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US1244989A
|
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Water-purifying apparatus.
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CA175660A
|
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Water purifying apparatus
|
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CA177901A
|
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Water purifier
|
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GB191303687A
|
|
Improvements in Pockets Filters.
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|
GB191204318A
|
|
Improvements in Filters.
|
|
GB191124260A
|
|
Improvements in Hinge-pins and the like.
|
|
GB191119172A
|
|
An Improved Filtering Diaphragm or Film.
|
|
GB190405370A
|
|
Improvements in and relating to Filters.
|
|
GB190328328A
|
|
Improvements in Filters.
|
|
GB190310831A
|
|
An Improved Manufacture of Filtering Mediums
|
|
GB190200464A
|
|
Improvements in Filters.
|
|
GB189503188A
|
|
Improvements in Filters, and in the Manufacture of a Felt or Filtering Medium for use therein.
|
|
CA39548A
|
|
Filter
|
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CA197978A
|
|
Filter
|
