Adjustment of TDS (Total Dissolved Solids) Using the Blending Valve
IMPORTANT NOTES:
• Typical TDS (Total Dissolved Solids) values for coffee are 80-200 ppm and occasionally lower for espresso, depending upon taste
preference.
•
The blending valve should be set at start-up and checked periodically, for example when changing filter cartridges. The valve is a
precision metering valve that may be locked using a small allen wrench.
• In order to set the blending valve, it is important that no bypass water be mixed with the blended RO water. Thus, the TDS of the
blended water must be measured from a sample taken from the tank or from the line going to the tank while the valve is being
adjusted. Use the sample valve at the tank to collect the samples. The TDS of the sample must be measured using a TDS meter
(not supplied). The TDS meter on the TFS450 RO filtration system may not be used to set the blending valve. The meter will read
the TDS of water exiting the system, and this is not always blended RO water.
1. Close the outlet shut-off valve to downstream equipment and the tank shut-off valve and open the sample valve at the tank.
2. After about two (2) minutes, collect a sample and measure the TDS using a TDS meter (not supplied).
3. Rotate the blending valve to the left (counterclockwise) to increase the product water TDS and to the right (clockwise) to decrease
the product water TDS. The valve should be opened intermittently at 1.0 to 1.5 turns at a time. Check the TDS after each
incremental opening and again two (2) minutes after the desired TDS value is reached. Re-adjust and check, as needed.
4. Lock the blending valve using a 0.05 inch allen wrench.
5. Close the tank sample valve, open the tank shut-off valve and open outlet valve.
IMPORTANT NOTE:
The TDS Meter is push-button operated and requires two (2) 357A batteries.
Automatic Bypass Pressure Adjustment
When the pressure in the remote storage tank falls below the bypass pressure set on the pressure regulator, the automatic bypass will
begin to open to allow a flow of filtered water to maintain the product water demand flow. The bypass pressure setting should be checked
and adjusted if necessary at system start-up and periodically when the filter cartridges are changed. The regulator is shipped in the
“closed” position and must be set to 30 psi (207 kPa) prior to system start-up. The setting should be checked and adjusted periodically,
for example when the filter cartridges are changed.
IMPORTANT NOTE:
Do not set bypass pressure greater than 30 psi (207 kPa).
1. Close the shut-off to the outlet to downstream equipment and the tank shut-off valve.
2. Open the tank sample ball valve and direct the flow to drain or to a collection vessel. This step relieves outlet pressure supplied
by the RO membranes and the blended water being produced.
3. Adjust the pressure to 30 psi (207 kPa) as seen on the final (post) filter pressure gauge (on the right side of the filtration system).
Rotating to the right (clockwise) increases the pressure setting. Rotating to the left (counterclockwise) decreases the pressure
setting. At start-up, this step may require several revolutions.
4. Relieve pressure using the sample valve on the outlet to decrease gauge reading. Note the pressure and re-adjust the regulator,
as
necessary.
5. Tighten the lock nut to secure the pressure regulator.
6. Open outlet valve. Close both sample valves and open the tank shut-off valve.
7. The tank will now begin to fill with RO water. The necessary times to fill tanks of various drawdown volumes are given in the table
above. Allow the system to run until the tank is full and you can no longer hear the permeate pump clicking. The first tank of
water should be sent to drain to properly flush the RO System. The tank may be drained by opening the tank sample valve and
directing the flow to drain. (The tank may also be drained by opening the outlet sample valve and directing the flow to drain. Using
the outlet sample valve further serves to properly flush the final (post) filter cartridges.)
8. System is now ready to use
12
Fill Times for TFS450 Tanks*
Tank Drawdown Volume
Approximate Time to Fill
10 gallons (37.8 liters)
0.8 hours
20 gallons (75.7 liters)
1.6 hours
40 gallons (151 liters)
3.2 hours
*@70°F (21°C) Water Temperature
TFS450 - Estimated Water Production without Blending
0
100
200
300
400
500
600
40
50
60
70
80
90
Water Temperature (F)
P
ro
d
u
c
ti
o
n
r
a
te
(G
P
D
)
50 psi
90 psi
TFS450 System Overview
Module/Element
Part Number
3M ID
TFS450-BP Water Booster Pump Module (Sold Separately)
62339-01
TFS450 RO Filtration System with Pre- and Post Filters Included
56239-01
70-0202-1775-1
TFS450 RO Filtration System without Pre and Post Filters and
Bypass Plug in Final Filter Head
56230-02
70-0202-1776-9
Tank 20-Gallon Draw-Down (Sold Separately)
55984-08
Tank 40-Gallon Draw-Down (Sold Separately)
55984-09
Description
56239-01
(Qty)
56239-02
(Qty)
Base unit assembly (see Figure 2)
1
1
Pre-filter Cartridge HF95
1
0
Final (Post) Filter Cartridge HF90
1
0
Final (Post) Filter Bypass Plug
0
1
RO Membrane Cartridge
2
2
TDS meter
1
1
Installation Manual
1
1
5
Parts List
The following parts are included with the TFS450 reverse osmosis filtration system. Unpack the contents from the product box and
check to verify that all of the parts are included. Should any parts be missing, please contact 3M Purification at 866.990.9785.
Figure 1
