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PEX Crimps

PostPosted: Thu Jan 10, 2013 10:28 am
by DTCOOPER
Trying to plumb my CTC using PEX. I bought one of the 100 dollar crimper kits from Lowes.. I'm going fresh tank,water heater, kitchen sink, indoor shower, outside shower, toilet.. Anyhow, I'm having troubles getting the crimps to crimp without leaking.. I have "Calibrated" the crimpers a few times. And I'm using the "pro" crimp rings.. Any suggestions or tips/tricks for an easy, foolproof seal? :thinking:

Re: PEX Crimps

PostPosted: Thu Jan 10, 2013 11:30 am
by bobhenry
I investigated using pex and asked the boys at my little plumbing shop about it. They will loan out the crimp tools with a deposit, so there was no need to invest in tooling.

After weighing the pros and cons I have all but convinced myself to use galvanized steel piping. No worry about an errant screw or nail and no worries about a crimp letting go after being sealed in the wall.

I do not have more than 8 feet of run for the hot and about the same for the cold so weight is not a killer issue in my tiny house build. So I am probably gonna kick it old school and hard plumb with steel pipe.

Re: PEX Crimps

PostPosted: Thu Jan 10, 2013 5:19 pm
by Shadow Catcher
I had to do some re plumbing in CR and not wanting to buy a crimper and clearance would have made some of the joints impossible to make so I went with SharkBite fittings, not cheap but removable and seem to be leak proof.

Re: PEX Crimps

PostPosted: Thu Jan 10, 2013 7:16 pm
by 48Rob
I had to do some re plumbing in CR and not wanting to buy a crimper and clearance would have made some of the joints impossible to make so I went with SharkBite fittings, not cheap but removable and seem to be leak proof.


Probably a good choice.
I prefer the pex/quest mechanical fittings.

Pex crimps are okay, but can fail if the lines freeze as the water freezing expands and loosens the crimps.
I've seen a lot of damage over the years to homes plumbed with crimp fittings where a line/fitting froze, then thawed and relaxed (spewing water) while the homeowner was at work/sleeping, etc...

Rob

Re: PEX Crimps

PostPosted: Thu Jan 10, 2013 8:30 pm
by bdosborn
Thanks for the heads up Rob. I've got pex crimps in my trailer but luckily only in areas where it doesn't freeze or will be drained if it ever does. Thank goodness, our garage doesn't freeze! The only thing I learned from using the crimp tool was to make sure you can get the tool in where you need to make crimps. I had one under the sink that I screwed up because I just couldn't get the tool in the small space where the crimp lived.

Is freezing a problem with the Shark bite pex fittings?

Bruce

Re: PEX Crimps

PostPosted: Fri Jan 11, 2013 2:00 am
by Bogo
I haven't used the crimps yet. I plumbed my house using these fittings from FarmTek, and their orange PEX pipe. They tighten down using regular wrenches. This was before the big box stores handled PEX tubing.

http://www.farmtek.com/farm/supplies/cat1;ft1_plumbing_accessories-ft1_tekcoil_radiant_coil_14;ft1_tekcoil_orange_fittings_14.html

On a RV I'd use a FDA approved 3/8" high pressure and temperature braided hose for most of the water lines. Where they go through the walls I'd run them through their own electrical conduits. That way they can be replaced if needed. For the connections I'd use regular brass hose barb fittings with double band clamps on each barb. That way if one fails, the other will continue to hold. For the main water inlet, I'd use a pressure regulator to lower the supply pressure to around 50PSI. The stuff can be worked using standard tools in most tool boxes.

This is the type of braided hose I'm thinking of, but I don't know if this one will handle hot water.
http://www.farmtek.com/farm/supplies/prod1;ft1_plumbing_accessories-ft1_bulk_hose;pgwf1050_WF1060.html

Re: PEX Crimps

PostPosted: Fri Jan 11, 2013 8:35 am
by 48Rob
The new pex don't explode in the cold anymore, you must be talking about the white lines from years ago.


Mr. Busy,

I didn't say the Pex exploded.

Water freezes in the lines and expands.
When the water expands, the pipe (tubing) and in turn the crimp band expands, causing it to become loose on the pipe and fitting.
When it becomes loose, it can leak.

There were issues years ago with gray pipe failing (Polybutylene) though 99% of the failures I dealt with were from the crimps failing, not fom compromised pipe or fittings.
Didn't seem to matter much to the lawyers though, one they hand their fingers in the pie, any failure was the pipes fault...

The makeup of the clamps seems to have changed over the years, with the modern version being more resistant to changes in hot/cold- expansion/contraction, which caused a majority of the issues.
However, this still happens today, pointing to the vulnerability of a compressed band clamp when faced with freezing water.

Rob

Re: PEX Crimps

PostPosted: Fri Jan 11, 2013 8:51 am
by 48Rob
Is freezing a problem with the Shark bite pex fittings?

Bruce



Bruce,

Freezing is an issue with any pipe/fitting.

Copper tube will swell and split.
Brass fittings will split.
Crimps will expand.
Shark bite fittings will crack.
Quest fittings will crack.
Freezing water in a contained space is a very powerful force.

Some materials are more flexible/resiliant than others, but it is far better to avoid having water freeze in a line.
I prefer and use Quest mechanical/compression fittings.

Image

Along with Quest/Pex line, they fare a little better than copper tube, being able to expand somewhat without breaking.

