Abstract: By mutually interconnected specimens of a suppression element (100) according to the invention, there can be formed a strong and reliable construction of a tube around a tubular element. The suppression element (100) has a first fin structure (141) which is extending helically along a portion (121) of a first longitudinal edge (121, 131, 131 A, 131B), and a second fin structure (142) which is extending helically along a portion (122) of an opposite second longitudinal edge (122, 132, 132 A, 132B). In said tube, first fin structures and second fin structures of the various suppression elements are lying helically in-line relative to one another for effectively reducing vortex induced vibrations. The suppression elements (100, 200, 300, 400) are compactly stackable relative to one another.

Abstract: By mutually interconnected specimens of a suppression element (100) according to the invention, there can be formed a strong and reliable construction of a tube around a tubular element. The suppression element (100) has a first fin structure (141) which is extending helically along a portion (121) of a first longitudinal edge (121, 131, 131 A, 131B), and a second fin structure (142) which is extending helically along a portion (122) of an opposite second longitudinal edge (122, 132, 132 A, 132B). In said tube, first fin structures and second fin structures of the various suppression elements are lying helically in-line relative to one another for effectively reducing vortex induced vibrations. The suppression elements (100, 200, 300, 400) are compactly stackable relative to one another.

Abstract: A cladding tube (1) for enveloping an underwater conduit (2), such as a pipeline or a cable line, has at least one clamping portion (6), which comprises at least one deformation portion (6A, 6B, 6C) being integrally manufactured with the cladding tube (1), which deformation portion (6A, 6B, 6C) is a first wall portion of the cladding tube (1), which has a larger thickness in the radial direction than at least one second wall portion (8) of the clamping portion concerned, in such manner that by the larger thickness the first wall portion is, and the at least one second wall portion (8) is not, pressed against the underwater conduit (2) by a tensioning strap (7) being tensioned all round. The deformation portion concerned is easy to produce, durable and reliable. Thanks to the at least one clamping portion the cladding tube can be designed in harder and lower-cost materials than the soft, flexible poly urethane, which is usually applied nowadays.

Abstract: A fairing (1) for improving fluid flow around a circular-cylindrical object comprises a first fairing-element (11) and a second fairing-element (12), which are releasable relative to one another. The fairing-elements are easy to manufacture, compactly stackable, and easy to install around the object. In installed condition, the first fairing-element and the second fairing-element are mutually connected in circumferential direction of the fairing, while forming a twin-fin fairing, which reduces vortex-induced vibrations around the object, while providing favourable flow resistance, and without performing galloping motions.

Abstract: A dadding tube (1) for enveloping an underwater conduit (2), such as a pipeline or a cable line, has at least one clamping portion (6), which comprises at least one deformation portion (6A, 6B, 6C) being integrally manufactured with the cladding tube (1), which deformation portion (6A, 6B, 6C) is a first wall portion of the cladding tube (1), which has a larger thickness in the radial direction than at least one second wall portion (8) of the clamping portion concerned, in such manner that by said larger thickness the first wall portion is, and the at least one second wall portion (8) is not, pressed against the underwater conduit (2) by a tensioning strap (7) being tensioned all round. The deformation portion concerned is easy to produce, durable and reliable. Thanks to the at least one clamping portion the dadding tube can be designed in harder and lower-cost materials than the soft, flexible poly urethane, which is usually applied nowadays.

Abstract: A plastic envelope element for an underwater pipeline comprises at least one local spring portion manufactured integrally with the envelope element. The envelope element is modular in circumferential direction of the pipeline. The local spring portion is at least formed by a wall portion of the envelope element in the relaxed condition projecting on the inner side of the envelope element. In its tensioned condition, the local 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 local 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.

Abstract: 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.