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NH3 Refrigerator Oil Emulsification (Moisture Ingress)

Likely causes

Shaft seal worn or damaged → moisture and air ingress (milky white emulsion in oil)

Check: Take oil sample — check for white emulsion (moisture) or brown discoloration (oxidation). Acidity test (pH ≤6 or TAN >0.3 mgKOH/g) → replace oil immediately if above limit

What to do: Before replacing shaft seal: nitrogen pressure test at 3 bar on seal area to locate leak. After seal replacement, replace entire oil charge with NH3-specific oil (PAG or mineral oil rated for NH3) — never use general-purpose synthetic oil

Oil separator drain valve not opened → moisture accumulates, entire oil charge contaminated

Check: Open oil separator drain valve weekly; check color and odor of drained fluid — milky white indicates moisture contamination

What to do: Replace full oil charge. Establish weekly drain valve opening routine. Oil change interval: 8,000 running hours or annually

Oil cooler water-side leak → pinhole in water-cooled oil cooler tube allows water to mix in

Check: Hydraulic test on oil cooler (≥10 bar) → replace tube bundle if pinholes found

What to do: Replace tube bundle, then replace full oil charge. NH3 reacts with moisture to form NH4OH — causes metal corrosion and acidity rise

Field tip

Drained NH3 oil still contains residual ammonia — always wear NH3 detector and seal waste oil container immediately. Must use NH3-specific oil (PAG or mineral oil rated for NH3); never use general-purpose synthetic oil.

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