A two speed pump is a hydraulic pump which usually contains a safety relief valve and a has an internal setting for a pressure changeover. Typically it creates more flow at lower working pressures and lower flow at higher working pressures. This allows for optimal efficiency across increasing pressures in hydraulic cylinders or other hydraulic applications.
When found in a manual hydraulic tool, the two speed pump is typically preferred as it allows for a lower handle effort at higher pressures, here’s how it works:
Functions of a Two Speed Pump
The two speed pump’s relief valve is set to a pressure which is typically referred to as a changeover pressure. When the pressure increases in the cylinder or hydraulic system and reaches the changeover pressure, the two speed pump switches from low to high pressure piston.
A two speed pump will switch from low to high pressure pistons when the cylinder hits the changeover pressure (200 PSI for example) as the pressure is increasing. This changeover will occur automatically internally.
Winshaw Hydraulic Tools’ Model HP, manually operated hand pumps come in aluminum or steel. The HP227 and HP232 two speed pumps are some of our most common, manual hydraulic pumps and an example below shows their operation.
Advantages of a Two Speed Pump
While a two speed pump is usually a higher cost than a single speed pump, a two speed pump offers many advantages. For instance, it is easier to operate manually at higher pressures, with less demand on the operator.
The Hi Force HP manually operated two speed pumps come in a variety of models. Most models feature two way valves, but four way valves are also available. With their easy operation and lightweight design, these pumps are a great choice.
To learn more about our two speed pumps and other hydraulic tools, contact Winshaw Hydraulic Tools today.