Castrol Perfecto MSO ASA III is a highly stable mineral oil for use in oil film barrier seals on rotating equipment which also incorporates an additive system to improve the conductivity of the fluid and so help prevent a build up of static charges within the lube oil reservoir. Perfecto MSO ASA III reduces the risk associated with static electricity discharges in process gas equipment, particularly where inert gas blanketing of oil reservoirs is not available.

Perfecto MSO ASA III electrical conductivity exceeds 50 p/Sm as is indicated as the desirable minimum in BS 5958 “Control of undesirable electricity”. Top up using a concentrate of electrical conducting agents is unnecessary as the level of conductivity will not change significantly during life cycle of the oil. Perfecto MSO ASA III will greatly reduce the risk of high static electrical discharge over standard non additive mineral oils.

Perfecto MSO ASA III contains no additives which form films of any kind, ensuring that oil seal life is not compromised by the use of an anti-static oil.


  • Oil barrier seals in gas compressors

Technical Data

Name Method Units Perfecto MSO ASA III
Kinematic Viscosity at 40°C IP 71 mm²/s 32
Kinematic Viscosity at 100°C IP 71 mm²/s 5.3
Relative Density at 15°C IP 160 g/ml 0.871
Conductivity IP 274 pS/m 80
Pour Point IP 15 °C -12
Open Flash Point IP 36 °C 216
Demulsification at 54°C ASTM D1401 mins 20
Demulsification IP 19 secs 180
Foam Sequence I (tendency/stability) IP 146 ml 0/0

The above figures are typical of those obtained with normal production tolerance and do not constitute a specification.

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