Corrugated Stainless Steel Tubing (CSST) and Appliance Connector Safety


Corrugated stainless steel tubing (CSST) is a flexible, stainless steel piping system used to supply natural gas and propane in residential, commercial, and industrial structures. Standard CSST is coated with a yellow exterior plastic coating. It has been safely used in homes and businesses since 1990 and is an effective means of delivering natural gas and propane gas to homes and businesses. CSST has typically 75% fewer fittings than traditional pipe which means a safer system, less leak potential and reduced callbacks.

Like all gas piping systems, CSST must be properly installed by a qualified professional and in accordance with the Manufacturer’s Design and Installation (D&I) Guide, which now expressly includes bonding and grounding of the system in new installations. A bonding connection installed on a gas piping system, as with any metallic system within a house, will reduce the likelihood of electrical arcing to or from other bonded metallic systems in the structure.

However, some previously installed CSST systems prior to 2006 may not have the proper bonding for optimal safety: If lightning strikes on or near a structure, there is risk it can travel through the structure’s gas piping system and cause a leak, and in some cases a fire. If you have yellow CSST that was installed prior to 2006, it’s possible that it does not meet current installation requirements, and it is strongly recommended that you contact a licensed electrician to make sure that your system is properly bonded. For more information, please visit Note: CSST should not be confused with flexible gas appliance connectors – the product that joins a moveable appliance to your home or building’s gas supply line. The difference is flexible connectors attach directly to the moveable appliance from the wall or floor. CSST is usually routed beneath, through and alongside floor joists in your basement, inside interior wall cavities and on top of ceiling joists in attic spaces.

Appliance Connector Safety

Damaged and improperly maintained interior piping and connectors may present hidden dangers to customers, so your gas connectors need to be inspected regularly and replaced as needed. Certain kinds of flexible connectors manufactured between 1970 and 1980 may fail over time and need to be replaced.

  • Only a qualified heating or plumbing professional should check your connector and replace it if needed. Do not try to do this yourself.
  • If you need to disconnect or move a gas appliance, gas connectors should always be removed by a professional, and the fuel line should be plugged and capped.
  • Gas pipes should be properly maintained and never used for unintended uses such as hanging clothes.