1. It is strictly prohibited to connect the boiler that was not supplied with steam with the steam main tube in operation. 

2. After the boiler has been damped down, it is required to prevent rising of boiler steam pressure. The draining valve of the superheater shall be opened.  When necessary, open the air bleeding valve to the atmosphere within short time, but the stability of the steam pressure shall be ensured as far as possible. 

3. After the boiler has been damped down, the boiler water level shall be kept normal. When the boiler is not fed with water, open the recirculation valve; When water is required to feed, close the recirculation valve for feeding water again. 

4. If it takes too long time for damping-down, in the middle way, the temperature-rising shall be started again. After the temperature rises to normal, damping-down can be done again.

5. It is not allowed not to monitor the damped-down standby boiler and its accessory equipment. 

6. The equipment and thermal meter for the damped-down boiler for standby  shall not be repaired or misused discretionarily.