A.George Flach, former chief electrical inspector for New Orleans, responds: Gas pipes often supply equipment and appliances that are also powered electrically — such as gas-electric central heating furnaces and gas heaters with pumps used for warming water in swimming pools, or gas clothes dryers and gas ranges with illuminated ovens and spark igniters — and they may become energized by the branch circuits that power these units.

To reduce that risk, Section 250.104(B) of the 2005 NEC requires that all gas pipe be bonded. However, the NEC also recognizes the equipment grounding conductor of each branch circuit as a bonding means for the gas piping, and requires no additional bonding or grounding.

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