US Patent Class 138
PIPES AND TUBULAR CONDUITS-- Main Headings
 Electronic File Wrappers |  Electronic Patent Documents |  Paper Patent Documents | Current as of: June, 1999
|  and Services |
| Electronic File Wrappers | Electronic Patent Documents | Paper Patent Documents | Current as of: June, 1999
| and Services |
| CLASS NOTES | ||
| 26 | DF | WITH PRESSURE COMPENSATORS {2} |
| 32 | DF | THAWING AND FREEZE PROTECTION {3} |
| 36 | DF | WITH WEAR INDICATOR |
| 37 | DF | WITH FLOW REGULATORS AND/OR BAFFLES {3} |
| 89 | DF | WITH CLOSURES AND PLUGS {7} |
| 96 R | DF | END PROTECTORS {1} |
| 97 | DF | REPAIRING {1} |
| 100 | DF | BREAKJOINT {2} |
| 103 | DF | COMBINED {6} |
| 111 | DF | PLURAL DUCT {4} |
| 118 | DF | FLEXIBLE {8} |
| 140 | DF | DISTINCT LAYERS {8} |
| 154 | DF | SPIRALLY SEAMED |
| 155 | DF | JOINED SECTIONS |
| 156 | DF | LONGITUDINALLY SEAMED {8} |
| 172 | DF | REINFORCED {2} |
| 177 | DF | STRUCTURE |
| 178 | DF | MISCELLANEOUS |
| ****************************** | ||
| DIGESTS | ||
| ****************************** | ||
| DIG 1 | DF | Adhesive |
| DIG 2 | DF | Glass fiber |
| DIG 3 | DF | Teflon, Kel-F |
| DIG 4 | DF | Air conditioning |
| DIG 5 | DF | Pre-stress |
| DIG 6 | DF | Corrosion |
| DIG 7 | DF | Resins |
| DIG 8 | DF | Bent shaped retained |
| DIG 9 | DF | Cellular |
| DIG 10 | DF | Metal foil |
| DIG 11 | DF | Shape |