Thermo Scientific Barnstead
Pacific TII
Pure water System
17
9. How Pacific TII functions
Tap water of max. 6 bar pressure flows into the system.
In stand-by mode and during standstill, feedwater solenoid valve V2 is closed. This prevents
feedwater from flowing into the system when it is not in operation, and so protects the tank
against overflowing.
Semi-permeable membrane A-F2 retains dissolved salts in the feedwater within the specified
retention quota. Further to this, the molecular size of the pores of the membrane ensures Ø
99% retention of bacteria, pyrogens and particles.
Following reverse osmosis, the permeate flows past conductivity probe QIA 300 and through
the downstream purification stages such as deionization, adsorption and UV-disinfection (only
UPW) into the tank.
The retained feedwater constituents are flushed away with the concentrate flow.
The special conductivity probe QIA 301 (with temperature compensation) determines the
conductivity of the high purity water (subsequent to the filter cartridge), that can be called to
display in the microprocessor control menu.
Pure water is pumped to the user by a downstream tank with pressure pump A-P2. Float switch
LIS 100 senses the filling level in the tank.
Pump A-P2 simultaneously serves to recirculate the water stored in the storage tank. It so
prevents bacterial growth during standstills and ensures a uniform water quality.
.
Pressure hold valve V3 has been pre-adjusted at the factory. Changes to
the adjustment could result in damage to the reverse osmosis module!
Because of possible fluctuations in feedwater temperature and pressure,
the adjustment of the valve and the concentrate flow that it governs must
be checked on starting up and re-adjusted as necessary by Service at
regular intervals.
Concentrate flow for Pacific TII
Check and readjust all 6 months
Version Permeate
flow
Concentrate
flow
adjustable
up to
[L/h] [L/h]
≙
WCF-rate
[%]
WCF-rate
[%]
Pacific TII/TII UV 3
3
40
33
Pacific TII/TII UV 7
7
40
13
33
Pacific TII/TII UV 12
12
60
17
33
Pacific TII/TII UV 20
20
60
25
40
Pacific TII/TII UV 40
40
100
28
40
