Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6238556 | Filtration system including a back washable pre-filtration apparatus | William D. Hawk | 2001-05-29 |
| 5932092 | Filtering apparatus having positively buoyant and negatively buoyant particulate | William D. Hawk | 1999-08-03 |
| 5723043 | Filtering apparatus having positively buoyant and negatively buoyant particulate | William D. Hawk | 1998-03-03 |