Loadsensing

Load sensing is a hydraulic control concept used to match pump output to the actual demand of a hydraulic system. In a load-sensing arrangement, the pump (typically a variable displacement or pressure-compensated pump) uses a sense line that monitors the pressure at the actuators (the load pressure) and regulates its displacement to maintain a defined differential between that load pressure and a reference pressure on the pump’s displacement control.

When a hydraulic actuator requires more force, the load pressure rises, and the pump increases displacement to supply more flow while maintaining the set differential. If demand falls, displacement is reduced, lowering flow and pressure accordingly. This feedback ensures that the system delivers only the amount of pressure and flow needed, improving energy efficiency and reducing heat generation in the hydraulic circuit.

Key components include a variable or pressure-compensated pump, a load-sense line, a load-sense valve or sensor connected to the pump’s control, and actuators such as hydraulic cylinders or motors. In multi-actuator systems, the sense line provides a common feedback signal that helps the pump respond to the highest demand among actuators, preventing oversupply elsewhere.

Applications are common in mobile hydraulics and industrial systems where energy efficiency, reduced heat, and precise speed/force control are important, such as tractors, loaders, excavators, and automated machinery. Limitations include added system complexity and the need for careful routing of sense lines and avoidance of leaks, which can degrade performance. Load sensing is often contrasted with fixed-pressure or simple flow-control systems.