In addition to all other proper subjects for rules and regulations, the board of directors of a metropolitan utilities district may adopt rules and regulations, in the interest of public health and safety and the conservation of gas, relating to the use, installation, and maintenance of piping, equipment, and appliances for gas on the premises of consumers. Such district may adopt and promulgate rules and regulations to establish priorities for the use of gas, including the curtailment and denial of its use. All rules and regulations shall be published once in the official paper of the particular city within such district and be kept posted at the main office of the district for public inspection. When such rules and regulations are so adopted, published, and posted, they shall have the same legal force and effect as a city ordinance and be binding upon the consumers of the district as one of the conditions to their service. Nothing in this section shall be construed to prevent any qualified person or persons from installing or maintaining appliances in connection with any of the public utilities mentioned in this section.