RO/DI PSI help!

[ReeferMadness80G]

I bought a used RODI system, replaced the auto shut off and psi meter. I have it hooked up at my washer connection and at best I get like 35 psi. My tds meter says I'm putting out 0 TDS after the DI chamber, however when I've tried to simulate a full reservoir by shutting off a ball valve on the feed, I still have waste water coming out.

Idk if it matter but if I pinch the waste water line it shot the pressure up to 60 psi and activated the Auto Shut off.

Now I know you're gonna tell me I need a booster pump, but I refuse to believe I'm only getting 35 psi. Is it possible there's something wrong with the unit causing me to get a 35 psi reading? Can I just put a ball valve on the waste water line and close it a little bit so my pressure will go up?

Cause right now I'm getting 0 TDS and pretty decent trickle for a 75 GPD system, I just need it to shut off the waste water when it's done filling. I'll post some pics so you can tell me if something looks wrong.

 

[ReeferMadness80G]

 

[ReeferMadness80G]

Do I need a flow restrictor? Bc I don't have one

 

[PedroYoung]

you can buy a cheap gauge to go on the washer connection at Home Depot and check what the base water pressure is. 35 psig is about what I get, but I'm on a well (and use booster pump to get it up to 85 psi).

 

[ReeferMadness80G]

Yeah, I'm on city water. What does a flow restrictor do? I don't have one installed and don't know if I should

 

[Potatohead]

You probably have a flow restrictor. It sits inside the waste line where it leaves the DI resin container, or at least it should be. Yes, you need one.

How do you have this plumbed? The line leaving the sediment goes to a Tee with the gauge, but I can't see where it goes from there. Usually that would go into the carbon block.

 

[ReeferMadness80G]

You probably have a flow restrictor. It sits inside the waste line where it leaves the DI resin container. Yes, you need one.

How can I check? Would not having one cause poor psi?

 

[Potatohead]

How can I check? Would not having one cause poor psi?

Absolutely

You can take the line off the fitting and it will be inside. Sometimes it is difficult to remove the line if you have one in there.

 

[ReeferMadness80G]

I don't see anything

 

[Potatohead]

Watch about 10:20 mark in this video

 

[ReeferMadness80G]

Watch about 10:20 mark in this video

Yeah I definitely didn't see one of those guys in there. My question is tho, why do I need one? And will it help my psi? My psi is like 35,

 

[Potatohead]

The whole point of it is to restrict flow so you get the pressure in the membrane you need. Typically the ratio is about 4:1 waste to product water. Right now you are likely making a lot more waste than that and losing a lot of pressure in the process. You can run the unit and measure out how much more water is coming out the waste side than the product side, just collect for 15 seconds each and see how much comes out. As stated should be about 4:1, maybe more like 4.5:1 with low pressure. I bet you are higher.

 

[ReeferMadness80G]

The whole point of it is to restrict flow so you get the pressure in the membrane you need. Typically the ratio is about 4:1 waste to product water. Right now you are likely making a lot more waste than that and losing a lot of pressure in the process. You can run the unit and measure out how much more water is coming out the waste side than the product side, just collect for 15 seconds each and see how much comes out. As stated should be about 4:1, maybe more like 4.5:1 with low pressure. I bet you are higher.

Holy cow mr potato head!! Look at this! 15 seconds for each one!

RODI feed

waste water feed

 

[Potatohead]

LOL

So yeah, get the proper waste restrictor for your membrane gpd, and you will be good.

 

[ReeferMadness80G]

LOL

So yeah, get the proper waste restrictor for your membrane gpd, and you will be good.

Thanks, can I use a ball valve on the waste water line until the restrictor comes?

 

[Potatohead]

Thanks, can I use a ball valve on the waste water line until the restrictor comes?

I don't see why not, just set it around 4:1

 

[ReeferMadness80G]

I don't see why not, just set it around 4:1

You're awesome! Thank you!

 

[Potatohead]

All good man

 

[Pete1968]

Booster pump

 

[ReeferMadness80G]

All good man

Thanks for helping me, your information solved my problem! I put a ball valve on it and dialed it back to a 4:1 ration which was 1/4 cup vs a full cup in 15 seconds. I'm getting so much more rodi water now and my pressure is 55-60 psi! And I'm still dialed in at 0 TDS! And I also called the person I bought the unit from and asked him about a flow restrictor and he told me he forgot to give it to me! Thank you so much @Potatohead, since I got this unit in I felt like I was missing a piece of the puzzle and you helped me find it! I'll sleep good tonight thank you!
Edit: #mods can we get this guy/gal a cookie!?