Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5704343 | Furnace condensate trap | Alex M. Hofman | 1998-01-06 |
| 4621686 | Water vapor-condensing secondary heat exchanger | — | 1986-11-11 |
| 4611622 | Drain for condensate from flue gas | — | 1986-09-16 |
| 4478206 | Furnace having water vapor-condensing secondary heat exchanger | — | 1984-10-23 |