Wärtsilä 31 Lube Oil Bypass Filter Unit

The Wärtsilä lube oil bypass filter unit is an OEM-validated filtration solution officially field-tested and approved by Wärtsilä for use on the Wärtsilä 31 marine engine, as part of a product line also validated for a range of other Wärtsilä engine types including the W20, W25, W26, W32, W34, W38, W46, and W50 series. Designed for both marine vessels and power plant installations, the unit offers an alternative to traditional centrifugal separators for maintaining lubricating oil cleanliness.

The bypass filter unit draws oil at a flow rate of 1.0–6 m³/h from the engine-driven main lubrication oil pump, filtering a continuous side-stream of the total lubricating oil volume rather than the full flow. As a product line, Wärtsilä rates this filtration approach at a 99.5% separation rate for particles ≥10 µm, delivering fine particulate removal without the higher operational costs typically associated with centrifugal separation.

By continuously removing fine contaminants from circulation, bypass filtration helps extend engine life, reduce wear on bearings and other lubricated components, and lower long-term maintenance and operational costs. This makes it a relevant option for operators of Wärtsilä 31 engines seeking to optimize lubricating oil system performance without the added complexity of a full centrifugal separator installation.

Exact dimensions, OEM part numbers, and installation-specific configuration should be confirmed against the official Wärtsilä Online spare parts catalogue or an authorized Wärtsilä dealer prior to ordering, as configuration may vary by installation and engine variant.