What are the hazards of scaling?

　　1) The thermal resistance of scale is very high, which will reduce the heat transfer effect of the heating surface, which will cause the boiler exhaust gas temperature to rise and the thermal efficiency to drop.

　　2) Increase the temperature of the metal wall on the heated surface, which may cause bulging, deformation of the pressure-bearing parts, and overheating tube failure in severe cases, which may damage the equipment and shorten the service life.

　　3) Scaling in the tube reduces the effective cross-sectional area of the flow, increases the flow resistance of the working fluid, and destroys the normal boiler water circulation. The deposition of some shed scale can also cause local blockage or poor circulation.

　　4) Scaling will eventually lead to a decrease in boiler output, a shortened service life and poor economic efficiency.

　　5) Under-deposit corrosion may occur.