Training institutions. It belongs to Daxing District of Beijing. As of June 3, 20221,boilers in Daxing District need to go to training institutions first, and then go to the Bureau of Quality and Technical Supervision to apply for the exam. Boiler book is a kind of operation certificate of special safety high-voltage equipment, and only when it is certified can it be safely employed. From low to high, it can be divided into three categories, two categories and one category.