| 摘要 |
The unit (1) has an intumescent material, which is arranged around a pipeline or cable extended in an axial direction of the unit. The intumescent material is arranged at the inner side of a metal casing (2) so that the metal casing surrounds the material during the occurrence of the fire. The metal casing lies around a pipe line in a circular manner. Several perforations are provided in the metal casing. The perforations are arranged in several perforation lines (3a). The perforation lines are extended in the circumferential direction of the casing. |
