Teledyne 6600 Operating Instructions Manual page 134

Part III
NOTE: To avoid excessive foaming, when a new polypropy-
lene filter is installed, it is recommended to flush the filter with tap
water for 1 hour prior to installation. This removes chemicals used
to manufacture the filter and which cause the foaming.
7.9 316 Zero Filter Cleaning Procedure
Because of its construction, the filtering element may be recovered after use
by employing the proper cleaning procedure. This procedure extends the useful
life of a given element immeasurably. The procedure should be faithfully
adhered to, and is as follows:
1. Remove the filter element from the housing, and the gaskets from the
filter element.
2. Immerse the element in a boiling bath of 15% reagent grade caustic soda
solution for30 minutes. DO NOT FLOW THROUGH THE ELEMENT
AS CAUSTIC PARTICLES COULD BE REMOVED BY THE CLEAN-
ING AND FORCED INTO THE FILTER MEDIUM - THUS CLOGGING
THE ELEMENT.
CAUTION: Wear protective goggles and gloves, when dealing with
chemicals such as caustics or acids!
3. Neutralize the boiled filter by immersing it in a 160F bath of 10% Nitric
acid for a period of not over 5 minutes.
4. Immerse the filter in a tank of flowing water and rinse until the pH of the
water is neutral. Again, do not force water through the filter, but allow
the water to overflow from the container holding the filter. Periodically
stop the flow of water and check the pH of the water in the container
holding the filter.
5. After the rinse water is verified as being neutral, remove, drain, and air
dry the element. Store in a plastic container, or place back in service.
1-44 Part III
Teledyne Analytical Instruments
Model 6600