As a core control component in high-pressure and high-risk industries such as oil and gas, chemical engineering, and marine engineering, API Gate Valves are directly related to system safety and API compliance. Daily maintenance must follow the preventive principle, and inspection procedures shall strictly comply with API 600, API 598, and API 6D to ensure standardised operations and traceable data.​

1. Regular Inspection and Condition Monitoring

Inspection Frequency: Determined based on API recommendations and operating condition intensity. Once a day for general working conditions, once every 4 hours for high-pressure and corrosive medium conditions, and increased to once every 2 hours for marine environments or flammable and explosive medium scenarios.​

Core Inspection Items:
① Sealing Status: No visible leakage at the valve stem packing box and flange connections, meeting the "zero visible leakage" requirement of API 598;
② Operational Performance: Flexible manual/electric operation without jamming, smooth valve stem lifting, and normal indicators and torque protection function of the electric actuator;
③ Appearance and Environment: No corrosion on the valve body, intact coating, no deformation or wear of the valve stem, no debris accumulation around, and no residual corrosive gas;
④ Auxiliary Components: Normal status of pressure gauges, seals, and explosion-proof devices, with data within the rated range.

2. Lubrication and Maintenance

Lubrication Parts: Valve stem threads, packing box, actuator transmission components, and flange sealing surfaces.​​

Lubrication Requirements: Select a grease matching the working conditions. Clean the surface of components before each lubrication to avoid mixing impurities.
Lubrication Cycle: Once a month for general working conditions, once every 15 days for high-frequency operation or harsh conditions. The amount of lubricant per application should be sufficient to cover the friction surface without overflow.​

3. Protective Measures​​

Corrosive Environment: Regularly inspect and touch up the anti-corrosion coating of the valve body and valve stem, and cover the flange sealing surface with an anti-rust protective film.​

Low-Temperature Working Conditions: Implement thermal insulation measures to prevent freezing and cracking of the valve stem and seals, following the protection requirements for low-temperature valves specified in API 600.

Long-Term Out-of-Service Valves: Perform a full-stroke opening and closing operation once a month to avoid valve stem jamming. Keep the sealing surface slightly open to prevent adhesion, and ensure moisture-proof and dust-proof sealing.​

Daily maintenance and inspection of API standard gate valves are crucial for ensuring the continuity and safety of production in high-pressure and high-risk industries. Strictly following the standard procedures described in this document can not only effectively extend the service life of valves and reduce failure rates but also ensure operations comply with API series standards, avoiding safety risks and compliance penalties.