Raintight EMT fittings

kwired

Electron manager
Location
NE Nebraska
Many guys do not know that there are two types of compression fittings and think all of them are rain tight..
Like I said, a solution in search of a problem.
That is a better answer than what I had in mind. They were all rain tight before someone discovered they could put an additional nylon ferrule inside and a gasket at the base and thought it was better. There is still more water from condensation involved in most installs than the "non raintight" compression fittings will ever allow to leak into the raceway.:thumbsdown:
 

JDBrown

Senior Member
Location
California
Why do you think that? I would take emt over pvc any day of the week and many jobs dont have the budget for rmc or imc
Agreed. Steel EMT is just as galvanized as steel RMC, and it usually ends up getting painted, providing just a bit of extra protection from the elements. Unfortunately, it seems that many people see EMT as an indoor-only wiring method; I've seen a few sets of standard specs for different facilities we've designed for that specifically prohibit EMT from being installed outdoors. But hey, I guess if they really want to pay for RMC instead...
 

kwired

Electron manager
Location
NE Nebraska
Agreed. Steel EMT is just as galvanized as steel RMC, and it usually ends up getting painted, providing just a bit of extra protection from the elements. Unfortunately, it seems that many people see EMT as an indoor-only wiring method; I've seen a few sets of standard specs for different facilities we've designed for that specifically prohibit EMT from being installed outdoors. But hey, I guess if they really want to pay for RMC instead...

RMC will corrode also, just has a heavier wall to corrode away before it gets a hole in it.
 

iwire

Moderator
Staff member
Location
Massachusetts
In this area of the country EMT exposed to the weather rusts away much quicker than RMC or IMC.

http://education.randmcnally.com/classroom/action/viewLargerMapImage.do?mapFileName=RMC_US_Acid_Rain.png



Most of our job specs prohibit running EMT outside.




RMC will corrode also, just has a heavier wall to corrode away before it gets a hole in it.
I don't want to get into a long drawn out discussion here but I don't see RMC or IMC rusting out except where feild threaded and not recoated.
 

kwired

Electron manager
Location
NE Nebraska
In this area of the country EMT exposed to the weather rusts away much quicker than RMC or IMC.

http://education.randmcnally.com/classroom/action/viewLargerMapImage.do?mapFileName=RMC_US_Acid_Rain.png



Most of our job specs prohibit running EMT outside.






I don't want to get into a long drawn out discussion here but I don't see RMC or IMC rusting out except where feild threaded and not recoated.
I generally don't see RMC/IMC rust out either. I do see increased corrosion underground, but seldom complete disintigration. Most EMT I see issues with would generally last longer if better care were taken on installing it. That "shall be arranged to drain" wording definitely applies to many of those installs. I do see some increased corrosion in RMC/IMC that has not been arranged to drain either.

But local environment can make a big difference. Run anything galvanized in the vicinity of anhydrous ammonia and you will find that black iron pipe would have lasted longer.
 
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