interchangeability, control valves produced by different manufacturers of the same size and specifications can be interchanged, so that users do not have to spend a lot of time choosing a manufacturer.

¢Ú In order to achieve interoperability, control valves produced by different manufacturers should be able to work together with products from other manufacturers without signal mismatch or impedance mismatch.

¢Û Standardized diagnostic software and other auxiliary software enable different manufacturers' control valves to diagnose their operating status, analyze operating data, etc.

¢Ü Standardized selection process. The selection of control valves is still a matter of great concern for self-control designers. By using standardized calculation programs and based on the data provided by the process, the flow coefficient of the required control valve can be accurately calculated to determine the piping and select suitable materials for the valve body, valve core, and valve internals, thus standardizing the design process and improving design quality.

(2) Refinement and miniaturization To reduce the weight of the control valve, facilitate transportation, installation, and maintenance, the following measures have been taken for the miniaturization of the control valve.

¢Ù Adopting a compact actuator. By using lightweight materials and replacing one set of springs with multiple sets of springs, the height of the actuator can be reduced. Generally, the control valve composed of a compact pneumatic thin film actuator has a height reduction of about 30% and a weight reduction of about 30% compared to the control valve composed of the same type of pneumatic thin film actuator, while the flow capacity can be increased by about 30%.

¢Ú Change the flow path structure. For example, changing the movement of the valve core to the movement of the valve seat, changing linear displacement to angular displacement, etc., reduces the volume and weight of the control valve.

¢Û Adopting electric actuators. Not only can it reduce the need for air source devices and auxiliary equipment for pneumatic actuators, but it can also reduce the weight of the actuator. For example, Fisher's 9000 series electric actuators have a height of less than 330mm for the Type 20, reducing the weight of the entire control valve (with digital controller and actuator) to 20-32kg. Due to the advantages of rotary control valves, such as ball valves, such as relatively small volume, low flow resistance, large adjustable ratio, good sealing performance, good anti blocking performance, and large flow capacity, the proportion of rotary valves has increased in the new variety of control valves. Especially in large-diameter pipelines, ball valves, butterfly valves and other types of control valves are commonly used. From the perspective of foreign products in recent years, the proportion of rotary valve applications is increasing year by year.

(4) The safety of safety instrumented control systems has received attention from all aspects, and the requirements for control valves in safety instrumented systems (SIS) are becoming increasingly high, manifested in the following aspects.

¢Ù The requirements for diagnosing and processing pressure control valve fault information have been raised, which not only requires passive maintenance of the control valve after the fault occurs, but also preventive and predictive maintenance before the fault occurs. Therefore, it has become more important to conduct statistical analysis of the components that make up the control valve and provide timely maintenance recommendations.

¢Ú Require timely, reliable, and safe operation of control valves used in emergency parking systems or safety interlock systems. Ensure that these control valves can respond sensitively and accurately.

¢Û The certification process for control valves used in hazardous areas should be simplified. For example, fieldbus instruments for intrinsic safety applications can be simplified to adopt the FISCO fieldbus intrinsic safety concept, simplifying the certification process for intrinsic safety products.

¢Ü Similar to the safety of other field instruments, explosion-proof technology, fire prevention technology, safety enhancement technology, intrinsic safety technology, spark free technology, etc. can be used for the safety of control valves; For fieldbus instruments, physical concepts, intrinsic safety concepts, FISCO concepts, and non flammable (FINCO) concepts can also be used.

(5) Energy conservation, reducing energy consumption, and improving energy utilization efficiency are development directions for control valves. There are mainly the following development directions.

¢Ù Adopting a low pressure drop ratio control valve. Reducing the proportion of control valves in the overall pressure drop of the system, thereby reducing energy consumption, is one of the development directions for designing low pressure drop ratio control valves; Another development direction is to use low impedance control valves, such as butterfly valves, eccentric rotary valves, etc.

¢Ú Adopting a self operated control valve. For example, a self operated control system is directly composed of the pressure of the medium behind the valve, and the energy of the controlled medium is used to achieve pressure control behind the valve.

¢Û Control valve with electric actuator. Pneumatic actuators require a certain amount of air pressure throughout the entire operation of the control valve. Although amplifiers with low consumption can be used, over time, the air consumption is still enormous. By using an electric actuator, power supply is required when changing the opening of the control valve. When the desired opening is reached, power supply can be stopped. Therefore, from the perspective of energy saving, electric actuators have significant energy-saving advantages over pneumatic actuators.

¢Ü Adopting piezoelectric control valve. In intelligent electrical valve positioners, piezoelectric control valves are used, and the gas source is only consumed when the output signal increases.

¢Ý Adopting a valve core with a balanced structure to reduce the thrust or thrust torque of the actuator, shrink the diaphragm chamber, and lower energy requirements.

¢Þ Using variable frequency speed regulation technology instead of control valves. For applications with high voltage drop ratio, if energy consumption is high, variable frequency speed regulation technology can be used to change the speed of relevant operating equipment using a frequency converter, reducing energy consumption.

(6) Protecting the environment has become a public hazard, and the pollution caused by control valves to the environment mainly includes control valve noise and control valve leakage. Among them, the control valve noise has a particularly serious impact on environmental pollution.

¢Ù Reduce control valve noise. Develop various methods to reduce the noise of control valves, including the design of control valve flow paths, the design of control valve internals, the analysis of noise sources, and measures to reduce noise. Mainly includes the design of noise reduction control valves and internal components of noise reduction control valves; Reasonably allocate pressure drop and use external noise reduction measures, such as increasing isolation and using mufflers.

¢Ú Reduce atmospheric pollution caused by control valves. The atmospheric pollution caused by control valves refers to the "running", "emitting", "dripping", and "leaking" of control valves. These leaks not only cause waste of materials or products, but also pollute the atmospheric environment. Sometimes, they can also cause accidents such as personnel injury or equipment explosion. Therefore, the development of control valve packing structures and packing types, as well as the development of control valve seals, will be an important research topic for control valves in the future. The development of high-tech science and technology such as computer science, control theory, and automation instruments has promoted the development of control valves, such as the development of fieldbus control valves and intelligent valve positioners, and the implementation of digital communication in control valves. The development of control valves has also promoted the development of other scientific and technological fields, such as research on anti-corrosion materials, methods for weakening and reducing noise, and fluid dynamics. With the development of fieldbus technology, control valves will also be open, intelligent, and more reliable. They will have higher precision, more obvious control effects, and play a more important role in China's modernization construction. Other industrial automation instruments and computer control devices will work together to make the functions of industrial production process control more complete and precise.