Cavitation can cause mayhem and destruction when it comes to hydraulic systems, in particular with pumps. This is why it’s essential to make smart decisions when it comes to the design of your system, especially with the suction line.
Cavitation is the name given to when there are bubbles in a liquid. In hydraulic systems that are incorrectly designed, it’s possible for a vacuum to form which pulls trapped air from the fluid to make bubbles. These bubbles can cause a great amount of damage in any hydraulic system and they are best avoided.
Fortunately, there are ways to avoid cavitation from occurring in hydraulic systems, and we’ve listed them below:
- Smart hydraulic reservoir design. Most air bubbles originate in the reservoir. When new oil is introduced, it can create a flow that will bring air into the fluid and result in cavitation. By designing a reservoir that uses downer tubes that allow for the new oil to enter the reservoir from the bottom of it, it’s possible to avoid this from occurring.
- Add a breather filter to the reservoir. The reservoir needs to be supported in functioning properly. When fluid is removed, air will need to take the place of it in the reservoir, a breather filter ensures that this is done in a way that will help to avoid cavitation.
- Install suctions lines of the right size and configuration. Being the biggest cause of cavitation in hydraulic systems, it’s crucial that the best design is used. For example, minimal fittings, correctly sized ball valve and the pipe needs to be large enough to allow for the correct flow of fluid. Ideally the suction line will have a lock to prevent accidental closure or partial closure of the line when the pump is operating.
- Suction line filters to be removed. The position of filters make it difficult to maintain them, which can backfire and clog lines that prevent the pump from receiving needed oil. Filter the oil as it enters the reservoir instead.
- Pump needs to be of the correct size. The pump needs to be able to handle the flow rate of the fluid. Only an experienced engineer can decide the best selection for this as several variables need to be considered.
- Fluid temperature to be maintained correctly. If the fluid is not warm enough, it will become too viscous, leading to more cavitation through pressure drop. If it’s too warm it’s too thin and won’t lubricate the pump correctly. Heating elements may need to be added to the reservoir and monitoring of temperature should be performed.
- A flooded suction should be used for the pump. The pump should be placed below the fluid level for best suction which means that gravity will aid in ensuring the pressure is correct.
By considering these design elements, a hydraulic system can be protected against cavitation and therefore protecting against destruction and damage of hydraulic pumps.