Did you know that Airco-Fin can produce the extruded finned tubes with extended aluminium sleeve? But what is the purpose for this……
Many of our customers want to prevent the base tubes from corrosion. Corrosion on the inside of the finned tubes, can be prevented by choosing the right type of material or designing the heat exchanger based with corrosion allowance on the wall thickness of the tubes.
For the outside of the base tubes the solution is the heat of the tubes. Raindrops from the outside don’t get the chance to form any corrosion before they vaporize. Unless the heat exchanger is out of service and the tubes are cooled down. The extruded finned tubes the complete tube is covered with aluminium, except the unfinned ends between the tubesheet and the finning. Here the bare tube is facing all the weather conditions from the outside and corrosion from the outside has impact on this part of the tube.
The solution is to use the unfinned sleeve / aluminium extension.
After the finning process the unfinned ends are produced and part of the finning will be removed by machining only the finning and leaving an aluminium sleeve of approx.. 0.8 mm on the base tube. This way the complete tube is covered with aluminium after installation in the air-cooler bundle and aluminium is protecting the base tubes from all possible causes for corrosion from the outside.
Feel free to contact us, if you need more information on this type of unfinned end.