Replacing old Poly stuff with PEX, have ?

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lisamaechilders
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Joined: Mon Dec 23, 2013 10:51 pm

Sat Oct 04, 2014 11:49 am

We are replacing the old polybutalane with PEX . The original installation is such: Hot water tank and main supply line come in at 1 end of the 70' trailer. It has a main run down the middle with supplies branching off for all the fixtures. Currently the main line drops down to 1/2" shortly after the hot water tank supply and main cold water supply. It then runs the length of the trailer to the bathroom at the other end on a 1/2" main line. At every supply branch the main trunk is 1/2".

I've read here several posts mentioning the main trunk line should be 3/4". Is this correct? Someone mentioned the reason it drops is to increase the pressure to get it all the way to the other end.... but it seems to me that the 1/2" main trunk size may be what is reducing the pressure at the other end.

Can anyone comment on this and suggest the best choice. 1/2" main trunk line or 3/4".


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Greg
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Sat Oct 04, 2014 12:04 pm

As long as you are replacing everything, I would go the 3/4" Main and 1/2" branch. You will have much better flow at faucets in the middle & far end. Cost difference should be minimal.

Remember to add shutoffs at every faucet as long as you are doing it. Don't buy the cheap plastic ones or stop valves, they fail when you need them the most. Brass or stainless Ball (1/4 turn) or gate valves are what you want.

Greg
"If I can't fix it, I can screw it up so bad no one else can either."

lisamaechilders
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Sat Oct 04, 2014 12:09 pm

yes... replacing everything. The old is brittle and has broken off when simply moved to look at something in 2 different places. The underbelly and floors are pretty open. So it all coming out. Shutoff valves already in plan.

lisamaechilders
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Sat Oct 04, 2014 12:09 pm

and yes thank-you 3/4" was what I was thinking. Just wanted to confirm.

bobfather99
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Mon Oct 06, 2014 12:04 am

Love those 1/4 turn valves.....easy to shutoff in an emergency.

I've done two homes in PEX, all used 3/4 for the main run and 1/2 for the branches, great results.
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jimncheryl
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Mon Oct 06, 2014 9:55 am

Try to use fittings that can be removed , replaced or adjusted if need be. Many fittings on the market must be cut off to replace which makes your tubing runs to short. Plan for the future by using fittings that can be removed with out much difficulty.
I have 2006 Karsten home, in 2012 and 2013 we had leaks in the factory fittings, some did major damage others we caught in time, but all the fittings had to be cut off to replace them making the
tubing runs to short causing us to add extensions to make the repairs complete. We have since replaced all of the factory fittings and now hope we don't have worry about water leaks any more. If a leak does start I can replace or fix it quickly without cutting the tubing.

Jim

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JD
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Wed Oct 08, 2014 10:41 am

The push fittings can get quite expensive when doing a whole home replumb. The reason for my post is different though. I have been plumbing homes for many years using PEx, with great results, until recently. If you have seen my posts, I tout the use of PEx and still do actually. But I wanted to let everyone know that I did a whole home replumb earlier this year, and have had two call backs for leaks. Both leaks were defects in the brass fittings, an actual hole corroded into the fittings. I am really worried about this. The fittings had discolored, turning a dark dull color, while unaffected fittings were still shiny brass. Since I bought these fittings at the beginning of this year, they should not be from the bad batch from many years ago, but that is exactly what it seems like. It seems like there was some inferior compounding of metals in manufacturing. So provided you don't get defective fittings, I still say PEx is the best choice, but I can no longer say 100% integrity of materials.
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All information and advice given is for entertainment and informational purposes only. The person doing the work is solely responsible to insure that their work complies with their local building code and OSHA safety regulations.

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Greg
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Wed Oct 08, 2014 6:10 pm

Who was the fitting manufacturer? Are they willing to stand behind them and offer up some type of compensation?

Greg
"If I can't fix it, I can screw it up so bad no one else can either."

jimncheryl
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Thu Oct 09, 2014 4:05 pm

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Greg
Not sure if your asking about the brass or plastic fittings?
The one caused all the damage in our home are the plastic type made by a company called Flairit

http://www.flairit.com/

They said they did not install them and can not be responsible, I understand this, they where installed by Karsten at the factory. Here are some pictures of the failed fittings, I have replaced all the fittings I could get at, still cheaper than repairing all the damage.

jpingram5
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Thu Oct 09, 2014 5:59 pm

There are a couple lawsuits against some the of the companies that make the brass fittings. I believe it is Zurn & Kitec. I had a bad experience using Sharkbite brand PEX tubing. I had it split on me in a house I did some re plumbing in. And it wasn't because it froze. I had sent a piece of it out to Sharkbite because they wanted to examine it to figure out what happened. PEX will have it's mishaps like everything else.

