RAL Series - AIR/OIL heat exchangers

The cooler element, in high resistance aluminium alloy, is obtained by means of a braze-welding process carried out under vacuum.
Each data sheet provides the technical information about the heat exchanger used for cooling oil hydraulic system and about fans operated by electric or hydraulic motor.

Core’s technical specification 

  • material: aluminium
  • Working pressure: 26 bar 
  • Test pressure: 39 bar 
  • Max working temperature: 120°C 

Please contact HYDRAPAC ITALIA for aggressive ambient 


The heat exchanger should be installed in such a way that there should be no obstacles to the air flow, respecting the minimum distance from the wall (1/2 fan diameter) so as to ensure a natural flow of cooling air.
The cooler can be fitted in vertical and horizontal position.
RAL series coolers are normally used for cooling hydraulic circuits and installed on the return lines: they must be protected from impact and mechanical vibrations by support and must be connected to the circuit with flexible pipes. To prevent any damage caused by changes in flow, hammering and pulsations we recommend installing a by-pass valve


  • mineral oil
  • water-oil emulsion
  • water-Glycol

For other fluid consuls HYDRAPAC ITALIA


Cleaning oil side 
After having dismantled the exchanger, carry out the cleaning procedure by circulating de-greasing substance inside the radiator compatible with steel. Wash with hydraulic oil before reconnecting the cooler. 

Cleaning air side
Carry out this procedure using compressed air. Make sure that the direction of the jet is parallel to the fins so that they are not damaged. If the blockage of the exchanger is caused by build up of oil or grease, c1eaning can be carried out using a jet of steam or hot water. During c1eaning procedures the electric motor must be adequately protected.


During operation of heat exchangers observe following instructions:

  • Do not remove the fan grilles
  • Electrical connections must be made by skilled electricians in accordance with the attached electrical diagrams 
  • Exterior surfaces of heat exchangers may reach high temperatures so adequate guards must be installed or the unit must be mounted in an inaccessible position 
  • Do not perform work on the hydraulic motor until the hydraulic pipelines have been disconnected

Hydraulic Systems and Components