During flushing the water level indicator, the phenomenon that the steam communicating valve and water communicating valve are closed at the same time shall be avoided, because which will cause the steam and water not to enter the water level indicator at the same time, the water level indicator is quickly cooled, and the cooling water is reversely extracted into the water level indicator through the water draining valve, making the cooling speed quicker; when the water communicating valve or steam communicating valve are opened again and the medium enters, the temperature is bigger, the water level indicator will be damaged.

When the water level indicator is flushed under the working pressure, the water draining valve shall be turned down, because the difference between the water level indicator and the external environmental pressure is very big, if the water draining valve is turned up excessively, the steam and water will expand severely and the flow will be very higher, the sheet mica may be damaged or the water level indicator will explode. The above mentioned phenomenon will be more obvious if the water draining valve is turned up excessively. In addition, when the water level indicator is flushed, personal safety shall be paid attention in order to prevent the bursting of steam and water from scalding people.