Issued Patents All Time
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5370149 | Line blind valve | Curtis W. Clarkson, Nicholas J. Williams | 1994-12-06 |
| 5271426 | Gate valve | Curtis W. Clarkson, Milton E. Jennings, Nicholas J. Williams | 1993-12-21 |
| 4846442 | Gate valve with lock ring | Curtis W. Clarkson | 1989-07-11 |
| 4688597 | Gate valve | Curtis W. Clarkson | 1987-08-25 |