Abstract: An outer pipe casing (20) and a concrete tube (26) cast inside, form a pre-stressed concrete pipe in its elementary form. Prior to casting, a layer of non-cohesive material (28) is sprayed on the inside of the pipe casing and an annular ring (32) is welded inside adjacent to each end. A resilient seal ring (46) is captivated into the inwardly facing legs (38) of the second channel (36) of each annular ring and a temporary seal (52) separates each annular ring from the material (28). After the concrete of the tube cures, a pressurized solidifying compound (54) is inserted under pressure to a pathway (42) formed into each annular ring and it is also extruded into a region (30) coated by the non-cohesive material. Pressurization of the compound is sufficient to cause the pipe casing to bulge outwardly and compression of the concrete in the tube is achieved. When the compound hardens, the compressive force remains and pre-loads the pipe.

Abstract: A method is provided for lining a pipe wherein a thermoplastic liner is initially formed in a cylindrical shape with a diameter slightly larger than the internal diameter of the pipe. The liner is temporarily deformed at an elevated temperature to a different cross-section, preferably U-shaped, to reduce its overall cross-sectional dimension to facilitate insertion into the pipe to be lined. The deformation occurs with substantially comparable elongation of the pipe lining along its opposite sides thereby precluding variations in wall thickness and stress in the pipe. Once inserted, the liner is pressurized and reheated first to a temperature below its crystallization temperature to round the lining in the pipe and subsequently, further pressurized and reheated to a second temperature higher than the crystallization temperature to cause the liner to retain its original round shape.

Abstract: Method is provided for lining a pipe wherein a thermoplastic liner is initially formed in a cylindrical shape with a diameter slightly larger than the internal diameter of the pipe. The liner is temporarily deformed at an elevated temperature to a different cross-section, preferably U-shaped, to reduce its overall cross-sectional dimension to facilitate insertion into the pipe to be lined. Once inserted, the pipe liner is reheated to the crystallization temperature of the thermoplastic material to cause the liner to return to its original cylindrical shape. Pressure within the liner is also increased in two stages to cause the liner to conform to the interior surface of the pipe. An expansion pig may also be employed to ensure even more exact conformance. After expansion, ends of the liner which extend beyond the pipe are flared into engagement with the pipe flanges. Service fluid under pressure is introduced into the liner to maintain the liner in its cylindrical shape.

Abstract: Method is provided for lining a pipe wherein a thermoplastic liner is initially formed in a cylindrical shape with a diameter slightly larger than the internal diameter of the pipe. The liner is temporarily deformed at an elevated temperature to a different cross-section, preferably U-shaped, to reduce it overall cross-sectional dimension to facilitate insertion into the pipe to be lined. Once inserted, the pipe liner is re-heated and pressurized so that the shape memory characteristics of the thermoplastic material causes the liner to return to its original cylindrical shape. Pressure within the liner is increased in two stages to cause the liner to conform to the interior surface of the pipe. An expansion pig may also be employed to ensure even more exact conformance. After expansion, ends of the liner which extend beyond the pipe are flared into engagement with the pipe flanges.

Abstract: The strengthening and stiffening of long, curved or tapered tubes is achieved by using internal strengtheners. The strengthening element conforms to the internal shape of the tube as it is inserted into the tube. The parts of the strengthening element which are then in contact with the inside of the tube have pre-formed welding material attached to them; a solid connection between the strengthener and the tube is achieved by selective heating, welding or by blowing adhesive material through the tube.If a tube has the non-welded strengthener in place, the forming or bending of the tube may proceed, since the strengthener takes the form of the tube at any stage of forming. The process is especially suitable for tubes with different cross-sections along their length.

Abstract: S-shaped opening and closing element for controlling the flow of a fluid or body (powder, granulate) and adaptable to any form of package or fitting containing fluids, characterized in that its shape in two S-bends permits both an instantaneous stoppage of the flow of the fluids and an instantaneous flow of said fluids; this, as a function of the given position, by manual or mechanical traction on the element. The S-shape ensures very effective fluid-tightness, without supplementary elements. The opening and closing element can be employed for controlling flow from a container having a supporting device for the element. The container can have more than one compartment.

Abstract: A process for the manufacture of hose or tubing conditions plastic high pressure hose having at least one reinforcing layer of steel wires, cords or longitudinal segments thereof. The hose is internally pressurized for a predetermined period of time which provides a residual permanent elongation of at least 0.5% and increases the interior volume by at least 2% upon release of the pressure.

Abstract: A technical hose with foam insert, expediently a maritime swimming hose for drawing-off oil, as well as to the process for the production thereof. The hose according to the invention consists of the elastic cross-linked elastomer layer containing also fibre-reinforcement, of the foam layer with closed cells arranged above said layer and assuring swimming ability, as well as of the new type of outer coating sheet.The outer coating sheet is a multi-layer system, the elementary layers are previously partially cross-linked, in their cross-section inhomogenous elastomer layers, stretched longitudinally in a given case, being interconnected and connected to the foam layer, respectively, by means of thermally and/or chemically activated adhesive layers.

Abstract: A plain concrete pipe having an evenly distributed steel wire reinforcement is disclosed, said pipe being suitable for water piping and the like; this pipe being reinforced with a reinforcement constituted by thin wires evenly distributed and arranged in a circumferential pattern and a longitudinal pattern; a method is also disclosed for the manufacture of the pipe on an industrial scale in an efficient and economical manner (FIG. 3).

