One of the most common mistakes in any hydraulic system, or in specifying components for that hydraulic system, is to incorrectly size the components. Component sizing is critical to each and every component used in a hydraulic system! Either under-sizing or over-sizing is a significant problem, and can be the source for poor system performance.
Perhaps the more critical error of the two is to under-size a component in a hydraulic system. There are several potential results from under-sizing components:
- Under-sizing a cylinder, motor, or pump could cause the component to be unable to perform its assigned task whether that means the affected performance is force, torque, flow or pressure.
- Under-sizing valves could cause low flow and thereby restrict the speed of actuators in the system. This low flow condition leads to system inefficiency as well as heat generation.
- Under-sizing either reservoirs or heat exchangers can cause a heat rise in the hydraulic fluid. This heat rise will break down the fluid itself and thereby cause premature fluid deterioration as well as shortened component life.
- Under-sizing fluid conductors – that is, tubing, hoses, and fittings – will also create heat and restrict the flow of fluid to the machine. The restricted flow results in slower machine functions.
- Under-sizing the filter, or even choosing the incorrect element media within the filter, will cause premature wear in the hydraulic components as well as heat and inefficiency.
- Under-sizing an accumulator within a hydraulic system could lead to poor system performance such as reduced production. But worse, under-sizing the accumulator could affect the circuit’s ability to perform a prescribed emergency function. If there is insufficient discharge flow at the desired pressure from the accumulator, the failure to perform the emergency function could cause personal injury or death.
Generally speaking, over-sizing does not affect system performance as much as under-sizing, but over-sizing simply adds unnecessary cost to the system. Merely matching port sizes of components is not a good way to specify them – calculations must be performed for pressure and flow characteristics.
Quality Hydraulics & Pneumatics, Inc. has developed specialized software to assist in sizing components for your particular application. But software alone is not enough. Correct component sizing requires not only the right tools, such as our custom software, but also qualified Fluid Power Specialists who understand the system requirements and can work with the software to insure accurate component selection.
For more information contact Bob Wojcik, Fluid Power Specialist, at (847) 680-8400.