| 1 | United Pipe Nipple Company | | USA |
| 2 | DC Duct & Sheet Metal | | USA |
| 3 | MRC Global | | USA |
| 4 | Harwood Engineering Co. Inc. | | USA |
| 5 | GDS Inc. | | USA |
| 6 | Ultraflo Systems Inc | | USA |
| 7 | A Metal Source LLC | | USA |
| 8 | Wellmaster | | USA |
| 9 | U.S. Industrial Piping Inc. | | USA |
| 10 | Insul-Tek Piping System Inc. | | USA |
| 11 | Blue Diamond Industries LLC | | USA |
| 12 | All Metal Sales Corp | | USA |
| 13 | Wrayline Industrial Products | | USA |
| 14 | American Cast Iron Pipe Company | | USA |
| 15 | Centek Industries Inc. | | USA |
| 16 | Rovanco Piping Systems Inc | | USA |
| 17 | Berg Steel Pipe Corp. | | USA |
| 18 | Minnotte Manufacturing Corp. | | USA |
| 19 | Century Industrial Supply Inc. | | USA |
| 20 | Asahi/America Inc. | | USA |
| 21 | MAXPRO Technologies Inc. | | USA |
| 22 | Naylor Pipe Co. | | USA |
| 23 | WL Plastics Corp. | | USA |
| 24 | Haskel International | | USA |
| 25 | Reliable Source Inc. | | USA |
| 26 | MetalTek International | | USA |
| 27 | Busada Manufacturing Corporation | | USA |
| 28 | Westlake Pipe & Fittings | | USA |
| 29 | IPEX | | USA |
| 30 | Future Pipe Industries | | USA |
| 31 | Southeast Texas Industries Inc. | | USA |
| 32 | Farmer’s Marine Copper Works Inc. | | USA |
| 33 | Quality Pipe Products Inc. | | USA |
| 34 | Litek Composites Corp | | USA |
| 35 | Charlotte Pipe & Foundry Co. | | USA |
| 36 | Pena-Plas Co. | | USA |
| 37 | ABT Inc. | | USA |
| 38 | J & D Tube Benders Inc. | | USA |
| 39 | Aquatherm | | USA |
| 40 | Island Fitting | | USA |
| 41 | Lawson Mechanical Contractors | | USA |
| 42 | Stainless Specialties Inc. | | USA |
| 43 | Gs-Hydro US Inc. | | USA |
| 44 | Titanium Fabrication Corp. Phoenix Group | | USA |