Corragated steel tubing-the fix

[Robert Metheney]

Hi guys I run into csst on at least every other inspection and I am frequently asked for the fix for this problem. Is there a repair that is short of replacing with hard pipe?

[Jerry Peck]

Hi guys I run into csst on at least every other inspection and I am frequently asked for the fix for this problem.

What is the problem?

[Jim Luttrall]

Please explain what you are referring to as the problem. Do you mean the lightning strike problem or some other.

[Robert Metheney]

I am referring to the lack of a substantial bond between the gas piping and the electrical appliance.

[Jim Port]

The appliance is considered grounded by the EGC in the circuit conductors.

Bonding the CSST is covered by the installation instructions, not the NEC.

[Jerry Peck]

Bonding the CSST is covered by the installation instructions, not the NEC.

Bonding is covered by both the installation instructions and the NEC, however, if the installation instructions are more stringent (most are) then the installation instructions take precedence.

The newer types of CSST, such as CounterStrike, FlashShield, and the other brands like those require no additional bonding other than what is specified in the NEC.

[Jim Port]

The NEC does not mention additional CSST bonding that I am aware of. Not being an installer of gas lines I have not seen the installation instructions for CSST. Gas line bonding is covered as both of us have stated.

[Jim Luttrall]

I am referring to the lack of a substantial bond between the gas piping and the electrical appliance.

When I see CSST without the required updated bonding (as is part of the class action suit/settlement) then I recommend having a licensed electrician to install the bonding and supply a link to the installation instructions from the manufacturer. It is my understanding this will reduce but not eliminate the risk associated with lightning.
Beyond bonding, total replacement with iron pipe.

[Jerry Peck]

The NEC does not mention additional CSST bonding that I am aware of.

The NEC addresses CSST the same way it addresses galvanized gas piping, and the same way it addresses black iron pipe or copper pipe used for gas piping - no type of gas piping is mentioned by name or type, it is all just "gas piping":
- 250.104 Bonding of Piping Systems and Exposed Structural Steel.
- - (B) Other Metal Piping. Where installed in or attached to a building or structure, a metal piping system(s), including gas piping, that is likely to become energized shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with 250.122, using the rating of the circuit that is likely to energize the piping system(s). The equipment grounding conductor for the circuit that is likely to energize the piping shall be permitted to serve as the bonding means. The points of attachment of the bonding jumper(s) shall be accessible.

The CSST installation instructions require bonding per the NEC (as stated above), the installation instructions for regular CSST require an additional bond (in addition to the bonding stated in 250.104(B) ), whereas CounterStrike, FlashShield and the others like those do not require any additional bonding to what is required by 250.104(B).

[Jim Luttrall]

This may also be covered in the Fuel Gas Code as noted below from the fireengineering.com site:



"The 2009 edition of NFPA 54, National Fuel Gas Code, includes new requirements for bonding CSST gas piping systems to the grounding conductor of the building's electrical system, to reduce the possibility of damage by lightning strikes by reducing the electrical potential between metallic objects and building systems, including gas distribution."

"7.13.2 CSST. CSST gas piping systems shall be bonded to the electrical service grounding electrode system at the point where the gas service enters the building. The bonding jumper shall not be smaller than 6 AWG copper wire or equivalent."