1. Report the shift chief-operator to ask for instructions of boiler shutdown. 

2. Increase the boiler feed water, maintain normal water level of steam drum and reduce boiler load, put the standby boiler into use as soon as possible or increase the evaporation capacity of other operating boiler. 

3. If during maintaining operation, the drum water level continues to drop or the leakage point threatens the adjacent pipe, the boiler shall be stopped immediately. 

4. After the boiler is shut down, close the main steam valve, open the draining valves at each part and the air bleeding valve to the atmosphere in order to maintain the operation of induced draft fan. 

5. In order to maintain the water level of steam drum, it is possible to continue feeding water to the boiler. Close all the water draining valves, it is forbidden to open the recirculation valve again. 

6. If the water feeding to the boiler with failure conflicts with the water feeding to the operating boiler, the operating boiler shall prevail, when necessary, one water pump shall be started additionally. 

7. After the humidity in the boiler has been eliminated, stop the operation of the induced draft fan, and cool the boiler according to the requirements of the maintenance. (If emergency maintenance is required after the boiler is shut down, the bottom materials shall be discharged when the boiler is shut down).