Red Seal Plumbing Practice Exam

During the filtering sequence, most tank-type water treatment filters work on a _____ flow system.

1. Up

2. Down

3. Circular

4. Reverse

The correct answer is: Down

Tank-type water treatment filters generally work on a down flow system during the filtering sequence. This means the water flows down through the filter and the contaminants become trapped and are removed from the water. Option A, up flow, is incorrect because this means the water would flow up through the filter and could potentially leave the contaminants at the top. Option C, circular flow, is incorrect because this does not provide a specific direction for the water to flow and could lead to uneven distribution of contaminants. Option D, reverse flow, is incorrect because this would cause the water to flow in the opposite direction and potentially push previously filtered water back into the untreated water. Hence, option B is the correct answer.