safe to use lubricant for pulling 1" poly thru existing 1.5" uponer pex?

[TX Hill Country]

I'd like to use an existing section of 1.5" uponer pex in a trench that runs under a new driveway as a sleeve for 1" black polyethylene pipe. There would be cts/Ford fittings on either end of the poly just past the end of the uponer pex. I'd like to avoid having both uponer pex fittings and poly cts fittings, 90% of fittings on my nearby sprinkler mainline will be for the poly.

My issue now is how to use the existing 35' section of 1.5" uponer pex already in a trench which crosses the driveway, but will now just be a short lateral for a hydrant (non-sprinkler).

Is it safe for me to use some form of electrical wire pulling (or other) lubricant? It will permanently be smeared on the outside of the polyethylene and the inside of the uponer.

Ideally the lubricant wouldn't cause any damage to either pipe, and be safe for potable water hypothetically since someone (not me) in the future might decide they want the higher gpm.

I'm a little fearful of trying to pull (actually will be pushing the black poly) and having it get stuck.

I just tried to find online ID/OD dimensions and couldn't find anything trustworthy, but checking small sections it seems the poly will slide into the pex.

There's a gradual 90deg turn in the pex with an approximate radius of 6ft.

 

[Reach4]

Not going to fit if you run 1 inch SIDR polyethylene pipe. https://www.electronicshub.org/pex-pipe-size-chart/ 1.5 inch PEX has ID 1.245

One inch CTS polyethylene pipe (including PEX) is smaller, and has an OD of 1.125. Still darned close. But with CTS, you will then have to adapt to the pipe that is used with irrigation.

I would consider 3/4 inch SIDR, unless you have a strong preference otherwise. It has an ID of 0.824 inch. 3/4 inch SIDR would fit standard 3/4 inch barbed fittings. It would be good for 7 GPM or more, which is quite a bit.

I cannot find that using wiring pulling compound is a bad idea, neither can I find an approval. Dish soap may be an alternative, but pipe pulling compound sounds even more gentle, to me.

 

[Sponsor]

 

[TX Hill Country]

Not going to fit if you run 1 inch SIDR polyethylene pipe. https://www.electronicshub.org/pex-pipe-size-chart/ 1.5 inch PEX has ID 1.245

One inch CTS polyethylene pipe (including PEX) is smaller, and has an OD of 1.125. Still darned close. But with CTS, you will then have to adapt to the pipe that is used with irrigation.

I would consider 3/4 inch SIDR, unless you have a strong preference otherwise. It has an ID of 0.824 inch. 3/4 inch SIDR would fit standard 3/4 inch barbed fittings. It would be good for 7 GPM or more, which is quite a bit.

I cannot find that using wiring pulling compound is a bad idea, neither can I find an approval. Dish soap may be an alternative, but pipe pulling compound sounds even more gentle, to me.

I have quite a bit of 1" poly left over, and I found the same thing that searching ID/OD for the materials I think I've used shows it won't fit.
But it does since I (a few weeks back) stuck a piece of the poly into the pex just a few inches. I'll need to revisit the property and check more carefully what I used for both the pex and the poly, kind of a mystery right now.

Thanks for your comment!

 

[Integrity Repipe]

Using a wire-pulling lubricant or an NSF-approved water-based lubricant is a good idea when feeding 1” poly through your existing 1.5” Uponor PEX sleeve, as it reduces friction and makes the process smoother. Since this section runs under your driveway, you want to avoid excessive force that could kink or damage either pipe. Do not use petroleum-based lubricants, as they can degrade polyethylene and PEX over time. A water-soluble, silicone-free lubricant is the safest choice, especially if there’s any chance this line might be repurposed for potable water in the future. A thin layer inside the PEX and on the poly pipe, along with a pulling sock or tapered attachment, should help prevent snagging at the turn.