Concentrate Flow Adjustments

Definitions & Tools

• Concentrate: Water that is rejected by the membrane to Drain.
• Permeate: Water that has been purified - Product Water which flows to the tank.
• CCW: Counter Clock Wise (direction of concentrate pressure valve adjustment).
• CW: Clock Wise (direction of concentrate pressure valve adjustment).

To adjust the Concentrate Flow, you will need the following:

• Phillips Screwdrivers
• Volumetric Flask or Cylinder
• Stopwatch

Concentrate Flow Importance

• After installation of any unit with a Reverse Osmosis Membrane, the Concentrate Flow MUST be adjusted.
• Due to possible changes in feed water temperature and pressure, the concentrate flow must be checked and readjusted (if necessary) every 3 months to ensure proper water production and to maximize membrane life.
• Failure to adjust concentrate flow can result in membrane damage or failure.

Measuring Concentrate Flow

All Flows (concentrate & permeate) are listed in Liters Per Hour (LPH).

The "36 Second" Rule:

To save time, you do not want to measure the concentrate (reject) flow rate for one hour. The 36-second rule is based on a simple mathematical formula:

60 seconds x 60 minutes / 100 = 36 seconds

When units are in production mode (making RO water), fill a Volumetric flask or cylinder with the concentrate for 36 seconds (using a stopwatch).

Measure the volume of water in the flask or cylinder and multiply by 100. Your results will be the concentrate flow in LPH.

Example: 320ml of concentrate x 100 = 32 LPH Concentrate Flow.

Models Needing Concentrate Flow Adjustment

The following models require Concentrate Flow adjustment during installation and approximately every 3 months:

• Barnstead Smart2Pure
• Barnstead Pacific TII
• Barnstead LabTower RO
• Barnstead Pacific RO
• Barnstead LabTower EDI
• Barnstead LabTower TII

Smart2Pure Concentrate Adjustment

The unit must be producing water to measure the concentrate flow.

If the storage tank is full, drain enough water from the tank to lower the float. After a 3-minute delay, the unit will start producing water again.

Locate the Concentrate Tubing

The tubing is approximately 1/4" going to the drain.

Check and readjust every 3 months.

Based on 17% recovery, the concentrate flow can be adjusted to produce more water, especially if there are problems filling the tank. More water going to concentrate lowers back pressure on the membrane to produce water.

• Adjust concentrate flow down to 15 LPH is acceptable if necessary for permeate production.
• Change to 30 LPH is acceptable if necessary for permeate production.

Following the 36-second rule, compare the concentrate flow against the chart above. If the flows are not correct, adjustment is necessary.

Adjustment Procedure:

• Remove the blue cover and locate the Pressure Hold Valve (V2).
• Turn the concentrate valve CCW (Counter Clock Wise) to increase or CW (Clock Wise) to decrease concentrate flow in order to obtain the correct concentrate flow.

Image Description: A close-up view of a valve assembly, with a red circle highlighting a brass fitting, identified as the Pressure Hold Valve (V2). The image also shows labels "Konzentrat Concentrate".

Pacific RO Concentrate Adjustment

Locate the Concentrate tubing to measure the concentrate flow.

Check & readjust every 6 months.

Following the 36-second rule, compare the concentrate flow against the chart above. If the flows are not correct, adjustment is necessary.

Adjustment Procedure:

• Remove the back panel and locate the Pressure Hold Valve (V2).
• The valve is located at the top of the Distribution Block.
• Turn the concentrate valve CCW to increase the concentrate flow or CW to decrease the concentrate flow.

Image Description: A diagram of connection ports on a unit, showing labels for "Niveau-schalter level switch", "Druckeranschluß Printer connection", "Ko Concentrate outlet", "Ro Raw water inlet", and "High pu".

Pacific TII Concentrate Adjustment

Locate the Concentrate tubing to measure the concentrate flow.

Check & readjust every 6 months.

Following the 36-second rule, compare the concentrate flow against the chart above. If the flows are not correct, adjustment is necessary.

Adjustment Procedure:

• Remove the back panel and locate the Pressure Hold Valve (V2).
• The valve is located at the top of the Distribution Block.
• Turn the concentrate valve CCW to increase the concentrate flow or CW to decrease the concentrate flow.

Image Description: A close-up view of a valve assembly, with a red circle highlighting a brass fitting, identified as the Pressure Hold Valve (V2).

LabTower EDI Concentrate Adjustment

The LabTower EDI requires its RO Concentrate and EDI Product & Concentrate Flows to be adjusted. Adjust the RO Concentrate Flow first.

Locate the Concentrate Tubing

The Concentrate Outlet is located in the front of the unit, below the blue cover.

You will also need to remove the front panel of the LabTower base and adjust the EDI Flow rates via adjustable flow meters (V8 & V9).

Check & readjust every month.

Following the 36-second rule, compare the concentrate flow against the chart above. If the flows are not correct, adjustment is necessary.

Adjustment Procedure:

• Remove the back panel and locate the Pressure Hold Valve (V2).
• The valve is located at the top of the Distribution Block towards the front of the unit.
• Turn the concentrate valve to increase or decrease concentrate flow in order to obtain the correct concentrate flow.

Image Description: A close-up view of a valve assembly with a red arrow pointing to a fitting, identified as part of the adjustment mechanism.

LabTower EDI Product & Concentrate Adjustment

After adjusting the concentrate flow, the EDI Product & Concentrate Flows must be adjusted while the unit is running. Start with the Product Flow.

The Product Flow should be adjusted to the model by the flow meter:

• LabTower EDI 15 = 15 LPH
• LabTower EDI 30 = 30 LPH
• LabTower EDI 45 = 45 LPH

The Concentrate Flow should be adjusted by the flow meter to approximately 10% of the Product Flow:

• 15 LPH – Concentrate setting: 1.5-2 LPH
• 30 LPH – Concentrate setting: 3 LPH
• 45 LPH – Concentrate setting: 4.5-5 LPH

Image Description: Two flow meters are shown, one labeled "Product" and the other "Concentrate".

LabTower RO Concentrate Adjustment

Locate the Concentrate tubing to measure the concentrate flow.

The Concentrate Outlet is located on the front of the unit, below the blue cover.

Check & readjust every month.

Following the 36-second rule, compare the concentrate flow against the chart above. If the flows are not correct, adjustment is necessary.

Adjustment Procedure:

• Remove the back panel and locate the Pressure Hold Valve (V2).
• The valve is located at the top of the Distribution Block.
• Turn the concentrate valve CCW to increase the concentrate flow or CW to decrease the concentrate flow.

Image Description: A close-up view of a valve assembly, with a red circle highlighting a brass fitting, identified as the Pressure Hold Valve (V2).

LabTower TII Concentrate Adjustment

Locate the Concentrate tubing to measure the concentrate flow.

The Concentrate Outlet is located on the front of the unit, below the blue cover.

Check & readjust every month.

Following the 36-second rule, compare the concentrate flow against the chart above. If the flows are not correct, adjustment is necessary.

Adjustment Procedure:

• Remove the back panel and locate the Pressure Hold Valve (V2).
• The valve is located at the top of the Distribution Block.
• Turn the concentrate valve CCW to increase the concentrate flow or CW to decrease the concentrate flow.

Image Description: A close-up view of a valve assembly, with a red circle highlighting a brass fitting, identified as the Pressure Hold Valve (V2).

Revisions

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