Bending PEX with heat

[daddo]

This may not help you since it calls for a bender, but when running pex in this old house, I used copper on risers through areas under cabinets and other areas where the stray rodent may come in contact with the pipe. I needed to make a rather sharp bend that wouldn't kink and would be protected, so I did the following in the pics and it worked well (No room for the crimper either). These pics were of the test I did to make sure it would work, and no kinks.
 Making short copper pieces also makes a good place to use a clamp without contact with the pex. I used bees wax to lube any part (Clamp/hold down) that would rub during expansion- maybe not needed, but makes me feel better.


 The 1/2" pex fits perfectly snug in the 3/4" OD copper.





No kinks.

[TDKPE]

I appreciate all the suggestions, but I bit the bullet and bought crimper, cutter, some 90’s, two valves, and crimp clamps, and decided not to try to bend the stuff.  It was a royal pain to reach in there, which resulted in me messing up one clamp at the back-right nearest the heater (red), but I’ll test it tomorrow and hopefully it doesn’t leak.  It’ll be tough to cut it if it does, as I’ll have to reach in there with a Dremel tool and thin cutting wheel.  


Before:

   

After:

   

   

   

(Coulda’ done a better job vacuuming. 
 )

And daddo - that’s pretty slick. Reminds me of the little tube bending springs for toilet and sink supply lines.

[barnowl]

Very nicely done Tom.




All along, I was thinking of a three valve bypass.

[daddo]

Pex is so easy to work with. I piped ours so I can cut the water off to the entire house from the water heater closet in the hall. I can cut water to each section- bath, bath, kitchen, water heater, dishwasher, and so on. Now if something fails, I can shut it down and fix it when I get home and the rest of the house still functions.

[TDKPE]

Very nicely done Tom.




All along, I was thinking of a three valve bypass.

There's another method used in a lot of RVs, from what I've read at least, where a check valve is used at the water heater outlet, with a single diverter valve at the inlet to a plain tee at the outlet.  It does the same thing as the two valve method, only you turn just one valve to divert the flow before drawing in antifreeze.  Proper function depends on the check valve working properly, and since you have to add a tee rather than a second diverter, plus a check valve, I'm not sure it saves you any work or materials.  

Pex is so easy to work with. I piped ours so I can cut the water off to the entire house from the water heater closet in the hall. I can cut water to each section- bath, bath, kitchen, water heater, dishwasher, and so on. Now if something fails, I can shut it down and fix it when I get home and the rest of the house still functions.

I'm just unfamiliar with PEX, therefore I'm suspicious of it.  
  I'm used to copper plumbing with sweated joints.  I guess if I was a generation or two older, I'd be suspicious of PVC drain lines and think cast iron with poured lead is the best way to go, which is what all my houses up until this one had.  

[Stwood_]

Pex is pretty tough acording to plumbers I've talked to. Getting a hole rubbed in it is about mission impossible from what they say.

Speaking of plastic line, I've seen grooves rubbed in the tops of truck frames from plastic airlines rubbing on frames.
That's some tough plastic.

[Timberwolf]

I'm adding a pair of ball valves to the PEX plumbing in my little RV to bypass the Truma Combi water heater/space heater for winterizing.  Not supposed to put antifreeze in that unit, probably because it also provides hot air for heating the interior.

It's a really tight space where these valves will go, but I can get the crimper in there (one-handed style) to crimp the clamps.  But I'm severely limited in where I can actually put the valves unless I replumb the whole area, which I'm not about to do.  

It would help a bunch if I could put a little bit of permanent bend in the bypass tube I'm adding, so I don't have to use 90 degree fittings.  Is it possible to put a little bend in the tube with a heat gun, or will that compromise the tube?  I've never worked with PEX, so this is all new to me.  

At least it's a low pressure system.  

.............................
Tom, if the tubing wants to collapse when heated and bent, you could insert a door sppring inside it to prevent crimping, then remove when it cools.

[Timberwolf]

Pex is pretty tough acording to plumbers I've talked to. Getting a hole rubbed in it is about mission impossible from what they say.

Speaking of plastic line, I've seen grooves rubbed in the tops of truck frames from plastic airlines rubbing on frames.
That's some tough plastic.

...............................
Speaking of plastic line, I've seen grooves rubbed in the tops of truck frames from plastic airlines rubbing on frames.
That's some tough plastic.

That can happend due to vibration...The plastic become "embedded" with shap sand and wears away the steel as it vibrates.

[Robert Adams]

There's another method used in a lot of RVs, from what I've read at least, where a check valve is used at the water heater outlet, with a single diverter valve at the inlet to a plain tee at the outlet.  It does the same thing as the two valve method, only you turn just one valve to divert the flow before drawing in antifreeze.  Proper function depends on the check valve working properly, and since you have to add a tee rather than a second diverter, plus a check valve, I'm not sure it saves you any work or materials.  


I'm just unfamiliar with PEX, therefore I'm suspicious of it.  
  I'm used to copper plumbing with sweated joints.  I guess if I was a generation or two older, I'd be suspicious of PVC drain lines and think cast iron with poured lead is the best way to go, which is what all my houses up until this one had.  

            Pex has been around for about 40 years now and it's really good stuff. There are even tubings like it that are starting to replace copper linesets in HVAC. 

                As for copper.... If it was built in the last 20 ish years or so with copper I would be worried. There has been allot of houses built with poor quality copper tubing over that time. My parents neighbors were one of the unlucky that their house was built with the junk copper. They just spent thousands running all new cold and hot water lines in the house and the feed to the meter at the street. They had to run all the lines in the attic and then drop down into the walls where they had to tear off the drywall... 
               They had one large leak repaired shortly after they bought the house (new at the time). In the middle of the house and had to cut a large hole in the slab to get to it oh and I forgot the engineer consultation because it is a post tension slab as well. 

                Pex has proven very durable and without all those hundreds of soldered joints there are so few points of failure in pex since it is flexible. The number of failure points in pex is minuscule compared to copper. Also our water supply is unfriendly to copper which is often not thought about.

            Now the question is what is going to replace copper wire in the future seeing as we have replacements for other materials.

[TDKPE]

Well, I have a leak.  That one crimp that I know was improper, where the crimp tool jaws weren't angled square to the center of the tube.  Bent the clamp into a thin inverted "U" rather than a nice fat omega "Ω", so the tube isn't clamped as hard as it should be.  I can even see that it's not as compressed under the clamp in comparison with all the others.

I was going to cut it out with a Dremel tool and side cutter, but thought I'd give it a try.  Shoulda' gone with my instinct, of course.  Even the low pressure output of the pump made it squirt; good thing I didn't try city water pressure, which would have made a real mess.

   

   

It's really hard to judge how the tool is engaged with the clamp, and there's no room in there for a better look. Maybe I'll try some dry runs and use my phone to get pics from the side, before squeezing the handle and committing to the crimp.