Pressure water plumbing

Russell · Post by **Russell** » Dec 29th, '13, 17:19

I am thinking of replacing my pressure water (hot and cold) plumbing. The old polybutylene CD put in has become brittle with time and I am constantly repairing leaks, especially where hard bends are. Not going to be a fun project at all.

Wondering what people are using for replacement. I am leaning towards PEX.

mashenden · Post by **mashenden** » Dec 29th, '13, 17:35

PEX from a winterization perspective would be much better. Very forgiving to freezing - may not even need to winterize. My concern would be finding suitable connectors. My only experience with PEX connectors is with the type that are crimped with a metal ring. I'm not sure how resistant these rings would be to the salt air environment. That said, there may be non-metal options - dunno.

Russell · Post by **Russell** » Dec 29th, '13, 17:37

mashenden wrote:PEX from a winterization perspective would be much better. Very forgiving to freezing - may not even need to winterize. My concern would be finding suitable connectors. My only experience with PEX connectors is with the type that are crimped with a metal ring. I'm not sure how resistant these rings would be to the salt air environment. That said, there may be non-metal options - dunno.

There is all sorts of cool PEX interconnects out there, screw on compression fittings, push in fittings, etc. Mostly plastic with some SS. The available interconnects are what actually made me lean towards PEX.

Russell · Post by **Russell** » Dec 29th, '13, 17:43

Example of a brass, not plastic, intereconnect available for PEX:

http://www.sharkbite.com/

Example of the plastic push connect fittings:

http://www.freshwatersystems.com/c-500- ... tings.aspx

I think I prefer a proper compression fitting rather then push connect. I have my doubts as to push connect holding up to the constantly flexing and movement of a boat. PEX has so many connect options though which is what makes it appealing. Winterization is kinda a non issue with me, even the times i do get stuck someplace cold, its breif and my boat is heated.

mashenden · Post by **mashenden** » Dec 29th, '13, 17:58

Perfect. I would definitely go with this approach if it were me (barring any substantive search results to the contrary).

K Chiswell · Post by **K Chiswell** » Dec 29th, '13, 20:49

I'm glad you asked the question. I am also thinking about using Pex. The original pressure lines were run through my engine bed weldment and I cut them getting it out. I plumbed my entire house with Pex and it was far easier than any other plumbing I've used. I used the brass barbed fittings with crimp rings but might use the push in on the boat. The crimping tool takes a good bit of space to operate and I like the fact that the push in fittings can be reworked.

mashenden · Post by **mashenden** » Dec 30th, '13, 16:45

Since I'm sure I'll be crossing this bridge at some point, I did a bit more research. Pex seems to be a good choice.

There were some that expressed concerns about the push connect fittings being in an environment that had more vibration than a typical house application. The concern being that the teeth that hold the pipe in the connectors may work loose over time. I did not see any hard proof where that has actually happened, though.

There was a fair amount of positive feedback on using "Wirsbo/Uponor" brand. Apparently the connection is made by stretching the pipe a bit to insert the fitting, then the pipe shrinks back to size making a tight fit that is further secured with a compression fitting. This sounded ideal but the tool to stretch the pipe was expensive. I had to wonder if on a small scale it could be done with hot water and a wooden peg, though??

tjr818 · Post by **tjr818** » Dec 30th, '13, 16:52

mashenden wrote: ...There were some that expressed concerns about the push connect fittings being in an environment that had more vibration than a typical house application. The concern being that the teeth that hold the pipe in the connectors may work loose over time....

Couldn't we just add a hose clamp to be sure?

M. R. Bober · Post by **M. R. Bober** » Dec 30th, '13, 17:28

tjr818 wrote:
mashenden wrote: ...There were some that expressed concerns about the push connect fittings being in an environment that had more vibration than a typical house application. The concern being that the teeth that hold the pipe in the connectors may work loose over time....
Couldn't we just add a hose clamp to be sure?

No.

