The lubricating oil filter, code P51502-16, is a key protective element in the MAN L21/31 engine’s lubrication system, ensuring that circulating oil remains free from contaminants such as metal particles, soot, and sludge. By maintaining oil cleanliness, the filter reduces wear on bearings, pistons, and other precision components, significantly extending engine life and improving operational reliability. Its high filtration efficiency is especially critical under heavy-duty marine and power plant conditions where engines operate continuously and demand consistent lubrication quality.