CSST Gas Pipe Bonding

 

CSST - Corrugated Stainless Steel Tubing has been sold and installed In the US since 1988. As a result of legal actions stemming from the physical damage of lightning strikes manufacturers have agreed to new installation requirements regarding the bonding of CSST systems to the main grounding electrode of the structure were the CSST is installed.

 

Click here to review a study and some history of lightning strikes and CSST. At the current time Sangamon County is requiring that the gas line be bonded on non-metalic gas services at the entry into the home where a rigid nipple comes off the meter. A #6 solid is then required to be taken to the main grounding electrode of the structure. To my knowledge at this time no testing lab is listing a grounding clamp made to attach to the connector of the CSST. The gas and electric codes have not addressed this situation as of yet. – Michael Ashenfelter (Electrical/Mechanical Inspector)

 

Some additional information concerning the grounding clamps that might be used for bonding purposes provided by Donald Shields with UL: Currently, UL category KDER pg 172 in the 2007 White Book is the correct item for bonding of metallic piping. However, these products have only been evaluated for the connection to the round surface contours of pipe.

They have not been evaluated by UL  for any flat or shaped surfaces such as the HEX Fittings of a plumbing union or CSST connector. This could require the use and application of a short pipe nipple for the bonding connection to the CSST product or any surface that is not round.

Hopefully this information will help prevent any misuse of products listed by UL under the KDER category.