Maintenance · Powered by experts in compressed air
Air compressor PM schedule — rotary screw & piston
Preventive maintenance is the single most important factor in compressor longevity. A well-maintained rotary screw compressor will run 80,000–100,000 hours before major overhaul. A neglected one may fail at 20,000. The difference is discipline — following a consistent PM schedule and keeping records.
Use the interactive checklists below for your machine type. Check off tasks as you complete them, then print or download the completed schedule as your service record.
📅 Daily (every shift or every 8 hours of operation)
Check oil level in sight glass — add if below midpoint, never overfillDaily
Verify operating pressure is within set range on controller displayDaily
Check for unusual noise, vibration, or odor — investigate any change immediatelyDaily
Confirm auto-drain valve is cycling — manual test if uncertainDaily
Check discharge temperature on controller — alert if above 220°F (air-cooled)Daily
Review controller fault log — clear only after root cause identifiedDaily
📅 Weekly
Clean or blow out cooling fins and air-cooled heat exchanger with dry compressed airWeekly
Inspect air filter service indicator — clean or replace if in red zoneWeekly
Check V-belt tension and condition if applicable (non-direct-drive units)Weekly
Inspect oil separator tank exterior for leaks or corrosionWeekly
Record running hours, discharge temp, and operating pressure in logWeekly
📅 Monthly / Every 500 hours
Drain and inspect moisture separator — check float drain functionMonthly
Test safety/pressure relief valve — pull ring briefly and confirm it reseatsMonthly
Inspect all air/oil hoses for cracking, chafing, or oil seepageMonthly
Tighten all electrical connections in panel (vibration loosens terminals)Monthly
Check compressor room ventilation — clear any obstructions from inlet/exhaustMonthly
Verify oil cooler is clean — clogged cooler is the #1 cause of high-temp shutdownsMonthly
📅 Every 2,000 hours (or annually, whichever first)
Replace air inlet filter element — do not attempt to clean and reuse2,000 hrs
Replace oil filter element2,000 hrs
Replace oil separator element — high differential pressure across separator wastes energy2,000 hrs
Drain and refill compressor oil (use manufacturer-specified fluid only)2,000 hrs
Inspect and clean check valve — carbon buildup causes backslip and reverse rotation2,000 hrs
Replace minimum pressure valve if showing wear or delayed opening2,000 hrs
Inspect flexible coupling or V-belt drive — replace if worn2,000 hrs
Re-grease motor bearings per manufacturer specification2,000 hrs
Test all safety shutdowns — simulate high temp, low oil pressure, over-pressure2,000 hrs
Take oil sample for analysis — trending viscosity, metals, and water content reveals problems early2,000 hrs
📅 Every 4,000–8,000 hours (per manufacturer spec)
Inspect airend — check rotor tip clearances, bearing play, shaft seal conditionMajor
Replace shaft seal if any oil leakage observedMajor
Inspect and rebuild or replace unloader valve assemblyMajor
Inspect motor windings — megger test for insulation resistanceMajor
Replace all hoses regardless of visible condition (rubber degrades internally)Major
📅 Daily
Check oil level in crankcase sight glass — top off to full mark with correct viscosityDaily
Drain tank moisture — open manual drain valve fully until only air escapesDaily
Listen for unusual knocks, squeals, or rhythmic changes in exhaust noteDaily
Verify pressure switch cuts out at correct maximum pressureDaily
📅 Weekly
Clean intake filter element — blow out with dry air, never wash with solventWeekly
Check V-belt tension — should deflect 1/2" to 3/4" under moderate thumb pressureWeekly
Inspect all fittings and connections for oil or air seepageWeekly
Clean cooling fins on cylinder head and inter-cooler with dry airWeekly
📅 Every 3 months / 500 hours
Change crankcase oil — more often in dusty environments or high-humidity shops3 months
Replace or clean intake filter element (replace if damaged or heavily soiled)3 months
Test safety relief valve — pull ring and confirm it reseats fully3 months
Inspect tank exterior for rust spots — treat and paint any corrosion immediately3 months
Tighten all head bolts to manufacturer torque spec — thermal cycling loosens them3 months
📅 Annually
Inspect and replace valve assemblies (intake and discharge) — worn valves reduce capacity and increase energy useAnnual
Inspect piston rings — replace if ring gap is beyond spec or rings show step wearAnnual
Replace V-belt regardless of visible conditionAnnual
Inspect connecting rod bearings and crankshaft bearing for play or scoringAnnual
Have tank inspected per applicable pressure vessel code (ASME) — especially tanks over 10 years oldAnnual
Replace pressure switch if it shows any sticking or erratic cut-in/cut-outAnnual
📅 Daily
Refrigerated dryer: verify dew point indicator is in the green zoneDaily
Check all automatic drain traps are cycling — test manual override if unsureDaily
Check filter differential pressure indicators — service filter if in yellow/red zoneDaily
📅 Monthly
Refrigerated dryer: clean condenser coil fins with dry brush or compressed airMonthly
Manually drain all filter bowls — confirm no liquid carryover past coalescing filterMonthly
Desiccant dryer: verify switching cycle (tower A/B switching on schedule)Monthly
Check dew point meter calibration if facility uses process monitoringMonthly
📅 Annually
Replace all filter elements — coalescing, particulate, and carbon. Don't wait for ΔP alarmAnnual
Refrigerated dryer: check refrigerant charge and inspect for leaks (certified technician)Annual
Desiccant dryer: inspect desiccant bead condition — replace desiccant if beads are cracked, discolored, or oilyAnnual
Replace all automatic drain valve solenoids or floats — small cost vs. a failed-open drain wasting 10+ CFMAnnual
Verify carbon filter replacement date — carbon filters must be replaced on schedule regardless of flowAnnual
Sample and test downstream air quality for ISO class compliance if required by your industryAnnual
Keep a service log. Record every maintenance action with date, running hours, and any observations. A logbook is your best diagnostic tool — trends in oil consumption, temperature, and pressure reveal developing problems months before failure. our team can provide digital service log templates on request.
When to call our team service
| Symptom | Likely cause | Action |
|---|---|---|
| High discharge temperature alarm | Low oil, clogged cooler, high ambient, bad thermostatic valve | Stop unit, investigate before restart |
| Unusual metallic knock | Bearing wear, loose coupling, foreign material ingestion | Stop unit immediately — call service |
| Excessive oil consumption | Worn oil separator, worn shaft seal, overfilled oil | Check separator ΔP, inspect seal — service if persists |
| Low output pressure | Clogged inlet filter, worn valves (piston), worn airend (screw) | Check filter first; if clean, call service |
| Frequent cycling / short cycling | Undersized receiver, leaks, failed check valve | Leak test first; check valve if leaks are not the cause |
| Water in oil | Failed shaft seal, condensation in crankcase | Stop unit — water destroys bearings rapidly. Call service. |
| Oil in compressed air | Failed oil separator, clogged separator element | Replace separator element; if persists, call service |
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