Maintenance of Hexi Single-Screw Oil-Free Water-Lubricated Air Compressors

Equipment Overview and Operational Characteristics

The single-screw oil-free water-lubricated air compressor features a unique rotor design and water-lubrication technology, eliminating the need for lubricant during operation and effectively preventing oil–air cross-contamination. This model is widely used in industries with stringent air-quality requirements, such as food processing, healthcare, electronics, and precision manufacturing. Because it relies on water as both a lubricant and a sealant, the equipment’s stable operation depends heavily on proper water-quality control and regular maintenance.

Key Maintenance Points

To ensure the equipment operates efficiently over the long term, the following maintenance aspects require particular attention:

• Water Quality Management and Circulation Systems: Use only deionized or softened water that meets the required standards, and regularly test its conductivity and pH. It is recommended to replace the circulating water every three months and to clean sediment from the bottom of the tank to prevent microbial growth and scaling in the piping.
• End Seal and Bearing InspectionThe end-face seals of water-lubricated units are consumable parts and should be inspected regularly for wear based on operating hours. If leaks or abnormal friction noises are detected, the seals should be replaced promptly to prevent water from entering the main motor or compromising compression efficiency.
• Cleaner and Filter CleaningPlate or tubular coolers are prone to scale formation due to water hardness and require periodic backwashing or chemical soaking with a dedicated cleaning agent. The air intake filter element and the water–air separator should be inspected monthly, and replaced immediately if severely clogged, to ensure adequate air intake.
• Electrical and Control Module InspectionRegularly inspect the operating condition of pressure sensors, temperature probes, and solenoid valves, and remove dust and moisture from inside the control cabinet. Ensure that wiring terminals are securely tightened to prevent poor contact caused by vibration, which could lead to shutdown failures.

Routine Inspections and Periodic Maintenance

Operators should establish standardized inspection checklists and record exhaust pressure, water temperature, operating current, and any abnormal equipment noises daily. Weekly checks should verify that the补水阀’s automatic start–stop function is working properly and confirm that the water-level float is flexible and reliable. A comprehensive maintenance service should be performed quarterly, including replacing all consumables, calibrating the safety valve’s set pressure, and conducting professional measurements of the main unit’s rotor clearance.

Safety Precautions

Before performing any maintenance, disconnect the main power supply and release residual pressure from the air tank and piping; never remove components while pressurized. When replacing water‑line fittings, wear protective gloves to avoid burns from hot condensate. After maintenance is complete, slowly open the inlet valve to purge air, and only start the equipment for a trial run after confirming that all connections are leak‑free.