But these leaks like jimbcheryl posted above is why I like doing the "Homerun" style plumbing now. I redid my CPVC with PEX and used a manifold with homeruns. Works awesome!
2009 Skyline Sunwood Premier 14 x 80

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Greg
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Thu Oct 09, 2014 6:32 pm

I only use crimp type brass fittings. Lowes used to carry Zern, now they have Apollo (made in China) so Time will tell on those. It seems like there are problems with all the manufacturers, makes me wonder just how many makers there really are.

Greg
"If I can't fix it, I can screw it up so bad no one else can either."

ponch37300
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Fri Oct 10, 2014 9:01 am

I'm a little late to the party here but I will second the 3/4" PEX for the main run. 1/2" is too small and the thing with pex unlike copper is the fittings go on the inside of the tubing so the opening diameter gets even smaller at the fittings and restricts flow. 3/4" for mains and then use a 3/4x1/2x3/4" Tee and 1/2" pex for the branches going to the faucets and stuff. You have to remember there is a difference between water pressure and volume. Just because you have pressure doesn't mean you have good volume. You have to have an adequate diameter supply line to get get volume.

JPingram5 mentioned the other way to do it which is to run a 1/2" line back to a manifold where the supply comes in. This is a good way to do it and I have done it before in stick framed houses. But for MHs the 3/4" main and 1/2" supply lines are more economical and easier and good enough.

I've said it many times and maybe I'm going to jinx myself but I've never had a leak using pex and crimp rings. I love the stuff. I don't use "sharkbite" type fittings just because of the cost and I have a crimper already and if I would ever need to remove a fitting it's easy enough to do. If you replumb your house and put a good shut off valve at each fixture then that valve should last many years and the only thing you may have to change is the braided steel line going from the valve to the faucet. And if you would have to replace the valve you only loose an inch or so of pipe so the flex line going to faucet would still be plenty long enough. I'm a lot more confident in using crimp rings then in the sharkbite type fittings.

JD brings up a pretty big concern about the actual fittings leaking. There has been some problems over the years with this but I haven't heard about these issues in many years. This sounds like a bad manufacturing process or bad quality control. I guess this could happen with any type or style of fittings where you get a bad batch and lets hope it is a limited case. JD can you share the brand of fittings these were?

jimncheryl
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Joined: Fri Dec 20, 2013 1:12 pm

Fri Oct 10, 2014 2:04 pm

Here in beautiful Northern California some off the stores sell "Gator Grips and Gator Bytes and they are not approved for non access installations. They look just like Shark Bite but the quality is lacking. The plumbing code only allows Shark Bite fittings, I have only been able to find them at commercial plumbing only stores and yes they are costly but never had a failure yet "knock on wood" Makes me wonder if somebody knows somebody, you know follow the money.

jpingram5
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Tue Oct 14, 2014 8:59 pm

I prefer using the PEX Crimp Rings as well over any other style. Never had a problem unless I had the ring crimped on incorrectly but besides as long as you get it on right your good to go. Lowes came out with a One Hander Crimp Tool, like $70 I think it was but man, if you ever used the regular crimp tool to crimp a 3/4" or 1" ring that was above your head and you barely had any leverage.......you'd feel my pain. Expansion fittings for PEX? I worked with a plumber in new construction who would use nothing but the expansion fittings. No problems reported yet from him.....but I like my crimp rings.

Sharkbites, well I have one on my dads main water line coming in to the meter in his basement. It's been hold there for several years now. Was a great quick fix at 11:30 PM! Biggest thing is properly preparing the pipe. Deburr the pipes before using the sharkbite and you should be ok. I'd still feel funny burying one behind a wall. I used the sharkbites a little while back when I threw my tankless water heater in. Two of them on the H/C connections on the unit and then in the utility closet I used a few. All accessible though.
2009 Skyline Sunwood Premier 14 x 80

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JD
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Tue Oct 21, 2014 12:29 pm

These were Rifeng fittings which I bought from a company called PexSupply.com. They have now changed their name to SupplyHouse.com. I had used them for years with no issues and allowed me to buy very cheap in bulk. I presented the problem to them as well as a request for restitution. The very pleasant rep told me a supervisor would call me. It has been a couple of weeks and not call as of yet. I am pretty sure they will just ignore me until a law suit is presented and then they would probably kick my ass with money. I could get all into a rage over this, but frankly, I think all companies would do the same. My failure was trusting anything Chinese made. We have all come to a point where we want the lowest priced products, which I think is very short minded on a selfish level. What we get are dangerous products for our kids and families all while reducing jobs in the US as well as our economy.
☯JD♫
Today is PERFECT!

All information and advice given is for entertainment and informational purposes only. The person doing the work is solely responsible to insure that their work complies with their local building code and OSHA safety regulations.

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