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Direct Bore Conduit Question

Posted By: Yoopersup

Direct Bore Conduit Question - 07/21/10 02:52 PM

I have a Contractor who submitted American Ductile Iron pipe for direct bore under a river. The submittal said Water, Sewage pipe. Is there any other direct bore Conduit allowed besides HDPE ??
Posted By: gfretwell

Re: Direct Bore Conduit Question - 07/21/10 05:48 PM

I suppose he could use the water pipe as a sleeve and pull HDPE or some other appropriate wiring method through it.
FPL did a directional bore under the river next to me but I didn't get to see what wiring method they used. I think the bore casing itself was that thick wall (1 1/4" or so) PVC pipe because there were pieces of it on the side of the road.
Posted By: Yoopersup

Re: Direct Bore Conduit Question - 07/21/10 09:29 PM

I agree Putting Conduit inside of another pipe might be fine. But using water/Sewage pipe for Conduit I;d say thats a No No.This pipe is Iron with concrete lining.
Posted By: HotLine1

Re: Direct Bore Conduit Question - 07/21/10 11:35 PM

I've heard of the occasional AHJ insist that any 'sleeves' be UL listed/labeled as 'at least electrical material'. This came up on a resi multi family rental unit developement. The sparkies, and the cable & telco guys used scrap pieces of orange PVC leftovers from the sprinkler installers. The debate raged on for a few weeks & held the job up. Outcome was 'what was installed can remain, but do not use it anymore'.

As to your OP, I do not know of any other listed bore conduit other than HDPE.
Posted By: ghost307

Re: Direct Bore Conduit Question - 07/22/10 12:29 PM

As long as neither the fire ratings nor the structure is compromised, I see no problems with using anything that's handy as the sleeve that the conduits go through.
Posted By: HotLine1

Re: Direct Bore Conduit Question - 07/22/10 01:20 PM

I tend to agree with you on that if the rated wall was not compromised, there is no issues.

As I said, the basis of the debate was using non-electrical materials, similar to using plumbing PVC for electrical conduit.

Posted By: gfretwell

Re: Direct Bore Conduit Question - 07/22/10 05:58 PM

If the installer calls it a "duct" I am not sure which article the AHJ could cite. "Ducts" are talked about in the derating articles but they are never defined.
White PVC driveway sleeves are the norm here in new construction and I have never seen it cited as a violation.
Posted By: HotLine1

Re: Direct Bore Conduit Question - 07/22/10 07:16 PM

Finding a citable article was brought up in the debate & that AHJ could not substantaite, other than 90.4, which did not totally stand.

Yes, white pipe in driveways (resi) happens here. Personally, I have no issue with it, as I had no issue with the above mentioned 'orange PVC.

Posted By: renosteinke

Re: Direct Bore Conduit Question - 07/23/10 12:16 AM

I think there's some 'legal amnesia' taking place. What did we use before there was HDPE? After all, HDPE is pretty new to the code. Were we not doing direct bores before then?

Just because one product is listed for a specific use, that does not mean that only that product can be used.

As for re-tasking materials from their original use and applying them to electrical uses, that's a call for the AHJ to make. While the code says 'use one of these ...,' the code also recognizes that the AHJ can waive / approve / make exceptions; that's why he's called the "AHJ."

Make your case as to why the substitution is justified, and let him earn his pay.
Posted By: Yoopersup

Re: Direct Bore Conduit Question - 07/23/10 11:40 PM

Conduit (HDPE ) VS Pipe
Taken from handbook of Poyethylene pipe.
In general plastic pipes and plastic pipes are very similar in structure &composition , but deployment is where they differ.
#1 Conduits do not have long term interial pressure.
#2 Externial forces are unchecked if ovalized during installtion, may not recover during service.
#3 Long term stress rupture is not a factor ( Hydrostatic
design basis is not required in material selection.
Because we used improper methods before now that we have them is there any reason not to install it correctly now???
#4 Conduit ID is chosen by cable occupancy,where internal clearences are critical.whereas for pipeing applactions ID is based on volumetic flow requirements.
And theres tons more on why Proper Conduit should be installed.

Posted By: HotLine1

Re: Direct Bore Conduit Question - 07/24/10 02:02 AM


Did you see this:

Posted By: Yoopersup

Re: Direct Bore Conduit Question - 07/24/10 03:03 AM

Hotline 1
I know about the Approved & correct methods , But some contractors want to use Water line, Sewer line, ect.
I feel if the Correct method to do the job is out there it should be used. I don't think the AHJ has the power to say , Use whatever . Yoopersup
Posted By: Yoopersup

Re: Direct Bore Conduit Question - 07/26/10 09:53 PM

Point of Info on HDPE:
Called Factory & they told me Water pipe & Conduit HDPE same except water pipe stronger, Comes off same line even. Conduit marked as such. They said you could use water pipe as Conduit but not conduit as water pipe. Interesting hey!
Posted By: George Little

Re: Direct Bore Conduit Question - 07/26/10 11:07 PM

Ernie- I've run into this before and it was explained to me that water pipe is tested for pressure and conduit isn't and that conduit is tested for crush resistance and water pipe isn't.
Posted By: Yoopersup

Re: Direct Bore Conduit Question - 07/27/10 02:49 AM

Like I said talked to factory both same pipe, Come off same assembly line, But more hardner added to Plumbing pipe. According to there there Teck guy Water pipes better. Yes I know & went over testing with him also. He said they put different lables on each.
Posted By: gfretwell

Re: Direct Bore Conduit Question - 07/27/10 04:17 AM

That is probably important to the people who use RNC for outside hose bibs and such. So far I have never heard of a problem with it and you see a lot of gray pipe on docks and even solar collectors although they usually use ABS for that.
Posted By: renosteinke

Re: Direct Bore Conduit Question - 07/27/10 01:43 PM

Ultimately, it comes down to either an engineering decision or an administrative one.

Whether a material is adequate for the job is, I would hope, the primary question; "code compliance" is silly if the final effort is a failure.

I've been in a number of situations where it simply wasn't possible to 'meet code' and still have things work. These situations have included 'green' insulation on 'hot wires,' use of steel wire as a conductor, and the use of plumbing pipe as conduit. Mind you, in each of these instances there were details that made the choice the only physically possible choice - I'm not talking about simple convenience.

Perhaps the best example was the use of plastic water pipe as conduit -in the days before there was any listed product - for extremely corrosive conditions. That particular jurisdiction still, to this day, does not allow plastic pipe for either plumbing or electric, but was willing to accept its' use where corrosive conditions justified the use.

Getting closer to the OP, I think we've all used 'non-listed' materials for direct bore .... every time we've passed wires under a sidewalk or driveway. Naturally, my saying this opens up the debate as to 'what constitutes direct boring?" All I can say is that I was using a water pipe with a nozzle on it to drill holes through dirt long before special tool sets were sold, then passing some form of pipe through the hole. If anyone expects me to purchase a 1000 ft. reel of HDPE for a 30" sidewalk job ... keep dreaming.

"Listing and labelling" has its' uses; the presence of a UL label can make it easier to judge whether a product is suitable. That's no comfort, though, for the 'fringe' applications where the circumstances have not been encountered enough for someone to think there's a market to serve.

Posted By: Yoopersup

Re: Direct Bore Conduit Question - 07/28/10 01:18 AM

This job is 160 to 200 ft of 6 inch under a river & up to handholes each side.
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