Why is stainless steel preferred over aluminum heat exchanger?

Why is stainless steel preferred over aluminum heat exchanger?

Stainless steel is generally preferred over aluminum for heat exchangers because of its longevity and corrosion resistance. While aluminum is lightweight and has high thermal conductivity, it is more likely to erode at high flow rates and has lower resistance to corrosion. Stainless steel heat exchangers, on the other hand, operate very effectively at high flow rates and have high resistance to both uniform corrosion and oxidation. Additionally, stainless steel is suitable for intended fabrication techniques such as forming and welding and has toughness at cryogenic temperatures and strength at elevated temperatures. It also has resistance to galling.

Overall, While stainless steel is more expensive than aluminum, it is stronger and can be reduced to far below 1 mm in wall thickness, while cast-aluminum has a minimum of approximately 2.5 mm. Stainless steel has proven to be an exceptionally reliable and durable material for heat exchanger construction.