| 210 / | HD | LIQUID PURIFICATION OR SEPARATION |
| 294 | DF | DIVERSE DISTINCT SEPARATORS {3} |
| 295 | DF | .~ Including a filter {5} |
| 299 | DF | .~.~ Including constituent trapping feature {10} |
| 300 | DF | .~.~.~ Alternate filters and traps in series {1} |
| 301 | | .~.~.~.~ Plural traps |