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Water system spray

Posted: Mon Jun 15, 2009 4:47 pm
by Quetzalsailor
As Chris noted, there indeed was a nasty discovery the next morning. I filled the 110gal water tank, turned on the pressure pump, found the valves that I'd left open when I'd winterized, closed 'em, watched the pink stuff come out of the faucet and then wondered why the pump did not cycle off. Opened the engine compartment to see water spraying all around. A valve had split, either out of sheer cussedness or out of faulty winterizing. That was the source of the drip noted while I was pouring sweat over the transmission.

I had replumbed the boat in my first spring fitout. I used the Despots' finest CPVC tubing and ball valves, made copper adapters for the transition between 1/2" CPVC and the 1cm copper of the faucets and water tank dip tube. I arranged the system so that I could isolate and drain the 5 gal HWH and readily charge only the water supply and pump with antifreeze. I preassembled as much of the system as possible and 'slipped' it into the space under the galley sink. Needess to say, the failed valve is closely surrounded by other fittings and valves but precious little pipe. It will be possible to replace the one faulty valve by cutting out two valves, a tee and some pipe and I'll have enough room for new couplings.

This is pretty unsuitable, that is, not being able to change out failed components; I had already broken another valve by trying to turn it against its stops (can't see it and happily it was on the Gusher and was in the correct position to be ignored).

So, I don't want to do the traditional hoses, fittings and clamps: too many in horrible places. I'm thinking about replacing the whole shebang piecemeal using PEX and Probite( http://www.probite.com/push-to-connect- ... oducts.htm ) or Watts Quick-connect ( http://www.watts.com/pro/whatsnew/whats ... nnect2.asp ). Comments? Issues, besides the bother, are cost and fatigue failure. The CPVC is tougher than PVC and is temperature tolerant. The PEX should be better than the CPVC. One negative of the CPVC is that the fittings do not come in the 'correct', useful angles I need so I used a hot air gun to make my own bends. The PEX should bend as needed and save fittings.

It wasn't on the list for this spring!

Re: Water system spray

Posted: Mon Jun 15, 2009 5:47 pm
by Hirilondë
PEX is top shelf for pressurized water systems. Do you have access to the flaring tool?

Re: Water system spray

Posted: Mon Jun 15, 2009 5:53 pm
by bcooke
I have used Pex/Watts type of push on fittings in high tech industrial applications. Seems to work okay. Occasional leak with a new connection but easy to rectify.

I am a little turned off of CPVC myself since I have run into issues with the pipe to hose connections not fitting the hose very well. That and I don't find straight runs to be as long or as space saving as I thought they would. I lean towards suffering with the old dependable hose and AWAB hose clamps but the push on's are tempting. I just don't have enough long term experience with them. My experience was in initial building of new machinery that only had a lifespan of about five years and I never got into the maintenance side of the operation anyway.

Re: Water system spray

Posted: Mon Jun 15, 2009 8:32 pm
by Chris Campbell
Aargh. Remove all of it and go back to foot pumps?

Re: Water system spray

Posted: Tue Jun 16, 2009 7:54 am
by Tim
I used PEX when I built my house 3 years ago. Being a good stubborn Yankee who had always used sweated copper, I was a bit skeptical, and it took me a while to warm up to installing the stuff, but there's no doubt I would use it again. It is quick and simple and inexpensive, and because the tubing bends so well (there are limits, of course) you can eliminate all the fittings except end fittings, which is great for limiting (or eliminating) leak potential.

I installed each supply as a "home run" type, with a dedicated hot and cold line to each fixture from a main manifold that I built--therefore, no connections hidden in impossible places, like inside walls. I would try to do this on a boat, too, though it means more tubing and clutter--but I think the benefits outweigh the negatives.

Houses aren't boats, of course, but nonetheless I would (and will) seriously consider appropriate PEX tubing and end fittings when plumbing any boat in any future situation that dictates it. The tubing itself is nearly indestructible (other than by excess heat or flame), and has now been in solid, well-respected use shoreside for many years. Few people who have ever used it would say anything but positive comments.

Re: Water system spray

Posted: Tue Jun 16, 2009 10:34 am
by Oscar
I ran H2O out to my workshop using PEX and love it. I strongly echoe Tim's sentiment to NOT hide any connections. I had one connection that developed a drip. Of course it was my own fault as I had failed to properly remove the extrusion ridge that was present. But had it been hidden I would have not found it or been able to repair it.

Re: Water system spray

Posted: Thu Jun 18, 2009 9:37 am
by Quetzalsailor
I, too, much prefer sweated copper in the house, and have replaced much of the supply plumbing over the last 15 years. My parent's house was built in 1955 with well-supplied water and, of course, copper. The well water contains manganese (!) and chews pinholes in the copper in about 40 years. They've replaced and patched since then, usually in copper but these days in CPVC. The well water is hard and corrosive enough to destroy faucets in about 10 years.

So, my question is: I wonder how well the (I presume) brass snap-on fittings do over time? Tims' insistence in keeping the fittings out of concealed spaces is tough enough in a house, but pretty much impossible on a boat. Of course, the cast fittings for sweated copper are brass, too.

The original copper on Quetzal was badly corroded. Very little is now left. Interestingly, the lazarette lids have copper drains glassed into the gutters (!) and I can only dread the inevitable replacement; they're corroded where the glass is lapped onto the copper.

Re: Water system spray

Posted: Thu Jun 18, 2009 11:09 am
by Oscar
I'm the opposite......on a boat the added electrolytic aspect almost mandates a "plastic" of sorts. Also the flexible nature would allow the hidden runs to be solid, and the connections to be accessible.

Re: Water system spray

Posted: Fri Jun 19, 2009 7:30 am
by Tim
I don't think it's impossible at all to keep fittings out of concealed spaces on board (or in a house). But it does require perhaps a different approach to the installation, an approach that will pay benefits for years to come but might be different from that to which you are accustomed.

I haven't looked into the various fittings available for (or applicable to) use on board with PEX, so I can't comment on any of that at this time. I'm only pointing out that using this newer material requires rethinking the whole job to better suit its pros and cons. Don't try and force the installation into your known and comfortable methodology. It requires a different approach than "traditional" methods, and this can be hard to get one's head around--until you've done it once.

Re: Water system spray

Posted: Fri Jun 19, 2009 12:50 pm
by Oscar
Thinking about this, I would probably have a number of distribution manifolds in accessible locations, and run non-stop lines from there to each outlet. Compared to copper the tube is cheap, you can run extra, in bundles if needed.

Re: Water system spray

Posted: Mon Jun 22, 2009 8:40 am
by Quetzalsailor
Done. Split valve: the thing split along the parting line in the mould; perhaps that was where the plastic came together during the moulding process. The internal pressure caused by the seals on the ball split the valve; there would not have been much water at that place: dry on once side, the ball, and the relatively short distance to the place where it's certain that the water was purged during winterizing. The tube glued into the socket was not split.

Replacing the whole system is hereby deferred...until the next failure. Now, there really is very little pipe and nearly all fittings.

I used the 3/4-round saw blade in the Fein. It zipped through the tubing very quickly and neatly, did not shake things much. I had Sue hold a wood block behind the cut so that other nearby objects were not harmed. She also held the gluepot where I could reach it quickly (under the sink), since I had to cement and assemble three fittings at once.