500.8 (E) pretty much says it will be tapered NPT pipe thread.
Conduit threads are required to be tapered.I disagree. If you are threading conduit into a tapered thread then the conduit does not need to be tapered also. Take a look at 344.42 (b). One of the only place I can picture not being able to get running threads wrench tight is in a coupling. Your qualifier "pretty much" may be taking all of this into account so forgive me if that is the case.
The rule you cited does not permit the use of non-tapered threads at fittings.344.28 Reaming and Threading. All cut ends shall be reamed or otherwise finished to remove rough edges. Where conduit is threaded in the field, a standard cutting die with a 1 in 16 taper (3⁄4 in. taper per foot) shall be used.
Just an electrician.Don..who are you?..........you seam to know all about all ( I had the tapered thing though......but would not have been able to have sighted the verse so readily).
It is a 345 kV air break switch being opened....
also I must mention.....you're avatar.....looking hard into it I would think it's a Jacob's ladder or something......but every time I see it it reminds me of Judy Garland or Cindi Lauper.
It is a 345 kV air break switch being opened.
http://205.243.100.155/frames/mpg/345kV_SWITCH.MPG
I think that movie will live on in infamyDon..who are you?........
Kinda reminding me of " The Great and Powerful OZ".................................don't look behind that curtain..............
Respectfully,
Jack
snubber
Conduit threads are required to be tapered.
The rule you cited does not permit the use of non-tapered threads at fittings.
344.28 Simply states the die you are required to use to thread conduit. It says nothing about running threads.
What about 344.42(B)?
My 2008 says that only is for connection at couplings. Nothing mentioned about boxes or other fittings.
You are correct, but how can a running thread be usefull at a box or fitting?
Running threads can be used (in violation) in lieu of installing a three-piece coupling ("ericson"). The running threads on one conduit are long enough to screw the coupling on entirely. This is then butted to a second conduit with standard threads, the coupling is spun off the running threads and onto the threads of the second conduit and all is made wrenchtight.I didn't say anything about useful. How could it be useful in a coupling, the only instance mentioned?
Where would a running thread be useful at all? ...
Running threads can be used (in violation) in lieu of installing a three-piece coupling ("ericson"). The running threads on one conduit are long enough to screw the coupling on entirely. This is then butted to a second conduit with standard threads, the coupling is spun off the running threads and onto the threads of the second conduit and all is made wrenchtight.
Suffice it to say it can be done. Being a violation makes elaborating on the matter moot.How do you make it wrench tight without the conduits hitting each other inside the coupling? (And making a burr?)
How do you make it wrench tight without the conduits hitting each other inside the coupling? (And making a burr?)