Environmental pollution and climate change continue steadily. In response to these dramatic developments, laws have been passed to reduce pollution, such as the Euro standards for exhaust emission. Complying with these pollution limits calls for additional measures, such as installing extra exhaust treatment systems next to the combustion engine. This takes up a lot of space inside the machine, however. In addition, global pressure and the demand for higher energy efficiency rise. This finally results in the hydraulic tanks being given increasingly complex and smaller shapes. These designs significantly limit the amount of air separation that can take place inside the tank, so more free air circulates inside the hydraulic system.

Free air in hydraulic systems still represents a major technical challenge today. As long as the air is dissolved in the oil, it does not change its technical characteristics. Undissolved air, however, i.e. air bubbles, causes the following:

• Signs of corrosion on pumps and controls,
• Efficiency loss of pumps and hydraulic motors
• Increased compressibility and thus possible stuttering movements of the output element,
• Accelerated oil aging, varnish
• Noise
• Component damage (e.g. cavitation)
• Escaping oil, foam development in the tank
• Temperature increase
• Dynamic operation problem
• Micro-diesel effect
• Reduced filter capacity
• Changes to the viscosity

An optimisation of the tank system with improved air separation is essential in order to counteract the problems with air in oil and to remain globally competitive.

HYDAC sees the opportunity of optimisation and reducing the tank in every existing tank system.

The reduction in tank volume not only saves material and oil costs, it also brings the customer additional space on his machine and protects the environment.

Maximum air separation and thus optimisation of the tank can only be achieved by a combination of an optimised filter and tank. HYDAC has developed a new filter series for this purpose. These special filters offer the best way to protect the system from air and the resulting consequences. 

The innovative filters provide the following features for optimum air separation:

• Low outlet velocity
• Minimised turbulences in the tank
• Smooth oil blending in the tank
• When flowing from below, outlet above the oil level is possible
• Coalescence of air bubbles at the integrated deaeration windows and thus faster air separation