Does anybody have examples of a boosted hydraulic system that uses nitrogen applied directly onto the free surface of the oil within the reservoir? the boost is between 3-8bar.
Large hydraulic presses have direct contact balancing systems with nitrogen in free contact with the oil. They also have pre-fill tanks above the main cylinder the keep the cylinder full on the rapid down strokes. These are air loaded to maintain a positive pressure.
The are also lots of free contact accumulators in the market.