Section 192.355 - Customer meters and regulators: Protection from damage(a)Protection from vacuum or back pressure. If the customer's equipment might create either a vacuum or a back pressure, a device must be installed to protect the system.(b)Service regulator vents and relief vents. Service regulator vents and relief vents must terminate outdoors, and the outdoor terminal 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; and(3) Be protected from damage caused by submergence in areas where flooding may occur.(c)Pits and vaults. 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.35 FR 13257, Aug. 19, 1970, as amended by Amdt. 192-58, 53 FR 1635, Jan. 21, 1988