Culligan M1 Series Installation, Operation And Service Instructions page 22

Pressurized Storage Tank
The product water can be stored in a pressurized storage tank with the reverse osmosis unit controlled by a pressure
switch. Use the same components used for direct feed (see Figure 16) with the addition of a pressure switch which needs
to be wired to the control panel (see
number D1013880. Connect the product tubing to a bulkhead fitting at the top of the storage tank such as P/N 01005095
(2-gallon), P/N 01004776 (3-gallon), or P/N 01004765 (9-gallon).
Non-Pressurized Product Water Storage Tank
Connect the product tubing to a bulkhead fitting at the top of the storage tank.
Depending on the type of application, a level control may be required to turn the unit off when the storage tank is full.
Install the level control according to the instructions provided with the control. Refer to the wiring section in this manual for
electrical connections.
NOTICE If a repressurization pump is used, an additional level control is recommended to prevent the
pump from running dry if the storage tank is empty.
To maintain high water quality, a hydrophilic air vent filter, vacuum breaker, pop-off valve, ultraviolet lamp, and pressure
relief valve may be required.
Direct Feed
If the product water is to be used directly, without storage, a few precautions are necessary to prevent damage to the
elements. Install a pressure gauge, pressure switch, and a normally-open ("dump") solenoid in the product water line as
shown in Figure 16, or use pressurized storage kit (P/N D1013880). The pressure gauge will allow the operator to monitor
the product water pressure. The switch, which should be set to open at 40 psig, will prevent the product water pressure
from exceeding 40 psi. The dump solenoid will relieve all pressure when the unit is off.
Wire the direct feed/pressurized storage solenoid valve in parallel with the motor.
Valve SV4 closes when the RO pump runs; SV4 opens when the pump stops, allowing all membrane back proessure to
be relieved.
NOTICE Product back pressure will decrease the net pressure pushing water through the reverse osmosis
elements. Therefore, the flow of product water will decrease.
18 Culligan® M1 Series Reverse Osmosis
Figure 22 on page 28). A pressurized water storage kit is available under part
Figure 16. Direct feed connection.
18 Cat. No. 01022940