AQUAPHOR APRO 1000 LPH, Manual

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10.8 PRESERVATION OF RO AND NF SYSTEMS
The elements of RO system must be preserved any time the plant is shut down for more than a maximum of 48 h to
prevent biological growth. Depending on the previous operational history of the plant, it will be necessary in almost
all cases to clean the membranes prior to shut-down and preservation. This applies to cases when the membranes are
known or assumed to be fouled. After cleaning, the preservation should follow within the next 10 h as follows:
1. Totally immerse the elements in the pressure vessels in a solution of 1
–
1.5% SMBS, venting the air outside of
the pressure vessels. Use the overflow technique: circulate the SMBS solution in such a way that the remaining
air in the system is minimized after the recirculation is completed. After the pressure vessel is filled, the SMBS
solution should be allowed to overflow through an opening located higher than the upper end of the highest-
pressure vessel being filled.
2. Remove the Viking module and fill the gap with SMBS.
3. Move the switch at the top to the CIP position to enter the CIP mode.
4. Press
“Ok” ▀
button to open the feed valve (the solution starts flushing the system with raw water) and leave
for 10 minutes.
5. Press
“Ok” ▀
to turn of the feed valve and exit the CIP mode.
6. Separate the preservation solution from the air outside by closing all valves. Any contact with oxygen will oxi-
dize the SMBS.
7. Check the pH once a week. When the pH becomes 3 or lower, change the preservation solution.
8. Change the preservation solution at least once a month. During the shut-down period, the plant must be kept
frost-free, and the temperature must not exceed 113°F (45°C). A low temperature is desirable.