58
Culligan® Premier Series Automatic Deionizer
58
Cat. No. 01024000
Caustic Draw
Backwash Inlet and Backwash Outlet valves (A1 and A5) are now closed. Water enters through the Pressure Regulator
(PR) “Bypass” through the cation tank. The Anion inlet valve (A3) opens and directs water to the top of the tank. The caus-
tic chemical pump is activated and caustic from the chemical container is fed at connection AP. The mixture of caustic and
water (normally 4–6 percent) is directed to the top of the resin bed. The Caustic flows down through the bed removing the
Anions collected during Service Cycle. The excess caustic and the waste anions exit the Anion Column and flow through
to Drain. This drain water is caustic (high pH) and must be neutralized prior to sending it to the city sewage system.
C1
C4
A5
C2
A3
A1
A2
A4
C3
A6
C5
CP
AP
PR
2
CAUSTIC
SUPPLY
CAUSTIC
PUMP ON
TO
NEUTRALIZATION
TANK
SODIUM
HYDROXIDE
Figure 22.
Caustic draw cycle.
The percentage of the caustic can be adjusted with use of the adjustment knobs on the air regulating valve. Samples of
the diluted acid are taken at the test cock near valve A4 to verify that the mixtures are similar: immediately from the top
of the tank (1), and then 20 minutes later from the bottom of the tank (2). The specific gravity of the solution is used to
determine the percentage of caustic. Refer to the specific gravity chart—see
"Appendix B Regeneration Specifications"
Sodium Hydroxide (Caustic Soda).
