Auto shut off valve on RO/DI system.

MTBake · May 21, 2019

Are these thing supposed to lower pressure going into the membrane?

I installed an auto shut off valve so I can automate my water system. I also added a drinking water add on kit at the same time.

Long story short, my pressure going into the membrane dropped from 75 psi down to 50 psi. The production of water seems to have slowed as well. I checked the install several times and I'm 99% sure it's hooked up right.

Is this normal? Has anyone else experienced this?

I'll tag @Buckeye Hydro as this kit came from Russ.

Battlecorals · May 21, 2019

just thought, do you have a check valve on the line out of the membrane housing that feeds the pressure tank?

MTBake · May 21, 2019

Battlecorals said:
just thought, do you have a check valve on the line out of the membrane housing that feeds the pressure tank?

There's a check valve between the permeate line and the shut off valve. And another check valve between the low pressure output on the ASOV and the inline carbon filter. The check valves have a red release ring on the output side of the valve.

Here's a pic of the jumbled mess of hoses I have going on right now. I want to clean this up but need to make sure this is working before I do. Don't want to undo everything if it isn't right.

Buckeye Hydro · May 30, 2019

MTBake said:
Are these thing supposed to lower pressure going into the membrane?

I installed an auto shut off valve so I can automate my water system. I also added a drinking water add on kit at the same time.

Long story short, my pressure going into the membrane dropped from 75 psi down to 50 psi. The production of water seems to have slowed as well. I checked the install several times and I'm 99% sure it's hooked up right.

Is this normal? Has anyone else experienced this?

I'll tag @Buckeye Hydro as this kit came from Russ.

Should we be notified when someone tags us?

Anyway... no - you shouldn't expect a substantial drop in incoming pressure when you install an ASOV.
When you add a drinking water add on kit you will see an increase in BACK pressure. RO membranes are dramatically affected by their NET DRIVING PRESSURE. That is calculated as:
Feed Water Pressure minus Back Pressure

When a typical ASOV is installed, back pressure from a filled tank will be about 66% of incoming pressure.

Make sense?

Russ

Buckeye Hydro · May 30, 2019

MTBake said:
There's a check valve between the permeate line and the shut off valve. And another check valve between the low pressure output on the ASOV and the inline carbon filter. The check valves have a red release ring on the output side of the valve.

Here's a pic of the jumbled mess of hoses I have going on right now. I want to clean this up but need to make sure this is working before I do. Don't want to undo everything if it isn't right.

Looks like there is an error in the plumbing mods you've made. Want to give us a call when you're in front of the system?

Russ

KStatefan · May 30, 2019

Buckeye Hydro said:
Should we be notified when someone tags us?

Russ

I get an alert that someone mentioned me in a post.

MTBake · May 30, 2019

Buckeye Hydro said:
Looks like there is an error in the plumbing mods you've made. Want to give us a call when you're in front of the system?

Russ

It's actually working great right now. Psi is at 70 while operating.

But yeah, I can give you a call around 4:30pm cst.

Buckeye Hydro · May 30, 2019

Is your left hand housing "in" connected to your center housing "out"?

MTBake · May 30, 2019

Buckeye Hydro said:
Is your left hand housing "in" connected to your center housing "out"?

I'll have to double check when I get home from work.

The top three canisters flow right to left and the bottom 3 (DI stages) flow left to right.

Here's the order it's setup in;

Sediment
Carbon
Carbon
In on ASOV (labeled IN)
Out on ASOV (labeled OUT)
Into ro membrane
Out of ro membrane
Through check valve
In side with screws of ASOV
Out of ASOV
Into a T
That T feeds DI, pressure tank and inline carbon filter. I have a valve installed to shut off flow to the DI when not in use. There is a check valve on the line that flows to the inline carbon filter/pressure tank.

Hope that makes sense.

Buckeye Hydro · May 30, 2019

understood. The potential issue I see is that in its original configuration, the middle housing DID NOT flow to the left hand housing -- it flowed up to the membrane. I can't tell from your pics how the middle housing and the left housing are attached, if at all.

MTBake · May 30, 2019

Buckeye Hydro said:
understood. The potential issue I see is that in its original configuration, the middle housing DID NOT flow to the left hand housing -- it flowed up to the membrane. I can't tell from your pics how the middle housing and the left housing are attached, if at all.

Gotcha. I did reroute the tubing to go through the third canister before the membrane.

Buckeye Hydro · May 30, 2019

What did you find - what was causing your issue?

Buckeye Hydro · May 30, 2019

One more thing. Is the RO water that goes to your DI coming out of the pressure tank?

MTBake · May 30, 2019

Buckeye Hydro said:
What did you find - what was causing your issue?

I did nothing at all. The pressure was good after a day of having everything hooked up.

MTBake · May 30, 2019

Buckeye Hydro said:
One more thing. Is the RO water that goes to your DI coming out of the pressure tank?

The RO water does not flow from the pressure tank through the DI. There's a check valve to prevent that. It's installed on the line that feed the inline carbon filter and pressure tank. Water shouldn't be able to back flow through the DI.