Terra-Dome Earth Shelter Build

[SamWalton]

I as an electrician that is some good conduit work and fore thought on the runs.

Just thinking out loud I wonder if you heat the pex and pull it it might get a taper on it and then hook it to your fish to create a tapered end.

I don't recommend using jet line or conduit measuring tape to pull in your runs (the measuring tape is great to measure the precut your runs though).
I've had them cut in to the sweeps and get stuck in the pipes, and unless you pull perfectly vertical on the riser it will cut at the top of the pipe.
I use a fiber glass fish with a 12" cable leader to fish and pull most all my runs and if that wont pull in a run I use a piece of #12 thhn with some pulling lube, that is slicker than snot on a door knob as my grandfather would say.

tom

I too have been considering the possibilities. Since the PEX is quite stiff and the cut edge could get hung up in a joint. Just as you said, heat up the PEX slightly to provide better flexibility, trim or shield the cut ends and use both a push and pull with a clean conduit with possibly some water to lubricate the movement. I will install PEX into one of the conduits with the most bends on both the ｾ and 1- ｼ before pouring the slab to verify it will work. I don稚 want to find out after the slabs are poured that we can稚 get our water lines installed.
In your experience have you ever pulled PEX water lines through conduit?

 

[patrick_g]

If anyone has experience pulling PEX through conduit please provide your thoughts.

Well... when installing the PVC you want to put a good strong line through it to later use to pull a stronger line to use to pull the PEX.

OK, Too late? PVC is assembled? There are little electrician's "fluff balls" to which you attach light weight mono-filament line. You then use a shop vac's discharge side to blow the fluff ball through the PVC dragging the light weight mono-filament line behind it. once you have the little mono-filament in place you can pull in a more HD line to use to actually pull the PEX. You can use the same lubricant on the outside of the PEX (inside of the PVC) as is sold at all the big box stores for wire pulling. This stuff comes in quarts and larger and is a water based lubricant which will not harm the PEX or the PVC. Use it liberally.

Cut a few notches in the end of each PEX to accept the pulling line. I know this may seem a little complicated but it isn't and it works quite well. If the runs are quite short and the PEX is a very loose fit you may be able to just shove the PEX through the PVC, with or without lubricant depending on how hard it seems to be to shove it through.

I have done this also with flexible poly pipe as the conduit too. The above assumes no elbows in the PVC.

Pat

 

[patrick_g]

I don稚 want to find out after the slabs are poured that we can稚 get our water lines installed.
In your experience have you ever pulled PEX water lines through conduit?

If there are no 45 or 90 elbows and the PEX is not a tight fit, you should be able to pull it. DO USE LUBRICANT electrician's conduit lube available at most big box stores and electrical supply houses) on all but very short runs.

Heating the PEX at the end to taper it may work fine but cutting the PEX to give a finely tapered bevel to the end is fast and easy too. you want to cut some notches to accept the pulling cord (leader.) An electrician's steel fish taqpe will work OK as will the screw together fiber glass wands. I have used nylon rope with good success too.

It is virtually impossible to use too much lubricant and if somehow you are concerned with just leaving the lubricant in place then flush it with water as it is water soluble and easily washes right out after the pull is complete. I have pulled water lines and compressed air lines through both PVC water pipe and the grey PVC non-metallic conduit.

So far my hardest water line job was for a friend/neighbor. It was removing a leaking copper tube from a continuous plastic chase tube in a concrete slab. It had some bends in it. I ended up using Channel locks to grip the copper tube and my tractor to pull it out. Replacing the copper with PEX was really easy even without lubricant (short run of 12-15 feet.)

It was the 2nd time I helped a friend replace a copper run with a pinhole using PEX. I will NEVER use copper again if I can help it.

Pat

 

[SamWalton]

If there are no 45 or 90 elbows and the PEX is not a tight fit, you should be able to pull it. DO USE LUBRICANT electrician's conduit lube available at most big box stores and electrical supply houses) on all but very short runs.

Heating the PEX at the end to taper it may work fine but cutting the PEX to give a finely tapered bevel to the end is fast and easy too. you want to cut some notches to accept the pulling cord (leader.) An electrician's steel fish taqpe will work OK as will the screw together fiber glass wands. I have used nylon rope with good success too.

