Top IPC subclasses
1
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C02F
|
1
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Treatment of water, waste water, sewage, or sludge
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2
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C23G
|
1
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cleaning or de-greasing of metallic material by chemical methods other than electrolysis
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3
|
C23F
|
1
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non-mechanical removal of metallic material from surfacesinhibiting corrosion of metallic materialin
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