Section 16-11-40 - Regulator stations(a)Regulators(1) All distribution main systems, other than low-pressure systems, that are being supplied through a pressure reducing valve or regulator, shall be protected by suitable safety devices to insure that the failure of a regulator shall not impose pressure on any part of a system beyond those for which it is designed to operate. (2) In all low-pressure systems, the down stream of the regulator station shall be protected to insure that the pressure of gas shall at no time exceed a maximum of two pounds per square inch gauge at the inlet of any gas service lateral. (3) Regulators supplying distribution systems shall be checked once a month to determine that there is no gas leakage in the station and that the equipment is in operable condition. Once a year this equipment shall be inspected internally, and overhauled if required.(b)Ventilation.(1) All district regulator enclosures shall be ventilated in a way to remove accumulations of gas or shall be closed to prevent intentional or accidental introduction of sources of ignition into the enclosures.(2) Ventilation shall also include provision for the venting of diaphragms of regulators and pressure relief devices to the outside atmosphere. The vent shall be of a size no smaller than the connection provided by the manufacturer and so installed as to relieve the entire capacity of the relieving device. All vents shall terminate outside buildings, pits, and confined spaces in rain proof fittings and shall be installed with due regard to hazards to life and property by the venting of gas into the atmosphere.(c)Drainage. Underground regulator stations shall not be connected by drain lines to a public sewer. Provision shall be made to minimize the entrance of water or for its removal, or the equipment shall be designed to operate properly if submerged.(d)Shutoff valves. A shutoff valve shall be provided in the inlet line of each regulator station supplying a low pressure distribution system. This valve shall be in an accessible location not closer than twenty-five feet from the nearest wall of the station nor preferably more than one thousand feet distant. These valves shall be checked at least once each year by closing and operating insofar as operating conditions permit.(e)Auxiliary equipment.(1) Where electrical equipment is required in regulator stations, it shall be designed and installed in accordance with Article 500 of the latest edition of the National Electrical Code and shall meet the requirements thereof for Class I locations. (2) Where regulators require supports, they shall be of fireproof material.Conn. Agencies Regs. § 16-11-40