Raw Water Intake on Head

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Duane Yoslov

Raw Water Intake on Head

Post by Duane Yoslov »

As plumbed from the factory, the raw water intake on the head goes straight from the thru-hull to the pump on the head. This creates the possibility of a siphon if the valve is left open. Twice now I've had inexperienced guests flood the bowl...

My question is - would it be unorthodox to bring the raw water on the head above the water line to a vented loop to prevent this from happening?

Duane Yoslov
CD330 #142
Mystic



yoslovd@aol.com
Joe

Re: Raw Water Intake on Head

Post by Joe »

Duane Yoslov wrote: As plumbed from the factory, the raw water intake on the head goes straight from the thru-hull to the pump on the head. This creates the possibility of a siphon if the valve is left open. Twice now I've had inexperienced guests flood the bowl...

My question is - would it be unorthodox to bring the raw water on the head above the water line to a vented loop to prevent this from happening?

Duane Yoslov
CD330 #142
Mystic
I don't know. I replaced the head in our 330 with a Groco K-H which has a spring loaded footpump which cannot be left open. It solved the "inexperienced guest" syndrom.

Joe



tgjournal@gestalt.org
Brewer Ezzell

Re: Raw Water Intake on Head

Post by Brewer Ezzell »

Duane

I think that is where the loop should be. In my installation (early CD36), the system loop was between the head and the discharge thruhull. I replumbed the holding tank this spring and now all flow goes first to it. I didn't take out the vented loop between the head and tank. I wish that I had. My over board discharge waste pump is right at the thruhull, and the thruhull is never unlocked and open except when I am pumping. The vested loop at the raw water seacock would be the safest place, especially if the discharge side is always closed except when under supervision.

Brewer



bemf249@murphyfarms.com
Jon Larson

Re: Raw Water Intake on Head

Post by Jon Larson »

Duane,

Boy, do I understand that concern about somebody leaving both the seacock and the head valve open.

But, I wonder if you put the anti siphon valve on the intake hose prior to the pump on the head, does the head generate enough suction to both lift the water over the anti siphon loop and also overcome the amount of air that the anti siphon valve would admit into the intake hose while the water is being drawn into the boat and not turn pumping the head into a more miserable job than it is? I honestly don't know. Given the fact that the anti siphon valve would work, at least the "intake half" the intake hose will have a lot of air, if the valve on the head is left open the "head half" of the intake hose will also be full of air, or some combination of both, how would the air affect the operation of the pump? Would one be tempted to pump more to assure a good flow and will this cause more water to be flushed into the holding tank? Again, I don't know.

Let us all know if you do it, it might actually work quite well and be a good idea, though I'd suspect that manufacturers would have caught on to this a long time ago were that the case.

It's a scary problem, actually. Before leaving for a long delicious shore dinner, your guest......

While it's not the most socially pleasant topic to begin a days sail with, I always start the day with a "lesson" on flushing the head which includes always closing the bronze seacock on the intake hose after each use. Always! I would have to say that so far, I've been lucky. I also don't leave the boat ever for any length of time without checking the seacocks that might have erroneously been left open.

Jon Larson
Cape Dory 30 PERI
San Francisco Bay

Duane Yoslov wrote: As plumbed from the factory, the raw water intake on the head goes straight from the thru-hull to the pump on the head. This creates the possibility of a siphon if the valve is left open. Twice now I've had inexperienced guests flood the bowl...

My question is - would it be unorthodox to bring the raw water on the head above the water line to a vented loop to prevent this from happening?

Duane Yoslov
CD330 #142
Mystic


jon9@ix.netcom.com
Dennis Ward

Re: Raw Water Intake on Head

Post by Dennis Ward »

Duane Yoslov wrote: As plumbed from the factory, the raw water intake on the head goes straight from the thru-hull to the pump on the head. This creates the possibility of a siphon if the valve is left open. Twice now I've had inexperienced guests flood the bowl...

My question is - would it be unorthodox to bring the raw water on the head above the water line to a vented loop to prevent this from happening?

Duane Yoslov
CD330 #142
Mystic
Duane, I put the vented loop between the bowl and the output side of the fresh water pump. The setup worked great for me.
Duane Yoslov wrote: Dennis Ward
CD 33
Little Rock


DWard34@aol.com
John R.

Re: Raw Water Intake on Head

Post by John R. »

Duane Yoslov wrote: As plumbed from the factory, the raw water intake on the head goes straight from the thru-hull to the pump on the head. This creates the possibility of a siphon if the valve is left open. Twice now I've had inexperienced guests flood the bowl...

My question is - would it be unorthodox to bring the raw water on the head above the water line to a vented loop to prevent this from happening?

Duane Yoslov
CD330 #142
Mystic

Duane;

The vented loop on the head intake line should be installed between the pump body and the bowl and mounted as far above the waterline as you can get it.
Olli Wendelin

Re: Raw Water Intake on Head

Post by Olli Wendelin »

I have a simple, but time consuming method. I do not let guests operate my hull valves. When a guest wants to go to the head, I, or one of my crew, open the sea cocks for them. When they are done we shut the valves. When I leave the boat I double check that the valves are shut. It is very disconcerting to be sailing along and notice water spilling over from the toilet bowl.

One day (soon ??) I will install a large water tank, a large holding tank, and an electric head. Then my guests can flush to their heart's content and I will not be worried about the position of the hull valves.

Olli Wendelin
BLUE MOON
Charleston, SC
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