138. What type of diesel engine lubricating oil filtration scheme filters a small portion of the output of the lubricating oil pump prior to delivery back to the sump via a fine filter?

A bypass filter filters a small portion of lubricating oil pump output through a fine filter and returns it to the sump, distinguishing it from full-flow filters which filter all oil to the bearings, and batch filters which imply offline filtration; the described arrangement is specifically termed a bypass filter.