The media must ensure a certain minimum amount of lubrication, not contain any solid matter and be chemically compatible. Benzins, solvents, etc. are never permitted. In electrostatic chargeable fluids, it is important to follow the instructions provided by the respective fluid manufacturer in order to prevent electrostatic charges. The operator must comply with the flash point, minimum ignition temperature and media-specific properties. Never have explosive mixtures inside the device. Dry running is not permissible.