.-No maintenance or repair involving cutting or rewelding of any pipeline shall be carried out except under following conditions, namely:-(i)an experienced engineer shall inspect the section requiring maintenance or repair before the work is undertaken and issue a written permit specifying therein the precautions to be observed and the procedure to be followed for carrying out the work. The permit so issued shall be preserved by the owner of the pipeline for a period of six months;(ii)all work involving cutting or welding shall be carried out by an experienced person in accordance with the permit referred to in clause (i);(iii)the section of the pipeline shall be isolated and drained before starting repairs or maintenance;(iv)only mechanical cutters shall be used for cutting the pipeline or any connection thereof unless the section of the pipeline and its connections have been purged with an inert gas;(v)no hot work shall be carried out on any pipeline until the section thereof requiring repair has been isolated, drained and purged with inert gas or steam or kept filled with water or until such section has been prepared in a manner approved in writing by the experienced engineer;(vi)the section of the pipeline in which repairs or maintenance work has been carried out shall be used for transporting petroleum until such sections are replaced with hydrostatically pretested sections and the repaired weld joints pass the radiography test;(vii)no section of any pipeline and no valve fitted to it shall be separated until an efficient electrical bond has been established between the parts to be so separated which shall not be broken until the separated parts have been rejoined.
