Filtration

When sizing an offline oil filter (bypass-filter) the following basic information about the oil system should be provided:

• Oil volume in the system or tank
• Oil type (ISO VG)
• Oil Temperature (normal operation and ambient temperature)
• Oil contamination problems
  – Particles
  – Oil degradation products, sludge, and varnish
  – Water (ingress or accumulated)
• Application
• Associated equipment and/or engine model number
• Machine operation hours per day
• Available power supply

Full flow filtration is where all of the oil pump output is filtered before going to the engine. The full-flow filter provides essential engine protection. The full-flow filter must capture and retain damaging contaminants.

Bypass Filtration is where a proportion of the oil flow is filtered to a considerably better degree than in a full flow filtration system, before traveling back to the oil sump. A bypass filter is sometimes referred to as a secondary filter. Bypass filters working in a separate circuit (kidney loop) do not supply the engine with clean oil directly. A bypass filter improves oil cleanliness.

A bypass filter is usually a much finer filter to capture smaller particles than the full flow filtration system. Because it has higher efficiency, it will have a much lower flow rate than a full-flow filter; particularly when the oil is cold. A bypass filtration system is designed to improve the overall cleanliness of the oil without compromising the flow rate to the engine.

Combination Filtration is where both full-flow filtration and bypass technology are utilized in filtration. A combination filter is sometimes referred to as a two-stage filter.