(a) If the customer's equipment or supplemental gas supply might create either a vacuum or a back pressure, a device must be installed to protect the distribution system. Commingling of a customer's supplemental gas supply with utility supplied gas is permissible provided the customer verifies that the supplemental gas is interchangeable with the gas supplied by the utility.
(b) The outside terminal of each service regulator vent and relief vent must:
(1) be rain and insect resistant;
(2) be located at a place where gas from the vent can escape freely into the atmosphere and away from any opening into the building (a minimum of 18 inches (457 millimeters), where practical);and
(3) be protected from damage caused by submergence in areas where flooding or ice accumulation may occur.
(c) Each pit or vault that houses a customer meter or regulator at a place where vehicular traffic is anticipated, must be able to support that traffic.