Bonding Ductile Iron Pipe

[Rock86]

A thread was posted back in 2022 regarding ductile iron pipe and bonding it as a GEC in the following thread.. https://forums.mikeholt.com/threads/water-authority-conflicting-with-nec.2571447/page-3

The picture below is a domestic water line without the meter installed. The meter will be a flanged ductile iron meter replacing the copper pipe in the image. I have been asked how to bond it, but I am questioning the electrical continuity of the system with all of the flange gaskets. My mechanical counter part said they should scrape some of the coating off to install the bond, but I don't believe that is the correct method. With the gaskets and powder coating, would they create discontinuity within the system making it an ineffective Ground Electrode? The previous thread eluded to that, but I cannot find anything in our specifications or the manufacturer's which would say otherwise.

I do not know what the street connection is. My thought is if I cannot get an answer, is to go out the site and test the connections for continuity.

 

[synchro]

It doesn't seem that gaskets between the flanges would be the limitation because continuity could be provided through the bolted connections. Any powder coating under the bolted connections could be removed if that was a concern.

 

[Rock86]

Here is the connection just outside of the building.

 

[tom baker]

There are bonding wedges for bell and spigot joints used outside. Where the pipe has 90s those are some type of restrained joint. You should check with a utility supply company, or find the right person at the city water company, or even a DI pipe company mfg

 

[Rock86]

It doesn't seem that gaskets between the flanges would be the limitation because continuity could be provided through the bolted connections. Any powder coating under the bolted connections could be removed if that was a concern.

I don't like the idea of removing powder coating. Then it would become a liability game if there was ever a leak or issue at that connection. Additionally, if you remove the bolt, now you've removed the bond.

 

[tom baker]

That SS tapping sleeve with the red valve had a gasket underneath, no continuity there. You may be able to get bonding on customer side of meter

 

[don_resqcapt19]

Here is the connection just outside of the building.
View attachment 2571180

If the length of pipe between that fitting and the building is less than 10' you don't have a metal water pipe grounding electrode.

 

[ptonsparky]

Using it as a GEC?

 

[Rock86]

Using it as a GEC?

That was the design intent, but it looks like the real world application may change that.