The general idea though is that if damage occurs, I want to know about it right away, on the first water check of the season.
If a line or fitting is cracked, water will appear where it shouldn't be and you can make repairs.
With a loose crimp, it may not leak right away, leading you to believe all is fine, and giving you a nasty surprise when least expected.

Rob

Re: PEX Crimps

PostPosted: Fri Jan 11, 2013 10:10 am
by Shadow Catcher
We have not hit really cold temps this winter, I think the lowest is about 15F. When I parked CR for the winter I blew out the lines with compressed air and part of the re plumbing was to install a valve and fitting so that I can pull RV antifreeze through the pump and into the lines with out having to add it to the fresh water tank. I also went with tygon tubing on the pump goesinta and goesouta to try and reduce pump vibration/noise.

Re: PEX Crimps

PostPosted: Fri Jan 11, 2013 11:17 am
by Bogo
We have exposed water lines on the farm. They freeze thaw every winter. The piping is black plastic water piping that comes in rolls and is 1-1/4" diameter. It is flexible and will easily handle freezing. For fittings I use machined brass ones only. Plastic fittings break. When I install a fitting, I push the pipe on the hose barbs but leave the center part of the fitting bare, then I clamp with two worm gear clamps. I figure the water in the fitting first starts to freeze in the center of the fitting first due to the metal conducting the heat out. The freezing area expands out from there to the ends, and no pressure is built up inside the fitting. All the excess water is pushed out the ends into the expandable pipe. Now these fittings are 1-1/4" so are relatively large so they would easily first freeze at the metal surface. Also the plastic piping is not as good of heat conductor so the water in it freezes slower too. In combination that saves the fitting. With smaller diameter fittings like 3/8" and 1/2" it may not work as well or reliably, but may be worth a try. I'd have the middle of the fitting exposed to free moving air for a length of around 3/4th to the full diameter of the fitting, no more.

On valves, we don't put them in the above ground lines except at the head ends of lines or where they can be drained. I don't know of any valves that are freeze safe. At the head end of a group of lines is a buried valve that is drain back. At the top of the pipe coming out of the ground is an air inlet valve, then a valve for each line. The air inlet valve is there to allow the lines to be drained as best possible, and to allow the drain back valve to work. Stock tank valves are removed every winter.

Re: PEX Crimps

PostPosted: Fri Jan 11, 2013 11:46 am
by 48Rob
Rob, get your facts straight, the new pes doesn't burst when frozen. The old pex that you maybe using will crack and leak in the cold.
I've been doing this for years and I've seen it all and I have my plumbers that know their stuff with years of installs and education.
Here in Canada it's frowned on to use shark fittings as they're crap and leak. Also it's illegal to install them behind walls.
Also it's bixie not busy, clean your glasses


My glasses are fine.

My facts are quite straight.

Please re-read all my responses.
I did not suggest anyone use shark fittings, or use them in a wall.

Once again, I pointed out that the crimp ring can stretch if water freezes in a pipe under it.

I've been doing professional home repair, including plumbing for 35 years.
I may not be an expert like you, but I stand behind the help I offer on the boards.

I'm not interested in arguing with you.
As always, I am quite willing to admit fault if it can be proven.

Have a nice day.

Rob

Re: PEX Crimps

PostPosted: Fri Jan 11, 2013 6:00 pm
by bdosborn
48Rob wrote:
Freezing is an issue with any pipe/fitting.



Rob,

Thanks. I went with PEX since it's so much easier to work with than copper (way cheaper too) and thought It offered some measure of freeze protection. The reality is I always drain the water out of the camper anyways when I put it to bed for the winter and as I mentioned, it doesn't freeze in our garage. I'll make sure and check the tubing joints if it ever freezes inside and there's water in the system.

Bruce

Re: PEX Crimps

PostPosted: Fri Jan 11, 2013 6:25 pm
by Wanna Be
The fittings from HE**

I WILL NOT use them again !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


Wanna Be

;) ;)

Re: PEX Crimps

PostPosted: Fri Jan 11, 2013 6:49 pm
by 48Rob
I went with PEX since it's so much easier to work with than copper (way cheaper too) and thought It offered some measure of freeze protection.


Hi Bruce,


Your thoughts are the same as many in the field.

Copper is a good water pipe material, but is quite expensive these days, and though it can take some swelling from freezing, it is not resilient.
Once it stretches, it doesn't go back
It is well known in the mobile home and RV arenas that flexible plastic pipe holds up better to freezing than copper and rigid pipe because it is resilient to a degree.

Winterizing is of course the best bet with an RV, but there are times when plumbing that is "in use" can and does freeze.
Areas such as water heaters on an outside wall, or bathtub plumbing that is too far from a good heat source coupled with wind and below freezing temps will make a homeowner glad that the plumbing can take a little abuse without breaking.
It is not designed for that purpose, and shouldn't be counted on to endure repeated cycles, but it is a good option. :thumbsup:

Rob

Re: PEX Crimps

PostPosted: Fri Jan 11, 2013 7:57 pm
by bdosborn
So you know the crimp I said I messed up under the sink? I fixed it by making a stainless steel wire clamp with a Clamp Tie tool. Worked like a charm and its still dry today. I threw it in the trailer just in case I ever need to fix a leak.

http://www.clamptitetools.com/

Image

Bruce