PVC conduit vs plumbing pipe

[Fred B]

Customer questioning the use of listed PVC conduit instead of cheaper white plumbing pipe. Other than code requirements I believe there is a physical difference as well. I know the plumbing pipe is more brittle. Does someone know the exact difference as to why it must be used instead of plumbing pipe under NEC?
He states that he's got a bunch of plumbing pipe and doesn't want to pay extra for PVC conduit.
I'm not questioning the use of listed pipe, but customer not satisfied with "the code says so" or that "plumbing pipe more brittle".

 

[brantmacga]

Plumbing pipe isn’t UV resistant like electrical conduit. They’re essential the same product but plumbing pipe is rated for pressure and wouldn’t have anything toxic that could get into the water. And of course wall thickness can vary with different types of plumbing pipe.


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[paulengr]

Customer questioning the use of listed PVC conduit instead of cheaper white plumbing pipe. Other than code requirements I believe there is a physical difference as well. I know the plumbing pipe is more brittle. Does someone know the exact difference as to why it must be used instead of plumbing pipe under NEC?
He states that he's got a bunch of plumbing pipe and doesn't want to pay extra for PVC conduit.
I'm not questioning the use of listed pipe, but customer not satisfied with "the code says so" or that "plumbing pipe more brittle".

Electrical is grey and has a UV protective additive. White plumbing pipe is “virgin” without the additive. In fact additives and other minor details are the only physical differences.

Plumbing pipe is pressure tested but the physical dimensions are identical. It’s not true that it is thicker. Both are schedule 40 PVC. I’ve seen the same BS about plumbing pipe is thicker but 2 minutes checking the actual specs shows something very different…actually the same.

But the big difference is PVC conduit is Listed (third party tested and labeled) for electrical use where plumbing pipe is tested Listed for plumbing use. Code requires everything to be Listed. You can’t use it. If it was legal nobody would pay extra for conduit.

 

[electrofelon]

Ive been using DWV pipe on some long underground runs due to the high cost of Electrical PVC. This was all USE conductors so no code issue. If you use it, I highly recommend pressure couplings or long line pvc couplings as regular DWV couplings suck and break apart easily.

 

[drcampbell]

Electrical conduit is also required to have a smooth interior finish that will not damage anything during a pull.
Definitely relevant for steel & iron pipe; I'm not sure it matters much with non-metallic.

 

[infinity]

There is also Cellular Core PVC Sch40 plumbing pipe that is not listed for pressure and is lighter and more brittle than regular PVC plumbing pipe.

 

[hbiss]

but customer not satisfied with "the code says so"

Simple. "If you want me to do the work that's what I'm required to follow. If you don't like it get the guy who cuts your grass to do it."

I'm sick of customer's BS!

-Hal

 

[petersonra]

I'm not questioning the use of listed pipe, but customer not satisfied with "the code says so" or that "plumbing pipe more brittle".

As another poster mentioned, there is no significant difference between PVC pipe designated for plumbing use and that designated for electrical use other than the use of UV inhibitors for electrical conduit and the markings found on the pipe.

It is like asking why the speed limit is set to a certain value. There is often no good reason. It is just another rule we have to follow that serves no real purpose sometimes.

 

[K8MHZ]

Wall Thickness​

Another difference that you’ll find between PVC pipe and PVC conduit, is in the thickness of the wall of the pipe. The wall of plumbing PVC pipe is typically thicker than the wall of PVC conduit. Because plumbing PVC is used in applications that have pressure to consider, the added thickness ensures that the pipe is strong enough to resist bending and that it will remain undamaged and intact. Conduit PVC isn’t required to withstand as much pressure, so it isn’t made with walls that are thick – that simply wouldn’t be a cost-effective design for manufacturers.

The Difference Between Plumbing PVC and Electrical Conduit PVC

Polyvinyl chloride (PVC) is a combination of plastic and vinyl that is used to make PVC pipes. These popular types of pipes are commonly used in plumbing as an alternative to more expensive copper piping. PVC is also used to produce electrical conduit. While regular PVC and electrical conduit...

www.commercial-industrial-supply.com

 

[Frank DuVal]

I'm not sure where commercial-industrial-supply got their information, but tables on the internet say schedule 40 PVC is the same wall thickness for plumbing pipe and conduit.

