| Client name | City | Country |
|---|---|---|
| Weber Engineering GmbH & Co. KG | Dortmund | Germany |
| Weber Engineering GmbH & Co. KG | Pulheim | Germany |
| Wehrle-Werk AG | Emmendingen | Germany |
| Welland & Tuxhorn AG | Bielefeld | Germany |
| Welter, Thomas | Weilerswist | Germany |
| Westfälische Hochschule | Gelsenkirchen | Germany |
| Westlake Vinnolit GmbH & Co. KG | Hürth | Germany |
| WeylChem Frankfurt GmbH | Frankfurt | Germany |
| WIG Industrieinstandhaltung Leuna | Leuna | Germany |
| Wilhelmshavener Raffineriegesellschaft mbH | Wilhelmshaven | Germany |
| Wintershall Holding GmbH | Kassel | Germany |
| WIP Engineering GmbH | Krefeld | Germany |
| Worley Projects GmbH | Köln | Germany |
| WPD Wartungs- und Prüfungsdienst GmbH | Speyer | Germany |
| WTE Wassertechnik GmbH | Essen | Germany |
| WWV Wärmeverwertung GmbH | Leuna | Germany |
| WWV Wärmeverwertung GmbH & Co. KG | Kandel/Pfalz | Germany |
| XERVON Instandhaltung GmbH | Münchsmünster | Germany |
| XOMOX Int. GmbH & Co. OHG | Lindau | Germany |
| YARA Brunsbüttel GmbH | Büttel | Germany |
| Yncoris GmbH & Co. KG | Hürth-Knapsack | Germany |
| Yokogawa Deutschland GmbH | Ratingen | Germany |
| Zimmer AG | Frankfurt | Germany |
| Zwick Armaturen GmbH | Ennepetal | Germany |