Issued Patents 1982
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4321797 | Quick connector and shut-off valve assembly for heat recovery system | Gerald W. Keller | 1982-03-30 |
| 4316367 | Heat recovery and hot water circulation system | Gerald W. Keller | 1982-02-23 |