I'm thinking of running my rodi waste line during the summer months outside to a storage tank and use the waste water for plants. It will need to go up 7-8' to accomplish this. I don't foresee any problems with it. Thoughts?
How high will ro/di waste line push water?
- Thread starter goodtimes
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EllisJuan
Active Member
I agree, 7-8 foot would not be a problem at all. I would be curious to know that in extreme circumstance like having the waste water pushed 30-40 feet up how it would effect production of RODI.
Lengthening or raising the waste line will change your waste ratio so ALWAYS measure the waste ratio when you make a change and adjust it back to the factory specs using a capillary tube flow restrictor you trim yourself using the new parameters.
Its not so much that it affects production, just that it lowers the waste so the membrane is not flushed as well when in use.
Its not so much that it affects production, just that it lowers the waste so the membrane is not flushed as well when in use.
thejuggernaut
Active Member
34' of water column is one atmosphere which is 14.7 psi. Most RODI shut-offs engage around 40 PSI. So 8' would be around 4.5 PSI. I bet you could push the water up over 60' before it shut off the RODI.
Regards,
Taylor
Regards,
Taylor
SaltyReefer
Active Member
AZ, does it matter if the line run is up/down or parallel? or only if you are going up with the line?
thejuggernaut
Active Member
Only vertical height will add to your head pressure. Friction from a very long length of tubing might increase back pressure a little bit, but I would imagine it is a very small amount because of the slow flow through the line. He is right though that back pressure on the waste water line will change the pressure differential between the two sides of the membrane. If you're really concerned about it you can put a pressure gauge on the outflow side before the flow restrictor. That will give you quantitative data on how much extra pressure you are creating.
Regards,
Taylor
Regards,
Taylor
thejuggernaut
Active Member
Only vertical height will add to your head pressure. Friction from a very long length of tubing might increase back pressure a little bit, but I would imagine it is a very small amount because of the slow flow through the line. He is right though that back pressure on the waste water line will change the pressure differential between the two sides of the membrane. If you're really concerned about it you can put a pressure gauge on the outflow side before the flow restrictor. That will give you quantitative data on how much extra pressure you are creating. Or like he said, get a bucket and stop watch....
Regards,
Taylor
Regards,
Taylor
Any excessive length or elevation change does matter. The line is 1/4" and there is quite a bit of friction loss when you consider the velocity from the waste on a 75 GPD or larger membrane at 4:1 waste ratio. Same with the height since additional head will change the waste ratio and cause your membrane to fail since it is not being flushed as it should be during use.
Its not the total shutting off of the RO/DI you should be concerned with, which raising the waste wil not do since all the water would then come out of the treated line not the 4:1 it should be. It is the altering of the waste that is the concern and easy to correct with properly trimmed capillary tube flow restrictor.
Its not the total shutting off of the RO/DI you should be concerned with, which raising the waste wil not do since all the water would then come out of the treated line not the 4:1 it should be. It is the altering of the waste that is the concern and easy to correct with properly trimmed capillary tube flow restrictor.
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