Working with rigid

Eddie702 said:
The other reason for straight threads (I was told) that RGS going into a coupling both conduits are supposed to be screwed in far enough so the ends of the conduit would touch with no gap.
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And I was taught that the conduit ends should never touch as that could create a ridge that could damage the conductors when they are pulled in.
 
hbiss said:
Tapered threads on the conduit would provide a watertight seal. (Hopefully.)
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Note even close to watertight when used with straight thread couplings. especially in vertical applications. The water runs down the outside of the conduit, hits the top of the coupling and then runs down the treads and ends up inside the conduit.
 
Eddie702 said:
Supposed to ream it so there is no ridge.
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There is no ridge when your start to assemble the coupling and conduits, but when you butt the ends together, that thin reamed part pushes against the thin reamed part of the other conduit and creates a very sharp ridge.
 
jared123 said:
I am JIW with mainly commercial experience. Have bent/threaded rigid mainly for underground changovers so precision wasnt paramount.
What technical advice do you have for working with rigid. Eg if i calculate the gain so i can predermine the length of rigid and thread it before bending do you assume it wont fully thread on and take that into account?
Thanks
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I understand exactly what you’re asking.

Learn your threader and adjust the depth of your threads per conduit fittings as not all are equal. Example, meyers hubs that I use need the conduit threads really deep in order to not have half the threads hanging out not engaged.
 
I always do 1” length threads and can usually do my math for 1” or 7/8” to give my self a little wiggle room
 
The technique of using parallel thread or adjusting the depth or length of the threads to get things to fit reminds me of the parable of the Fox and the Cat. The Fox had many tricks to avoid the dogs, but the Cat only had one. As the Fox was explaining the various tricks to the the Cat, the dogs suddenly arrived on their trail. The Cat used the only trick it knew, climbing a tree. The Fox, while deciding which trick to use, was overtaken by the dogs.

Sometimes you can use an adjustable threader and do Fox tricks (parallel pipe, depth of thread, length of thread). Sometimes you only have a manual threader and can only do Cat tricks (length of pipe and maybe length of thread - it can get tough with larger sizes to keep going past a standard, full thread).

Adjusting the length of pipe while threading a standard, tapered length is always available. I'm going to stick with it.
 
I Do appreciate all the advice. Is there any other major differences in how you run your rigid compared to emt?
I imagine you probably prioritize ease and would never do multiple bends on a single pipe?
 
jared123 said:
I Do appreciate all the advice. Is there any other major differences in how you run your rigid compared to emt?
I imagine you probably prioritize ease and would never do multiple bends on a single pipe?
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Sometimes you gotta do multiple bends on a single pipe with rigid because there might not be room to spin individual pieces, or thread individual sections. Also, with EMT the couplings function like unions with rigid, in that you don't need to spin the sections together. BUT with EMT it isn't any harder to pull through a coupling than through a length of pipe, while with Rigid it is significantly harder to pull through a union than through a length of pipe. With rigid, unless you are using unions, you get only one shot for installing a piece that cannot be spun on. Choose wisely.

There is another consideration - do you start at the power end, the field end or in the middle of a run. With EMT it doesn't matter much. With Rigid there is more of a consideration. To avoid unions, it is sometimes best to start in the middle if the run requires some oddball combination of bends. If that is not the case, I prefer to start from the power end and work toward the field end. My thinking is that if something needs to be changed (now or later) it is easier to work backward from where you left off, than from where you started. The field end is more likely to change than the power end.
 
Sometimes you can avoid an Erickson (union ) by assembling ridgid on the floor and raising it up in one piece. Can't always do that do to obstructions. But a little planning instead of jumping in and running pipe can help.

Nothing wrong with threadless connectors on Rigid either.
 
IMHO putting a threadless box connector on rigid you wrench the connector into a box put the rigid in and tighten the set screw is a better ground than two locknuts you have to hammer on.
 
Is it benefitial to install more pull boxes compared to emt or more condulets to limit having to thread bends on?
 
jared123 said:
Is it benefitial to install more pull boxes compared to emt or more condulets to limit having to thread bends on?
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That is not beneficial when you go to pull wire...every pull point adds labor and additional risk of damaging the conductors.
With planning most runs of threaded conduit can be installed without unions.
 
jared123 said:
Is it benefitial to install more pull boxes compared to emt or more condulets to limit having to thread bends on?
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It all depends on the run. It sucks having to pull wire for someone that made the run easy for them it install with unions all over the place and LBs 12 feet off the ground when there could have been a sweep up there and a pull point waist high. You gotta balance out where the run can go, with how you will secure it, to how you will pull the wires.
 
TwoBlocked said:
It all depends on the run. It sucks having to pull wire for someone that made the run easy for them it install with unions all over the place and LBs 12 feet off the ground when there could have been a sweep up there and a pull point waist high. You gotta balance out where the run can go, with how you will secure it, to how you will pull the wires.
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I agree with that 100%. In most cases with a little thought the pull boxes and LBs need to be where you can actually pull not way up in the air.
 
Eddie702 said:
I agree with that 100%. In most cases with a little thought the pull boxes and LBs need to be where you can actually pull not way up in the air.
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I learned a long time ago, that is is best that the same crew that installs the conduit pulls the wire.
 
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