Tightening of RGS or IMC

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Michaelf2244

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I may be mistaken but I seem to remeber the NEC usee to stae a minimum ammount of threads required to be engaged to a fitting ( I think it was 4-5), I cant find any reference to this condition. I have a contractor trying to slide some shoddy work and my only defense is the "loosely joined" card. I dont know if they quit making 460's or chain/strap wrenches but hand tight 4" RGS does not fly with me.... Can anyone refresh my memory or give me a reference.
Thanks All!
 
The stuff is listed I'm sure the are listing and labeling instructions .This may be of help also 250.120 talks of tools

http://www.steelconduit.org/pdf/ConGuide.pdf

4.3.3.4 Threaded fittings


Threaded joints, both fitting to conduit and fitting to
threaded integral box entries, shall be made up
wrenchtight.
(NOTE: Avoid excessive force. Generally a force
equivalent to handtight plus one full turn with an
appropriate tool is recommended. This should assure engagement of at least three full threads.)
 
Wrenchtight is the general requirement.

There are places in ART 500-516 that mention minimum number of threads to be engaged but that is for maintaining explosion proof characteristics than for general tightening information. I know 500.8(E) requires minimum of five threads to be engaged, some bell box entries would never even have 5 threads available to engage, but they are not for use where explosion proof enclosures are needed either.
 
Thanks for the help !

Thanks for the help !

I appreciate the input gentlemen, being out of the trade for a while has definitely taken a toll on my code finding skills!Thanks again!
 
Is there a general wrench-tight requirment? When you spin on an elbow and you cannot get another 1/2 turn you back it off a 1/2 turn.
 
Michaelf2244 said:
I may be mistaken but I seem to remeber the NEC usee to stae a minimum ammount of threads required to be engaged to a fitting ( I think it was 4-5), I cant find any reference to this condition. I have a contractor trying to slide some shoddy work and my only defense is the "loosely joined" card. I dont know if they quit making 460's or chain/strap wrenches but hand tight 4" RGS does not fly with me.... Can anyone refresh my memory or give me a reference.
Thanks All!
Click to expand...

They probably did have 460's and that was the problem. 460 channies will barely grab 4" rgs and forget about getting a grip on the larger diameter couplings. They needed the aforementioned wrenches or the "big azz channellock 480". Thats the actual name they are marketed under. 4" rgs is big!
 
infinity said:
Is there a general wrench-tight requirment? When you spin on an elbow and you cannot get another 1/2 turn you back it off a 1/2 turn.
Click to expand...

That is a good question. I will say this, with tapered threads backing up 1/2 turn probably still leaves it pretty tight and with good continuity, but backing up a full turn or more probably does not. I will also say, back up 1/2 turn with the elbow and then back up the coupling, if that is what the elbow is threaded into, another 1/4 turn is probably an even better practice.
 
Spinining on fittings...

Spinining on fittings...

I remember back when I was installing duct banks and we had to roll offsets I would take a steel locknut and use it as a jam until we tied everything off. worked better on RGS smaller than 2" but it was better than having to deal with some spaghetti noodled offset or stub up... Running rigid is a lost art & it seems everyone uses unions & 3pc couplings like regular couplings or they use threadless couplings on threaded pipe!!!
 
Michaelf2244 said:
I remember back when I was installing duct banks and we had to roll offsets I would take a steel locknut and use it as a jam until we tied everything off. worked better on RGS smaller than 2" but it was better than having to deal with some spaghetti noodled offset or stub up... Running rigid is a lost art & it seems everyone uses unions & 3pc couplings like regular couplings or they use threadless couplings on threaded pipe!!!
Click to expand...
Hurry up and get it done takes precedence over details most of the time today. Sometimes the details come back and haunt you but it is hard to tell that to the boss sometimes.
 
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