Legal analysis: the shape of the hole in the pipeline should basically match the envelope shape of the connected pipeline interface and be reinforced according to the design requirements. The opening position of drainage and instrument pipelines should not be on the weld, and the distance from the girth weld of any pipeline should not be less than the aperture and not less than 50 mm The size of the opening in the pipeline should be determined according to the actual needs, and it should not be too large or too small. 5.3.4 Elbows and tees of pipes shall not be opened. When the drainage and instrument pipelines open holes in the pressure pipeline, mechanical drilling should be adopted, and flame cutting is not allowed. 5.3.6 After opening, the interior must be cleaned, and no chips or other sundries can be left. Drainage, when there is no specified depth requirement, the position where the instrument pipe is inserted into the opening shall not exceed the inner wall of the mother pipe. 5.3.8 After opening the hole, immediately install the instrument or empty the short pipe and the pipe socket, so as to avoid missing the orifice and causing errors. 5.3.9 It is forbidden to drill holes in the installed rubber-lined pipes. After the tubing is cleaned and sealed, it is not allowed to drill holes on it, otherwise it must be cleaned, inspected and sealed again.

Legal basis: technical specification for polyethylene gas pipeline engineering

1.0. 1 In order to make the design, construction and acceptance of buried polyethylene pipeline and steel skeleton polyethylene composite pipeline project for transporting town gas meet the requirements of economic and safe construction, and ensure the engineering quality and safe gas supply, this regulation is specially formulated.

1.0.2 this procedure is applicable to the design, construction and acceptance of buried polyethylene pipeline and steel skeleton polyethylene composite pipeline engineering for town gas with working temperature of -2040℃, nominal diameter of no more than 630mm and maximum allowable working pressure of no more than 0.7mpa.

1.03 polyethylene pipes and steel-framed polyethylene composite pipes are strictly prohibited for indoor aboveground gas pipelines and outdoor exposed gas pipelines.

1.0.4 the quality of town gas transported by polyethylene pipes and steel-framed polyethylene composite pipes shall conform to the current national standard "Code for Design of Town Gas" GB50028.

1.0.5 The unit undertaking the engineering design, construction and supervision of buried polyethylene pipeline and steel skeleton polyethylene composite pipeline for urban gas transmission must have corresponding qualifications; Construction personnel should receive professional and technical training before taking up their posts.

1.0.6 The design, construction and acceptance of buried polyethylene pipeline and steel skeleton polyethylene composite pipeline engineering for urban gas transmission shall comply with the provisions of current national standards in addition to the implementation of this regulation.