| 摘要 |
<p>A plastic envelope element (1) for an underwater pipeline comprises at least one spring portion (5, 6) manufactured integrally with the envelope element. The envelope element is modular in circumferential direction of the pipeline. The spring portion is at least formed by a wall portion of the envelope element in the relaxed condition projecting on the inner side (3) of the envelope element. In its tensioned condition, the spring portion does not project, or projects to a lesser extent than in the relaxed condition, on the inner side of the envelope element, such that in its fitted condition the spring portion presses under its spring force against the pipeline. The projecting wall portion extends bridgingly between two mutually parallel and mutually spaced hinge edges of the projecting wall portion. Between the non-adjoining portion of other edges, on one side, and remaining portions of the envelope element located next to the spring portion, on the other, in the relaxed condition at least one passage is formed in the envelope element.</p> |
