RGS vs Rigid Aluminum

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mshields

mshields

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Boston, MA
I have always specified RGS for outside and exposed applications. Is Rigid Aluminum equal, not as good, better or a little of both?

Thanks,

Mike
 
In soil or above ground?
coastal - e.g near slat water.

Case history - Honolulu airport, many decades ago, new construction used Al rigid underground. Within 3 years ome already deteriorated due to iron/sulpher, etc. content of volcanic soil. Only galvanized now, or stainless in some applications.

What is the chemistry of your areas?
 
junkhound said:
In soil or above ground?
coastal - e.g near slat water.

Case history - Honolulu airport, many decades ago, new construction used Al rigid underground. Within 3 years ome already deteriorated due to iron/sulpher, etc. content of volcanic soil. Only galvanized now, or stainless in some applications.

What is the chemistry of your areas?
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I would never put aluminum underground.

But exposed to most elements, it's preferable to GRS.



Sent from my moto e using Tapatalk
 
I used to see a lot of AL for traffic signal risers on poles, from ped signals up to weather heads. Most signals use mast arms so wiring is UG, where exposed RGS
 
Aluminum is for environments where steel would corrode faster then normal. I worked at an orange juice plant. We installed AL conduit and PVC coated steel. Never uncoated steel.
 
Untreated aluminum cannot be used underground. For above ground like on a roof it's better than steel RMC.
 
I used aluminum underground back when it was allowable to do so. (Requirements were the same as for RGS as far as corrosive environments.) I recently had to dig up a section and I was surprised to see that it was as good as the day I buried it 40 years ago here in the NE.

Just don't run it through or under concrete. It will turn to toothpaste.

-Hal
 
infinity said:
Aluminum won't rust away and is much easier to install which IMO makes it better. (y)
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I labor it higher than I do rigid. It often does not thread well, and you really can't adjust a bend like you can with rigid because it work hardens, and instead of adjusting the original bend, you end up with a bend in a new spot on the pipe.

The only time I would consider aluminum is if it is needs because the materials in the area corrode rigid and don't aluminum.
 
Some years ago, I had to remove a 4" aluminum LB from aluminum conduit to re-route an outdoor feeder.

The bottom line is that I had to cut the LB hub in three places to get it off of the conduit. And, I really tried.
 
hbiss said:
The buried run I was talking about unscrewed from a coupling like I did it yesterday. I remember using Penetrox on the threads.
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I tried to unscrew it after each cut. It still took hard hitting with a hammer after the third cut, which divided the body in two, to separate the pieces from the conduit. The threads were filled with oxidation.
 
LarryFine said:
Some years ago, I had to remove a 4" aluminum LB from aluminum conduit to re-route an outdoor feeder.

The bottom line is that I had to cut the LB hub in three places to get it off of the conduit. And, I really tried.
Click to expand...
I did a "try" fit up, only hand tight into an LB, and ended up crushing the pipe to get it out, and it had a lubricant on the threads.
 
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