| 摘要 |
The invention relates to an apparatus. In order to achieve efficient sealing, the apparatus comprises a sealing with a plurality of sealing elements (2"") arranged generally in a ring configuration around a center opening. Each sealing element comprises a sealing surface facing the center opening. At least one chamber (13"") is included for receiving sections of the sealing elements (2""). An inlet to a fluid source provides the at least one chamber (13"") with fluid in order to generate an overpressure acting on the sections of the sealing elements received in the at least one chamber (13""), and for pressing and moving the sealing surfaces of the sealing elements towards the center opening. |
