Dielectric union in gas line

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Galt

Senior Member
Location
Wis.
Occupation
master electrician and refrigeration service tech.
This is in regards to LP gas , all the local suppliers are isolating the underground copper gas lines with a union. Isn't this a lightning hazard?
 

mopowr steve

Senior Member
Location
NW Ohio
Occupation
Electrical contractor
This is in regards to LP gas , all the local suppliers are isolating the underground copper gas lines with a union. Isn't this a lightning hazard?

I would think so! By the way just because it's a union doesn't mean that it is a dielectric union.
Although they may have done it because of some instances where service personal were getting shocked from tank/underground copper lines due to faulty grounding/ open neutral. Which should have been corrected instead they tried to isolate there gas lines/tanks.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
The code says that the gas piping in the building must be bonded. The code says that underground gas piping can't be a grounding electrode. If there is no dielectric union the under ground pipe becomes a grounding electrode.

All of the natural gas lines in this area had dielectric unions on the street side of the meter...now they just use non-metallic piping from the street main to the building so there is no need for that now.
 

Galt

Senior Member
Location
Wis.
Occupation
master electrician and refrigeration service tech.
What happens if lightning hits a tree in the yard close to the tank or the underground line? I have repaired a lot of lightning damage over the years it seems to me it does the most damage when it has to jump a gap of some sort. Can a dielectric union take this without failing?
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
What happens if lightning hits a tree in the yard close to the tank or the underground line? I have repaired a lot of lightning damage over the years it seems to me it does the most damage when it has to jump a gap of some sort. Can a dielectric union take this without failing?
Lightning jumps miles...it will have no problem jumping the dielectric union. There would likely be damage at the union.
 
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