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Old 03-06-2009, 04:08 AM
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Quote:
Originally Posted by midgetwaiter View Post
You are making this harder than it needs to be.

Your membrane flush is on the waste water side so you never come in contact with RO and it goes down the drain anyway, so it doesn't matter.

In order to switch the RO on and off to fill your holding tank I'd seriously suggest switching the input water. If you switch on the output side you will need to use an RO safe valve and you have increased leak potential because the unit will be pressurized. There's at least twelve points on a pressurized RO/DI unit that could fail but it you shut off the feed you only have one fitting that has any pressure.

OK, Heres the deal.
This is for an automation of a 4 tank setup. The setup is going to be PLC(Programmable Logic Controller) controlled. The RO unit WILL have a main Solenoid controlling inlet. But also solenoids to run the RO unit for 20 min before filling the Main reservoir. Also, there will be a Run timer that after X hrs of water making, the RO unit will go into a Membrane Flush mode. When the reservoir gets to a pre determined level, the PLC will control the RO unit for a Purge, and fill of the Res. The PLC will also control independent level of 4 tanks. With this PLC, there will be safety timers for maximum RO run time as well as level control is managed bu Ultrasonic non contact level sensors. Nothing to stick, no salt creep to worry about etc.

Once this is complete, I'll be making a lighting program with another PLC.

I LOVE designing and building things
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Dan Pesonen


Umm, a tank or 5
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