How to quickly identify whether the air compressor lubricant needs to be replaced?

DateTime：2025-07-24Source：u-air chainHits：

Lubricant is the "blood" of screw air compressors, and its deterioration directly leads to equipment wear, overheating, and even failure—especially critical for pharmaceutical and manufacturing industries relying on stable operation. Mastering quick identification methods for lubricant replacement can effectively avoid hidden dangers. Here are the key judgment criteria.

Visual inspection: Observe color and turbidity

Take a clean glass rod, dip it into the lubricating oil, and observe it against the light. New oil is transparent and bright (usually light yellow or amber). If it turns dark brown, black, or appears turbid with suspended particles, it means the oil has oxidized seriously or mixed with impurities. In summer, high temperatures accelerate oxidation—check the oil sight glass weekly; once turbidity appears, replace it immediately to prevent sludge clogging cooling channels.

Sensory judgment: Smell and viscosity

Normal lubricant has a faint mineral oil smell. If it emits a pungent burnt smell, it indicates the oil has been overheated and degraded. For viscosity testing, dip two fingers in the oil and rub them gently: new oil feels smooth and consistent, while deteriorated oil becomes sticky, or conversely, too thin (a sign of oil dilution by moisture). In humid summer, moisture intrusion is common—viscosity abnormalities often signal water contamination.

Equipment performance feedback: Abnormal signs

Pay attention to the compressor’s operating state. If the exhaust temperature rises suddenly (exceeding the normal range by 10℃ or more) without cooling system issues, it may be that the lubricant’s cooling capacity has declined. Increased operating noise or vibration also suggests poor lubrication due to oil degradation. Additionally, if the oil pressure drops and the oil level decreases abnormally (without leakage), the oil may have deteriorated and lost its proper properties.

Time and usage basis: Don’t exceed the limit

Even without obvious abnormalities, replace lubricant according to the recommended cycle. Under standard conditions, the cycle is 4,000 operating hours, but in summer or dusty environments, shorten it by 20%-30% (to 3,200 hours or less). For compressors used in GMP-compliant pharmaceutical facilities, strictly follow the maintenance schedule and record replacement times to ensure compliance.

By combining these quick identification methods, enterprises can replace lubricant in a timely manner, avoiding equipment failures caused by oil deterioration and ensuring the stable operation of air compressors.

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