(a) At least 30 days prior to the start of construction or reconstruction of any transmission line or main designed to operate at 125 psig (862 kPa) or more, each operator shall file a letter of intent and a report of specifications identical with Form A of Appendix 7-D of this Title. The letter of intent need not include said specifications where the length of the line is less than the following:

(b) Before any pipeline designed to operate at 125 psig (862 kPa) or more is placed in operation, a report shall be filed certifying the maximum allowable operating pressure and also certifying that the line has been constructed and tested in accordance with the requirements of the rules herein prescribed. The report shall also include the results of all required strength tests. No pipeline shall be operated at pressures in excess of that to which it was certified.