Water Tank Drains When Heeling

[Ziggler]

Morgan 323 sailboat. When on a starboard tack and heavily heeling in strong winds, the fresh water tank under the starboard settee rises higher than the galley foot pump faucet on the port side and drains the tank.

I have stared at highway interchange of water hoses under the galley sink and cannot figure out how to defeat this problem.

I've considered or tried the following:

• Add siphon break: This is not a siphon issue. When the tank is higher than the faucet the water will bypass the siphon break and empty into the sink. Right
• Rubber cone stopper stuffed into the end of the faucet: Creates back pressure when we invariably forget to take it out and stomp on the pump, looks inelegant, etc.
• Add on/off valve under the sink: See above problems, plus having to open and reach under the sink while in heavy conditions is just one more problem.
• Buy on/off valve "Whale FT1160 Telescopic Swivel Tap with On/Off Control-White". Maybe will work, but the first time someone forgets to turn it off we lose all 40 gallons of our fresh water.

Thank you all for any help.

 

[dLj]

Personally I'd go with option 4. I don't think there is a simple option.

dj

 

[Tally Ho]

The tank rises higher than the faucet connected to the foot pump? It doesn’t seem like it should drain just because it is higher than the foot pump.

Doesn't the pump stop water flow unless it is being pumped? Maybe the pump needs to be rebuilt or replaced. I would think an operable pump would not allow water to pass through unless it was being pumped.

If I read you notes correctly, you are saying the faucet also allows water to flow even if the valve is closed? Sounds like you may also need a new faucet.

But I don’t have any foot pumps on my boat, so just speculating.

Greg

 

[dlochner]

I'm having a hard time imaging the heel angle that would be a safe and fast angle that would put the water tank above the outlet of the faucet since the sink is near the midline. And it is even harder to imagine that Ted Brewer would design such a boat.

Two theories on why this is happening. The foot pump is most likely a diaphragm pump. These pumps have integral check valves. It is possible the valves are worn or installed backwards, allowing water to flow when it should not. Rebuild or replace the foot pump, they don't last forever.

Or, you are sailing the boat at too high an heel angle which places the water tank higher than the sink. The solution, sail at a more comfortable and efficient heel angle less than 20°. Sailing at any higher angle makes the boat go sideways more than forward.

The problem may be due to a little of each.

 

[Will Gilmore]

This is not my area of expertise, so I am only speculating.

Your water tank will probably have three ports in it. One port is the fill port, the second would be the sink and pump from which you access the water in the tank, the third is probably going to be the pressure release valve that allows air to replace the water you take out. If that pressure valve is opened when the tank is lifted, there will be no vacuum holding the water in the tank, air will freely rush in to replace the emptying water. If that valve is opened all the time, you might need to redesign it to work only with the faucet turning on. Thus, when not trying to pump water from your tank, there will remain a pressure seal that prevents air from entering the tank to replace the spilling water.

I don't know if what I described above is available, a faucet that controls the pressure release valve at the same time as the outflow of water from the tank, but it is my guess that such a faucet exists.

-Chill Will

 

[Ralph Johnstone]

Have you actually seen the faucet draining while the boat is heavily heeled over. This we must know.

Add siphon break: This is not a siphon issue. When the tank is higher than the faucet the water will bypass the siphon break and empty into the sink. Right

No. Not exactly.
The siphon break will have its vacuum breaker mounted well above both the water storage tank and the faucet when the boat is at maximum at heel. This, of course will look like hell hanging off the wall so ignore this cure.

Doesn't the pump stop water flow unless it is being pumped?

Greg may have the answer. If it's a diaphragm pump, it may not.
@Ziggler , could you please supply the make and model of your foot pump so we can check the internals of the pump.

Not knowing your pump, I took a wild guess and looked at a Whale Gusher Mk3 manual galley foot pump to see how a double acting diaphragm pump works. Your pump is likely similar :

This shows the two strokes of a double acting diaphragm pump which is likely similar to your foot pump. The check valves will have light weight springs but unlikely sufficient to oppose a positive head on the suction side of the pump. Unfortunately, when your supply tank is above your faucet this pump will probably drain your storage tank. But as I said before .................. we need the make and model of your pump.

Another possible solution is a spring loaded vertical check valve :

Vertical Check Valve Spring Loaded | in-line Low Cracking Pressure CF8

Description: Spring check valve size: 3/4" 、1/2 female to female NPT connections Check valve body material:Stainless steel 304, cracking pressure: 4.5 psi Check valve working temperature: -60℉ to 450℉(-51℃ to 232℃); seals:NBR; max pressure:1000 Psi for water, oil, gas (WOG1000) H12W check valve...

www.dernord.com

About $20.00 for a 3/4" check valve.

Swing check valves cannot be mounted vertically. Vertical check valves rely on a spring to seat the valve disk. You would have to check the resistance of the spring. It may be enough to resist any pressure you may experience. Do NOT use metal if you drink the water as you will get a metallic taste. Use plastic spring loaded check valves for drinking water.

One (or two) of these mounted in the discharge or suction line may be enough to do the job.

 

[justsomeguy]

Option 2.

 

[Urban Hermit]

Install a piston-type electric water pump.