Use of Dielectric Unions, Corrosion Protection, and Venting of Regulators (Grandfathering Provisions)

[LOGO] # MISSISSIPPI INSURANCE DEPARTMENT 501 N. WEST STREET, SUITE 1001 WOOLFOLK BUILDING JACKSON, MISSISSIPPI 39201 www.mid.ms.gov MAILING ADDRESS Post Office Box 79 Jackson, Mississippi 39205-0079 TELEPHONE: (601) 359-3569 FAX: (601) 359-2474 WATS: 1-800-562-2957 (Incoming-USA) MIKE CHANEY Commissioner of Insurance State Fire Marshal DAVID BROWNING Deputy Commissioner of Insurance # MISSISSIPPI INSURANCE DEPARTMENT # OFFICE OF THE STATE FIRE MARSHAL # BULLETIN NO. 2026-5 April 23, 2026 ## USE OF DIELECTRIC UNIONS, CORROSION PROTECTION, AND VENTING OF REGULATORS (GRANDFATHERING PROVISIONS) The Mississippi Liquefied Compressed Gas Board and the Commissioner of Insurance for the State of Mississippi (the authority having jurisdiction (AHJ)) are issuing this Bulletin to clarify the application of certain provisions in the National Fire Protection Association (NFPA) 58 – LP Gas Code (2024). The provisions of NFPA 58 are hereby modified and clarified as follows: (1) Dielectric Unions – Pursuant to NFPA 58, para. 6.11.3.17 (2024 version), dielectric fittings are now required for underground metallic piping, tubing, or both that convey LP-Gas from a gas storage container. Dielectric fittings shall be installed above ground and outdoors at the building to electrically isolate it from the above ground portion of the fixed piping system that enters a building. This requirement was not in place for systems installed using the 2017 version of NFPA 58. Grandfathering for Tank Swap-outs: If your company is swapping a tank out on an existing system, which was installed using the 2017 version of NFPA 58 or earlier, but not performing any new installation or other work on the yard line, the system will continue to be “grandfathered in”, and will not require installation of the dielectric fittings. If the tank swap requires a new installation of any portion of the piping/tubing, or any work on the yard line, then the system will no longer be “grandfathered in”, and compliance with dielectric fitting requirements of NFPA 58, para. 6.11.3.17 (2024 version) will be required. (2) Corrosion Protection – Pursuant to NFPA 58, para. 6.20 (2024 version) compliance with corrosion protection requirements is required for all new installations, as well as any system modifications or alterations involving a new installation of any portion of the piping/tubing, or any work on the yard line. Grandfather for Tank Swap-outs: If your company is swapping a tank out on an existing system, which was installed using a previous version of NFPA 58, but not performing any new installation of any portion of the piping/tubing or other work on the yard line, the system will continue to be “grandfathered in”, and will not require updated compliance with the corrosion protection requirements of NFPA 58, para. 6.20 (2024 version), although any corrosion protection already in place on the system should be maintained appropriately. (3) Venting of regulators – If you are venting regulators using PVC, then NFPA 58, para. 5.10.3.1, the use of gray electrical conduit is required. ISSUED this the 23rd day of April, 2026. MIKE CHANEY COMMISSIONER OF INSURANCE STATE FIRE MARSHAL