Abstract: The present invention relates to a repair sleeve comprising a flexible, hose-like main part (1) and a spiral spring (2), which, when the sleeve is mounted in a pipe line, pretensions the hose-like main part (1) into sealing engagement against the inner wall of the surrounding pipe. The invention also includes an insertion device (4) for the repair sleeve, said device being a cylindrical body (5) mounted on wheels. At the ends of this body (5) there are latching means (7, 8) which are releasably fastenable to the ends of the spring (2). The latching means comprise a pin (7) biased to thrust out through the wall of the body (5) and into holes at the ends of the spring (2) wound round the body (5). Both pins (7) are simultaneously releasable with the aid of a linkage system (11, 13, 14, 15) on actuating the system. Eyes or cages (8) accommodating the ends of the springs are also associated with the pins (7).

Abstract: For distributing the pressure exerted by a binding cable (2), more especially contained in a sheath (10) with a grease filling, over a tubular body (1), such as a forced duct or a concrete silo, surrounded by this cable, there are inserted between said cable and said body shoes (3) formed by sections of a solid shaped bar of rubber which have the general shape of a C with constricted opening defining a cylindrical groove (4) adapted for jointingly receiving the cable and which are defined, on the side opposite the opening of the C, by a flat rectangular bearing face (6).

Abstract: A concentric walled conduit for incorporation within a tubular conduit string, and particularly for use in a subterranean well, is provided with one of the walls corrugated for substantially its entire length, preferably the inner tubular member. The annular space defined between the concentric tubular member contains a high heat resistant insulating material disposed around the outer surface of the inner tubular member. Each end of the annular space containing the insulating material is effectively sealed, and secured, such as by welds. The inner wall may be prestressed in tension for counteracting the forces which may be produced by a temperature differential between the tubular member walls of concentric conduit.

Abstract: Insulated pipes are generally bared of insulation at their ends in order to make joints, for example welds, between the pipes. A reinsulating method and assembly is provided for the bared joints, wherein a support comprising a coiled member, for example a helical coil, is positioned around the pipe, a recoverable cover recovered into engagement with the support, and thermally insulating material introduced between the cover and the pipe. The invention is suitable for straight, T, and bent joints.

Abstract: According to the method of the invention there is wound, around a hollow body (1) and in substantially contiguous turns, a flexible strip (2), the latter strip being fixed onto the hollow body. The strip is of a material, the tensile limit of which is in excess of that of the material of which the hollow body (1) is made, and when wound around the hollow body, a tension is applied thereto which is sufficient for the stresses which may develop within the body and the winding of the strip (2) to reach their permissible maximum limits at substantially the same time, when the hollow body is used under pressure.

Abstract: Disclosed are heat recoverable connectors for use as a protective covering about a plurality of joined articles such as wire splices or tubing junctures. The connectors are open-ended and feature at least one internal wall extending for at least a portion of the distance along the length of the connector to provide a plurality of open-ended channels within the connector for respectively containing one or more of the plurality of joined articles so as to insure their separation during the process of shrinking the connector by heat.

Abstract: An elastomeric pre-stretched tubular member comprising from about 2.5 to about 25 volume percent carbon black, from about 0.8 to about 3.0 volume percent of platelet-shaped conductive particles, and optionally high permittivity inorganic fillers and platelet-shaped inorganic dielectric fillers, with the balance being the compounded elastomeric component.

Abstract: A compact one-piece shrinkable sleeve of minimal outside diameter made from either a resilient material or a heat shrinkable material having elastic memory and adapted to be secured to the end of an electrical cable and/or tubing bundle having one or more electrical conductors and/or tubes extending therefrom to provide a barrier to the flow of gas or vapors therethrough. The sleeve contains a cavity at one end thereof that when the sleeve is in an expanded state is adapted to receive the end of the bundle. The sleeve contains one or more internal channels at the opposite end thereof that are separated from each other by walls that are directly or indirectly integrally related to the wall of the remainder of the sleeve and are adapted to permit the one or more conductors and/or tubes to extend therethrough from the bundle end in the cavity.

Abstract: The present invention relates to a device which is used to repair a damaged insulating jacket on an electrical cable. The device is shrunk down around the cable without the use of heat to provide an impervious, protective covering. More particularly, the invention includes a sheet or sleeve which is elongated and held in that state by removable support struts. After covering the damaged area of the cable jacket, the struts are withdrawn to allow the sheet or sleeve to shrink down around the cable.

Abstract: Flexible hollow articles comprise an expanded elastomeric inner member and an outer restraining means. The restraining means has score lines thereon, and is made of a notch-sensitive material so that the score lines can be propagated through the material by distorting the article. The stiffness and elongation of the restraining means, and the peel strength of the bond between the inner member and the restraining means, are so chosen that at least part of the restraining means can be pulled away from the inner member by manual force. The articles are useful for covering substrates, especially splices and terminations in electrical cables.

Abstract: Rigid pipe sections of a dredger are pivotally connected to allow universal movement therebetween and a flexible, elastic bellows communicates the adjacent ends of the pipe sections. The bellows in its free state is prestressed so as to be under compression and is further compressed when in place between the ends of the pipe sections.

Abstract: A dredging pipe assembly includes at least two rigid sections physically connected together by a cardan joint and connected for fluid continuity by a pair of flexible sections disposed in spaced apart relation with the cardan joint between them. A flexible duct serving additional equipment bridges the cardan joint without interfering with the flexible sections.