Filtration versus purification distinction defeats exemption for water treatment devices combining both functions

An exemption notification limited to filtering apparatus of a specified capacity was held inapplicable to Aquaguards that combined filtration with ultraviolet purification. The tariff entry was broader and covered filtering and purifying machinery, but the exemption was confined to water filters alone. The distinction between filtration and purification was treated as material, and the notification could not be extended by analogy to a device performing an additional purification function beyond filtration. The exemption claim therefore failed.

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Issues: Whether Aquaguards, which filter water and then treat it with ultraviolet radiation, were entitled to the benefit of the exemption notification applicable to water filters of a limited capacity.

Analysis: The tariff entry covered both filtering and purifying machinery and apparatus for liquids, whereas the exemption notification was confined to filtering apparatus of a specified capacity. A device that performs both filtration and purification does not fall within a notification limited to filtering apparatus alone. The distinction between filtration and purification was material, and the exemption could not be extended by analogy to a product that used an additional purification method beyond filtration.

Conclusion: The Aquaguards were not entitled to the exemption notification and the claim for exemption failed.

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