The intrinsic flow rate deviation in the water-wall of boiler and its overtemperature tube-burst conditions have been briefly analysed.It is believed from analysis that the intrinsic flow rate deviation is insufficient to result in pure overtemperature of the water wall

but in case of blocking at the water side and leading to increase of vapor content

the deterioration of heat transfer and tube-wall overtemperature have to be aroused.Hence

enhancing circulation ratio in the water-wall

and thoroughly eliminating blockage at the water side in manufacture and repair of the boiler

etc.are very advantageous for preventing pure overtemperature of the water-wall and tube-burst.