1. The boiler shall be evenly fed with water, it is required to maintain the boiler water level within normal water level in the steam drum water level. The water level shall have slight fluctuations, the permissible rangeshall be ±5mm. During  normal operation, it is forbidden to interrupt the boiler feed water.When the steam drum water level value is high value 1: + 50 mm, alarm will be given. when it is high value 2: + 160 mm, the emergency discharge valve is opened. When the water level comes back to the high value 1, the emergency discharge valve is closed; Three value + 250 mm, MFT acts. When the steam drum water level is in low value 1: - 50 mm, alarm will be given; low value 2: - 160 - mm, the secondary alarm will be given; Low value 3: -200mm,  MFT acts. 

2. The boiler feed water shall be adjusted according to the water level gauge instructions of steam drum. Only when the water supply automatic adjustment device, low-read water level gauge and alarm are in good condition, can the instruction of low- read water level gauge be relied to adjust the boiler water level. 

3. When the automatic adjustment device of water supply  is put into operation, the change of boiler water level shall be still be monitored regularly in order to keep the change of water amount even and to avoid the excessive big adjustment range. The water supply flow and steam flow shall be often contrasted to check whether they are conformed mutually( When the water feed flow is larger than the steam flow by 1-3 t/h), if the automatic adjustment device of water supply is in failure, it shall be changed to manually controlled to adjust the water feed amount, it is required to notify the thermal maintenance persons for processing. 

4. During operating, it is required to regularly monitor the change of the water supply pressure and water supply temperature, when the water supply pressure or feed water temperature is lower than the specified value, it is required to contact the relevant persons to adjust. 

5. During operation, it is required to keep the steam drum water level gauge complete, indication correct and clearly visible and lighting sufficient . 

6. When the boiler is in cold state, the procedures for putting steam drum water level gauge into use are: Confirming that the drum water level gauge has been repaired and the lighting is complete, opening the primary air and secondary air valves at steam side and water side of the steam drum, and closing the water discharging valve. The temperature and pressure of the drum water level gauge are rising together with boiler.  

7. When the boiler is in hot state, the procedures for putting  steam drum water level gauge into use are: 

(1)Confirming that the drum water level gauge has been repaired and the lighting is complete, and the steam and water valves and water-discharge valves all are in the closing state. Slighting open the water-discharge valve for one circle and fully open the primary valves at steam and water side. 

(2) Slightly open the secondary valve at the steam side for one-fourth circle, and preheat the water gauge for about 40 minutes. 

(3) close the secondary valve and water -discharge valve at steam side.

(4) Open the secondary valve at the  water side for one-fourth circle, and guide the hot water slowly to the water level gauge .

(5) Open the secondary valve of  steam side for one-fourth circle and guide the steam slowly to the water level gauge.

(6) Open the steam valve and water valve entirely and alternately. 

(7) Observe the water level of the water level gauge , it should have tiny fluctuations.