Thermal Spray in Boilers

Thermal Spray is a protective coating made on the tubes of the boiler.  The Thermal spray prevents corrosion, damage to the tubes and unscheduled breakdowns.   The material used for coating is usually an alloy.

Alloys based on Iron with added Chromium are used.  Low carbon steel can also be used as a thermal spray as it resembles the weld overlay.  Aluminium based thermal sprays are also used. 

There are different methods of applying the Thermal spray.  The metal is melted by using an electric arc or a gas flame and sprayed on to the tubes.