// Catalogue

Load Sensing Pumps: LS Variable Pumps for Mobile and Industrial Hydraulics

Load sensing pumps read the pressure the load needs and deliver just enough flow and pressure to move it, plus a small margin. TSA Hydraulics Engineering supplies them within the Servo & Control family of our Motors & Drives range, for cranes, loaders and tractors.

That small margin, usually 15 to 30 bar, decides how the machine feels. Set it too low and every function goes lazy. Set it too high and the oil runs hot. Most swaps go wrong when nobody records it. Send the pump code, control code and margin setting, and we will match a genuine LS pump or an equivalent.

// Buying guide

How Load Sensing Works

Each work section on the valve picks up its load pressure.
Shuttle valves pass the highest load pressure down the LS line to the pump.
The pump’s LS control holds the outlet pressure at load pressure plus the margin.
With no function moving, the pump drops to a low standby pressure.
A pressure cut off limits the maximum pressure for the whole system.

Why Choose Load Sensing?

Less wasted energy than a fixed pump dumping over a relief valve.
Cooler oil and smaller coolers.
Smooth control of several functions at once.
Flow that stays steady as the load changes, so the operator gets a predictable feel.

Types of Load Sensing Pump

Variable axial piston pumps: the most common LS pump on mobile machines and industrial units.
Variable vane pumps: for lower pressure industrial circuits.
Fixed pumps with an LS priority or unloading valve: a lower cost option on simpler machines.

The valve bank must suit load sensing too. A closed centre LS valve is needed to make the system work.

Common Load Sensing Faults

Slow functions: the margin is set too low, the pump is worn or the LS line is restricted.
Pump stuck at full pressure: a blocked or leaking LS signal, or a valve section passing pressure when it shouldn’t.
Hunting or unstable pressure: air in the LS line, or a damping orifice that is blocked or missing.
Hot oil: the margin or standby is set too high.

Check the LS line and the margin with a gauge before replacing the pump.

Matching a Replacement

Read the full pump code, including the control code.
Record the margin, standby and cut off pressures if you can measure them.
Check the rotation, flange, shaft and any through drive.
Note the LS port location and thread.

Load Sensing Pumps Specifications to Check

Displacement and maximum pressure
LS margin and pressure cut off range
Rotation, flange and shaft
Through drive option
Port positions, including the LS port
Speed range and drive source

Why Buy From TSA Hydraulics Engineering

As a load sensing pumps supplier, we match the control, the settings and the mounting, so the machine feels the same as it did before the swap. You get OEM or equivalent options, and help sourcing load sensing pumps replacement parts such as LS controls, seal kits and shaft seals. We tell you upfront whether a pump is genuine or an equivalent.

// FAQs