JayBee
Well-Known Member
Does anyone have experience of teeing off the engine raw water cooling system to supply a galley hand pump?
Galley salt water pump
- Thread starter JayBee
- Start date
Refueler
Well-Known Member
Interesting .... one way to reduce number of hull holes ..
Mine is via dedicated seavalve just fwd of the keel .. it supplies both galley and wash area fwd ..
Mine is via dedicated seavalve just fwd of the keel .. it supplies both galley and wash area fwd ..
Minerva
Well-Known Member
I have a standalone inlet for both galley sink and engine. I suspect you’d run the risk of introducing air into the engine cooling line and have resultant issue around priming the coolant system should you share
wonkywinch
Well-Known Member
If you t off before the engine water pump then there will be reduced pressure in the line with the engine running (as it sucks water in) so opening the tap will result in water/air being pulled back down the galley supply pipe and into the engine pump.
If you t off after the engine water pump, the water will be pressurised and opening the tap will deprive the engine some of it's design coolant. The water flow would be very restricted this side if the engine wasn't running as the impellor/engine pump would be blocking the water supply.
So, no, it's not a good idea.
I had thought of putting a t in mine with a length of hose that could act as an emergency bilge pump or a line to the heads sea water sea cock so if the engine sea water feed was blocked (we have a sail drive), then the sea water could come from the heads inlet instead.
Both would rely on the low inlet side pressure generated by the engine water pump.
If you t off after the engine water pump, the water will be pressurised and opening the tap will deprive the engine some of it's design coolant. The water flow would be very restricted this side if the engine wasn't running as the impellor/engine pump would be blocking the water supply.
So, no, it's not a good idea.
I had thought of putting a t in mine with a length of hose that could act as an emergency bilge pump or a line to the heads sea water sea cock so if the engine sea water feed was blocked (we have a sail drive), then the sea water could come from the heads inlet instead.
Both would rely on the low inlet side pressure generated by the engine water pump.
KevinV
Well-Known Member
Apart from the above points I'd also want to be sure the galley inlet is upstream (and preferably the other side of the keel) of the heads outlet
wonkywinch
Well-Known Member
Refueler
Well-Known Member
I think that may not be too much of a problem .. as the inlet and T would presumably be below waterline ... it may be an idea to fit a non return valve in the galley line ? Given that the water flow that seavalve is capable of ... and most engines do not require that amount ... I think it could work. And that most galley taps are positive LIFT whether manual or electric. BUT its one of those 'maybe' situations that unless someone can actually show works or not - best to avoid.
Think you'd be surprised how much water can pass that impellor ... but anyway - who wants their water after passing into engine pump ?
Bog is an excellent bilge / emergency water pump !!
KompetentKrew
Well-Known Member
You're right that it will reduce pressure, but presumably the effect on the engine will depend on the water pressure at the through-hull, and that will depend on how far below the waterline it is?
I would have thought that water would be supplied at quite a decent pressure, hut I don't know.. I'll have to take a look at my hull, but I would have thought the through-hull might be as much as 12" below the water line, but I don't know. It could be less than 6" also, for all I know.
wonkywinch
Well-Known Member
The pressure won't/can't be sufficient to ever push the water above sea level (as Archimedes discovered). If you had a transparent hose, you would see the ambient water level in the pipe exactly the same as the level outside unless there was a syphon effect going on.
I've seen even the smallest almost invisible crack in the clear lid of a sea strainer be sufficient to stop the flow of water into the pump as suction was lost with the air leaking in.
KompetentKrew
Well-Known Member
Silly me. Thank you, @wonkywinch
wonkywinch
Well-Known Member
No probs, I often see posts on forums about the fear that strikes people with the thought of removing the depth/speed log device. They come with a little flap but even with that missing, the flow rate is quite manageable and resting your hand or a cloth over the hole stops the water coming in. I think people imagine a fountain that would strike the ceiling.
vyv_cox
Well-Known Member
It is usually the amount of light that comes in that surprises me most! Especially in Greek sunshine over a sandy seabed.
Refueler
Well-Known Member
Many speed log thru-hulls do not have a flap ...
wonkywinch
Well-Known Member
I'm sure they don't but I reckon there must be Airmar products in 90% of the boats made in the last 20 years and whether they are badged Raymarine, Garmin, Simrad, B&G etc. Airmar fit a plastic flap in their removable transducers, whether it's still there or not when you pull the transducer is another matter.
BobnLesley
Well-Known Member
First Hand Experience:
In 2011 we teed off the inlet hose to a 3GM30F to fit a foot-pumped seawater tap. It was intended to be 'temporary' installation until we next hauled out, but by the time we reached Spain eight months later, we thought why introduce that extra hole into the hull. It was still connected there when we sold the boat in NZ in 2020 and we'd never had any related problems with either the engine cooling or the seawater tap. We used heavy/good quality tee, hose and jubilee clips for the installation and also fitted a 'just in case' inline stop valve in the galley feed immediately after the tee; we never used the stop tap but would do the same if I fitted another.
In 2011 we teed off the inlet hose to a 3GM30F to fit a foot-pumped seawater tap. It was intended to be 'temporary' installation until we next hauled out, but by the time we reached Spain eight months later, we thought why introduce that extra hole into the hull. It was still connected there when we sold the boat in NZ in 2020 and we'd never had any related problems with either the engine cooling or the seawater tap. We used heavy/good quality tee, hose and jubilee clips for the installation and also fitted a 'just in case' inline stop valve in the galley feed immediately after the tee; we never used the stop tap but would do the same if I fitted another.
PabloPicasso
Well-Known Member
Why not tee off the heads inlet? You would only be using the heads pump, or a sink pump, not both together.
Refueler
Well-Known Member
That crossed my mind as well .. but something about using a bog connection turned me away even though it should be fine ...
Visitor notices one tap is SW .... "I see you have SW via one tap and FW via another ?"
"Yes - FW from the tank .. SW from the toilet inlet ......"
Visitor expression changes !!
Bodach na mara
Well-Known Member
Forgive me for a daft question but why?
Refueler
Well-Known Member
I'm not original questioner for this - but I can see the idea that no need to cut another hole in the hull ... close seacock and fit T and piping .. open seacock .. all done while still afloat ...
vyv_cox
Well-Known Member
The well known whiff of H2S on first flush after a week or more of toilet inactivity is due to microbial contamination in the suction pipe, blowblack through the poorly efficient suction valve. So that same water could reach the galley for flushing your pots.