ASTM D1785 and ASTM F441 - PVC and CPVC Pipes Schedule 40 & 80

Standard dimensions and weight of PVC - Polyvinyl Chloride - and CPVC - Chlorinated Polyvinyl Chloride.

www.engineeringtoolbox.com

PVC Rigid Conduit - Allied Tube & Conduit | Electrical Conduit

Allied PVC conduit and duct is for commercial, industrial and utility usage; durable and effective in underground, encased and exposed applications

www.alliedeg.us

 

[petersonra]

Wall Thickness​

Another difference that you’ll find between PVC pipe and PVC conduit, is in the thickness of the wall of the pipe. The wall of plumbing PVC pipe is typically thicker than the wall of PVC conduit. Because plumbing PVC is used in applications that have pressure to consider, the added thickness ensures that the pipe is strong enough to resist bending and that it will remain undamaged and intact. Conduit PVC isn’t required to withstand as much pressure, so it isn’t made with walls that are thick – that simply wouldn’t be a cost-effective design for manufacturers.

The Difference Between Plumbing PVC and Electrical Conduit PVC

Polyvinyl chloride (PVC) is a combination of plastic and vinyl that is used to make PVC pipes. These popular types of pipes are commonly used in plumbing as an alternative to more expensive copper piping. PVC is also used to produce electrical conduit. While regular PVC and electrical conduit...

www.commercial-industrial-supply.com

Interesting, however the charts I looked up comparing the ID and OD for PVC pipe and conduit all showed them the same for the same schedule. Maybe this article has it wrong. Would not be the first time an article written by the web marketing team got something materially wrong.

 

[infinity]

Interesting, however the charts I looked up comparing the ID and OD for PVC pipe and conduit all showed them the same for the same schedule. Maybe this article has it wrong. Would not be the first time an article written by the web marketing team got something materially wrong.

I was always under the impression that SCH40 was a standard and anything that was labelled as SCH40 had a standard thickness, just like a wire gauge number.

 

[don_resqcapt19]

There is also Cellular Core PVC Sch40 plumbing pipe that is not listed for pressure and is lighter and more brittle than regular PVC plumbing pipe.

There is at least one manufacturer of listed Cellular Core PVC conduit.

 

[infinity]

There is at least one manufacturer of listed Cellular Core PVC conduit.

Interesting, I've never seen it but I have seen the plumbing version.

 

[pv_n00b]

In theory, you could use the plumbing PVC, just not as a listed conduit. In that case, it's just a protective covering that serves no code-related purpose. For instance, if you were burying direct bury rated conductor and put it in plumbing PVC that would probably be accepted by the AHJ. But if you need listed conduit plumbing PVC is a code violation.

Your client needs to understand that their satisfaction is not required if it's a code requirement. It's your license on the line and a lot of rework if it's found out.

 

[synchro]

I was always under the impression that SCH40 was a standard and anything that was labelled as SCH40 had a standard thickness, just like a wire gauge number.

I believe that's true, and it's established by the standard ASTM-1785 for PVC plastic pipe.
As shown on the following document from Cantex, PVC conduit meets the ASTM-1785 standard for "dimensions only".

https://www.cantexinc.com/Portals/0/Documents/Product-Literature/Facts-about-CANTEX-PVC-Pipe.pdf

 

[electrofelon]

Yeah, I think "Korey" doesn't know what he is talking about. The schedule defines the dimension. Then he also says this:

"Be aware that Schedule 80 PVC piping is also gray in color like PVC conduit piping, but Schedule 80 is a plumbing pipe, similar to the white Schedule 40 PVC piping. Therefore, Schedule 80 pipes should not be used as an electrical conduit"

 

[K8MHZ]

Interesting, I've never seen it but I have seen the plumbing version.

https://southern-pipe.com/catalogue/cellular_core_cutsheet.pdf

 

[Knuckle Dragger]

Electrical conduit is also required to have a smooth interior finish that will not damage anything during a pull.
Definitely relevant for steel & iron pipe; I'm not sure it matters much with non-metallic.

Me thinks plumbing maybe required to be smooth as well

 

[Knuckle Dragger]

So Fred B,
What's the verdict? Are you going to use the white stuff or not?