| 1 | H-P Products Inc. | | USA |
| 2 | Steven M. Hain Co. Inc. | | USA |
| 3 | Piping Systems Inc. | | USA |
| 4 | Wisconsin Metal Tech | | USA |
| 5 | Electrosteel USA | | USA |
| 6 | Apex Piping Systems Inc. | | USA |
| 7 | DBJ Corporation | | USA |
| 8 | F.W. Webb Company Thermoplastic Piping Div. | | USA |
| 9 | Corr Tech Inc. | | USA |
| 10 | Corrosion Materials | | USA |
| 11 | Steel Forgings Inc. | | USA |
| 12 | C.G. Metals Inc. | | USA |
| 13 | Ultraflo Systems Inc | | USA |
| 14 | Jorgenson Metal Rolling & Forming Inc. | | USA |
| 15 | Conley Corp. | | USA |
| 16 | American Spiralweld Pipe Co. LLC | | USA |
| 17 | Texas Manufacturing Co. | | USA |
| 18 | Sue-Jac Inc. | | USA |
| 19 | American Cast Iron Pipe Company | | USA |
| 20 | ISCO Industries LLC | | USA |
| 21 | Ironhed LLC | | USA |
| 22 | Piping Technology & Products Inc. | | USA |
| 23 | Turner Industries | | USA |
| 24 | Cameo Fabricators Inc. | | USA |
| 25 | Naylor Pipe Co. | | USA |
| 26 | Morris Coupling Co. | | USA |
| 27 | Metal Works Corp. | | USA |
| 28 | Appleton Stainless | | USA |
| 29 | Chicago Metal Rolled Products Co. | | USA |
| 30 | Reliable Source Inc. | | USA |
| 31 | Honeyville Metal | | USA |
| 32 | Nordfab Ducting | | USA |
| 33 | White Racker Co. | | USA |
| 34 | PEP A Ryan Herco Flow Solutions Company | | USA |
| 35 | Anchor Fluid Power | | USA |
| 36 | IPEX | | USA |
| 37 | Micromold Products Inc. | | USA |
| 38 | ALRO Products International | | USA |
| 39 | AGRU America Inc. | | USA |
| 40 | Island Fitting | | USA |
| 41 | C.I. Thornburg Co. Inc. | | USA |
| 42 | J & D Tube Benders Inc. | | USA |
| 43 | Cooney Brothers Inc. | | USA |
| 44 | Holloway Co. Inc. | | USA |
| 45 | Auto-Jet Muffler Corp. | | USA |
| 46 | Heat Exchange Applied Technology Inc. | | USA |
| 47 | Everett J. Prescott Inc. | | USA |
| 48 | Pena-Plas Co. | | USA |
| 49 | United Pipe Nipple Company | | USA |
