15(1)Any officer authorised by a public gas supplier may at all reasonable times, on the production of some duly authenticated document showing his authority, enter any premises in which there is a service pipe connected with a gas main of the supplier for the purpose of—
(a)inspecting gas fittings ;
(b)ascertaining the quantity of gas supplied ;
(c)performing the duty imposed on the supplier by paragraph 1 or 2 above;
(d)exercising the power conferred on the supplier by paragraph 4(3) or 8(7) above ; or
(e)in the case of premises where the supplier has reason to believe that a compressor or compressed air or extraneous gas is being used, inspecting the premises and ascertaining whether the provisions of paragraph 8 above are being complied with.
(2)Paragraphs (a) and (b) of sub-paragraph (1) above do not apply where the consumer has applied in writing to the supplier for the supplier to disconnect the service pipe and cease to supply gas to the premises and the supplier has failed to do so within a reasonable time.
(3)In this paragraph " compressor", " compressed air" and extraneous gas " have the same meanings as in paragraph 8 above.