1. Eliminate stress. Various stresses caused by improper installation or combination. For example, high-temperature media produce thermal stress, which makes installation tight. Imbalance of solid force causes stress and so on. The imbalance of stress acts on the regulating valve, deforming the regulating valve stem and guide, and not being able to align with the valve seat correctly, causing leakage and increased deterioration. Therefore, maintenance work to eliminate stress should be carried out in daily maintenance.
2. Remove rust and dirt. Frequently check whether there is rust, welding slag, dirt, etc. in the connecting pipe of the regulating valve, and remove it in time after discovery. Because these dirt will cause wear of the valve core and valve seat of the regulating valve, and affect the normal operation of the regulating valve. Generally, filter devices such as filters can be installed in front of the regulating valve and cleaned regularly.
3. Check the control valve support. The control valve support makes the parts of the control valve in a position that is not affected by gravity. If the support is improper, the valve stem of the regulating valve and the valve seat will not be centered, which will increase the deterioration and reduce the sealing performance. Therefore, it should be checked whether the regulating valve support is appropriate.
4. Clean up the dirt that supplies energy such as air source and hydraulic oil. Air source and hydraulic source are the energy source for regulating valve operation. Impurities contained in the instrument compressed air and hydraulic oil can block the orifice and pipes, causing malfunctions. Therefore, it is very important to check the air source and hydraulic oil regularly, and to drain the filter device regularly.
5. Inspection of gear transmission. The gear transmissions of the hand-wheel mechanism, electric actuator and hydraulic actuator should be checked regularly and lubricants should be added to prevent seizure. Check whether the brake and limit device are flexible and easy to use.
6. Stuffing box inspection. The wear and compression force of the packing should be checked, and the stuffing box should be replaced regularly to ensure that the packing can seal while reducing the impact of its friction. Lubricating oil should not be added to the stuffing box without oil lubrication.
7. Inspection of safe operation. Regulating valves and related accessories used in explosive hazardous locations should be checked for their safe operation, such as whether the sealing cover is tightened, the operation of the safety barrier, and the power supply to ensure the safe operation of the regulating valve and related accessories.
8. Transportation and storage. During transportation and storage, the regulating valve should be fixed with a special bracket to prevent loosening; the relevant accessories installed on the regulating valve, such as valve positioner, handwheel mechanism, etc. should be firm, and the feedback lever connected to the regulating valve should be prevented from being subjected to external force Damage; each connection interface shall be covered with plastic film to prevent the intrusion of foreign objects; the connection port of the regulating valve can be sealed with matching flanges and blind plates, or adhesive paper can be used to seal to prevent foreign objects from intruding. A firm wooden box should be installed during transportation, and the impact of harsh transportation environmental conditions such as wind, sand, rain and dust should be taken. The environmental conditions for transportation and storage shall meet the requirements of the product specification.