Corrugated Stainless Steel Tubing Grounding

Corrugated Stainless Steel Tubing

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.

Since the codes, product standards, and installation requirements are not harmonized, builders and contractors may find differing and possibly conflicting requirements. Generally, the local jurisdiction having authority and code official will rely upon the manufacturer’s installation recommendations in lieu of other requirements. Currently, the CSST manufacturers’ installation requirements are the most stringent compared to the codes and standards. Users of CSST are advised to abide by the manufacturer’s instructions and also coordinate with local code officials to avoid inspection delays due to conflicting requirements.

Recently updated CSST manufacturer’s installation instructions now include the requirement to directly bond the CSST system to the electrical system grounding system.