What PSI to run RO at?

[FunnyFarm]

What PSI does everyone run there RO at? I've been running mine over 100 psi... I suppose i can run it lower and test. Just curious what everyone else is doing. I have a home built 150gpd setup been working great so far... Just cleaning up for the start of the season and thinking of ways to tweak for this year...

[bowhunter]

Run it to get the performance you want. If it's working ok then you're fine.

[maple flats]

That's hard to even guess if you made your own. How much does the pump move, what is it's max pressure, what about the membrane housing and the plumbing in the high pressure side of the membrane. Those will all figure in to this before an operating pressure can even be guessed at.

[FunnyFarm]

Hmm? my pump will push i believe 150psi. I'm using 3 residential housings connected
together with 1/4" poly tubing. I use a needle valve to control the pressure.
Should we be running at max pressure?

[mellondome]

Each home built unit will have a sweet spot where more pressure doesnt gain much more water removal per minute. Watch your flow meters and see where increasing pressure has very little to no effect on flow of permeate.
The home built unit I had that was about 175psi.
It will vary between builds and membranes.

[blissville maples]

i run springtech elite 600, membrane pressure max 500psi, i run around 425-450. over 500 you may rupture membranes and then youll pass sugar etc. its a fine line, more pressure higher%. the 500 max info comes from Mike Emerson he used to make them at leader., the man for springtech elites!! have an issue get in touch with him, extremely smart.

[FunnyFarm]

Thanks for the answers!

[maple flats]

My basic unit by Ray Gingerich runs best at 275 PSI with a 300 PSI max. if running sap, when I reconcentrate it runs best at 265 PSI. You just need to watch the flows (and need to know the unit's max. PSI). Then you can find the best pressure by watching the flow meters.

[blissville maples]

i think it makes a big difference as to what machine you have, check with dealer, and techs. my rig, pressure directly relates to concentrate %. the sap will only be in membrane for short time so the more pressure in that membrane the more water will be forced out before the sap mixture exits.

[Clinkis]

My old homebuilt RO with residential membranes I ran about 120psi. My new home built with XLE 4040 I run between 250-300 psi

[BAP]

There is a big difference in pressure required for a home built RO versus a Maple Manufacturer RO. Many of the components for ROs that were designed for home use weren't designed for high pressure. So be careful of advice from people who say their Leader or other maple brand RO says to run 400-500 psi because your components may not be able to take that much pressure.

[Teuchtar]

I run my homemade RO at 300 psi. My pumps can push the pressure higher than this, but this seems to be the safe upper limit for the membrane vessels end caps. If the caps are not clamped on properly, they can readily become a missile. I learned to keep spares on hand, and keep my head away from the vessels.
Barb and compression fittings on any plastic or poly tubing doesn't survive at this pressure. I had to replace all my 300 psi fittings with stainless JIC, and the hoses are food grade hydraulic style.
High pressure is definitely more fun !

Duncan