[TowerTalk] Sourcing PVC

Thu Jul 11 12:35:04 EDT 2013

OK, I'm sure this is all confusing to the OP. I know it was for me until I 
dug into it a bit. I am using PVC for a wood shop application, and I 
needed large diameter and light weight. Schedule 40 would have been just 
too darned heavy. I originally wanted to use the ASTM-D2729 pipe, as it 
was very thin wall and therefore very light. I'd used it very sucessfully 
in my shop in NJ, and now that I'm setting up my new shop in FL and I have 
some left over fittings for it, I figured I'd use the same stuff.

I don't know why anyone would want to slip one PVC pipe into another, 
unless its to make a mast. If its for a plumbing or conduit application, 
IMO you're better off using standard fittings. And if its a conduit 
application, DWV fittings make more sense than pressure fittings. For 
example, a DWV wye is a much better choise then a pressure T, and a DWV 
large radius sweep is better than a pressure elbow.

Here's the important thing about IPS sizing: The outside diameter is the 
same for all IPS pipe of a given trade size. And its the pipe OD that 
matters when you're looking for fittings. So a coupling made for 4-inch 
SCH40 will work on any other 4-inch IPS pipe, be it SCH80, SDR-21 or 
SDR-64, or anything in between. DWV and pressure fittings all fit. The 
inside diameter of the pipe varies, which doesn't affect standard fittings 
in any way. The number in "SDR-xx" is the ratio of OD to thickness of the 
pipe wall. So a 6-inch SDR-64 pipe has a wall thickness of 6.625/64 = 
0.103 inches.

And BTW, that "SDR-61" in my original messages should have been "SDR-64", 
there is no SDR-61.

There is a complete listing of IPS dimensions in this brochure from JM 
Eagle:

http://www.jmeagle.com/pdfs/2008%20Brochures/IPS%20Pressure_web.pdf

ASTM-D2729 pipe (sometimes called "S&D" pipe) and SDR-35 (often green in 
color) are not an IPS pipe and you have to get the fittings made 
specifically for them. That's not awful, it just might be a little harder 
to find, especially in the larger sizes, and you can't use electrical 
conduit fittings (boxes, sweeps, L-bodies, etc.) with it.  The big box 
stores here seem to have a reasonable selection in the 4-inch size. The OD 
of S&D and SDR-35 is the same.

As for Ferguson, permit me a short rant. Yes, they show ASTM-D2729 pipe in 
6-inch and 4-inch size available. I tried getting some of the 6-inch from 
Ferguson Water Works in Ocala (directed there by the local Ferguson 
plumbing store in Gainesville), and I quickly discovered that they really 
didn't have time for me, as I didn't want to buy a truckload of the stuff. 
They did not have it in stock and they flat out refused to bring it in 
from other Ferguson locations that had it. OTOH, the local Ferguson 
plumbing shop here in Gainesville has many IPS fittings in stock and can 
get those not in stock very quickly. The only downside is they were REALLY 
expensive compared to the big box stores. Sometimes as much as 3:1. But 
the big box stores don't carry some of the fittings I wanted, like large 
radius sweeps for 6-inch pipe.

I ended up getting 6-inch SDR-41 pipe from a local irrigation supply. They 
had no problem selling retail and cheerfully accepted my small order and 
delivered 20-foot lengths to my house without charge. Unfortunately they 
could not source the SDR-64 for me. And they could not get the fittings I 
wanted.

On Thu, 11 Jul 2013, Rick Karlquist wrote:

> Art Greenberg wrote:
>
>> easier to find. You can find IPS pipe in thinner wall than Schedule 40.
>> Pipes maked SDR-xx (except for the SDR-35) are IPS sizes. The larger the
>> number, the thinner the wall. Check with a local plumbing or irrigation
>> supply for SDR-41 or SDR-61 (the later having almost the same wall
>> thickness as 2729 pipe).
>
> Check out Horizon Irrigation's web site:
>
> http://www.horizononline.com
>
> They carry the SDR series.  This is important in the 4 inch IPS (which is
> actually 4.5 inch OD) because the thinner wall SDR has an ID slightly over
> 4 inches while the schedule 40 has an ID slightly under 4 inches.
> If you want to slide 4 inch OD irrigation pipe inside 4 inch IPS PVC
> pipe, it has to be the SDR type.  (Note, this only applies to the
> 4 inch size.  Schedule 40 is fine for 2 and 3 inch PVC).
>
> Another supplier for exotic pipe is Ferguson:
>
> http://www.ferguson.com
>
> Rick N6RK
>
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--
Art Greenberg
art at artg.tv