Re: [Amel Yacht Owners] Re: Watermaker and transmission fluid



Here is another prospective...I am not sure which is right.

I was in manufacturing for many years. All manufactures have to be very careful that their products are not misused because the umbrella generation will sue when something goes wrong that they were "allowed" to do. 

The Dessalator system has a "green" zone for the high pressure setting, which makes it simple and easy to use for half of users that do not know what they do not know. Probably, what many of us would like to see is BAR at specific salinity and temperature...BUT, Dessalator knows that they have to design something for the simple-minded user. Therefore, since they are basically forced to make the watermaker "child proof" we have the green zone on the HP gauge. And, since we have the green zone, a non-expert could and probably would over-pressurize for fresh or brackish water, which will cause issues.

I used the term "child proof" with the product development folks that reported to me. I would always ask if the new product was child proof and for their explanation...they knew what I meant.


CW Bill Rouse
Admiral, Texas Navy
Commander Emeritus

Amel School
720 Winnie St
Galveston Island, TX 77550

+1(832) 380-4970

Any opinions and conclusions expressed in this message are solely those of the author and should not be construed as representing the opinion of an expert. Manufacturers' and Expert's precautions must be considered when dealing with mechanical and/or electrical systems to ensure that you are NOT harmed, and/or the device and/or system is NOT ruined. If in doubt, do not touch any mechanical and/or electrical device or system referred to above.

On Fri, Aug 24, 2018 at 9:39 AM sangaris@... [amelyachtowners] <amelyachtowners@...> wrote:


You should be able to find CruiseRO Water and Power on the internet.  Try this link.
He very effectively clears up the no-fresh-water myth and also gives the technical explanation of how fresh water at high pressure will destroy a membrane.

The Filmtec notes you quote are pretty clear that fresh (or brackish) water is no problem.

The Dessalator warning is clearly one of those cover-your-ass disclaimers to prevent customer complaints and claims like the one discussed here recently from Alden Barbour warning against using tank water to cool the refrigerant. That was because of the remote possibility the line might rupture in the tank and contaminate the drinking water and kill you when you drink it, or the user might let the tank water run low and have inadequate cooling and complain on some cruisers' forum and give Alden Barbour a bad name.

Sure, you can, indeed, blow out your RO membrane if you run it with fresh feed water at high pressure. 
Uh, don't do that.

Craig SN68

---In amelyachtowners@..., wrote :

I'm now not so sure about this fresh water business.

In the Dessalator Duo 60 manual  it says:

Remember: The biggest enemy of the membranes is fresh water.

Fresh water should be always used with no pressure when going through the system
(pressure dial turned all the way anti clockwise) and the system should always run with no
pressure after a fresh water flush to dump all the fresh water that are in it, before making
freshwater from sea water (also with the pressure dial all the way anti clockwise).
When running the watermaker with the dial all the way anti clockwise, it will shut it self
down automatically after 1 minute. Only then, the watermaker is ready for use.

I have the Filmtec Membrane Technical Manual and I can find no discussion of this at all anywhere.

In fact a number of systems are illustrated that
1. Treat Brackish water
2. RO the RO water (double RO) to make ultrapure water.

So I don;t know where this freshwater enemy story comes from......nothing on a Google search.

If it really was a problem I would think Filmtec would warn about it.

Elyse SM437

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