Feedback on Watermakers

[goboatingnow]

out of interest what the ballpark pricing

[claire]

Finally got around to dive down and take the pic. This is on a 3JH4. This is our second, steel bracket. The first one in aluminum broke.

Good luck with your installation.

[Captain Bill]

The cheapest/smallest pump lists for about $2500 without a motor or an energy recovery unit. I have not found a price on the energy recovery unit, but they are very similar to the pumps so I would expect the price to be similar. Add a motor membranes and controls to this and you have a pretty expensive unit. In addition, it would appear that the high pressure pump requires a minimum input pressure of 145 PSI or 10 Bar. That would imply you need a pretty powerful feed pump.

[Tellie]

Originally Posted by Fabrizio

My Engine is a Yanmar 4JH2-TE

The following picture of a bracket is posted in the watermaker manufacturer website.

The engine is also a Yanmar very similar to mine. I am awaiting more pictures and information from them. Will post when I get them...in the mean time any help would be welcome.

The pic didn't come through. A few months ago I ran across for a third time a engine driven Cat pump that was mounted off to the side on a two cylinder Yanmar in a Catamaran. Smaller engines like these are very sensitive to vibration, especially on sail drives found often in Catamarans. The large Cat stlye pump amplified the slight vibration engines usually have. Hanging them off to the out side of the motor mount adds a lot of vibrational leverage on these smaller engines leading to very unacceptable engine shaking which leads to more problems with mounts, tranny, seals, etc.. That's why I asked what engine you had. I haven't seen any four cylinders with this problem yet but I don't see a whole lot of DIY water makers to have any real satistics.
What I have seen before, and I know some people blow it off, is serious side loading issues on smaller two and three cylinder engines that mount pumps and double belt them. Personally I'm not a fan of mounting these pumps to a boats main engine. I know it's done, but adding them to a separate engine, diesel or electric is a better set up in the long run.

[Tellie]

Originally Posted by claire

Finally got around to dive down and take the pic. This is on a 3JH4. This is our second, steel bracket. The first one in aluminum broke.

Good luck with your installation.

Claire, I'm curious how do you maintain steady pump rpms (I assume 1750 for that pump shown), engines rpms, and proper engine loading all at the same time?

[Fabrizio]

Tellie,

For this particular pump, the manufacturer recommended RPM is 1450. You have to decide at what RPM you will wish to run your engine when producing water. Lower (at anchorage) or higher (under way) or something in between, if you get what I mean...

The difference will be the size of the pulley attached to the engine. 1 to 1 size you will get the same RPM in the pump as the engine and as the pulley on the engine gets smaller, the rpm delivered the pump will get lower.

Here we will install 1 to 1 pulley.

[IMG]C:\Documents and Settings\Fabrizio\Desktop\Yanmar Bracket.jpg[/IMG]

[claire]

Tellie,

You are right on all accounts. This pump adds too much weight on the side of the engine. It is supposed to run around 1400rpm. In practice, we minimize the use of the WM as much as possible, run it only at the anchorage or at slow calm conditions with steady rpm below 1600. We have come to hate the belt driven idea and regret we didn't get the 12V pump instead. If we had to rely exclusively on the WM for water, we would convert to 12V.

[Hugh Maclean]

We have been using a Katadyn 180 12V WM for 4 years with no problems at all to date. It has put up with frequent pickling, use during a transatlantic and has sustained us well over the 4 years of live aboard cruising. They seem to do reasonably well on the Yachting World post-ARC equipment round ups as well.

[claire]

Again, I post these pics because someone asked me, but do not recommend installing a belt driven system. In fact, we have started the conversion process to DC.

[phorvati]

Claire, I would have to recommend against your conversion. I've built and used a electric motor driven, DC system for about 3 years. I didn't have a generator, so i had to use a DC motor. .75HP motor was not quite enough to push the adequate flow accross 2.5x40" membrane but was drawing a lot of electricity. End result was clogging of pressure vessels ports, high salt passage 300-450PPM, and a lot of failures with high pressure SS hoses, and fittings.
Ive since converted to an engine driven cat 290 car wash pump, and Ive been very happy with production. I am able to run the watermaker without the feed pump, I don't have a clutch so I install the belt every time I run the watermaker. I run it 2.5 hours per week, and keep the engine at 800RPMs This gives me 3+ gpm of brine for 40+ GPH of product. Pump is very "thirsty" as it draws about 10 Inches of vacuum. Its mounted below the waterline, but shares a 1" intake through-hull with engine raw water.
I do have a bypass regulator installed but its not really doing anything. My engine runs very smooth at idle. Im using a needle valve to control the system pressure.
Petar