Pressure oil piping for both jacking oil systems and lubricating oil systems on modern units is subject to special design precautions against oil leakage and fire risk. The oil piping is sized so that the oil velocity is between 1-5 m/s.
Oil piping from the pump discharge is contained within an enclosure/duct and the pipe-runs between pipe joints are as long as is possible. All pipe joints are of Class 1 welded construction. At the exit from the ducted area, the pressure oil pipe is contained within a protective pipe, so that any oil leakage would be contained and would be detected at 'tell-tale' drains. Pipe material up to the filters is mild steel; on some designs, the pipe-runs after the filters are in stainless steel to minimise the risk of corrosion products damaging the bearings. Automatic air venting of the pipework system from its highest points to the oil tank is provided where the air is not vented through the bearings. Oil filters are also provided with air vents to the oil tank; these ensure that any air accumulation, either in service or as a result of servicing or inspection, is vented to the oil tank.