Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7415943 | Single pass fuel-fired fluid heating/storage device | Gregory M. Welk, Jeffrey M. Haney, Phillip Stephens, Qian Zhang | 2008-08-26 |
| 7290503 | High efficiency, wet-base, downfired multi-pass water heater | Gregory M. Welk, Qian Zhang | 2007-11-06 |
| 7258080 | Fuel-fired dual tank water heater having dual pass condensing type heat exchanger | Gregory M. Welk, Phillip Stephens, Qian Zhang, Jeffrey M. Haney | 2007-08-21 |
| 6149424 | Undulated burner membrane | Willy Marrecau | 2000-11-21 |