# RO water shutoff valve



## eggshells (Mar 2, 2016)

Is there some sort of a device to shut off the water source of an RO system without a pressurized tank? I am just using a barrel with a float valve as a reservoir.


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## Paphluvr (Mar 2, 2016)

I'm not sure I understand your setup. Are you presently dumping the RO into a barrel and want to shut off the water when the barrel's full or....?


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## gego (Mar 2, 2016)

Any problem using a float valve on the ro tank? That's what I use.


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## gonewild (Mar 2, 2016)

eggshells said:


> Is there some sort of a device to shut off the water source of an RO system without a pressurized tank? I am just using a barrel with a float valve as a reservoir.



Do you mean you want to shut off the water supply line before the filter and not have a float valve or a second shutoff in addition to the float valve?


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## eggshells (Mar 2, 2016)

gonewild said:


> Do you mean you want to shut off the water supply line before the filter and not have a float valve or a second shutoff in addition to the float valve?



This. I want to shutoff the supply line (before the filter) when the barrel of filtered water is full.


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## eggshells (Mar 2, 2016)

gego said:


> Any problem using a float valve on the ro tank? That's what I use.



That is what I use also but when the the tank is full (float valve triggered) RO still producing waste water. Is it not what its supposed to do?


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## gonewild (Mar 2, 2016)

eggshells said:


> Is it not what its supposed to do?



I dont think so.


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## eggshells (Mar 2, 2016)

gonewild said:


> I dont think so.



Just to be clear. If it is not producing water i.e the float valve is triggered. It shouldn't output waste water?


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## gonewild (Mar 2, 2016)

You need one of these:
http://www.purewateroccasional.net/hwshutoffvalves.html


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## gonewild (Mar 2, 2016)

eggshells said:


> Just to be clear. If it is not producing water i.e the float valve is triggered. It shouldn't output waste water?



I assume you mean the float valve is closed?


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## eggshells (Mar 2, 2016)

gonewild said:


> I assume you mean the float valve is closed?



Yes


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## gonewild (Mar 2, 2016)

Here is another about the shutoff valve you need:

http://www.bulkreefsupply.com/instructions/article/Installing-an-auto-shut-off-valve


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## eggshells (Mar 2, 2016)

Fantastic. Thanks.


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## Ray (Mar 2, 2016)

It's called a hydraulic cutoff. There are 4 connections:

1) in from the prefilters 
2) out to the membrane housing
3) in from the pure water outlet of the system
4) out to the float valve in your case.

When the back-pressure in that pure waters line reaches 2/3 of the pressure of the water in from the prefilters, all water flow is stopped, including the flush water. When the float valve opens to refill the tank, that valve reopens and the water flow starts again.

http://www.firstrays.com/cart/Water-Purification/Parts-Components/Hydraulic-Cutoff-Switch


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## eggshells (Mar 2, 2016)

Ray said:


> It's called a hydraulic cutoff. There are 4 connections:
> 
> 1) in from the prefilters
> 2) out to the membrane housing
> ...



Thanks Ray, do I still need an inline check valve? or just this doodad.


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## Paphluvr (Mar 2, 2016)

gonewild said:


> You need one of these:
> http://www.purewateroccasional.net/hwshutoffvalves.html



The shutoff valve you refer to depends on back pressure of the tank in order to function. You have no back pressure in an open tank system. I'd rather see a float switch in the tank with a solenoid valve prior to the RO system.


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## gonewild (Mar 2, 2016)

Paphluvr said:


> The shutoff valve you refer to depends on back pressure of the tank in order to function. You have no back pressure in an open tank system. I'd rather see a float switch in the tank with a solenoid valve prior to the RO system.



Are you sure a pressure tank is required? I was under the impression the auto valve would close with the restriction of the float valve creating elevated line pressure.


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## eggshells (Mar 3, 2016)

I appreciate all the replies. But I am a little bit confused. Do I need just the auto shutoff valve or do I need both inline check valve and auto shutoff valve?


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## gonewild (Mar 3, 2016)

eggshells said:


> I appreciate all the replies. But I am a little bit confused. Do I need just the auto shutoff valve or do I need both inline check valve and auto shutoff valve?



It seems you need both. But you may already have the check valve in your system now. Obviously Ray is the one to give the final answer since he sells the parts.


