Screw Chiller Oil Filter Clog (ΔP 0.15 MPa, Replace Every 2,000 Hours)

Question

Screw Chiller Oil Filter Clog (ΔP >0.15 MPa, Replace Every 2,000 Hours)

Accepted Answer

Over 2,000 operating hours without replacement — sludge and metal particles cause ΔP increase. Check: Check oil filter ΔP daily — schedule replacement at 0.10 MPa, replace immediately if >0.15 MPa. Confirm cumulative hours from hour meter What to do: Replace oil simultaneously when replacing filter → after installing new filter, remove air via purge valve → top up oil to midpoint of sight glass Oil degradation (TAN >0.5 mgKOH/g) — oxidation sludge formation. Check: Request oil sample analysis (every 6 months recommended): TAN, viscosity, metal content. Separately inspect bearing wear if excessive metal particles What to do: Replace all oil + replace filter. If metal particles abnormal, consider early bearing replacement — replacing filter alone does not solve the root cause Refrigerant liquid mixing into oil — oil dilution and accelerated contamination. Check: Check for oil foaming and abnormal noise immediately after startup. Verify crankcase heater operation (failure is a cause of refrigerant migration) What to do: Replace/repair crankcase heater. Establish 2+ hour pre-start heater operation procedure. Replace oil + filter

Screw Chiller Oil Filter Clog (ΔP >0.15 MPa, Replace Every 2,000 Hours)

Likely causes

Over 2,000 operating hours without replacement — sludge and metal particles cause ΔP increase

Oil degradation (TAN >0.5 mgKOH/g) — oxidation sludge formation

Refrigerant liquid mixing into oil — oil dilution and accelerated contamination

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