Thread: Metal pipe bonding

Just checking, when PVC pipes are present do gas and any copper through separation wall still require bonding? I'm feeling like its a yes but wasn't sure.

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Originally Posted by Marc M

Just checking, when PVC pipes are present do gas and any copper through separation wall still require bonding? I'm feeling like its a yes but wasn't sure.

I believe any metal plumbing pipe over 10 feet long needs bonding.

Originally Posted by John Kogel

I believe any metal plumbing pipe over 10 feet long needs bonding.

Not as easy as that, at least not here in the states ...

- 250.104 Bonding of Piping Systems and Exposed Structural Steel.
- - (A) Metal Water Piping. The metal water piping system shall be bonded as required in (A)(1), (A)(2), or (A)(3) of this section. The bonding jumper(s) shall be installed in accordance with 250.64(A), (B), and (E). The points of attachment of the bonding jumper(s) shall be accessible.
- - - (not posting 1, 2, 3)


- - (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.

Okay, define "system" ...

In the places that I've been, the riser from the tub valve to the shower head, and the drop to the tub spout are *not* considered a "system".

On the other hand, many builders used to run PB, and now PEX, underground as it can be installed as one continuous piece (no joints to leak), and, where that stubs up through the slab, they would switch to copper. All that copper was a "system" which needed to be bonded, each and every section of it which was discontinuous due to being connected to the plastic underground non-metallic piping.

Is one 10 foot stick of copper a "system"? Probably not.

Is a 50 foot long coil of soft copper run through the house a "system"? Probably.

That is where the code is gray (there really are not many areas which are gray like that) and where the AHJ decides by interpretation.

There are some that would not consider it a system unless it was the same material from start to finish. A partially metallic system would not meet their definition.

Originally Posted by Jim Port

There are some that would not consider it a system unless it was the same material from start to finish. A partially metallic system would not meet their definition.

Even if the underground was plastic by the entire rest of the house above ground was copper?

The does *not* say "complete" system, just "system".

In that example I would consider that a system even with the change in materials once the water enters the house.

So the reason I'm asking is out here there are a lot of homes re-piped in plastic but have copper in the garage up to the separation wall, then plastic. So its the garage pipes I'm mostly wondering about.
Now that you're speaking about systems, I suppose the gas piping (a system) regardless of the interior supply piping still must be bonded...correct?

Originally Posted by Marc M

So the reason I'm asking is out here there are a lot of homes re-piped in plastic but have copper in the garage up to the separation wall, then plastic. So its the garage pipes I'm mostly wondering about.
Now that you're speaking about systems, I suppose the gas piping (a system) regardless of the interior supply piping still must be bonded...correct?

The gas piping system is bonded through the EGC feeding a glass appliance, like the cord on a gas range. No further bonding is required. Newer systems with CSST piping may have further bonding requirements.

Originally Posted by Robert Meier

The gas piping system is bonded through the EGC feeding a glass appliance, like the cord on a gas range. No further bonding is required. Newer systems with CSST piping may have further bonding requirements.

So if the range is plugged in then there doesn't have to be a bond at the water heater for example, like in this pic?

Originally Posted by Marc M

So if the range is plugged in then there doesn't have to be a bond at the water heater for example, like in this pic?

IMO it's not required but may offer further protection as outlined in the FPN:

250.104(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 elec-
trodes used. The bonding jumper(s) shall be sized in accor-
dance 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.
FPN: Bonding all piping and metal air ducts within the
premises will provide additional safety.

Originally Posted by Marc M

So if the range is plugged in then there doesn't have to be a bond at the water heater for example, like in this pic?

If the gas piping is CSST, then it likely needs to have an additional bond to it.

If the gas piping is steel piping, no problem, it is bonded through the grounding conductor.

Schooled...thanks.