As a common control component in industrial pipeline systems, ball valves are widely used in petroleum, chemical engineering, water treatment, energy, and other fields due to their advantages of fast opening/closing, excellent sealing performance, and low flow resistance. Their operating status directly affects the safety and stability of the entire pipeline system. Therefore, mastering scientific daily operation and maintenance methods is crucial for reducing equipment failure risks and extending service life. The following details the key points of daily ball valve management from three dimensions: operation, regular maintenance, and troubleshooting.
I. Daily Operation: Standardized Operation is the "First Line of Defense"
1. Opening and Closing Operation: Avoid "Violence" and Follow the "Smooth Principle"
- Manual Ball Valve Operation: Apply uniform force when turning the handle. Do not use wrenches or other tools to forcefully pry, as this may cause stem deformation or damage to the sealing surface. After fully opening or closing, rotate the handle 1/4 turn (approximately 90°) in the reverse direction to prevent the stem from being in a tight state for a long time and reduce wear on the sealing components.
- Electric/Pneumatic Ball Valve Operation: Before starting, check if the power supply (voltage, current) or air supply (pressure, cleanliness) is normal, and ensure there are no obstacles around the valve. Observe the valve's operating sound during operation; if abnormal noises (such as jamming or friction sounds) occur, stop the machine immediately for inspection to eliminate jamming or loose component issues.
- Operation in Special Scenarios: When transporting high-temperature, high-pressure, or corrosive media, slowly increase the pressure when opening the valve for the first time. After the medium flows stably, gradually adjust to the normal working condition to avoid instantaneous pressure impact damaging the sealing structure.
2. Operation Monitoring: Real-Time Observation to Detect Anomalies in Time
- Pressure and Temperature Monitoring: Regularly check the values of the pressure gauges and thermometers at the inlet and outlet of the valve. If there is a sudden rise/fall in pressure or an abnormal increase in temperature, investigate whether there are issues such as internal leakage, blockage, or medium crystallization in the valve.
- Sealing Status Inspection: Focus on the stem packing box and the valve body flange connection. If medium leakage (such as dripping or smoking) is found, handle it promptly (e.g., tighten the packing gland, replace the sealing gasket) to prevent safety accidents or environmental pollution caused by medium leakage.
- Operation Frequency Control: Avoid long-term operation of the ball valve in the "half-open and half-closed" state. In this state, the medium scouring force is strong, which easily accelerates the wear of the sealing surface and shortens the valve's service life.
II. Regular Maintenance: Scientific Maintenance Extends Equipment Life
1. Daily Cleaning: Maintain External and Internal Cleanliness
- External Cleaning: Wipe the valve surface with a cloth every week to remove dust and oil stains. If the valve is in a humid or corrosive environment, apply anti-rust grease (such as petroleum jelly) regularly to prevent valve body rusting.
- Internal Cleaning: For ball valves transporting media containing impurities (such as sewage, mineral slurry), close the valve every 3 months, disassemble the valve core for cleaning, and remove impurities and scale attached to the sealing surface to avoid jamming caused by impurities affecting the sealing performance.
2. Lubrication Maintenance: Reduce Friction and Improve Operational Smoothness
- Lubrication Parts and Cycle: Moving parts such as the stem, valve core, and bearings require regular lubrication. Under normal circumstances, add lubricating oil (e.g., 32# mechanical oil) once a month for normal-temperature working conditions. For high-temperature working conditions (>150℃), high-temperature resistant grease (e.g., molybdenum disulfide grease) should be used, and the lubrication status should be checked once every 2 weeks.
- Key Points of Lubrication Operation: Clean the oil filling port before adding lubricating oil to prevent impurities from mixing in. Control the oil quantity during lubrication, adhering to the principle of "small amounts and multiple times". Excessive grease easily absorbs dust, which instead increases component friction.
3. Inspection and Replacement of Sealing Components: Ensure Sealing Performance and Eliminate Leakage
- Inspection Cycle of Sealing Components: Vulnerable parts such as seat seals and packing box gaskets should be inspected once a month to check for aging, cracking, deformation, etc. For ball valves under high-pressure working conditions (>10MPa), the inspection frequency should be increased to once every half a month.
- Standardized Replacement Operation: When replacing sealing components, select products matching the original model (e.g., nitrile rubber seals are suitable for oil media, and fluororubber seals are suitable for corrosive media). Clean the sealing surface before installation and apply sealant (e.g., PTFE sealant) to ensure tight sealing.
III. Common Troubleshooting: Quick Inspection and Efficient Resolution
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Fault Type
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Possible Causes
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Solutions
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Valve Jamming During Opening/Closing
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1. Impurities attached to the valve core or stem; 2. Insufficient lubrication; 3. Stem deformation
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1. Disassemble and clean the valve core and stem; 2. Add lubricating oil; 3. Replace the deformed stem
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Valve Body Leakage
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1. Aging of flange sealing gasket; 2. Valve body cracks; 3. Loose bolts
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1. Replace the sealing gasket; 2. For small cracks, use welding repair; replace the valve body for large cracks; 3. Tighten the flange bolts evenly (diagonal tightening method)
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Internal Valve Leakage
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1. Wear of the sealing surface; 2. Valve core deformation; 3. Damaged sealing components
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1. Grind and repair the sealing surface (for slight wear); replace the valve core for severe wear; 2. Replace the deformed valve core; 3. Replace the sealing components
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Electric Ball Valve Fails to Start
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1. Power supply failure; 2. Motor damage; 3. Control circuit open circuit
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1. Check the power supply voltage and circuit connection; 2. Repair or replace the motor; 3. Repair the open circuit
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IV. Maintenance Precautions: Safety First, Standardized Operation
- Safety Protection: Before performing maintenance operations, close the stop valves upstream and downstream of the ball valve, release pressure, and drain the medium in the pipeline. If the medium is toxic, flammable, or explosive, wear protective masks and gloves, and conduct ventilation if necessary to prevent personnel poisoning or explosions.
- Record Management: Establish a ball valve maintenance file, and record the maintenance time, content, fault conditions, and handling results in detail each time. This facilitates tracing the equipment's operating status and formulating targeted maintenance plans.
- Regular Calibration: Conduct a comprehensive performance calibration (such as sealing performance test and opening/closing torque test) on the ball valve once a year to ensure all indicators of the valve meet the operating requirements. For ball valves used in key processes, calibration should be performed once every 6 months.
In conclusion, the daily operation and maintenance of ball valves should follow the principles of "prevention first, standardized operation, and timely handling". Through scientific operation methods, regular maintenance measures, and efficient troubleshooting, not only can the service life of the valve be extended (under normal maintenance, the service life of the ball valve can be extended by 3-5 years), but also the safe and stable operation of the pipeline system can be ensured, and the risk of production accidents can be reduced.