Working environment and function requirements of electric valves

April 10, 2019
Industry News

In pipeline engineering, the correct selection of electrically operated valves is one of the guarantee conditions to meet the requirements of use. If the electric valve used is not properly selected, it will not only affect the use, but also bring about bad consequences or serious damage. Therefore, the electric valve should be correctly selected in the pipeline engineering design.

Working environment of electrically operated valves

In addition to the pipeline parameters, the environmental conditions of the electric valve operation should be well considered, because the electric actuator in the electrically operated valve is an electromechanical device, and its working condition is greatly affected by its working environment. Usually, the working environment of the electric valve is as follows:
1. Indoor installation or protective measures for outdoor use;
2. Outdoor open-air installation, wind, sand, rain, sun and other erosion;
3. Flammable, explosive gas or dust environment;
4. Wet tropical and dry tropical environment;
5. The pipeline medium temperature is up to 480 ° C or more;
6. The ambient temperature is below -20 °C;
7. Environment vulnerable to flooding or immersion in water;
8. Environment with radioactive materials (nuclear power stations and radioactive material testing devices);
9. The environment on the ship or dock (with salt spray, mold, moisture);
10. Where there is severe vibration;
11. Where it is prone to fire.

For electric valves in the above environments, the structure, materials and protective measures of the electric devices are different. Therefore, the corresponding valve electric device should be selected according to the above working environment.

Electric valve function requirements

According to the engineering control requirements, the control function of the electric valve is completed by the electric device for electric valves. The purpose of using an electric valve is to achieve non-manual electrical control or computer control of the valve opening, closing and adjustment linkage. The current use of electric devices is not just to save manpower. Due to the large differences in functions and quality of products from different manufacturers, the selection of electric devices and the selection of valves are equally important to the project.

Electrical control of electric valves

As the requirements of the industrial automation level continue to increase, on the one hand, the use of electric valves is increasing, and on the other hand, the control requirements for electric valves are becoming higher and more complex. Therefore, the design of electric valves in electrical control is constantly being updated. With the advancement of science and technology and the popularization and application of computers, new and diverse electrical control methods will continue to emerge. For the overall control of electric valves, attention should be paid to the choice of the control method of the electric valve. For example, depending on the needs of the project, whether to use centralized control mode, single control mode, linkage with other devices, program control or computer program control, etc., the control principle is different. The valve electric actuator manufacturer only gives the standard electrical control principle, so the user department should make technical disclosure with the electric actuator manufacturer and clarify the technical requirements. In addition, when selecting an electric valve, consideration should be given to whether or not to purchase an electric valve controller. Because of the general situation, the controller needs to be purchased separately. In most cases, when using a single control, it is necessary to purchase the controller, because it is convenient and cheaper to purchase the controller than the user design and manufacture it. When the electrical control performance does not meet the engineering design requirements, the user should ask the manufacturer to propose modifications or redesigns.