The following are recent modifications requiring bonding or grounding of Corrugated Stainless Steel (CSST) flexible gas tubing which has been mandated by the manufacturers due to a class action lawsuit. Licensed plumbing, mechanical and fireplace contractors have been notified of the mandatory requirement to bond or ground CSST installations.

Re:
CSST Gas Pipe Bonding
Gas Pipe Hangers

Bonding. Proprietary flexible gas piping such as CSST (corrugated stainless steel tubing) is required to be installed in accordance with the manufacturer’s installation instructions. Effective immediately, all gas piping systems utilizing CSST shall be bonded to the building’s grounding electrode in accordance with the manufacturer’s installation instructions. A lightning strike can arc to or from another metal system, creating a hole in the wall of the pipe if the flexible gas piping is not appropriately bonded.

In most cases, this would probably require No. 6 AWG ground wire clamped to one of the brass fittings or a rigid portion of the piping system, but not to the flexible tubing. The clamp needs to be a listed bonding clamp and the wire can be connected to the grounding electrode or the ground wire coming from the electric panel. However, the grounding wire shall not enter the electrical panel.

Please make sure that your installers are provided with the most up to date installation instructions for the specific type of flexible gas piping that is being installed, as some have changed from earlier versions.

Hangers. Hangers for all gas piping must conform to MSS SP-58. This standard requires that all hangers for gas piping must be metal, not plastic. The referenced standard requires hangers to maintain their strength up to 650 degrees for approximately 15 minutes, to keep the gas piping in place in the event of a fire.