How to rate a reverse osmosis machine

[softmaple]

How do I rate my ro if it gets 60 gallons of fresh water an hour.

[mellondome]

Ro ratings are really arbutrary when it comes to real production rates.

If it works for what you do.. then give it 3 stars. If it exceeds your expectations 5 stars.. was a money pit that didnt work right 1 star. Lol

Each mfg rates them differently.. but I think most are rated with quite warm temp (50*+) sap @ 75% removal.

[ennismaple]

How do I rate my ro if it gets 60 gallons of fresh water an hour.

You need to add the permeate and concentrate flows together to get the "rating" of your RO. Membranes are rated at a certain temperature - I think ours is 13 Celcius. That means it will pass a total of 600 GPH (concentrate plus permeate) if the sap is at the rated temp. Lower than that temp and you process less sap per hour. For example, the slushy sap I processed on Sunday was going through the RO at -1 Celcius and I was only able to process 3.5 GPM concentrate, 8.5 GPM permeate = 12 GPM x 60 = 720 GPH which is not good for 2 membranes but the sap was so cold the membrane pores are closed very tight and you can't push much as much through it.

[Sunday Rock Maple]

able to process 3.5 GPM concentrate, 8.5 GPM permeate = 12 GPM x 60 = 720 GPH which is not good for 2 membranes but the sap was so cold the membrane pores are closed very tight and you can't push much as much through it.

That is how we do it as well -- total amount of sap processed per hour counting both permeate and concentrate. I've been setting concentrate at 2 gpm and it's been yielding 14% with 2% sap at 43 degrees but only about 11 gpm total flow (660 per hour total ) with two Mark E8's. Not used to boiling 14% though, we had to throw a few pails of water in today after the float stuck. We found it in time but the sap in the front pan was down to about 1" and I thought that would be OK (it wasn't) lesson learned!