What are the requirements for the quality of chemical cleaning of boilers?

1 Scale removal rate: (1) For cleaning scale primarily composed of carbonates, the scale removal area should be at least 80×10-2 of the original scale coverage area. (2) When cleaning silicate or sulfate scale, the area cleared of scale should be 60×10-2 or more of the original scale coverage area. (3) If the scale removal rate is below the specified value, or even if the requirements are met but the main heating surfaces of the boiler are still covered with scale that is difficult to remove, the boiler should be operated for about 1 month while maintaining the alkalinity of the boiler water at the upper limit of the quality standards, after which the boiler should be shut down to manually remove the detached scale and residual deposits. 2. The surface of the cleaned boiler should have a proper passivation coating; there should be no secondary rust formation on the metal surface, nor any pitting. 3 The average metal corrosion rate measured using corrosion indicator sheets should be less than 6 g/(m2·h), and the total corrosion amount should not exceed 72 g/m2. 4 All the water wall tubes and convection tubes in the boiler should have unobstructed flow.

Requirements for cleaning quality acceptance 1: Scale removal rate: (1) For scaling caused mainly by carbonates, the area cleared of scale should be at least 80×10-2 of the original scale-covered area. (2) When cleaning silicate or sulfate scale, the area cleared of scale should be 60×10-2 or more of the original scale coverage area. (3) If the scale removal rate is below the specified value, or although the requirements are met the main heating surfaces of the boiler are still covered with scale that is difficult to remove, the boiler should be operated for about 1 month while maintaining the alkalinity of the boiler water at the upper limit of the quality standards, after which the boiler should be shut down to manually remove the detached scale and residual deposits. 2. The surface of the cleaned boiler should have a proper passivation coating; there should be no secondary rust formation on the metal surface, nor any pitting. 3 The average metal corrosion rate measured using corrosion indicator sheets should be less than 6 g/(m2·h), and the total corrosion amount should not exceed 72 g/m2. 4 All the water wall tubes and convection tubes in the boiler should have unobstructed flow. For pipes that were already blocked before cleaning and remain clogged even after cleaning, they should be repaired or replaced by a qualified entity.