Multi-part line having an insulating element for insulating a transition region between connector assemblies

A multi-part line, wherein line parts are provided, at ends of said line parts, with at least one connector assembly having at least one retaining element, wherein a connector part of the connector assembly of a line part and a coupling part of the connector assembly of the adjacent line part can be or are connected by overplugging and locking the at least one retaining element. At least one insulating element is arranged in the overplugging region of the connector part of the connector assemblies that can be or are connected to each other, which insulating element is designed as an axially compressible closed ring made of a material that has low heat conduction at least in the outer region of the insulating element, which ring has an inner passage opening in order provide insulation in the overplugging regions between the connector assemblies, in which overplugging regions no heating by, for example, the engine of a vehicle or other heat sources occurs, which insulation enables economical and also effective insulation during the operation and also during the standstill of a vehicle and is protected against unintentional or inadvertent removal.