Maintenance and Servicing Intervals for Screw Air Compressors

I. Daily Inspection and Maintenance (Daily or Per Shift)

Routine inspections are the first line of defense against equipment failures, and operators must perform basic checks before and after starting up the equipment.

• Check the oil level:Ensure the lubricant level remains within the normal range to prevent overheating or damage to the main unit caused by insufficient oil.
• Discharge condensate:After shutdown or before startup, drain the condensate from the oil–gas separator, the cooler, and the piping to prevent water from entering the compressed air system.
• Operating Parameter Monitoring:Record the discharge pressure, discharge temperature, and motor current to ensure that all parameters remain within their normal operating ranges.
• Abnormal Sound and Vibration Inspection:Monitor the noise and vibration levels of the host unit and motor during operation, and shut down and troubleshoot promptly if any abnormalities are detected.

II. Regular Maintenance (Weekly to Monthly)

This phase focuses on cleaning the equipment and verifying the condition of its basic components to maintain an optimal operating environment.

• Clean air filter:Use low-pressure compressed air to blow dust off the surface of the air filter element from the inside out. If the filter element is damaged or severely clogged, it must be replaced promptly.
• Inspect the piping system:Inspect all connecting pipelines, fittings, and valves for air or oil leaks.
• Clean the cooler:Clean dust from the surface of air-cooled radiators, or check the inlet–outlet water temperature differential of water-cooled coolers, to ensure cooling efficiency.
• Transmission Component Inspection:Inspect the belt tension and wear, or check the condition of the coupling’s elastomer.

III. Mid-term Comprehensive Maintenance (every 500 to 2,000 hours)

Mid-term maintenance involves replacing critical consumables, and the specific service interval should be adjusted as needed based on the dust concentration and humidity of the equipment’s operating environment.

• Replace the air filter element:The air filter element must be replaced when the specified service life is reached or when a differential pressure alarm is triggered.
• Replace the oil filter:Regularly replace the oil filter to prevent metal wear particles and contaminants from entering the main unit, thereby protecting the rotor and bearings.
• Replace the oil-gas separator element:Replacement is performed when the oil‑pressure differential reaches the set value or when the operating time meets the specified threshold, thereby reducing energy consumption and minimizing oil carryover.
• Electrical System Inspection:Tighten the electrical wiring terminals, inspect the contactor contacts, and clean out dust from inside the control cabinet.

IV. Long-Term Comprehensive Maintenance (every 4,000 to 8,000 hours)

Long-term maintenance involves a systematic inspection of the equipment and a comprehensive replacement of consumables, ensuring its reliable operation over the long term.

• Lubricant replacement:Completely drain the old oil, flush the oil system, and fill with a fresh, specification‑compliant, dedicated lubricant.
• Host and Motor Maintenance:Inspect the motor bearings for proper lubrication, and replenish or replace the bearing grease as needed; assess the main unit’s operational efficiency.
• Safety accessory verification:Calibrate or replace safety valves, pressure gauges, and temperature sensors to ensure that the protective devices are sensitive and reliable.
• System valve maintenance:Disassemble and clean the intake valve, minimum pressure valve, and temperature control valve; replace internal seals and the repair kit.

V. Maintenance Precautions

When carrying out the aforementioned maintenance schedule, strict adherence to safety operating procedures is required. Prior to maintenance, ensure that the equipment has been shut down, de-energized, and that any residual pressure in the system has been relieved. All consumables and lubricants replaced must comply with the equipment’s technical specifications; never use inferior substitutes. In addition, it is recommended to establish a comprehensive equipment maintenance record, meticulously documenting the date, scope of each service, and details of any components replaced, to facilitate tracking the equipment’s operational status and optimizing future maintenance plans.