If a particular bank or vessel in a reverse osmosis system has an abnormally high salt content (conductivity) in the product water, this is a clear indication that an o-ring is leaking or that an element has failed. The key in locating the problem is to have a system designed to detect and pinpoint any malfunctioning membrane or associated component. This is accomplished by having a series of sampling ports for each vessel and unit subsection, which allows one to trace a problem from the output product water to the problem vessel. Each vessel should have the capability to insert a sampling tube into the product water tubes whereby the conductivity can be measured and the problem located.

O-ring leakage problems are a common source of poor quality product water. However, if a membrane element has been identified as the culprit, it may be advisable to have an autopsy of the element to ascertain the cause of the problem. Dow offers a wide variety of membrane analysis services.

Please see the following link  System Tests - Visual Inspection, Most Effective Cleaning, Profiling and Probing (76KB PDF) for instructions on:

• Visual inspection
• Determining the type of foulant for most effective cleaning
• Localization of high solute passage through profiling and probing

Additional Information:
High Salt Passage (117KB PDF)
FILMTEC™ System Optimization Services (SOS) 

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