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R/O Unit Problems

  • #41
Chrono, as far as i know it shouldnt pulse, the only ones that will pulse are those equipped with a permeate pump... which yours doesnt have

have you confirmed the ASO hookups?

and your output should be zero ppm or close to it with a DI equipped system

lets go back and take the tds measurements again, do all the same test points

inlet

outlet from prefilter
'
inlet to membrane

outlet from membrane

inlet to DI

outlet from DI

waste water

and now we need to check pressure at the membrane inlet with output flow at max

and we need to know brine rate now to verify restrictor adjustment


Ill be honest chrono, if you get out of this without replacing the membrane and/or beads you'll be lucky... but you will know RO inside and out, it is an investment that you will probably get use from for many years... so in the long run the education you have gained is at least an unintentional benefit, I know that doesnt help a whole hellva lot at the moment

but lets not jump to that yet... not without the numbers

BTW, I have an extra quart of beads Ill donate to the cause if you need them

Av
 
  • #42
Well I had originally thought that the DI beads were already all used up, but when I drained the water from the capsule.. half of them still had their original color. So they should still be of use for the time being.

I think before I start taking those TDS measurements again, I need to deal with another issue. Since readjusting the flow restricter, the unit has yet to produce anymore than a couple dribbles of water.. so I decided to restrict the flow a bit more to see if it fixes that problem. I should know by tomorrow morning.. then I will take those readings again. Since I have to work tomorrow I may not be able to get them then, but Thursday I will. I also ordered a better restricter that just has two settings.. flush and restricted.. nice and simple. (I's the one you recommended, Andy. It was rated for 75-100GPD, I left a note in my payment saying that I need it to be for 100 GPD membranes so I'm not worried about that.)

Oh and about the bursts of water. I think that was just a side effect of the system rebuilding pressure after the DI capsule was emptied. I'm thinking of just shutting down the system until the new flow restricter arrives.

It seems like no matter what setting I put the restricter on, it still won't give me any more than a small spritz of water which still gives me a 48ppm reading.
 
  • #43
okie dokie,

FWIW you should be able to tell if the flow restrictor is sized correctly by checking the pressure on the inlet of the membrane, assuming your system inlet pressure is about right the inlet to the membrane should be at least 40psi... as you open and close your adjustable flow restrictor you should see this pressure increase and decrease. Proper setting would be at least 40psi, then once you have this pressure set you can check brine rate/rejection ratio and determine for sure if your membrane is shot

the point of the adjustable flow restrictor is the ability to increase this backpressure as the membrane ages, which is actually kind of nice but it sure does complicate the installation process

Av
 
  • #44
Well when I finally get my pressure gauge hooked up.. I'll be sure to check for 40 psi. Does that mean I should put the pressure gauge right before the membrane?

Andy, I got a reply from Aqua-Safe tech support from that email you wrote up for me. It just says this...

"Hi this is not enough to analyze the problem...try screwing the variable flow resister in more...ed"

Awesome, replying to a three paragraph message with one sentence..nice... unless he's JUST now getting the one I sent with all that TDS data like 4 days ago.
 
  • #45
systematic approach chrono, by the numbers

isolate the bladder tank (turn it's ball vavle off)

first... what is the line pressure going to the inlet of the system with the system output at full flow (exactly where you see my gauge at in the pic)

above 45?... then proceed, below 40 then we've got a problem with the supply pressure

second.... with the system output at full flow what is the pressure at the membrane inlet

less then 40 then see if you can close off the adjustable flow restrictor to get it to 40

more then 40 then see if you can open the adjustable flow restrictor to lower it to 40 or set it at mid travel and record pressure

third.... now measure brine rate

brine rate 3:1 to 5:1?... if yes then proceed, if no then try to adjust flow restrictor to achieve something in that range and recheck pressure at membrane inlet... record the new pressure reading
(open adjustable flow restrictor to increase the ratio, close it to lower the ratio)

forth....measure tds at membrane inlet and outlet, record the numbers and caclulate rejection ratio



and it will only trickle a little flow with the bladder isolated, thats why we need the bladder... to store up the flow so when we do need it, it will have a decent pressure and flow behind it
 
  • #46
It looks like I've done something right.. the TDS is down to 12!

I must've gotten the right brine ratio last night when I was messing with it. It's produced quite a lot of water in just one day too. I still ordered a better restrictor.. because really the one I have is not user friendly at all. I don't like dealing with the uncertainty of it. I just wanted a simple restrictor that means.. flush or restricted.. simple as that. I hope it gets here soon.
 
  • #47
What are you going to do with the adjustable one? :) I wouldn't mind checking it out.... :D
 
  • #48
I'm going to burn it at the stake for giving me so much trouble.
 
  • #49
oh, good! As long as it has a destiny other than sitting in the "junk drawer" for 4 years before someone says "What the heck is this???" "I dunno, not mine." "Okay, I'm going to throw it away." haha
 
  • #50
:beer:

cool.... i recommend you still take all the readings and put them in a safe spot, then if you have future issues you will have some baseline numbers to compare with

and do you have a pretty good understanding of the process now?

nice work

and its all about pressure differentials:

Reverse osmosis separation technology is used to remove dissolved impurities from water through the use of a semi-permeable membrane. RO involves the reversal of flow through a membrane from a high salinity, or concentrated, solution to the high purity, or "permeate", stream on the opposite side of the membrane. Pressure is used as the driving force for the separation. The applied pressure (P) must be in excess of the osmotic pressure of the dissolved contaminants to allow flow across the membrane. (General Electric's Membrane Division)

Av
 
  • #51
Well.. I spoke too soon.

Just now I went to fill a gallon jug with the water and I checked the TDS. It's 26 now. That didn't bug me all that much because I figured as the tank got less full, the TDS would get lower. But actually.. the opposite happened. It slowly went from 26 to 30 and it just kept going up steadily from there until it got to 41 just as the tank emptied.
 
  • #52
then you need to take the measurements... if tds is low coming out of the membrane but high coming from the tank then the membrane isnt the prob... (just an example...)

i cant tell you if your membrane is good or bad without knowing the numbers, no one can

if... your brine rate is between 3:1 to 5:1

and

if your water temp is "normal"

and

if your pressures are correct

and

if your rejection rate is less then 90%

then the membrane is junk, it's cut and dry

if the rejection rate is more then 90%

then the membrane is damaged but servicable, more then 95-97% and its in great shape

its that easy... but you got to do it systematically or you will continue to go in circles mate

Av
 
  • #53
The reason the TDS went back up is because the waste line slipped off of the hole in the drain pipe so the pressure was put back on the membrane again. I fixed this by extending the hose so that it actually goes into the drain pipe.. which is actually probably what I was supposed to do in the first place, but the waste line came pre-attached and I once again assumed that nothing more needed to be done with it. Now the system doesn't reach the nails that it had been hanging on (I don't know WHY they had to make some of the hoses so short and others incredible long.) but it's not that big of a deal...

Now the TDS should be going back down now. I still can't wait to get that new restrictor.. apparently it was just now shipped today so it probably won't get here until Monday or so.. but I had to move it from the setting that I had it on before so now I'm not sure if it's the right ratio. 4 1/2 turns I did.. it better be right.
 
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