Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4608181 | Water filtration apparatus having upflow buoyant media filter and downflow nonbuoyant media filter | Andrew K. Hsiung, Brian W. Hemphill | 1986-08-26 |
| 4199451 | Split flow water treatment plant | Andrew K. Hsiung | 1980-04-22 |