Instructions for use, maintenance and maintenance of electric control valve

With the rapid development of international industry, electric regulating valves are more and more widely used in metallurgy, petrochemical and other fields, and their stability and reliability are becoming more and more important. Its working condition will directly affect automatic control. Process, this article will elaborate on the use and maintenance of the electric control valve.
1 installation and use precautions
The newly designed and installed control system, in order to ensure that the regulating valve can work normally when driving and make the system operate safely, the new valve should first check whether the nameplate mark on the valve matches the design requirements before installation. At the same time, the following items should be debugged.
Basic error limit; full stroke deviation; hysteresis; dead zone; leakage (when required)
If the control valve in the original system is overhauled, in addition to the above items, the sealing check of the stuffing box and joints of the old valve should be checked.
Many of the regulating valves are used in the field, which are often caused not by the quality of the regulating valve itself, but by improper installation and use of the regulating valve, such as the installation environment, improper installation position and direction, or unclean pipes. Therefore, the electric control valve should pay attention to the following aspects when installing and using:
(1) The regulating valve belongs to the field instrument, and the ambient temperature should be in the range of -25 to 60 °C, and the relative humidity is ≤ 95%. If it is installed in open air or high temperature, waterproof and cooling measures should be taken. Keep away from vibration sources or increase anti-vibration measures where there is a source.
(2) The regulating valve should generally be installed vertically. Under special circumstances, it can be tilted. If the tilt angle is large or the valve itself is too heavy, the support should be added to the valve.
(3) The pipeline for installing the regulating valve should not be too high from the ground or the floor. When the height of the pipeline is more than 2m, the platform should be set as much as possible to facilitate the operation of the handwheel and easy maintenance.
(4) Before the installation of the regulating valve, the pipeline should be cleaned to remove dirt and welding slag. After installation, in order to ensure that impurities do not remain in the valve body, the valve should be cleaned again, that is, all valves should be opened when the medium is introduced to avoid jamming of impurities. After using the handwheel mechanism, you should return to the original neutral position.
(5) In order to make the production process continue in the event of failure or maintenance of the regulating valve, the regulating valve should be added with a bypass line.
At the same time, special attention should be paid to whether the installation position of the regulating valve meets the requirements of the process.
(6) The electrical part of the electric control valve should be installed according to the relevant electrical equipment construction requirements. If it is a flameproof product, it should be installed in accordance with the requirements of "Installation Specifications for Electrical Equipment in Explosive Hazardous Locations". For example, the field wire adopts SBH type or other six or eight cores, and the outer diameter is Φ11.3.
Install the cable for the rubber around mm. In the use of maintenance, it is strictly forbidden to open the cover and repair the explosion-proof surface in the explosive place. At the same time, do not scratch or scratch the explosion-proof surface during disassembly and assembly, and restore it to the original explosion-proof requirement state after maintenance.
(7) After the gear unit of the actuator is disassembled, attention should be paid to lubrication. Low-speed motors are generally not required to be disassembled and refueled. After assembly, check that the valve position and valve position opening indication match.
2 common fault locations and causes analysis
The performance of the regulating valve will directly affect the working quality of the entire regulating system. Since the regulating valve is in direct contact with the medium to be tuned in the field, the working environment is very harsh, so it is easy to generate various faults. In the production process, in addition to eliminating these faults at any time, regular maintenance and regular maintenance must be carried out. Especially for the control valve with particularly harsh environment, more attention should be paid to maintenance and regular maintenance.
Different types of regulating valves have different faults and their causes. Taking the straight-stroke electric regulating valve produced by Shanghai Chuanfu Fluid Machinery Co., Ltd. as an example, the general failure and maintenance method of the electric regulating valve are explained.