Watermaker Intake

[Mais78]

Got it. The alternative for me is to install a sophoscope valve, big job and extra water drag. If I could share the engine water inlet and use the watermaker only when engine is off I would be happy.

[Sailmonkey]

Originally Posted by Mais78

Got it. The alternative for me is to install a sophoscope valve, big job and extra water drag. If I could share the engine water inlet and use the watermaker only when engine is off I would be happy.

A new through hull fitting adds minimal drag, especially a flush mount variety.

If your dead set on sharing a seawater suction with something, why not use a seawater supply for the head instead. With a 3-way valve you eliminate the possibility of pulling air, and worst case is you leave a little something in the head until you remember to turn the valve back.

[Mais78]

This is beyond my knowledge. The boat is a Pogo 36 and being fast the yard told me that it needs a sophoscope valve as previous installations without one did not go well. Also I think the valve cannot be too far from the watermaker.
How does a 3-way valve work?

[CassidyNZ]

Originally Posted by SV THIRD DAY

Insanity...do you know how many problems I troubleshoot over the phone for the last decade caused by Cruisers sharing a through hull? A Gazillion....

Don't share a Through Hull for a water maker folks...it's just STUPID I don't know how else to say it more politely.

So I’m guessing that you’re saying specifically that a watermaker should not share a thru-hull with an engine? Because I share a thru-hull between my watermaker and the galley salt water pump and it works just fine.

My shop manual tells me exactly how to do it - I built my own watermaker and consequently also “wrote the manual” so I get no contradictions.

[Cheechako]

The one time I tried to share an intake with the engine intake, it allowed bubbles of air into the intake. I think it was either a toilet or a faucet. It wasn't the fact that the engine needed more water, but the suction allowed the bubbles in somehow. One way to do it, if it's not an engine intake is use a 3 way ball valve so or etc so it's one or the other, not both.

[Sailmonkey]

Originally Posted by Mais78

This is beyond my knowledge. The boat is a Pogo 36 and being fast the yard told me that it needs a sophoscope valve as previous installations without one did not go well. Also I think the valve cannot be too far from the watermaker.
How does a 3-way valve work?

Ok, that changes things a bit. You don’t want a water intake that is exposed to air bubbles while sailing.

[Mais78]

The saildrive leg is deeper than the sophoscope valve so air bubbles should not be a problem. Does this 3-way valve solve any potential issue of sharing the intake with the engine? Thanks

[Cheechako]

Originally Posted by Mais78

This is beyond my knowledge. The boat is a Pogo 36 and being fast the yard told me that it needs a sophoscope valve as previous installations without one did not go well. Also I think the valve cannot be too far from the watermaker.
How does a 3-way valve work?

It's just a manual valve you would have to turn to use either appliance. So you can have the water go "left or right"... I wouldn't put one on an engine intake, you might forget.
Another advantage of not splitting an engine intake for a water maker, is you can make water while motoring. You may end up motoring for 8 hours some times and you can make a lot of water without draining batteries.

[Mais78]

Got it. But if I accept not to make water while motoring do you see any risk for the engine?

[Cheechako]

Originally Posted by Mais78

Got it. But if I accept not to make water while motoring do you see any risk for the engine?

I don't see why there would be, the valve closes off the side not used, so it wont be any different than it is now. Be sure to label the valve, they can be confusing.
https://www.amazon.com/Apollo-Bronze.../dp/B002KU6RXC

[Mais78]

What if u don’t use a valve that is either or? Thats risky if the valve is shut for the engine, you forget, you start motoring and the engine is gone. I was thinking more of a setup with shared intake but for good practice you abstain from making water while motoring

[Cheechako]

Originally Posted by Mais78

What if u don’t use a valve that is either or? Thats risky if the valve is shut for the engine, you forget, you start motoring and the engine is gone. I was thinking more of a setup with shared intake but for good practice you abstain from making water while motoring

Well, you could just put a Tee in and a valve only on the watermaker side. If you do that, just put the valve in a convenient spot up near the water maker filter or etc...

[Mais78]

Thanks!