A hydraulic power-unit frame must carry the reservoir, motor, hydraulic pump, valves, cooler, accumulator and pipework while preserving service access. Centre of gravity, lifting points, vibration, drainage, spill containment and transport limits should be reviewed before fabrication.
A hydraulic reservoir is not simply a welded box. Usable volume, oil residence time, separation of suction and return, internal baffles, access covers, breathers, sensor ports, drain slope and internal cleanliness all influence hydraulic pump reliability and contamination control.