An exemplary stator disk of an electric motor stator includes a set of recesses. Each recess being configured to receive a cooling pipe. The stator disk includes one or more positioning elements for aligning the stator disk with another stator disk. The one or more positioning elements being positioned to the stator disk such that when the stator disk is set to a rotated position with respect to the other stator disk in order to align the recesses of the disks for receiving of cooling pipes, the positioning elements of the two disks become only partly aligned with each other.