On Fri, 23 Oct 2015 12:57:42 -0700 (PDT), safecsst
wrote:

most of the discussion is on gas piping outside the house. It would be a good idea to electrically bond the internal gas piping - that is the piping that is downstream of the gas meter - to the electrical ground electrode. The reason being that if the gas piping is energized it can conduct electricity same as water pipe. Typically the gas appliance ground will suffice, but if there is an overvoltage from a transformer surge or lightning, the high impedance of the appliance ground wire doesn't provide a low impedence path to ground. For most CSST, the gas piping MUST be bonded to the electrical ground. So to answer your question:

- Is it required by code? YES but the appliance ground is usually used as the bonding means, so that satisfies the code.
- Is it recommended? YES especially if you have CSST or flexible appliance connectors.
- Wire size? Most use a 6 gage bare grounding wire - stranded if its available.
- Daisy Chain? You should be able to daisy chain from water pipe if its electrically continuous.

On Monday, July 31, 2006 at 12:45:10 PM UTC-4, blueman wrote:
When we had our electric service upgraded, the electrician (as
expected) ran a ground wire from the cold water main inlet to the
ground on the panel.

I read somewhere that one should also run a similar grounding wire to
the natural gas pipe inlet but the electrician didn't do that.
- Is it required by code?
- Is it recommended?
- Should one use the same gauge wire as for the water pipe?
- Any special considerations?
- Can I daisy chain it from the water pipe or do I need to run a
separate ground back to the panel?

Thanks

Interior piping is required to be bonded where likely to become
energized and this normally happens via the EGC in the equipment
served.
Water pipe shall be bonded using table 250-66, the same as any other
ground electrode. (ie: 4ga for a typical 200a service)