The boiler drain drain pipe belongs to the installation unit and is self laid according to the site conditions, most of which are laid along the boiler. The leakage of this kind of pipe has the following cases: the leakage is caused by poor welding conditions on the back of the pipe and welding defects, and the leakage is caused. The leakage of the butt welding joint of the pipe and valve is more, the reason is that the pipe does not beat the groove and is not concentric, partial and powerful. Leakage, mainly because the pipe is fixed on the steel frame, and the joint with the expansion of the furnace, because the boiler rise and stop frequently, lead to welding fatigue; pipe because of internal and external corrosion thinning and detonating pipe, mainly internal non flow drainage and external rain corrosion caused by water. For this kind of leakage, the spectrum and thickness measurement of the drainage pipe of the boiler can be checked, the thinned pipes are replaced, and all the welding joints are reformed and the nondestructive inspection is carried out. Re - adjust the dilated pipe.