1. When the newly installed boiler is put into operation. ,

2. When a boiler that has been out of service for more than one year resumes operation. ...

3. After major repairs or replacements of boiler transformation and pressure-bearing components, if the number of replacement pipes for the water wall exceeds 50%, the superheater, reheater, economizer and other components are replaced in groups, and the steam drum undergoes major repairs. ...

4. When the boiler is seriously overpressured 1.25 times the working pressure and above. ...

5. When the heating surface of the boiler is deformed in a large area after severe water shortage. ...

6. When there are doubts about the safety and reliability of equipment operation according to the operating conditions.