DIY Watermaker

[beau]

All up and running, works well.
I used the leo litchfield plans as a base.
I bought 2 x 2.5 X 40 filmtec membranes and cylinders set up is series,
I used a 6.5 hp honda pressure washer with brass pump. Fed by a shurflo diaphram pump
I couldn't get a CAT pressure regulator so ended up using a brass gate valve. A water pressure gauge, filters etc .
Cost me under $2,000.
Puts out about 150 liters an hour.
I must admit it was amazing seeing salt water going in one end and tasting fresh water coming out the other end.

[joey69]

MORE INFO. PLEASE

[beau]

Like what,
remember I am in Brisbane, Australia and not everything is available cheap as it is in the USA.
I did find that the expensive pressure regulator was a waste of money and that the gate valve worked fine.
I have a spare seal kit for the Gasoline pressure washer.
As Brent Swain says the whole concept is incrediabily simple once you understand it.

[aegean adrift]

Hi Beau,

Do you have diagrams of this? Or links to Litchfield plans you'd be kind enough to share? Maybe pics of your set-up? Thanks!

Some of us are just learning, and really appreciate specific steps and pointers by those of you who are further along.

[Minggat]

Originally Posted by beau

I couldn't get a CAT pressure regulator so ended up using a brass gate valve.

As quickly as you can, or before you get any more use out of it, highly recommend you change out the gate valve at least for a ball valve. A gate valve will not stay at the setting you're trying to maintain.... if I uderstand correctly, that you are using it in place of a regulator. Of course the regulator would be the first choice.

[Minggat]

Originally Posted by beau

I did find that the expensive pressure regulator was a waste of money and that the gate valve worked fine.

As Brent Swain says the whole concept is incrediabily simple once you understand it.

A gate valve has no place on a boat. The best reason I can think of is that they only act like new for a short time. They are not intended for anything other than open or closed. When they are in between, they have a tendency to go closed. If they are cranked hard open and left that way for a long time, they may let you down when you want to close them.

I understand the desire to save a buck. The designer wasn't forgetting that when he put the regulator in there. It's not always about causing the consumer to spend more.

Way too many years in Industrial Water Treatment and large scale desalination plants. Trust me. I have no financial interest behind this post.

[goboatingnow]

Its important to remember that a regulator is only needed where variable speeds. hence varying throughput is expected. For a reasonable fixed rpm, system a simple needle valve will be sufficient and isnt much more expensive then a gate valve

Theres no need for fancy back pressure regulators in such systems.

Dave

[beau]

Ok guys I will look for something better than a gate valve, however I am not paying $2,000 for a cat valve(australia) as it was, the reg valve I was recommended at $200.00 doesn't work properly.
There is no flucation on the pressure gauge, but I do agree a needle valve may be better.
At least it all works.

[Khagan1227]

Beau,

Perhaps you can post the specs for the regulating valve you are looking for. Someone elsewhere around the world might be able to find something suitable and ship it to you. I even might be able to help.

Just a thought.

Good luck.

[Brent Swain]

I find a needle valve works best.
My book has all the info needed.

[Minggat]

Needle valve better than ball valve. Once you get it all set up, don't just turn it on and walk away each time. Check it and log any adjustments you have to make. The changes going on with the membrane are very gradual, so logging/tracking over a long period of time is helpful. A regulator sort of just takes care of the changes so they might not be as noticable.