Connecting 2" HDPE to 3/4" meter

[oldkroh]

Hello,

I'm wondering what is the simplest or otherwise recommended way to go from a 3/4" water meter connection (FIP) to a 2" HDPE IPS supply pipe. It would be great if there was a single fitting but I'm not finding anything on the interwebs that talks about the best way to do this. I'm guessing a 3/4" MIP x 2" PEP doesn't exist.

Thanks

 

[oldkroh]

I see in another post the recommendation for a threaded bell reducer. I found one 3/4" x 2" here:

https://www.bpssg.com/2-x-3-4-lf-std-brass-thd-reducing-cpl-lead-free

I suppose a 3/4" nipple -> 3/4" x 2" bell reducer -> MIP brass x 2" PEP compression would do the trick?

https://www.ferguson.com/product/ay...brass-straight-coupling-m7475333k/_/R-2472393

On a side note, holy crap that 2" PEP fitting is expensive! It just looks beefy and more reliable, but I've seen other posters mention that brass barbs and 2 hose clamps work just fine. Is it possible that I could spend $10 instead of $200 for the same reliable connection?

 

[Sponsor]

 

[Reach4]

On a side note, holy crap that 2" PEP fitting is expensive! It just looks beefy and more reliable, but I've seen other posters mention that brass barbs and 2 hose clamps work just fine. Is it possible that I could spend $10 instead of $200 for the same reliable connection?

Barbs are for SIDR pipe, which have a Standard Inside Dimension that fits the barbs.

 

[Fitter30]

2" compression x 2" female pipe thread coupling
2" x 3/4" brass threaded bushing
https://hdpesupply.com/2-ips-compression-x-2-female-threaded-transition-fpt/

 

[wwhitney]

Nice. Or a 2" compression x 2" male coupling, with the brass bell reducer mentioned earlier:

https://hdpesupply.com/2-ips-compression-x-2-male-threaded-transition-mpt/

Cheers, Wayne

 

[oldkroh]

Thanks for the suggestions, I hadn't been considering compression fittings like these. Are they preferable to barbed fittings because they are easier to work with or is there some other advantage? My local plumbing supply has 2" IPS SIDR 7 in stock so I was going that route, but I could order 2" IPS SDR 11.

 

[wwhitney]

Not so familiar with this type of pipe, but I believe I understand correctly:

IPS or SDR pipe has a controlled outer diameter. So any 2" SDR or 2" IPS pipe will be 2.375" OD. Compression fittings like the above can be used. Since you specified IPS size in your OP, those are the fitting suggestions you got.

SIDR pipe has a controlled inside diameter. Apparently 2" SIDR pipe is always 2.067" ID, which is the ID of 2" Schedule 40 IPS. [Not sure if that relation is true for other sizes.] So barbed fittings like the above can be used.

If you could find a Schedule 40 IPS 2" PE pipe (SIDR 13.42) of sufficient pressure rating, no idea if that exists, then you could use either type of fitting. And that is what the term "IPS SIDR" would imply.

As to the pros and cons of each version, no idea, other than the usual that larger inner diameter means lower frictional pressure drop (but the inner diameter variation is not going to be so great, I think).

Cheers, Wayne

 

[John Gayewski]

Opinion: call a plumbing contractor with a fusion machine. Have them fuse a 2" hdpe x 2" male pipe thread adapter (brass) onto your pipe. This will be the best connection and that's what you asked for. Then you can convert with threaded fittings into whatever you want or need.

 

[oldkroh]

Thanks for clarifying that. I'm just now wrapping my head around the HDPE pipe sizes and dimension ratios but I think I've got a handle on it and the somewhat confusing aspect of it is that IPS can be either SDR, or SIDR so I think it's fair to say that IPS is not interchangeable with SDR. However, there is no such thing as SIDR CTS, so it does make sense to think of SIDR HDPE pipe as a thing unto itself, especially because it flies in the convention of having a consistent O.D. typical of IPS. I've seen inside-diameter controlled 2" IPS HDPE pipe in SIDR-7, O.D. 2.681 (200psi), and SIDR-9, O.D. 2.545 (160psi). If there were such a thing as you suggest, Wayne, 2" IPS SIDR where the I.D. was 2.067 and the O.D. was 2.125, I'm not sure the pipe could support its own weight much less any meaningful water pressure.

The inner diameter variation doesn't seem inconsequential to me. At least it seems like every little bit counts when I'm looking to handle the friction loss of a long run uphill with 30+ GPM potential demand and between 1-3psi/100ft available for friction loss depending on how you figure it. Between various 2" pipe:

CTS SDR-9: ID 1.634"
CTS SDR-11: ID 1.723"
IPS SDR-9: ID 1.826"
IPS SDR-11: ID 1.926"
IPS SIDR-9/11: ID 2.067"

I may be overthinking the whole thing or not understanding some aspect, but it seems like according to chart 105.1(5) for SDR-11 plastic tubing in Appendix A of the UPC, the difference between 1.6" and 2" is something like 15-20GPM.

I like the idea of the compression fittings with SDR-11 IPS pipe. I also like the idea of fusing the 2" connection, thanks for that suggestion.

 

[Reach4]

Thanks for clarifying that. I'm just now wrapping my head around the HDPE pipe sizes and dimension ratios but I think I've got a handle on it and the somewhat confusing aspect of it is that IPS can be either SDR, or SIDR so I think it's fair to say that IPS is not interchangeable with SDR.

I hope you can get this clarified. It seems confusing to me.

SIDR is understandable. I thought IPS was understandable, but now I am not at all sure. Let's hope you can help clarify. I thought IPS stood for iron pipe sized. That would indicate that a nominal 2 inch IPS would be 2.375. https://taylorwalraven.ca/pipe-data-steel-iron-pipe-size.php

 

[oldkroh]

I'm using info from http://www.plasticpipe.com.cn/blog/peguide.pdf

Without having read ASTM D 2239, and based on the link you sent, I'm guessing that this standard (ASTM D 2239) for HDPE pipe conforms the inner diameter of the pipe to the Sched 40 IPS INNER diameter. Even though IPS is typically thought of as being controlled by outer diameter, which the various schedules of IPS sized pipe all conform to, the various schedules also have typical wall thicknesses, thus a standard inner diameter. For whatever reason, there is a standard for HDPE pipe that conforms to the inner diameter of Schedule 40 IPS.

 

[Reach4]

https://www.astm.org/Standards/D2239.htm says the D2239 spec is "Standard Specification for Polyethylene (PE) Plastic Pipe (SIDR-PR) Based on Controlled Inside Diameter".

But your idea that this might conform to schedule 40's ID is interesting.

However https://www.jmeagle.com/sites/default/files/jme_PEWaterandSewer.pdf includes dimensions for

• HDPE IRON PIPE SIZE (I.P.S.) PRESSURE PIPE
  
• S.I.D.R. PRESSURE PIPE ASTM D2239
  
• COPPER TUBING SIZES (C.T.S.) PRESSURE PIPE ASTM D2737

And in that document, the IPS pipe has the same OD as Schedule 40, Schedule 80, Schedule 120 etc.

 

[oldkroh]

yup, that makes perfect sense. The HDPE IPS pipe that has same OD as the rest of IPS pipe is ASTM 3035. The HDPE CTS pipe is ASTM 2723, and the HDPE IPS SIDR pipe that has the same ID as Sched 40 IPS is 2239. I actually only checked for 2" and 1 1/2", but the IDs were the same.