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Questions

2007

Hello,
I am doing my Masters Thesis and need your help in getting the following information:
1) What happens if drain time (dwell) time is too long?
2) What happens if rinse tank is allowed to flow continuously when not processing any work?
3) What happens to water line to prevent siphoning of solution into the water feed system?
4) What happens if high carbon/ leaded steel is pickled in excess?

Thanks.

Rick Smith
Student - Cincinnati, Ohio,USA

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2007

Will the title of your thesis be "Thesis", Rick? Your "Questions" don't reveal if you will be talking about plating, pickling, phosphatizing, or whatever :-)

1a. If the drain time is too long after a process tank or a rinse tank, the parts might rust, or they might dry and become passive. Other potential problems depend on what the parts are and what solution you are draining off of them.

1b. Too long a dwell time could give over plating, over etching, a powdery non-adherent deposit, etc.

2. Usually the only harm in a rinse tank flowing when not processing work is waste of money and resources, although it is vaguely possibly that the concentration of a contaminant could be reduced to the point where it is too high for discharge but too low to properly flocculate in the water treatment system.

3. There will be a formal or casual siphon breaker to prevent siphoning, and there may even be a positive backflow preventer.

4. Over-pickled work may not be salvageable.

Let's start over with what process you're talking about please :-)

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey