Can you ground an electrical system to a gas pipe?

[Yikes]

I have what is probably a dumb question, but when I searched the threads, I couldn't find it previously addressed elsewhere:

I saw a small building where the grounding for the electrical system was a clamp to the pipe on the gas meter. Is this a code-compliant method of grounding?

 

[fatboy]

Don't have a book with me, but I believe you can NOT use gas pipe as a grounding electrode, however, it must be bonded.

 

[Sifu]

Gas pipe is bonded to the grounding electrode system but it is not a grounding electrode.

 

[Yikes]

So maybe what I saw was bonding, not grounding...

 

[ICE]

There should be a dielectric fitting that isolates the underground pipe from the pipe in the building. So chances are that it is not acting as a grounding electrode. If the connection is on the utility side of the meter, it may be the grounding electrode. In that case a compliant electrode should be provided prior to any change with the gas pipe connection.

I read this somewhere and it might be factual:

The grounding electrode might have a voltage potential. Although small, the voltage might cause an equally small current. That, with moisture, will rot the pipe.

 

[Gregg Harris]

There should be a dielectric fitting the isolates the underground pipe from the pipe in the building. So chances are that it is not acting as a grounding electrode. If the connection is on the supply side of the meter, it may be the grounding electrode. In ghat case a compliant electrode should be provided prior to any change with the gas pipe connection.

NEC 250.104 (B) requires the bonding of gas piping and as Ice stated the service valve before the meter is a dielectric fitting that prevents the underground piping from being an electrode.

 

[Gregg Harris]

I have what is probably a dumb question, but when I searched the threads, I couldn't find it previously addressed elsewhere:I saw a small building where the grounding for the electrical system was a clamp to the pipe on the gas meter. Is this a code-compliant method of grounding?

NEC 250.52(B)(1)

(B) Not Permitted for Use as Grounding Electrodes. The following systems and materials shall not be used as grounding electrodes:

(1) Metal underground gas piping systems

(2) Aluminum

250.104 Bonding of Piping Systems and Exposed Structural Steel.

(B) Other Metal Piping. If 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, if of sufficient size; or to one or more grounding electrodes used. The bonding conductor(s) or 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.