What parts need to be replaced during the maintenance of a screw-type air compressor?

Core consumables: three filters and one oil.

In the routine maintenance of screw-type air compressors, the most fundamental components that must be replaced on a regular basis are known as the “three filters and one oil.” These consumables directly affect the quality of the compressed air and the operational condition of the compressor unit.

• Air filter (air filter)Its primary function is to trap dust and impurities from the air, preventing them from entering the compressor unit. If the air filter becomes clogged or damaged, it can lead to increased energy consumption and accelerated wear on the compressor; therefore, it should be cleaned or replaced regularly based on the ambient dust concentration.
• Oil filter (oil strainer)It is used to filter metal particles and impurities from the lubricating oil, ensuring that the oil entering the main unit remains clean. Clogging of the oil filter can cause the exhaust temperature of the main unit to rise; therefore, it must be replaced on a mandatory schedule based on operating hours.
• Oil–gas separator (oil separator): Responsible for separating lubricating oil from compressed air, ensuring that the oil content of the outlet gas meets the specified standards. An excessively high differential pressure across the oil‑separator element not only increases energy consumption but can also lead to oil carryover; therefore, it must be replaced regularly.
• Specialized lubricant: In screw compressors, it serves to lubricate, cool, seal, and reduce noise. When subjected to high temperatures over extended periods, lubricating oil oxidizes and degrades, losing its original performance; therefore, it is essential to periodically drain the old oil completely and replenish it with fresh oil.

Wear Parts for the Transmission and Control System

In addition to the core filtration and lubrication systems, the air compressor’s mechanical drive and valve‑control components also experience natural wear and tear, requiring inspection and replacement during routine maintenance.

• Drive belt or coupling elastomerFor belt-driven models, belt aging, elongation, or breakage can directly cause a shutdown; therefore, belt tension should be checked regularly and replaced as needed. For direct-drive models, the rubber elastomer inside the coupling that has aged or deteriorated must also be replaced promptly.
• Air intake valve and minimum pressure valve maintenance kitThese valves contain numerous rubber seals, O-rings, and springs. After prolonged operation, the seals can age and deform, leading to air leaks or sluggish actuation; during maintenance, it is typically necessary to replace the corresponding repair kit.
• Thermostatic valve core: Used to regulate the flow and temperature of lubricating oil. If the thermostatic valve spool fails, it may cause the machine to trip due to overheating. It is recommended to inspect its thermal expansion performance during maintenance and replace it if necessary.

Maintenance Schedule and Implementation Recommendations

A proper maintenance schedule is essential for ensuring the equipment’s longevity. After a new unit has operated for the prescribed number of hours during its initial run, it must undergo its first service, including the replacement of all filters and lubricants, to remove metal debris generated during the break-in period.

Subsequent routine maintenance intervals are typically determined based on the equipment’s cumulative operating hours. In practice, companies should adjust the maintenance frequency as needed, taking into account the ambient temperature, humidity, and dust levels in the equipment’s operating environment. During each service, in addition to replacing specified components, it is also essential to clean dust from the cooler’s surface and inspect all pipeline connections for looseness, ensuring that the equipment remains in optimal working condition.