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Prinz

rodi question

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i just pick up a marine depot 100 gpd rodi and when i tried using the line the makes the product water is squirting water like there is no tomorrow, i check both lines and the waste water line has a flow restrictor inside and the product water has none, prolly why product water is pushing that much water and almost none on the waste water

 

my question is that does the waste water and product water tubing need to have flow restrictors?

 

thanks

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I believe the flow restrictor is normally on the waste water side.  The product water side is naturally restricted by the membrane itself....

 

It should not be firing water out.  Is it possible that, like someone else recently, that you have the flush valve which bypasses the restrictor wide open?  That would cause the waste to fire out, but not the product water, though.  Or maybe they forgot to put a membrane in the RO chamber?  

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There should only be one restrictor, and it goes in the waste line out of the RO housing.  The restrictor has to be the correct length so that it generates the right ratio of waste:product water. 

 

The restrictor comes presized, but you really should check the actual ratio by running the RODI unit and collecting product water in one container and waste water in another.  You may have to trim the restrictor to get the right ratio. 

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thanks Jon, restrictor is about 6 inches long, i just spoke with marine depot rep and it seems like the membrane seal has been compromised, just ordered a whole replacement kit and hopefully that will fix the issue

 

thanks again wamas 

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It sounds like your RO membrane is not seated in the housing. If that happens, the waste side basically shorts to the product side and, because there's a restrictor in the waste line, most all of the water will flow out the product side.

 

Open the RO membrane cannister up and pull the membrane out. If it comes out easily, then it's probably not seated well. Push it back in and seat it and retry it. (There's an o-ring or two around the central tube at one end of the membrane. This is the end that goes into the housing first. Seating it requires that you push the membrane in firmly and all the way to drive these o-rings completely into the receiving end at the other end of the canister.)

 

Also, if the unit has a flush valve on it, make sure the flush valve is closed. This should be your first check actually.

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This is actually a pretty good video that should be able to help you check and reseat the membrane if it's not seated properly.

 

 

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2 hours ago, Origami said:

It sounds like your RO membrane is not seated in the housing. If that happens, the waste side basically shorts to the product side and, because there's a restrictor in the waste line, most all of the water will flow out the product side.

 

Open the RO membrane cannister up and pull the membrane out. If it comes out easily, then it's probably not seated well. Push it back in and seat it and retry it. (There's an o-ring or two around the central tube at one end of the membrane. This is the end that goes into the housing first. Seating it requires that you push the membrane in firmly and all the way to drive these o-rings completely into the receiving end at the other end of the canister.)

 

Also, if the unit has a flush valve on it, make sure the flush valve is closed. This should be your first check actually.

thats what i did, pull out the membrane it is seated properly buthe 2nd seal, closer to the cap, has already deteriorated thats prolly why its like the membrane is not there anymore even if its still, anyway, this one doesnt have all the bells and whistles, its just the membrane casing and media casing no tds meter, pressure gauge nor flush valve. i have ordered a full replacement kit as the previous owner mentioned it has been sitting for a while, hopefully it will fix the issue, 

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3 hours ago, AlanM said:

I believe the flow restrictor is normally on the waste water side.  The product water side is naturally restricted by the membrane itself....

 

It should not be firing water out.  Is it possible that, like someone else recently, that you have the flush valve which bypasses the restrictor wide open?  That would cause the waste to fire out, but not the product water, though.  Or maybe they forgot to put a membrane in the RO chamber?  

are all RODI unit the same as to where the waste water and product water comes out? please correct me if i am wrong and point me in the right direction, from what i read  for this particular RODI the waste water comes out of the membrane chamber and the product water comes out on the side next to one of the DI chamber, this one is the marine depot klean water model if that will be of any help

 

thanks

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2 hours ago, Prinz said:

are all RODI unit the same as to where the waste water and product water comes out? please correct me if i am wrong and point me in the right direction, from what i read  for this particular RODI the waste water comes out of the membrane chamber and the product water comes out on the side next to one of the DI chamber, this one is the marine depot klean water model if that will be of any help

 

thanks

Yes, RO membranes are standard. The central tube with the o-ring(s) is where the pure (RO) water collects. Consequently, the housings are pretty standard. There's one fitting on one end and two on the other end. The single one is the inlet. At the other end, there's a fitting that traces back more centrally to the housing and the second is closer to the edge. The edge is the waste line. The central fitting is the RO output. 

 

The large black seal around the body of the membrane is the brine seal. It separates the input side from the waste side. If that seal is deteriorated, then you will have strong flow out of the waste line, not the RO (pure water) output. Given that you may be mixed up about where the pure and waste outputs are, you may be seeing high flow out of the waste line (while thinking it's the pure water output). A brine seal failure would not cause a high output flow. In fact, it would probaby cause production to drop considerably as there would be no flow thru the membrane - it would all go around the membrane past the failed brine seal.

 

Again, the flow restrictor is supposed to be on the waste output line. 

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By the way, I think the guy in the video that I linked above takes you through the inputs and outputs of the RO canister. Watch it again. If your membrane housing looks different, post a picture or link to one that's identical to your setup. I'd be happy to look at it.

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12 hours ago, Origami said:

There's one fitting on one end and two on the other end. The single one is the inlet. At the other end, there's a fitting that traces back more centrally to the housing and the second is closer to the edge. The edge is the waste line. The central fitting is the RO output. 

 

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John has showd you the right labels above. He has a flush valve in his system, though, shown hanging off the tee.

 

Did you get the RO/DI used or was it new? If used, then the next most likely culprit (if it's not the membrane seating properly) is that the membrane is blown. I guess that it happens, but more often they seem to seal up and not pass any water at all (or very little) if they're left to sit for a long time without use. If that's the case, your replacement membrane that will come with the kit that you ordered should address the problem. Just remember that a new membrane has a preservative in it that you need to flush out before putting it into service. So, what you should do is remove your DI resin from the housing and just run the RO system for at least 30 minutes (but 2 hours is better) and just let everything (product and waste) run down the drain. At that point you can put the resin cartridge back in the housing. Also, don't forget to seat it completely.

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thanks, for all the help, i guess we will find out once the replacement kit arrive, i hope it will 

 

thank you again

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