| 1 | Conley Corp. | | USA |
| 2 | Advanced Drainage Systems Inc. | | USA |
| 3 | Calpipe Industries – Calbrite | | USA |
| 4 | Balzer’s Canada Inc. | | USA |
| 5 | Orion Fittings | | USA |
| 6 | Watertec Irrigation Ltd. | | USA |
| 7 | Fibrex | | USA |
| 8 | American Spiralweld Pipe Co. LLC | | USA |
| 9 | Harrison Machine & Plastics Corp. | | USA |
| 10 | Atlantic Tube & Steel Inc. | | USA |
| 11 | Fiberglass Fabricators Inc. | | USA |
| 12 | Canadian Tube Tooling | | USA |
| 13 | Kelolite | | USA |
| 14 | Continental Pipe Mfg. Co. Div. of Arrow Tank Co. | | USA |
| 15 | Platinum Grover Int. Inc. | | USA |
| 16 | International Reinforced Plastics | | USA |
| 17 | Chemetics Inc. | | USA |
| 18 | Columbia/MBF | | USA |
| 19 | Danplas Pipe Systems | | USA |
| 20 | TAD Pipe Canada Ltd. | | USA |
| 21 | Industrial Pipe & Plastics Inc. | | USA |
| 22 | Marcegaglia Spa | | USA |
| 23 | Pacific Poly-Pipe Products | | USA |
| 24 | DBJ Corporation | | USA |
| 25 | Corrosion Materials | | USA |
| 26 | Aquatherm | | USA |
| 27 | Fab-Tech Inc. | | USA |
| 28 | Farmer’s Marine Copper Works Inc. | | USA |
| 29 | Titanium Fabrication Corp. Phoenix Group | | USA |
| 30 | GreenMount Corp. | | USA |
| 31 | MRC Global | | USA |
| 32 | Corr Tech Inc. | | USA |
| 33 | Atlantic Screen & Mfg. Inc. | | USA |
| 34 | Cooney Brothers Inc. | | USA |
| 35 | Georg Fischer LLC | | USA |
| 36 | Rockwell Industries International Corp. | | USA |
| 37 | MAK Enterprises Inc. | | USA |
| 38 | Hobas Pipe USA | | USA |
| 39 | CRP Products & MFG LTD | | USA |
| 40 | Ultraflo Systems Inc | | USA |
| 41 | H.S. Martin Inc. | | USA |
| 42 | Ridalco Industries Inc. | | USA |
| 43 | US Fusion LLC | | USA |
| 44 | Ceresist Inc. | | USA |
| 45 | Falcon Metals | | USA |
| 46 | Multichair Inc | | USA |
| 47 | Stainless Metals Inc. | | USA |
| 48 | Perlen Steel Corp. | | USA |
| 49 | IPEX | | USA |
| 50 | NewAge Industries Inc. | | USA |
| 51 | Naylor Pipe Co. | | USA |
| 52 | Technical Glass Products Inc. | | USA |
| 53 | International Tank & Pipe Co. | | USA |
| 54 | NIBCO | | USA |
| 55 | Westlake Pipe & Fittings | | USA |
| 56 | IPEX | | USA |
| 57 | Victrex USA Inc. | | USA |
| 58 | Simtech Process Systems | | USA |
| 59 | Steel Forgings Inc. | | USA |
| 60 | Coltwell Industries | | USA |
| 61 | JM Eagle | | USA |
| 62 | Town & Country Plastics Inc. | | USA |
| 63 | Eagle Alloys Corp. | | USA |
| 64 | Pena-Plas Co. | | USA |
| 65 | Tube Methods Inc. | | USA |
| 66 | U.S. Industrial Piping Inc. | | USA |
| 67 | Stemmerich Inc. | | USA |
| 68 | Charlotte Pipe & Foundry Co. | | USA |
| 69 | Composites USA | | USA |
| 70 | Flexible Valve Corp. | | USA |
| 71 | Corrosion Products Inc. | | USA |
| 72 | CK Composites LLC. | | USA |
| 73 | Piping Systems Inc. | | USA |
