Large Diameter PEX Bending Question

152NP

<span style="font-size:12pt">I could use some advice on how to solve a problem I created for myself.  I am installing a coal fired hot water heating system in my home and detached garage. I already buried two 3” schedule 40 drain pipes between the house and garage to serve as chases for PEX. They run straight out of the basement wall and turn up with long sweep 90 degree elbows through the garage floor. My garage is actually elevated about 4 feet higher than the first floor of my house. The total run is about 30 feet.  I originally thought I would locate the boiler in my basement and run ¾ PEX out to radiation in the garage. Now I am locating the boiler in the garage and need to run 1 ¼ PEX back to the basement. I just got a 100 foot coil of 1 1/4" hePEX, and this stuff is stiff.  I can’t see how it is going to make the 90 degree long sweep bend.  Will running hot water through it make it flexible enough? Plan B would involve sending black pipe out with two 45 degree elbows configured to make the long sweep and hopefully be able to drop another length into it from the garage. The drop is about 6 feet. Would I be able to effectively tighten the drop pipe by wrenching it by its end, or would the pipe act like a torsion spring and absorb the tightening force? Plan C is dig the whole thing up again and just bury the hePEX. This would be a big deal and rquires a backhoe. Anyone have thoughts on how to approach this? </span>

zacmobile

pex pull

You may be able to pull it with a come-along or a winch using one of those mesh pulling socks electricians use. I had to do such a thing one time only it was 3/4" soft copper in 60' of 4" PVC sewer pipe, we used that method and it worked quite well. good luck!



PS: are you sure you need 1-1/4"? if you ran a really high delta T injection loop you could probably reduce the pipe size significantly.

JStar

hmm.

Maybe you can cut the lead end on a long, steep angle, to minimize the amount of material initially hitting the elbow. A flat piece of pex should take a turn more easily than a tube.

bob eck

pex

what is the btu load of your home? 1" could carry 71,000 btu and 1 1/4" 160,000 btu

Charlie from wmass

You may be able to pull it through.

Was the long sweep a drainage long sweep or a conduit long sweep? You can heat and flatten about 18" of the pex and drill three holes in it. Then thread 1/2" rope Poly or better and pull on that. Make sure it is a warm day and the PEX was stored somewhere warm before you start. Good luck and make sure you have someone pushing and someone pulling. You may want to check the local Electrical Supply for a safe lube that will not damage the tubing.  

Bob Vennerbeck

how much hot water can you make?

I've only tried this with 1" PEX, but it should scale up with only a bit more mess....



I connected one end of the coil of pex to my hot water heater with a variety of fittings from the junk box and a brand new Shark-Bite - then ran hot water full blast through the coil - I expected to have to work fast with water running everywhere, but actually it softened up quite quickly, and stayed limp as long as I valved back to just a trickle running through..... I was pushing the end of the coil up through our chase, and my wife was running ahead with a 5-gallon bucket - the shark-bite on the tank end allowed the loops to swivel, so the coil didn't snake around in knots - much anyway... an extra loop wrangler would have helped, but hey it worked!



Vbob

Robert_25

Heat it up!

Just putting the roll of pex in a warm room will make a big difference, running hot water through it will soften it even more. I think your best bet is to pull it through.



What type of coal boiler are you installing?