Issued Patents All Time
Showing 26–27 of 27 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4319634 | Drill pipe tester valve | Michael E. McMahan | 1982-03-16 |
| 4270610 | Annulus pressure operated closure valve with improved power mandrel | — | 1981-06-02 |
Showing 26–27 of 27 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4319634 | Drill pipe tester valve | Michael E. McMahan | 1982-03-16 |
| 4270610 | Annulus pressure operated closure valve with improved power mandrel | — | 1981-06-02 |