I had Wirsbro pipe in my old house. Good product for hot water subfloor heating systems. The the crimping tool was very expensive according to my plumber. The pipe does expand/contract enough that large radius bends are required (especially in unheated basements). The product is cloudy white in color and translucent. Brass manifolds were used at the connections. Plumber did a nice job. I think it would be difficult to run Wirsbro lines on a boat

Used PEX, with brass slide-on fittings when I added a water filter on STARVIEW. I used lots of clamps to prevent vibration of the fittings. So far (3 years) no leaks. Wirsbro is NOT PEX.

Mitchell Bober
Sunny Lancaster, (Where it's hot on the left.) VA

Russell · Post by **Russell** » Dec 30th, '13, 17:29

Whale makes a "marine" pressure water plumbing system, it uses push connect fittings. I am sure its just PEX marked up and labeled marine. But it does lend some confidence that push connect fittings can stand up to the environment of a boat.

Russell · Post by **Russell** » Dec 30th, '13, 17:50

More traditional collet with screw on collar type compression fittings for PEX:

http://www.ardipex.com/pex-fittings-compression.php

I would feel better using something like this, but would prefer plastic (kind of like the compression fittings CD used, I am sure someone makes something like that for PEX).

Russell · Post by **Russell** » Dec 30th, '13, 18:14

There is also the option of just using standard vinyl water hose, hose barb fittings and hose clamps, the stuff we use all over on boats. The pressure should not really be an issue, I use this stuff on my watermaker at up to 100 PSI and I looked and my house water pump is rated for 55 PSI. But you have the real issue of kinking, with as long as the hose runs are and all the odd bends that need to be made in hard to reach places, PEX wouldnt suffer that issue.

mashenden · Post by **mashenden** » Dec 30th, '13, 18:41

M. R. Bober wrote:.... Wirsbro is NOT PEX.

Mitchell Bober
Sunny Lancaster, (Where it's hot on the left.) VA

Good info - I was not aware that it is a different product altogether.

Russell wrote:Whale makes a "marine" pressure water plumbing system, it uses push connect fittings. I am sure its just PEX marked up and labeled marine. But it does lend some confidence that push connect fittings can stand up to the environment of a boat.

Sure seems like it.

mashenden · Post by **mashenden** » Dec 30th, '13, 18:47

tjr818 wrote:Couldn't we just add a hose clamp to be sure?

That was discussed on some other sites. Apparently the pressure applied by hose clamps does not approach the amount applied by the ring/tool often used on PEX, but then again our PSI is not as high either.

Knowing what I know now, if (when) it were me I'd use PEX and the brass fittings Russell posted (or comparable plastic connectors if they are found).

Steve Laume · Post by **Steve Laume** » Dec 30th, '13, 19:14

Raven has just about every type of plumbing there is. She originally had reinforced hose and grey compression fittings that screwed together. There is also some copper in the tank manifold which I redid to make things fit a bit better.

The clear reinforced hose comes from the water tanks and is not a bad choice for that application. there are not many fittings and it is all pretty much in the dark all the time so things growing in there is not a problem.

The grey stuff felt very secure but was sometimes hard to get to in order to tighten up the fittings. The old hose was also getting pretty stiff.

Most of the new stuff I did with PEX. It is easier to put together in in tight places but doesn't have the same feeling of security. I have had a whole bunch of it in place for a few years now and only ever had one problem. That was last year. I noticed that my pump was slowly cycling and just turned it off when not using water. Well of course I forgot about it one time and nearly drained one of my water tanks until I went below and checked the bilge. I was well on my way to Maine leaving from the CC canal and it was night time. I shut the pump off until morning and found the leaking joint. Where else would it be than under the cabin sole. The one thing I will say for PEX is that if you keep a selection of fittings and some hose on board it is very easy to fix.

I am sure it was my fault in the first place. Maybe not pushing the hose in far enough. The hose lengths are pretty critical when you have a whole mess of fittings close together but that is somewhat true for any type of fittings.

I would still use it again but you just want to be sure the tubing is fully inserted, Steve.

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