Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4454172 | Lining metal tubing with a corrosion- and abrasion-proof cement mortar | Wilhelm Schwenk | 1984-06-12 |
| 4390568 | Lining a steel pipe internally with a cement mortar | Wilhelm Schwenk, Rolf Mangen | 1983-06-28 |