Issued Patents All Time
Showing 1–12 of 12 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7500489 | Contained pipeline system with brine filled interstitial space and method for detecting leakage in same | — | 2009-03-10 |
| 7166177 | Method for forming double containment pipeline sections | Ralph Friedrich, Brian M. Francis | 2007-01-23 |
| 7011102 | Contained pipeline system with brine filled interstitial space and method for detecting leakage in same | — | 2006-03-14 |
| 6626467 | Closure for secondary containment pipe | Ralph Friedrich, Gordon G. Robertson | 2003-09-30 |
| 6170891 | Closure for secondary containment pipe | Hector P. Mercado, Robert Baxter | 2001-01-09 |
| 6026862 | Double containment pipe sections | Ralph Friedrich, Brian M. Francis | 2000-02-22 |
| 6022054 | Thin wall fiberglass pipe connectors | Duane G. Hemphill | 2000-02-08 |
| 5725920 | Fiber-reinforced resin pipe having improved impact resistance | Ralph Friedrich, Duane G. Hemphill, Brian M. Francis, Gordon G. Robertson | 1998-03-10 |
| 5683116 | O-ring push-pull pipe joint | — | 1997-11-04 |
| 5588685 | Push-pull pipe joint | — | 1996-12-31 |
| 5186500 | Fiberglass tubular coupling with liner | — | 1993-02-16 |
| 4519637 | Pipe coupling | — | 1985-05-28 |