Installing sea water tap inside pantry

[quakerfin]

Has anyone installed sea water tap inside pantry?

We have two sinks in our pantry and both have their own drain lines and seacocks and thru hulls.

Our boat is Bavaria 390 C. Problem is that 400 litres of water is not enought for 8-12 ppl when washing dishes etc. Thats why we are now thinking is there reason why both sinks have their own seacocks. Could we make them go in the same one and use other one for sea water tap. In that way there would not be need to drill new holes.

any ideas and comments?

Thanks!

[tiger79]

Yes, that could work, as long as the existing through-hulls are below the waterline.

If you decide to go ahead, I'd really recommend a foot pump (Whale Gusher Galley Pump is good) as it leaves both hands free for the pots.

[Symphony]

I think you will find the drains are either above the waterline or just on, so not a reliable seawater source. Suggest you "T" off the toilet intake, either with a Y valve or a stop valve in the line to the sink pump so you only turn it on when you want to use the pump at the sink. agree with the suggestion to use a foot pump. The only problem might be running the supply pipe from the toilet seacock, depending on where the toilet is located.

[sy_Anniina]

I would rather make a new through-hull than use toilet intake.

Manual toilet pump uses same cylinder for flushing seawater and waste, so you can get harmful bacteria to water lines. On some boats toilet sink and shower outputs are below waterline and you may be able to combine those and have the lower output rerouted to galley seawater input

See YouTube video https://www.youtube.com/watch?v=BnQq4d-NmkE for details on jabsco toilet pump construction and operation.

[quakerfin]

Ok guys, thanks for quick answers!

If kitchen drain is enough under waterline that would be suitable solution, right? Otherways the only wise thing to do is to make new hole thru the hull?

Any ideas why Bavaria has made own seacocks for both sinks on 1991? Could be safer to have only one? Amounth of water is not so huge anyways.

We have quite a lot seacocks and Im not so happy with those. Always possible to have some major problems on the sea.

[Symphony]

With 2 sinks draining into one outlet there is the possibility of backflushing from one to another. The diameter of the drain is small (12mm) whereas the normal intake for water is 19mm. If you are worried about contamination from the toilet then a non return valve in the pipes between the split and the pumps will resolve that and also allow you to use both pumps without isolating one. 

[Mirror45184]

Hi Symphony,
A single nonreturn valve will not prevent "contamination" going back to the sink sea water connection. The non return only works if there is a pressure difference across it, even then you can get "growth" through the seat when the water is static. That is the reason why special non return valves (RPZD) valves are used to separate drinking water supplies from non drinking applications. Better to put in a separate inlet for the raw water sink pump in a suitable position so it does not take in water from a drain or toilet discharge.
Cheers

[Salty]

I’d agree with Tommi and Mark on this, a sea water inlet totally separated from the toilet flushing water inlet would be  my choice, and as Mark said, in a location where it is unlikely to pick up anything that may have just been flushed..
I know that some are reluctant to put another hole in the hull, yet many of us are perfectly happy to replace through hull fittings changing from brass, bronze or DZR fittings to glass fibre or plastic through hulls and valves. We would all take great care when replacing a through hull to ensure that its fitting was watertight, so apart from the hole which would be new, for me I really don't see a problem.

[quakerfin]

Here is photo from our pantry+aft toilet. Kitchen has two separate drains.

Im still not 100% confidient is two separe drains neccessery?

Also kitchen seacocks are lower and 50cm closer to centerline of the boat.

Is it really stupid idea to take one of the kitchens seacoks and use it for a raw water tap? (lower or upper one?)

Is backglushing real problem because there are 80cm differens in height?

Im not really keen to use toilet intake for kitchen water. 😅

[Symphony]

That looks rather different from other installations I have seen. I assume the two seacocks are the two drains for the sinks. The potential problem with using one drain arises if the sink outlets are close to the waterline and there is not much fall before the two join the outlet pipe. Because the outlet is below water the flow outwards is slow, so when you empty one it has a tendency to surge up the other to equalise the levels before it drains. This worse if the boat is heeled.

However, there seems to be a good fall before the waterline (which is also the level of the water in the outlet pipe), particularly if you use the lower one for the common outlet and the upper one for the seawater inlet for your pump. Worth trying first before you install the pump.