Fresh Water System

[Andrew_Trayfoot]

I need to do some work on my fresh water system as I have been surviving on Tesco Value Mineral Water all season!

I have a couple of problems:

1. I have leak in one of the following that slowly dumps then contents of the tank into the bilge.
The tank - Stainless steel Westerly original behind the engine pain to get out.
In the pipework.
In the foot pump in the galley.

2. I also have an old problem, that I have been ignoring for years, in that when then boat heals to port the water siphons through the pump on the heads sink and either into the sink, or into the bilge, depending on the angle of heel. To get around this problem the previous owner fitted an in-line ball valve in the pipe below the sink. The problem with that is the everyone forgets to turn it off.... as the hand pump is also broken I no longer use the heads sink.

So I obviously need to find the leak, but I think I need to refurbish the whole system.

I was thinking of going electric - yes I know it will use more water - and was looking at one of these:

http://www.ebay.co.uk/itm/381394780467?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

As it is not much more then a new galley foot pump.

My question is will the water siphon though it into the heads sink?
Or has anybody got any better ideas as to how to stop the siphoning problem.

 

[Yngmar]

I was thinking of going electric - yes I know it will use more water - and was looking at one of these:

http://www.ebay.co.uk/itm/381394780467?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

Good pumps - but do go for the Aqua King (marine) models rather than the Trailer King (RV) ones. The difference is that the marine ones have a full plastic casing, while the RV ones have galvanised steel which will rust. Flojet make an almost identical pump in case you need options. The pumps have an internal check valve and water will not flow back from the pump. They should be fitted with a pressure cylinder just after the pump - a small one about the size of the pump will do.

Here's my setup:

That's a tank selector valve, a small inline strainer, the pump, then the pressure cylinder and from there to a manifold that feeds the sinks/shower/calorifier.

 

[VicS]

I need to do some work on my fresh water system

I was thinking of going electric - yes I know it will use more water - and was looking at one of these:

http://www.ebay.co.uk/itm/381394780467?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT


My question is will the water siphon though it into the heads sink?
Or has anybody got any better ideas as to how to stop the siphoning problem.

It is diaphragm pump similar to your foot pump.
I would think it will most likely still allow the water to siphon.

A sprung check valve (nrv) in the pipe work between pump and galley outlet should stop it syphoning with this pump or a foot pump

 

[Kwik Decision]

A sprung check valve (nrv) in the pipe work between pump and galley outlet should stop it syphoning with this pump or a foot pump

As I read this, the problem is water flowing from the tank to the sink when the boat is heeled. A check valve (whether in the pump, or external) wont stop this, as the water is flowing in the direction you want it to, unless it has a sufficiently strong spring to resist the static head from the tank when heeled. If it does have a strong spring, this may have an adverse effect on the pump operation, depending on the head the pump can generate, and the actual strength of the spring.

We have the same problem on our boat, and have overcome it in the same way as the previous owner of the OPs boat did.....

 

[ghostlymoron]

The first thing you need to do is check that the tank is sound. Disconnect the outlet hose from the tank and fit a tempoary blank cap. Fill the tank and measure the water level. Leave it for a day or more and then re-check. Once you've done that you can turn your attention to the other problems. Perhaps fit a solenoid valve in the supply to the sink so it only opens when the tap is open?

 

[Plum]

Good pumps - but do go for the Aqua King (marine) models rather than the Trailer King (RV) ones. The difference is that the marine ones have a full plastic casing, while the RV ones have galvanised steel which will rust. Flojet make an almost identical pump in case you need options. The pumps have an internal check valve and water will not flow back from the pump. They should be fitted with a pressure cylinder just after the pump - a small one about the size of the pump will do.

Here's my setup:

That's a tank selector valve, a small inline strainer, the pump, then the pressure cylinder and from there to a manifold that feeds the sinks/shower/calorifier.

