| 摘要 |
One pair of perforation elements connectible to one another presents an extremity, which can be connected to male and female units, in which the parts with reciprocal fixation function and the parts with sealing function are very distinct. In particular, the reciprocal arresting is achieved by troncoconic parts filleted in a way corresponding to the male and female parts; the seal is achieved by a cylindrical part of the male extremity, equipped with one or more washers, which part lodged into a cylindrical seat of the feminine part. |