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## eggshells (Mar 3, 2016)

Okay, thanks.

This is my unit and it seems like it doesnt have a check valve. I sent an email to customer support just to be sure. 

http://www.amazon.ca/gp/product/B00DOG64FM?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00


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## gonewild (Mar 3, 2016)

eggshells said:


> Okay, thanks.
> 
> This is my unit and it seems like it doesnt have a check valve. I sent an email to customer support just to be sure.
> 
> http://www.amazon.ca/gp/product/B00DOG64FM?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00



It does not look like it has a check valve in the pictures. Even if it does it wont hurt to have two.


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## Ray (Mar 3, 2016)

The check valve needs to be on the pure water outlet of the RO membrane housing, if you want to add the hydraulic cutoff.

What you have there is a Canadian copy of my "Counter Top" system, and it is intended for manual use only - turn the water supply on to collect RO, and off again when you're done. Upgrading it to automate the on/off is relatively easy, with those two components.


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## eggshells (Mar 3, 2016)

Ray said:


> The check valve needs to be on the pure water outlet of the RO membrane housing, if you want to add the hydraulic cutoff.
> 
> What you have there is a Canadian copy of my "Counter Top" system, and it is intended for manual use only - turn the water supply on to collect RO, and off again when you're done. Upgrading it to automate the on/off is relatively easy, with those two components.



Ok thanks Ray.

So I went to the plumb shop, talked to the guys and was able to get an ASV. He didn't think that I needed the check valve. He said that the non pressurized tanks doesn't have enough pressure to create a back water push thus the check valve is not needed.


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## gonewild (Mar 3, 2016)

(snake eyes)
The pressure tank does not create extra pressure in the line it simply provides a volume of space to regulate line pressure. 
So maybe that advice is not correct?


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## eggshells (Mar 3, 2016)

gonewild said:


> (snake eyes)
> The pressure tank does not create extra pressure in the line it simply provides a volume of space to regulate line pressure.
> So maybe that advice is not correct?



I am not sure. I will try and install the ASV tonight without the check valve. I'll post again what happens.


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## Ray (Mar 3, 2016)

In a residential application, the pressure tank is in between the RO system and the faucet, and the air behind the bladder does add some pressure to that line.

When I started building systems, the check valve was built into the membrane housing, then - without an obvious change in appearance - the manufacturer stopped doing that. Systems I shipped without the check valve (with tank) kept on flowing, even when the tank was full.


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## gonewild (Mar 3, 2016)

Ray said:


> In a residential application, the pressure tank is in between the RO system and the faucet, and the air behind the bladder does add some pressure to that line.



How? It cant add more pressure than the water supply pushes with.


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## eggshells (Mar 3, 2016)

Okay. I installed the two pieces and I can confirm that the inline check valve is needed for the auto shutoff valve to work.


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## Ozpaph (Mar 4, 2016)

Why go to all that trouble?
I put an electronic garden tap timer on the inlet (on the faucet/tap supplying the system). I worked out that it took 2 hours to fill the bucket (trial and error), so the timer turns on the inlet for 2hrs each day to fill the bucket.
Simple.
No waste.


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## eggshells (Mar 4, 2016)

Ozpaph said:


> Why go to all that trouble?
> I put an electronic garden tap timer on the inlet (on the faucet/tap supplying the system). I worked out that it took 2 hours to fill the bucket (trial and error), so the timer turns on the inlet for 2hrs each day to fill the bucket.
> Simple.
> No waste.



Actually this is just as easy if not easier than a timer once installed. No need to fiddle and set the time. It stops when it fills up and its actually cheaper than a timer.


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## Ray (Mar 4, 2016)

...and zero energy consumption.


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## Ozpaph (Mar 4, 2016)

"once installed" is the operative word. So far its 4 pages of how too........
Let us know how it goes.


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## Ray (Mar 5, 2016)

I don't know what instructions for installing those would have four pages. You cut two existing tubes, connect them to the appropriate ports on the cutoff (especially easy with push-in quick-connect fittings, as I get them), and you're done!


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## eggshells (Mar 5, 2016)

Ozpaph said:


> "once installed" is the operative word. So far its 4 pages of how too........
> Let us know how it goes.



Well everything new has a bit of a learning curve. I did state I was able to get it to work. Gonewild's link and Ray's instructions worked.


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