| S.no | Company Name | Founded | Country |
|---|---|---|---|
| 1 | Emerson Automation Solutions Regulators and Relief Valves | USA | |
| 2 | Siemens Corporation | USA | |
| 3 | Sorensen Systems LLC | USA | |
| 4 | Equipment & Controls Inc. | USA | |
| 5 | Unique Systems Inc. | USA | |
| 6 | Sylvania | USA | |
| 7 | Mechanical Dynamics & Analysis | USA | |
| 8 | Continental Controls Corp. | USA | |
| 9 | Dresser-Rand | USA | |
| 10 | Petrotech Inc. | USA | |
| 11 | VRC Co. | USA | |
| 12 | Control Associates Inc. | USA | |
| 13 | Lakeside Process Controls Ltd. | USA | |
| 14 | Applied Control Equipment | USA | |
| 15 | Spartan Controls Ltd. | USA | |
| 16 | American Governor Company | USA |
