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vwr.com I Instruction manual VWR® U Water System
5.3.2 pH Cleaning
pH cleaning is recommended for the following situations and it takes 90 minutes to complete.
1. RO water production rate decreased significantly;
2. RO rejection rate is significantly reduced.
pH cleaning are divided into acid cleaning and alkali cleaning. The acid cleaning is used to remove
scale and other inorganic compounds attached to the RO membrane, and the alkali cleaning is used
to remove adherent organic substances on the RO membrane.
The Acid cleaning steps are as follows:
a)
Switch the system to Standby mode and remove the left side panel.
b)
Remove the P Pack cartridge.
c)
Add 5 g analytical grade citric acid into the Cleaning Pack.
d)
Install the Cleaning Pack to the position of P Pack.
e)
Tap
Cleaning & Sanitization
on
Maintenance Menu
to enter setup menu.
f)
Click
Start
to enter cleaning process. Choose
Yes
on the pop-up dialog.
g)
System will be back to Standby mode after pH cleaning stops.
h)
Remove the Cleaning Pack and install P Pack back.
i)
Switch the system to Ready mode.
The Alkaline cleaning steps are as follows:
