The rule of thumb has been “three times flow”, but with pressures on space and economics sizing should be reviewed more carefully. The first thing that needs to be determined when sizing a hydraulic reservoir is the size and oil requirements of all components, such as cylinder displacements, accumulator volumes, etc. Secondly, heat must be a factor as this is resulted in any unused power being converted to heat. Dissipating this heat can only be effective if a reservoir is sized with a sufficiently large surface area which allows a temperature difference to exist between the oil and ambient environment in order to dissipate the heat.
Factors to consider when designing a hydraulic reservoir
- Enough oil must be kept for system function
- Adequate surface area to dissipate heat
- Sufficient volume to minimize turbulence and allow air bubbles to escape and contaminates to settle
- Keeping the suction and return lines separated
- The use of baffle plates between the suction and return lines
- Access for maintenance and cleaning
- Room for installing system components
Hydraulic reservoir design recommendations and standards NFPA/T3.16.2 and ISO 4413:2010 are essential documents when designing a new hydraulic power unit.
