Extended Reality technology (xR) contains Augmented, Virtual and Mixed Reality Technology (AR / VR / MR) is one of the key technologies of digital transformation. Thanks to the existing powerful immersive hardware systems, complex technical and natural systems can be digitally represented in a realistic virtual environment. This enables users to completely immerse in the virtual environment and to observe and interact with the systems and objects contained therein without major restrictions, or to augment real products and systems with digital data in runtime. This creates new opportunities to present the behaviour and functionalities of complex systems in a tangible and understandable way. Therefore, the xR technology has the ability to revolutionize learning and training methods, especially in the qualification of specialists and experts. Within the international project “International Cooperation on VR/AR Projects” (IC xR-P) – cooperation between University of Applied Sciences Karlsruhe from Germany, Turku University of Applied Sciences from Finland, and Higher Institute of Computer Science and Multimedia Sfax from Tunisia – the application of the VR technology in the training area in terms of supporting of cognitive skills will be investigated. IC xR-P focuses on the implementation of VR training apps for medical training, rescue and knowledge transfer. This paper presents and discusses the implementation of a VR-Training App for the installation of an industrial refrigeration Ammonia Compressor Pack (ACP). The VR app has been developed in cooperation with the German refrigeration technology manufacturer BITZER Kühlmaschinenbau GmbH. The implemented VR training App has been developed in terms of a feasibility study to demonstrate the aibilty of the VR technology to train Bitzer's customers to install the ACP worldwide. The VR app should support the customers engineers to perform an error-free installation of the ACP based on simplified and tangible virtual process description and virtual instruction. The VR training app comprises four main modules: VR logging and reception room, VR delivery and unloading process for the ACP, VR installation of the ACP, and VR visualization room for the refrigerant flow and technical details of the ACP. The VR app can be used as a single and multiplayer mode. A summary of the app evaluation by the engineers of BITZER will be presented at the end of the paper.