Threaded fittings

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Alwayslearningelec

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So per spec were allowed to use EMT in the slab But it can’t have threadless fittings. Can you use a threaded coupling with EMT? But then you need to thread the EMT Which I don’t think can be done as it’s thinwall.
 
No you cannot thread EMT. Someone would need to clarify what that wording means because it makes no sense.
 
infinity said:
No you cannot thread EMT. Someone would need to clarify what that wording means because it makes no sense.
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So if it didn’t specifically say EMT is allowed in the slab but DID say all conduits in slab must use threadless fittings you’d default to using RGS?
 
horsegoer said:
So if it didn’t specifically say EMT is allowed in the slab but DID say all conduits in slab must use threadless fittings you’d default to using RGS?
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Surely you mean threaded fittings. There is no way to thread EMT. There is no such thing as a threadless EMT fitting, there are set screw and compression fittings.

Rigid can be threaded. There are threaded couplings and if you are cutting threads or using factory threads then you don't need any connectors. However, there are threadless couplings and connectors available for rigid in compression and set screw.
 
So if it didn’t specifically say EMT is allowed in the slab but DID say all conduits in slab must use THREADED fittings you’d default to using RGS??? Even if it didn't specifically say you couldn't use EMT in the slab?
 
horsegoer said:
So if it didn’t specifically say EMT is allowed in the slab but DID say all conduits in slab must use threadless fittings you’d default to using RGS?
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If it said "conduits" it would mean EMT could not be used. EMT is not conduit, it is tubing and the engineer may be using the strict interpretation of conduit
 
I would imagine they were talking about RMC " rigid" or pvc conduit. As for those are both common methods ran in concrete slabs.

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Jake@01 said:
I would imagine they were talking about RMC " rigid" or pvc conduit. As for those are both common methods ran in concrete slabs.

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Now throw in the threaded vs threadless factor that was brought up and PVC is not typically threaded either. Is possible but not really a recognized termination method for it. Threading EMT would have to be a pretty shallow thread, and even then would be a failry weak point as what it left of the wall thickness after threading wouldn't be much.
 
Jake@01 said:
You definitely don't thread pvc or emt.

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I will admit to having threaded PVC before, can't even recall exactly why it has been so long but was for a pretty rare situation.

It don't thread as easily as you might think it should and is easy to break the pipe if you torque too hard.

Have threaded it a time or two for non electrical installation purposes as well. Made registration document holders for trailers with a piece of PVC, threaded the ends and put threaded caps on it and use a standoff strap or two to fasten it to the trailer, then it goes with the trailer regardless which vehicle you tow it with.
 
roger said:
If it said "conduits" it would mean EMT could not be used. EMT is not conduit, it is tubing and the engineer may be using the strict interpretation of conduit
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Many in the trade use that definition (exclude EMT), but if you look it up, the definition of conduit is “A pipe, tube, or trough for protecting wire or cable.” EMT fits the strict definition.
 
retirede said:
Many in the trade use that definition (exclude EMT), but if you look it up, the definition of conduit is “A pipe, tube, or trough for protecting wire or cable.” EMT fits the strict definition.
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That's going outside of the NEC and since the NEC has already defined conduit and tubing we don't have to look elsewhere. Starting with 342 read all the 3XX.2 sections through 362.2 and you will see the NEC definitely defines conduit and tubing differently
 
roger said:
That's going outside of the NEC and since the NEC has already defined conduit and tubing we don't have to look elsewhere.
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I don't see a definition in Article 100.

roger said:
Starting with 342 read all the 3XX.2 sections through 362.2 and you will see the NEC definitely defines conduit and tubing differently
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Those definitions all use the term "raceway" so I don't see how they inform the "tubing vs conduit" debate. What NEC reference do you that rules out the "conduit is a synonym for raceway" interpretation?

Cheers, Wayne
 
Also, on another note I'm sure that u can thread pvc. However it's not something we do in the trade for electrical installations. Nor is it common practice, or " industry standard " it's not meant to be threaded. This could ruin the structural integrity of the conduit. If you need threads u simply glue on a TA . I'm just saying. If I were you I would just run pvc. Or talk to your local electrical inspector and ask him what he suggests. They are usually more than happy to help.

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horsegoer said:
So if it didn’t specifically say EMT is allowed in the slab but DID say all conduits in slab must use THREADED fittings you’d default to using RGS??? Even if it didn't specifically say you couldn't use EMT in the slab?
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If it says threaded then your two choices are RMC or IMC.
 
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