(1) Towing and throwing of polyethylene pipes during transport, handling and storage, resulting in damage to the pipes;

(2) The roller bracket was not used in the welding and non-excavation retraction process of the PE tube straight pipe, resulting in scratches on the PE pipe wall;

(3) Failure to use sun protection and rain protection and other masking methods to maintain the tube deposited on the site, affecting the application function of the pipe and the application life of contracted pipe;

(4) After the excavation of the lower ditch, the pipeline was not filled in real time according to the delineation. For a long time, it was covered with slag, rainwater, etc., which affected the operation insurance and application life of the pipeline;

(5) Pipe and pipe parts have not reached the quality of the pipe and pipe parts.