Issued Patents 1989
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4838312 | Three-way valve | Rutger Berchem | 1989-06-13 |
| 4804207 | Connector pipe segment | Rutger Berchem | 1989-02-14 |
| 4795133 | Ball valve with a ceramic valve ball and ceramic seat rings | Rutger Berchem, Herbert Heidemeyer | 1989-01-03 |