Corrugated Stainless Steel Tubing for Fuel Gas Distribution in Buildings and Concerns Over Lightning Strikes

November 2011     
As the result of recent legal actions related to a potential for physical damage caused by lightning, manufacturers of corrugated stainless steel tubing (CSST) agreed to a settlement that, in part, places new requirements on the installation of their gas piping products. This paper provides background information on CSST and the actions taken by the manufacturers to address these concerns.

In summary, the primary issue is safeguarding against an electric potential in metallic piping. In the case of proximity lightning, a high voltage can be induced in metallic piping that may cause arcing; and for CSST there is concern that arcing may cause perforation of the CSST wall and therefore cause gas leakage. The fuel gas code, electric code, plumbing code, product standards, and manufacturer installation instructions have different methods of providing dissipation of electrical energy through techniques called bonding and grounding. Since the codes, product standards, and installation requirements are not harmonized, builders and contractors may find differing and possibly conflicting requirements.