test

A pressure compensator is a pump control that senses system pressure and reduces or stops pump displacement when demand falls, helping avoid wasted flow and heat. It can limit pressure, but it is not a relief valve and cannot remove oil from an open-loop system. This article explains how pressure compensation works and where its limits matter in a hydraulic circuit.

Pressure Compensator

Tomas: Hi Fraser, regarding pressure-compensators, which pumps/products have these, and what do they do exactly?

Fraser: Pressure compensation simply means “takes pressure into consideration”. Which can mean in valves that it adjusts to pressure changes to maintain the same performance, or far more commonly in pumps where it means to reduce pump flow based on system pressure. For a pump to reduce flow it must be a variable pump. Mostly piston pumps with a swashplate. However there are some variable vane pumps, but these are a legacy technology. Variable motors can also be pressure compensated.

Tomas: Would most variable pumps come with a pressure compensator by default then?

Fraser: Most open loop for sure. It is a very simple energy saving feature. But for closed loop it is less common, especially if there is an electronic control. Maybe 50/50. On motors it is one type control out of many. It is not an energy saving feature in a motor.

Parker variable piston pumps with pressure compensation at Lifco Hydraulics