| 1 | United Pipe Nipple Company | | USA |
| 2 | Dritherm International Inc. | | USA |
| 3 | Haitima Corp. | | USA |
| 4 | United Poly Systems | | USA |
| 5 | Steel Forgings Inc. | | USA |
| 6 | Federal Steel Supply Inc. | | USA |
| 7 | JFE Steel America Inc. | | USA |
| 8 | Flowline Alaska | | USA |
| 9 | JM Eagle | | USA |
| 10 | Riverside Plastics Inc. | | USA |
| 11 | Appalachian Piping Products Inc. | | USA |
| 12 | KO Supply LLC | | USA |
| 13 | Rovanco Piping Systems Inc | | USA |
| 14 | Paragon Industries Inc. | | USA |
| 15 | Berg Steel Pipe Corp. | | USA |
| 16 | ICSE | | USA |
| 17 | American Spiralweld Pipe Co. LLC | | USA |
| 18 | Oregon Steel Mills Inc | | USA |
| 19 | Stupp Corp. | | USA |
| 20 | Magnetizer Industrial Technologies Inc | | USA |
| 21 | Hwf Construction Inc | | USA |
| 22 | WL Plastics Corp. | | USA |
| 23 | Naylor Pipe Co. | | USA |
| 24 | Precision Welding & Fabrication | | USA |
| 25 | PEP A Ryan Herco Flow Solutions Company | | USA |
| 26 | Victrex USA Inc. | | USA |
| 27 | Southeast Texas Industries Inc. | | USA |
| 28 | Fuel Tanks | | USA |
| 29 | Future Pipe Industries | | USA |
| 30 | Gibb Robert & Sons Inc. | | USA |
| 31 | Pipeline Plastics | | USA |
| 32 | U.S. Industrial Piping Inc. | | USA |
| 33 | Hydril Pressure Control | | USA |
| 34 | Composites USA | | USA |
| 35 | American Tank & Fabricating Co. | | USA |
| 36 | Tube Methods Inc. | | USA |
| 37 | Mammoth Carbon Products | | USA |
| 38 | ABT Inc. | | USA |
| 39 | Triad Products Corp. | | USA |
| 40 | GreenMount Corp. | | USA |
| 41 | Island Fitting | | USA |
| 42 | P.A. Inc. | | USA |
| 43 | Perma-Pipe Inc. | | USA |
| 44 | FlexSteel Pipeline Technologies Inc. | | USA |
| 45 | MRC Global | | USA |
| 46 | Piping Systems Inc. | | USA |