What a neat setup! Very impressed! With this arrangement the water is under pressure from the pump to the sink(s) so obviously you must have a tap at each outlet (just like you have at home). With the tap off there will be no syphoning problem that Andrew is getting. Good recommendation.

Colin. Www.solocoastalsailing.co.uk

 

[Yngmar]

What a neat setup! Very impressed! With this arrangement the water is under pressure from the pump to the sink(s) so obviously you must have a tap at each outlet (just like you have at home). With the tap off there will be no syphoning problem that Andrew is getting. Good recommendation.

Thanks. I believe this is (mostly) how Bavaria Yachts built it in 2000, I've just serviced the pump (after 15 years the membrane wanted renewing - motor and bearings still absolutely fine) and occasionally clean the filter. And yes, there are taps in head and galley. In fact, they're standard one-handled mixer taps, same as for domestic use - I've just replaced them with a pair from a recent Lidl sale (one tap was leaking and the chrome had tarnished a bit in the same 15 years). The whole setup is mounted fairly high up in the boat, some 80cm above the waterline (which is probably why it gets serviced regularly - no crawling needed).

 

[VicS]

As I read this, the problem is water flowing from the tank to the sink when the boat is heeled. A check valve (whether in the pump, or external) wont stop this, as the water is flowing in the direction you want it to, unless it has a sufficiently strong spring to resist the static head from the tank when heeled. If it does have a strong spring, this may have an adverse effect on the pump operation, depending on the head the pump can generate, and the actual strength of the spring.

We have the same problem on our boat, and have overcome it in the same way as the previous owner of the OPs boat did.....

Yes it will only need to be fairly lightly sprung.
Sufficiently strongly so to remain closed against the head pressure developed when heeled ( probably less than the equivalent of 2 psi) but obviously well below the spec'd cut off pressure of the pump (2bar/30psi ???)


However a proper pressurised system such as Yngmar shows, with a tap at the galley sink although a major upgrade rather than a simple solution, solves the problem entirely and gives water on demand, just like home.


An alternative "simple solution" might be an antisiphon loop and valve between pump and outlet.

Yet another idea is a tap at the galley sink incorporating a switch for an electric pump. A simple pump with no pressure control would then be adequate.

 

[ex-Gladys]

I beg to differ about the Shurflo pumps... The repair kits are hugely expensive, and not easily available when I had one in Gladys which despite being less than two years old I couldn't stop it leaking. On the other hand the small Jabsco Par pumps are very common, and readily available bits, hence my current pump is a faultless Par

 

[Yngmar]

I beg to differ about the Shurflo pumps... The repair kits are hugely expensive, and not easily available when I had one in Gladys which despite being less than two years old I couldn't stop it leaking. On the other hand the small Jabsco Par pumps are very common, and readily available bits, hence my current pump is a faultless Par

ASAP has them in stock. Compared to the price of the whole pump, the parts are indeed a bit high, but then that goes for most things.

 

[rob2]

I believe you will syphon through the pump, it has multiple valves operated by a wobble plate, IIRC, thuogh it may offer some restriction. Electric systems can be either pressurised or on demand. The on demand system simply has a push switch to activate the pump, but as you have multiple outlets, they will need to have taps fitted or they'll all flow when the pump runs. Caravans used to use taps which switched the pump when they were opened. A pressurised system has the pump operating whenever the system pressure drops below a preset level, so a simple tap does the job - but you will need an expansion chamber to prevent pulsing which makes the tap squirt all over the place, and prevent water hammer. Of course, fitting taps does cure the syphon problem...

Rob.

 

[vyv_cox]

Yes it will only need to be fairly lightly sprung.
Sufficiently strongly so to remain closed against the head pressure developed when heeled ( probably less than the equivalent of 2 psi) but obviously well below the spec'd cut off pressure of the pump (2bar/30psi ???)

Yes, a check valve works well in this sort of arrangement, using the spring to prevent unwanted low-head flow. I have one in my central heating system in order to stop upstairs radiators heating up when only the hot water heating is in use.