[reflect]

Hi, please forgive my ignorance, but  really don't understand what a solenoid valve does. I would like to fill from the merlin directly into the van with an auto shutoff.   I understand how to use a float in the tank and in my mind thats the problem solved. The merlin has a shutoff  built inside and the booster has a pressure switch.  What I don't understand is what does the the solenoid do. is there some advantage that I can't see.

[Spruce]

Hi, please forgive my ignorance, but  really don't understand what a solenoid valve does. I would like to fill from the merlin directly into the van with an auto shutoff.   I understand how to use a float in the tank and in my mind thats the problem solved. The merlin has a shutoff  built inside and the booster has a pressure switch.  What I don't understand is what does the the solenoid do. is there some advantage that I can't see.

If you are using a Merlin or PRF then you don't need a solenoid valve.

A Merlin and the lastest model PRF are designed as under kitchen counter units for the American market. The pure is connected directly to the Faucet or tap in our English. Turn the tap off and the r/o switches off.  Turn the tap on and the r/o starts again.

So all you need in your tank is a ball valve. Once that shuts off then your Merlin or PRF stops filtering water. My mate has a Merlin and that's his arrangement.

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[reflect]

thanks, does that mean some ro units dont have a shut off inside and then you would need a solenoid, otherwise it would continue to make water and damage the ro   

[Spruce]

thanks, does that mean some ro units dont have a shut off inside and then you would need a solenoid, otherwise it would continue to make water and damage the ro   

The Merlin and the PRF are the only ones that work this way.

I have a normally off solenoid valve on my 4040 r/o. The float switch is in the tank. When the tank is full the float switch cuts current to the solenoid valve which then closes. The solenoid valve is before the prefilters on my setup.

There are shut off valves available that work off a pressure buildup on the pure delivery that switch the main water flow from the tap off.
I bought one when I had my 450gpd r/o but it didn't work for me.

http://www.ebay.co.uk/itm/1-4-Inch-4-Way-Auto-Shut-Off-Valve-For-RO-Reverse-Osmosis-Water-Filter-System-/182198625958?hash=item2a6be266a6

I got awakened in the middle of the night with water hammer in the pipes as the shut off valve opened and closed at a rapid rate.
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[Spruce]

Hi, please forgive my ignorance, but  really don't understand what a solenoid valve does. I would like to fill from the merlin directly into the van with an auto shutoff.   I understand how to use a float in the tank and in my mind thats the problem solved. The merlin has a shutoff  built inside and the booster has a pressure switch.  What I don't understand is what does the the solenoid do. is there some advantage that I can't see.

From experience the ball valve in your van's tank needs to be put where it doesn't foul on the top of the tank and not switch off. This will mean that your tank will only be slightly more than 3/4 full. We had 3 x 125 liter tanks linked together on my first trailer setup. There was a ball valve fitted to that and it was in the centre where the filler cap was. This allowed the float to rise higher into the filler cap space.