Long standing sales partner HYDAC has always been a leading force in the fluid control sector, driving innovations and pioneering the latest technology. With our relationship growing each year Leader Hydraulics have been at the forefront in offering HYDAC’s ranges to our growing customer base.

Today we wanted to cover one HYDAC’s latest innovations in tank optimisation, Air-X Technology.

Problems With Air In Oil

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:

  • 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
A conventional return line filter (right) against a smaller tank with optimised filter concept (left)

Air-X Technology

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


  • Reduction of oil volume,
    therefore, cost savings for end user and environmental protection
  • Reduction of tank size, 
    therefore, cost savings for OEM (material) and additional design space
  • Lower complexity,
    therefore, minimal effort with fittings, piping and connections and cost savings for OEM (material, assembly)