Flow restrictor for RODI System

[yman182]

Hello All,

I am using a Spectrapure 90GPD Membrane

https://spectrapure.com/products/sp...us-99-rejection-ro-membrane-90gpd-mem-sp-0090
and am about to replace my autoflush valve as mine seems to be defective. Does anyone know what the proper size for the filter I have is so I can purchase the proper new one?

Spectrapure mentions that I need to size it properly, but never says what the size is!

https://www.bulkreefsupply.com/aquatec-auto-flush-flow-restrictor.html
I know that BRS gives recommendations at the bottom, but I am not sure if those will work for the spectrapure RO membrane. I think they are just a 75GPD membrane that is rated 90GPD at a higher pressure.

Any help would be appreciated!

 

[Reef.]

You match your membrane, it’s just to make sure the amount of pressure going to the membrane does not over power it.

 

[yman182]

You match your membrane, it’s just to make sure the amount of pressure going to the membrane does not over power it.

What does that mean exactly? If my membrane is rated at 90GPD at 60PSI, how many ml/min flow restrictor do I need?

 

[Reefnman2]

I see what you mean, I would go with the 600 or 700 ml for 90gpd.

 

[yman182]

I see what you mean, I would go with the 600 or 700 ml for 90gpd.

Awesome thank you. Can I ask how you came to that number? I am very curious about how all this stuff works!

 

[Reef.]

Awesome thank you. Can I ask how you came to that number? I am very curious about how all this stuff works!

If you get no joy here I would open a live chat with BRS and ask their advice as the way I worked it out was 90g\24hours which gives 3.75 gallons you are making an hour, convert that to ml, gives 14,193ml then divided by 60 mins, which then gives 236.5ml so I would guess if my maths is right the 300ml would be the one but going by BRS’s recommendations they seem to recommend higher rated flow restrictors?

 

[Water Dog]

Spectrapure 90 GPD membranes are rebranded Dow Filmtec 75 GPD membranes. They used to be batch tested to get the 99% ratings though I’m not sure that is done anymore. They get the 90 GPD rating from the higher 60 PSI pressure recommendaction. Push water at 50 PSI through it and you’ll get 75 GPD.

 

[theMeat]

Hello All,

I am using a Spectrapure 90GPD Membrane

https://spectrapure.com/products/sp...us-99-rejection-ro-membrane-90gpd-mem-sp-0090
and am about to replace my autoflush valve as mine seems to be defective. Does anyone know what the proper size for the filter I have is so I can purchase the proper new one?

Spectrapure mentions that I need to size it properly, but never says what the size is!

https://www.bulkreefsupply.com/aquatec-auto-flush-flow-restrictor.html
I know that BRS gives recommendations at the bottom, but I am not sure if those will work for the spectrapure RO membrane. I think they are just a 75GPD membrane that is rated 90GPD at a higher pressure.

Any help would be appreciated!

Do you have a spectrapur unit , or just membrane?
Either way you could use a spectrapur flow restrictor, which is internal, and can be adjusted for your water pressure.
If not, 700 a good bet

 

[yman182]

Do you have a spectrapur unit , or just membrane?
Either way you could use a spectrapur flow restrictor, which is internal, and can be adjusted for your water pressure.
If not, 700 a good bet

I am not using a spectrapure system, just the membrane. I want to use one of the auto flush restrictors which is why I can’t use a capillary type.

 

[theMeat]

I am not using a spectrapure system, just the membrane. I want to use one of the auto flush restrictors which is why I can’t use a capillary type.

Ahh
You want about 4 to 1 waste/product ratio. If much less waste to product your membrane will expire prematurely, if much more your pre membrane filters will expire needlessly.
Would try a 700 and measure/test your ratio and go smaller if needed.

 

[yman182]

I did that earlier today and I was getting about 4.5 to 1 using an 800ml/m. I ordered a smaller one and will try to see what that gets me.