Straightening Pex tubing

[AlanB]

So I am doing my shop air with PEX. Have worked with the 1/2" stuff and found it extremely friendly but wanted to go to 3/4" on the air for more feed.

So I picked up the coil and started to unroll it and oh, my gosh this is the stiffest stuff I have ever seen. Brought it down in the basement hoping a little warmth may help but it is still unreasonably stiff to straighten out.

I am thinking some form of box with a small heater in front of it, or a hair dryer to get some pliability into this stuff.

Anyone else have some suggestions as to how to get it to lay flat or straight?

Thanks.

 

[Robert_in_NY]

Is it aqua pex or the Watts style pex with the crimps? Aqua pex will work easily with heat to straighten out. The Watts style pex is something that you just need to fight and as you unroll it against a wall or rafters you need to anchor it very often to hold it straight. Depending on your lengths between disconnects you can buy some pex in straight lengths.

 

[AlanB]

Is it aqua pex or the Watts style pex with the crimps? Aqua pex will work easily with heat to straighten out. The Watts style pex is something that you just need to fight and as you unroll it against a wall or rafters you need to anchor it very often to hold it straight. Depending on your lengths between disconnects you can buy some pex in straight lengths.

I think it would be aqua Pex. It is the water line style pex, or standard pex, made by Sharkbite, that Home Depot is now carrying.

I tried a small piece with hair dryer and it seems to work, think a hotbox and a small heater are in the future. Probably have to wait till tomorrow, SWMBO will convince me of the error of my ways if I work too much on Christmas.

 

[Robert_in_NY]

Aqua pex is clear and uses collars and an expansion tool instead of crimps for attaching to fittings. If the pex is warm it will be easier to with, I just don't know how that pex will react to extreme heat so you might want to check with the manufacturers website first.

 

[kennyd]

Is this rated for air pressure use?

 

[wdchyd]

Is this rated for air pressure use?

I was wondering the same.....is it safe ?......(I use type L copper)

 

[CurlyDave]

Is this rated for air pressure use?

I don't know if PEX is rated for air pressure use, but it is certainly rated for leak testing with air pressure, and page 39 of this presentation http://www.plasticpipe.org/pdf/pex_pipes_for_plumbing.pdf claims that it is both ductile and does not throw shards when it bursts.

I would still prefer metal or rubber lines, but PEX seems to be a reasonable candidate for use with air pressure.

If I had the option, I would go with the genuine Aqua PEX (Wirsbo Uponor) material instead of what they sell at Home Depot.

I have heated the white (uncolored) material with a heat gun until it turns clear and rubbery, which should remove the residual curvature, but this would be tedious for any reasonable length of 3/4" material.

 

[hr3]

What about hot water?? Take it to your basement hook it up to your water heater let the water run down your floor drain.. ??? Be careful when using plastics with compressors.. A friend of mine used plastic airlines,, "that were made for air" but after a few years the oil from the compressor broke down the glue.. :confused2:

 

[Robert_in_NY]

What about hot water?? Take it to your basement hook it up to your water heater let the water run down your floor drain.. ??? Be careful when using plastics with compressors.. A friend of mine used plastic airlines,, "that were made for air" but after a few years the oil from the compressor broke down the glue.. :confused2:

Pex systems does not use any glue. They use plastic collars that you expand and slide over the fitting to compress down (Aqua pex), crimps (Watts Pex) and push in connectors (Sharkbite). Those are the three I have experience with and know about.

 

[studor]

The hot water and heat gun both work -- so does unrolling it in a warm room and weighting the ends. Like everything, too much of a good thing can be bad and watch for overheating. Based on no actual facts , I think the PEX should hold up as well as copper or better for air

 

[heehaw]

i am curious why pex has got so popular for things like this, an water lines, when pvc for sure is cheaper, an maybe cpvc?
heehaw

 

[Robert_in_NY]

i am curious why pex has got so popular for things like this, an water lines, when pvc for sure is cheaper, an maybe cpvc?
heehaw

Pex is flexible and is so easy to install, just run the line to where you want, snip it off and a couple crimps or collars and its done. It only takes about 1/4 of the time of CPVC and 1/10 of the time of copper. Also, if the lines freeze pex will expand and is less likely to rupture then Cpvc or copper.

 

[simonds]

If you have to buy more you should buy the straight 20 ft. long pcs. It is so much easier to work with and does a nice neat looking job. Also they tell me that you cannot use pvc for hot water. Only cold.
Clayton

 

[KWentling]

i am curious why pex has got so popular for things like this, an water lines, when pvc for sure is cheaper, an maybe cpvc?
heehaw

Because pvc is brittle, especially when aged, and when it fails with compressed air or gasses, it send shards long distances. We had this happen to a 1" line @ 110 psi where I work. Pretty impressive. Glad no one was working in that area. Never use pvc for compressible air or gasses. There is a lot of stored energy there. When pvc fails with a liquid, you have a leak. When it fails with compressible air or gas, you have pretty close to a bomb.

Kim

 

[wdchyd]

I was wondering the same.....is it safe ?......(I use type L copper)

Kwentling,

I'm all for new stuff, but leary of the easy way out..

 

[wdchyd]

How about PEX & PVC in heat/fire conditions..?? is this a potential bomb also

 

[studor]

Big difference between PEX and PVC -- PVC is best used for central vacuums and drains -- does not even make good blade edge on a snow blade

 

[AlanB]

I chose pex because of it's low cost and ease of installation, minimum # of joints and fittings required.

I have worked in many shops with PVC airlines, and seen some rupture, and it just is not pretty. While there could be a failure with PEX, (as with any system) I do not believe it has the potential to shatter like PVC does.

I am using what this website calls the "standard Connection method"
PEX Information

While many folks refer to Sharkbite as the type of connector that grabs multiple different pipe, it is actually a brand, kind of like so many of us have "crescent" wrenches in our toolbox made by Craftsman.

I did not know the PEX came in straight lengths, had never noticed it before and will look at that tomorrow.

Current thoughts are a hotbox, and some clamps and go to town running it along the wall, but if I can readily find the straight lengths, that may be a better idea.

The one problem I see is noted on the front of the website above "PEX tubing does not transfer heat as readily as copper, and so conserves energy." what this means in my application though is that the moisture won't drop out as well either. On my drop leg for my plasma, I am going to put in a 1/2" drop of copper about 5' long with a drain at the bottom. Don't know if I need to or it will be enough, but think it is a good compromise for what I am doing.

I like the hot water idea, may have to try that one, and my heater needs to be flushed anyway.

When using it to run water to my dad's trailer was it nice, just a joint at each end, across the ceilings, through the pipes, under ground and down and up walls and no place to leak. Simple clamping up in a hole under the trailer that I would have absolutely hated to reach into with a torch to solder. Really sold me on the stuff, then once you bought the tool, the rest is competitively priced.

Oh, and I picked up a Zurn 3/4" standard crimp tool new from HD for $14 because they were changing brands. Gotta love that.

 

[KWentling]

Kwentling,

I'm all for new stuff, but leary of the easy way out..

I have heard of PEX being used this way and I expect it is all right. Would be easier alright.

Kim

 

[Kays Supply]

I installed PEX air lines in a dentist office several years ago. It has worked perfectly. One advantage, is no gritt or scale from the lines. I am planning a garage job in the near future. I am going to use the blue PE pipe under the slab for air. It is rated for slightly higher pressure than PEX. It uses the same fittings , and sleeves.