Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 8571395 | Track system for heater assembly | Donald E. Porterfield, Charles T. Whitfield | 2013-10-29 |
| 6950606 | Air conditioning apparatus with blower and electric heater in common housing | Colby Logan, Donald E. Porterfield, James W. Pickle | 2005-09-27 |
| 5833867 | System and method for backwashing multiple filtration vessels | — | 1998-11-10 |
| 5114595 | Multiple screen filter and method | — | 1992-05-19 |