1. Stress relief. Various stresses are caused by improper installation or combination. For example, the high temperature medium produces the thermal stress, the installation is tight, and the stress is caused by the unbalanced solid force. The unbalanced stress acts on the control valve, which makes the valve stem and guide parts deform and cannot be aligned with the valve seat correctly, resulting in leakage and increase of variation. Therefore, stress relief should be carried out in daily maintenance.

2. Remove rust and dirt. Regularly check whether there is rust, welding slag and dirt in the connecting pipe of the control valve, and remove it in time if it is found. Because these dirt will cause the valve core and valve seat wear, affect the normal operation of the control valve. Generally, the filter screen and other filtering devices can be installed in front of the regulating valve and cleaned regularly.


3. Check the control valve support. The support of the control valve makes all parts of the control valve in a position not affected by gravity. If the support is not proper, the valve stem and valve seat can not be aligned, which will increase the variation and decrease the sealing performance. Therefore, check whether the control valve support is suitable.



4. Remove the air source, hydraulic oil and other energy supply dirt. Air source and hydraulic source are the energy sources of regulating valve operation. The impurities contained in compressed air and hydraulic oil will block the orifices and pipes and cause faults. 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 device. The gear transmission device of hand wheel mechanism, electric actuator and hydraulic actuator shall be inspected regularly, and lubricant shall be added to prevent seizure. Check whether the braking and limiting devices are flexible and easy to use.

6. Stuffing box inspection. It is necessary to check the wear and compression force of the packing, and replace the stuffing box regularly to ensure that the packing can play a sealing role and reduce the influence of friction. No lubricating oil should be added to the stuffing box without oil lubrication.

7. Inspection of safe operation. Check the safety operation of the control valve and related accessories used in explosive hazardous areas, such as whether the sealing cover is tightened, the operation of safety barrier, power supply, etc., so as to ensure the safe operation of the control valve and related accessories.

8. Transportation and storage. During transportation and storage, the regulating valve shall be fixed with special support to prevent looseness; the relevant accessories installed on the control valve, such as valve positioner and hand wheel mechanism, shall be firm to prevent the feedback rod and other components connected with the control valve from being damaged by external force; all connection interfaces shall be covered with plastic film to prevent foreign objects from invading; The connection port of the control valve can be sealed with matching flange and blind plate, or sealed with sticky paper to prevent foreign objects from invading. During transportation, solid wooden cases should be installed and protected from the influence of bad transportation environment such as wind, sand, rain and dust. The environmental conditions for transportation and storage shall meet the requirements of product instructions.