Advice on connecting a freshwater pipe

[PatrickG]

On a recent overnight passage our hot water heater's fresh water out line came unmoored. I tried simply to hook it back up, and tightened the two ring clamps (in opposing directions) as tightly as I could. Unfortunately the line is under pressure, and despite seeming quite tight, within a few hours it has slipped off the nozzle again.

The brass nozzle connector is the type which should be easy to clamp a hose to, but on the other hand it looks like years and use have smoothed it somewhat, maybe reducing its effectiveness.

Any good advice for achieving a non-slip join between nozzle and hose? Picture attached, in which you can also see the hose and clamps in question. Thanks for all input!

Cheers,
Patrick

[Tellie]

That looks like 15MM pex pipe that has been rigged with some sort of insert. My advice is to change the fitting out to the proper Pex fitting and get ride of the bronze fitting.

I don't like the kinked over one down at the bottom either.

[David M]

Replace the existing nipple with a nipple with sharper ribbing. Example: http://www.westmarine.com/buy/west-m...le--P013854864 or the same thing in plastic.

Cut the hose back a few inches to where hose has never had a nipple inserted into it. If there is not enough length to do this then replace the hose.

Double clamp and use this type of hose clamp...http://www.westmarine.com/buy/aba-of...11_333_002_002 and not this type of hose clamp..http://www.westmarine.com/buy/breeze...ly--P011140324 Notice the band is pressed and not cut. Do not buy these at a home store where you may not get an all stainless steel hose clamp.

[donradcliffe]

Consider that your problem may be high pressure. When you heat water it expands, and if there is no place for it to go, the pressure can build up until something lets go, like your hose. In a boat hot water system, there is usually a check valve before the hot water heater which prevents back flow into the cold water side. There should also be a pressure relief valve on the water heater which opens if the pressure gets too high and dumps a little water into the bilge. If you don't have a pressure relief valve and you motored all night, the hose could have been the first thing to go.

[Cheechako]

It looks to me like that hose is too big for the fitting. There is goop all over the joint. I would replace that fitting.... some brass barbs are better at gripping than others/ marginal on fitting tight in the hose. Not an uncommon scenario at all by the way. I cant tell for sure but that barb doesn't look very "grippy".

[Tellie]

Use the right fitting when using 15MM. This fix is ten minutes and almost too easy done the right way.

http://www.defender.com/product3.jsp...3592&id=826047


www.HaldenMarineService.com

[PatrickG]

Many thanks for the great advice, all. And I never knew water expands when heated - should have paid better attention in science class. We're on the island of Naxos in Greece at the moment, so will have to keep fingers crossed we can find the right fittings in the few small chandleries here, but will give this a shot now. Thanks again!

[jwcolby54]

Originally Posted by donradcliffe

Consider that your problem may be high pressure. When you heat water it expands, and if there is no place for it to go, the pressure can build up until something lets go, like your hose. In a boat hot water system, there is usually a check valve before the hot water heater which prevents back flow into the cold water side. There should also be a pressure relief valve on the water heater which opens if the pressure gets too high and dumps a little water into the bilge. If you don't have a pressure relief valve and you motored all night, the hose could have been the first thing to go.

This is true. In your house you will find a little blue air tank with an air bladder in it. It allows the expansion to push water into this little tank, against the air bladder, compressing the air in the tank. Thus the system can "breath" as the pressure increases and decreases.

These things can be bought at home depot or Lowes.

Shop Utilitech 2-Gallon Expansion Pressure Tank at Lowes.com

[David M]

Water expands very very minimally when heated. The hose surrounding the water also expands when heated. That is not your problem. The problem is a relatively smooth hose barb and inadequate hose clamps that do not squeeze down hard enough. It's a very simple fix.

[Moontide]

One other piece of info. If the hose slips on easily over the pipe it is too big. Especially with barbed fittings you should have to work the hose on. Sometimes even need to soak it in hot water to soften it enough to let it expand a little to fit over the fitting. A hose a little too small is way better than one a little too big.

[Stemci]

You might be able to find John Guest pex push fittings where you are, as they are large mfg in Europe . Also , you might want to consider replacing that section of pex for piece of mind.


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[Cadence]

[QUOTE=PatrickG;1877191]On a recent overnight passage our hot water heater's fresh water out line came unmoored. I tried simply to hook it back up, and tightened the two ring clamps (in opposing directions) as tightly as I could. Unfortunately the line is under pressure, and despite seeming quite tight, within a few hours it has slipped off the nozzle again.

The brass nozzle connector is the type which should be easy to clamp a hose to, but on the other hand it looks like years and use have smoothed it somewhat, maybe reducing its effectiveness.

Any good advice for achieving a non-slip join between nozzle and hose? Picture attached, in which you can also see the hose and clamps in question. Thanks for all input!

Cheers,
Patrick[/QUOTE

You might try using a pex crimp if you can borrow a crimper.

[Wulf]

Is that second clamp (the one furthest from the end) actually fully on the fitting? Hard to tell from the picture but looks like it may be partially or completely off the fitting which would cause it to pull the hose off rather than clamping it. Also IMO those clamps are too large for the hose size. You should always try to match clamp diameter to hose diameter for best fit & performance....not to mention less chance of slicing yourself when working in the area.

[svlamorocha]

Originally Posted by PatrickG

Many thanks for the great advice, all. And I never knew water expands when heated - should have paid better attention in science class. We're on the island of Naxos in Greece at the moment, so will have to keep fingers crossed we can find the right fittings in the few small chandleries here, but will give this a shot now. Thanks again!

Much of the advice above is based on conflicting assumptions about the type of hose/tubing you have. Some posts are correct if you have PVC hose (which is not good for hot water) and other posts are correct if you have 15mm PE hose (which is good for hot water).

If you want to get useful advice it will be better if you can share with us a photo of the hose showing the markings (letters/numbers) in the hose.

[Djarraluda]

I would also note caution on Moontide's comment. A hose that is too small may be forced on the fitting, especially with some heating, but then it "shrinks" back after the fitting. This becomes a stress point and thus, potential to split or wear.
Match the correct hose type and size to the fitting, most plumbing supplies / hardware stores can help there.
Once the hose has been in place a few years, if it gets removed, best to cut the end and remake the joint rather than attempt to re-use the distorted end