All joints unless welded, shall be threaded joints, having approved standard threads. Threaded joints shall be made up with approved pipe thread compound or Teflon tape.
Gas piping may be installed in accessible above ceiling spaces, whether or not such spaces are used as a plenum. Valves shall not be located in such places.
Gas piping at multiple meter installations should be plainly marked by a metal tag or other permanent means attached to the pipe by the installing agency, designating the building or part of the building being supplied.
Changes in direction of gas pipe shall be made by the use of fittings and factory bends.
All rigid piping shall be adequately supported by metal straps or hooks at intervals not to exceed those listed in the Uniform Plumbing Code.
Ferrous gas piping installed underground in exterior locations shall be protected from corrosion by approved coatings or primer and wrapping materials. All horizontal metallic piping shall have at least twelve (12) inches of earth cover or other equivalent protection. Plastic gas piping shall have at least eighteen (18) inches of earth cover or other equivalent protection.
Underground ferrous gas piping shall be electrically isolated from the rest of the gas system with listed or approved isolation fittings installed a minimum of six (6) inches above grade.
Underground ferrous gas piping should be cathodically protected. New installations of underground ferrous gas piping shall be cathodically protected. It is recommended that existing underground ferrous gas piping be cathodically protected, or replaced with approved PE gas piping and anodeless risers.
All gas pipe protective coatings shall be an approved type, machine applied, and conform to recognized standards. Field primer and wrapping shall provide equivalent protection and is restricted to those short sections and fittings necessarily stripped for threading or welding. Zinc coatings (galvanizing) shall not be deemed adequate protection from corrosion in a manner satisfactory to the Administrative Authority.