Watermaker Plans

Martinini · #1 (**permalink**) 10-04-2009

After much searching I found this http://www.westward-ii.com/PDF's/How%20to%20build%20your%20own%20watermaker.pdf

dieselboy · #2 (**permalink**) 10-05-2009

Very interesting...

RichH · #3 (**permalink**) 10-05-2009

Litchfield's methodolgy and explanations are spot on. If you follow his directions, etc. you can build yourself an engine driven watermaker for ~$1000.00 for a system that will last for several years, double that for a system made of bronze/stainless. Costs will vary based on how well you can 'shop' for the parts.

Making your own watermaker is quite easy and a DIY watermaker can have most the components 'spread-out' all over the boat if you have storage volume issues.

I was involved in the engineering of sophisticated RO, etc. equipment for many many years and will say that what Litchfield presents is 'spot on'. For simplicity and cost savings, his 'manual control method' is also 'spot on' as there is nothing better than a 'cognizant human brain' when it comes to 'control systems'.

night0wl · #4 (**permalink**) 10-05-2009

Looks like a lot of the equipment here would be used for my A/C (intake thru-hulls, strainer, impeller based feed water pump, output thru-hull above the waterline, etc). What are opinions around t-ing into that existing equipment for this watermaker?

Another benefit for me is that my water tanks are already on the port side, right by where the A/C intake already is, so piping runs will be smaller to boot.

Although there would be a looong way to pipe for an engine mounted pump. May have to go 120V pump for the high pressure side of things.

RichH · #5 (**permalink**) 10-05-2009

Sure you can tee in a lot of line to other equipment. Only you have to be sure that the 'draw pressure' of the booster pump doesnt suck air back through the 'other' devices and cause a slug of air to hit the high pressure pump ... or worse the RO membrane. Such will work if you have valves on the discharge of the 'other' equipment that is 'tee'd into' the RO unit.

Using a 120v pump has definite downsides, as when you have 120v available you usually dont have 'decent' and low particle water to draw from (harbor marina, etc. etc.). Best is 12vdc or engine driven so that you can reliably take on water that has some degree of low particle burden - out in the open ocean or in some remote & not-close-to-*pooping-in-the-water-people*, location . ;-(

A high pressure deck wash pump is ideal to feed the lowside of a high pressure RO pump; and, you have the availability of the deck wash when the watermaker is not on.

night0wl · #6 (**permalink**) 10-05-2009

This project has me intrigued. What is a good source (online or otherwise) for membranes and membrane housings?

I suspect that this will be most difficult part to procure in addition to the high pressure pump.

Martinini · #7 (**permalink**) 10-05-2009

Membranes can be had here Seawater RO Membranes Elements for Seawater Desalination WaterAnywhere RO Seawater Membranes

Martinini · #8 (**permalink**) 10-05-2009

Something elese I have discovered is that you can find a lot of the componants needed on Ebay for a fraction of the cost.

RichH · #9 (**permalink**) 10-05-2009

Quote:

Originally Posted by night0wl

This project has me intrigued. What is a good source (online or otherwise) for membranes and membrane housings?

I suspect that this will be most difficult part to procure in addition to the high pressure pump.

Midwest RO Reverse Osmosis and Water Filters and Membranes in Illinois is probably the cheapest. Probable best and most compact hi Pressure pump is the Giant Model 218 @ $350.00 (brass head not bronze).

geraldartman · #10 (**permalink**) 10-06-2009

Glad I sail the Great Lakes. $70 filter will handle a couple of hundred gallons. Have to hand pump though.