How to maintain medium and high pressure valves?

Maintenance of medium and high pressure valves is crucial because they are usually used in high pressure, high temperature and high load conditions, and any failure may cause equipment damage or serious safety accidents. Regular maintenance can extend the service life of the valve and ensure the safety and stable operation of the system. The following are common maintenance methods for medium and high pressure valves:

1. Regular inspection
Appearance inspection: Regularly check whether the exterior of the valve has cracks, corrosion, wear, leakage or other obvious damage. Check the surface of the valve for cracks or deformation to ensure that the valve structure has not suffered external damage.
Check the sealing: Check the sealing surface of the valve to ensure that the sealing gasket, O-ring, etc. are not worn, aged or leaking. Especially under high pressure conditions, poor sealing may cause leakage or unstable system pressure.
Check the valve seat and valve core: Wear of the valve seat and valve core will affect the closing performance of the valve and increase the risk of leakage. Check these parts regularly and replace them in time if they are worn or damaged.

2. Cleaning and lubrication
Cleaning the valve and its accessories: Dirt, impurities or corrosive substances may accumulate on medium and high pressure valves during use, and these impurities may affect the operating performance and sealing effect of the valve. Therefore, valves and related parts should be cleaned regularly, especially key parts such as valve seats, valve cores and actuators.
Lubrication: For valves with moving parts (such as valve stems, actuators, etc.), regular lubrication is required. Use appropriate lubricants to avoid damage to parts due to friction or corrosion. Avoid excessive or improper lubricants when lubricating, and ensure that the lubricant is compatible with the medium.

3. Maintenance of actuators and control systems
Check pneumatic/electric actuators: Actuators are an important part of medium and high pressure valves. They are usually used to automatically control the opening and closing of valves. Regularly check the working status of the actuators, including the air source pressure of pneumatic actuators, the power supply of electric actuators, signal control, etc.
Pneumatic actuators: Check whether the air source pressure is stable, whether the connecting pipelines are unobstructed, and whether the actuators are flexible. If the air source is insufficient or the actuator is slow to operate, the air source and pipeline system should be checked in time.
Electric actuators: Check whether the electrical connection is reliable, whether the motor is working properly, and whether the adjustment system (such as inverter, switch) is working well.
Verify the control system: Check whether the signal feedback between the valve and the control system is accurate, and ensure that the valve action response is consistent with the set signal. If any abnormality is found, the electrical or pneumatic control system should be checked, and the damaged parts should be adjusted or replaced in time.

4. Check the opening and closing status of the valve
Valve operation test: Regularly test the opening and closing operation of the valve to ensure that the valve can open and close smoothly without jamming or inflexibility. Especially under medium and high pressure conditions, the valve may fail due to long-term non-use. Regular operation can ensure that the valve can be opened and closed reliably when needed.
Valve switch response time: Check the valve response time to ensure that it can quickly reach the set position. If it is found that the response is slow or it cannot be fully opened/closed, it may be due to actuator problems or valve seat wear, and maintenance is required.

5. Regular pressure and sealing tests
Pressure test: Regularly perform pressure tests on the valve to ensure that the valve can withstand the working pressure and remain sealed. Common test methods include step-by-step pressure test. During the test, the status of the valve and pipeline system should be observed to ensure that there is no leakage.
Leak detection: Perform leak detection on all joints of the valve, and check whether there are leaks in flange connections, threaded joints, welded joints, etc. If leakage is found, tighten the connectors or replace the seals in time.

6. Replace damaged parts
Replace seals: Due to the influence of high pressure, temperature and other factors, the seals of the valve are prone to wear or aging. Check the condition of the seals regularly and replace them in time if they are worn or aged.
Check the valve seat and valve core: The valve seat and valve core may be worn or damaged after long-term use, especially in the case of frequent switching. Regularly check and replace the valve seat and valve core that are severely worn to avoid air leakage, liquid leakage or failure to open and close the valve normally.
Replace actuator parts: Pneumatic or electric actuators may be worn or damaged due to long-term use. Regularly check the air tightness, electrical connections and internal components of the actuator, and replace them in time if problems are found.

7. Prevent corrosion
Anti-corrosion coating: The valve may be corroded during long-term use, especially in high temperature, humid or corrosive media environments. Regularly check the integrity of the valve surface coating and reapply the anti-corrosion coating if necessary to prevent corrosion damage.
Drainage and exhaust: For valves that may accumulate water at low points, the accumulated water should be removed regularly to prevent moisture from corroding the valve and pipeline system.

8. Keep the working environment clean
Keep the environment around the valve clean: Medium and high pressure valves are often used in high temperature and high pressure environments, and the surrounding dust and impurities may affect the normal operation of the valve. Keep the working environment clean to prevent dust and impurities from entering the valve.
Check the exhaust system: Make sure there is no dust or impurities around the valve that block the exhaust port, keep the exhaust unobstructed, and avoid causing work obstacles to the actuator or other components.
Summary
Maintenance of medium and high pressure valves is the key to ensuring long-term and stable operation of the valve. Regular appearance inspection, sealing inspection, cleaning, lubrication, maintenance of actuators and control systems, and testing of valve opening and closing performance can help to detect potential problems in time and prevent equipment failures. For valves in high pressure environments, special attention should be paid to leak detection, pressure testing and corrosion protection to ensure the safety and reliability of the valve under high pressure conditions. Through these maintenance measures, the service life of medium and high pressure valves can be effectively extended to ensure the smooth operation of the pipeline system.