CAB Maintenance Tips

Checking the Braze at the Furnace Exit
Part 3 of 5  - Burnt Extrusions

Burnt extrusion mainly has two causes:

If the distance between the accumulator or header and the airway is too small, operators may leave a thick trail of flux in this area. If the part then, is heated above 610°C (1130°F), cladding from the fin is drawn into this area through capillary action. Silicon from the cladding then erodes the base material and a hole is formed.

Other burn holes are usually just poor extrusion or an abrasive operation. In the bending machine, extrusion could be scraping against the dies. This reduces the wall thickness and a hole is burnt in the furnace.

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The latest design, materials and equipment specifications should be obtained from the company before any reliance is placed on the enclosed since changes may occur due to productimprovement.

|Go to Part 4 Burnt Airways |