It is virtually impossible to use too much lubricant and if somehow you are concerned with just leaving the lubricant in place then flush it with water as it is water soluble and easily washes right out after the pull is complete. I have pulled water lines and compressed air lines through both PVC water pipe and the grey PVC non-metallic conduit.

So far my hardest water line job was for a friend/neighbor. It was removing a leaking copper tube from a continuous plastic chase tube in a concrete slab. It had some bends in it. I ended up using Channel locks to grip the copper tube and my tractor to pull it out. Replacing the copper with PEX was really easy even without lubricant (short run of 12-15 feet.)

It was the 2nd time I helped a friend replace a copper run with a pinhole using PEX. I will NEVER use copper again if I can help it.

Pat

We do have 90 elbows and some bends with our oven. We are installing 3/4" PEX in 1-1/4" conduit and 1/2" PEX in 3/4" conduit. Check out pictures.

 

[mjncad]

We do have 90 elbows and some bends with our oven. We are installing 3/4" PEX in 1-1/4" conduit and 1/2" PEX in 3/4" conduit. Check out pictures.

I'm guessing mind you that the 1/2" PEX in the 3/4" conduit will give you the most trouble due to the limited clearances. Please let us know how much trouble, if any it gives you. I would think 1" conduit would have been better for the 1/2" PEX

 

[tommu56]

In your experience have you ever pulled PEX water lines through conduit?

No never pulled pex but some load cell cable we use at work is tough to pull in.

the fiber glass fishes work the best dont runs when they get (and they will sooner or later)

I prefer the ideal 31-186 rapid pack the one on the right
make sure you get the rubber gripper to get a hold of the fish don't use any pliers like you can on steel fishes

Another thought is use a pulling grip (Chinese hand cuff) or some shielding off a large cable as a grip (that is what I usually use )

patrick_g
your comments are confusing
"If there are no 45 or 90 elbows and the PEX is not a tight fit, you should be able to pull it. DO USE LUBRICANT electrician's conduit lube available at most big box stores and electrical supply houses) on all but very short runs."

then

"It is virtually impossible to use too much lubricant and if somehow you are concerned with just leaving the lubricant in place then flush it with water as it is water soluble and easily washes right out after the pull is complete. I have pulled water lines and compressed air lines through both PVC water pipe and the grey PVC non-metallic conduit."


tom

 

[patrick_g]

patrick_g
your comments are confusing
"If there are no 45 or 90 elbows and the PEX is not a tight fit, you should be able to pull it. DO USE LUBRICANT electrician's conduit lube available at most big box stores and electrical supply houses) on all but very short runs."

then

"It is virtually impossible to use too much lubricant and if somehow you are concerned with just leaving the lubricant in place then flush it with water as it is water soluble and easily washes right out after the pull is complete. I have pulled water lines and compressed air lines through both PVC water pipe and the grey PVC non-metallic conduit."


tom

I guess I just don't see what is confusing... Please be more explicit, I will strive to disambiguate the information as best I can.

Fewer or no 45 or 90 elbows makes it easier. You can't use too much lubricant but you will reach diminishing returns where more isn't better. Yes, it can be flushed out with water. Again, what part confuses you?

Way better is poly pipe or similar NOT PVC Sched 40 for the chases. NO FITTINGS and all gentle bends. Schedule 40 PVC with elbows is lousy for this job.

Pat

 

[SamWalton]

I'm guessing mind you that the 1/2" PEX in the 3/4" conduit will give you the most trouble due to the limited clearances. Please let us know how much trouble, if any it gives you. I would think 1" conduit would have been better for the 1/2" PEX

These runs are limited to under six feet with two 90 elbows at each end.

 

[patrick_g]

I don't get why anyone would run sched 40 PVC for a conduit for PEX. Is maintainability the issue? Pex can be run directly in concrete as can PVC but if you want to use PEX A N D be able to replace it then use an inexpensive continuous roll tubing and avoid all fittings in the "conduit."

This will make pulling the PEX way easier.

Pat

 

[SamWalton]

I don't get why anyone would run sched 40 PVC for a conduit for PEX. Is maintainability the issue? Pex can be run directly in concrete as can PVC but if you want to use PEX A N D be able to replace it then use an inexpensive continuous roll tubing and avoid all fittings in the "conduit."

This will make pulling the PEX way easier.

Pat

The conduit is better because you can get bends to land inside walls and it will allow replacement of failed PEX in future.