Insulated pipe systems

Claim 2

A heat insulated pipe system comprising: a plurality of insulated pipe units; each pipe unit including an axially rigid interior conductor tube, an exterior protective mantel tube of relatively rigid synthetic material, and a heat insulating material interposed between said interior and exterior tubes; each of said conductor tubes having an end portion extending beyond the end of the corresponding exterior tube of the respective pipe unit, the end portion of one conductor tube being axially rigidly joined with the end portion of another conductor tube to form a conductor tube joint, tube casing means for bridging the conductor tube joint and overlapping adjacent end portions of the exterior tubes, and clamping means for rigidly and sealingly clamping said tube casing means around the end portions of the exterior tubes, wherein said interior tubes, exterior tubes, tube casing means, and clamping means are constructed such that axial movement of the interior tubes with respect to one another and axial movement of the exterior tubes with respect to one another is substantially precluded with a consequent substantial limitation of axial movement of the interior tubes with respect to the exterior tubes at least in the area of said conductor tube joints during use of this system with temperature changes induced by a fluid medium flowing through said conductor tubes at a different temperature than the medium surronding the exterior tubes.

Claim 3

A pipe system according to claim 1, wherein said tube casing means comprises a plurality of part-cylindrical shells of rigid material.

Claim 4

A pipe system according to claim 2, wherein said plurality of part-cylindrical shells includes two half-cylindrical shells.

Claim 5

A pipe system according to claim 3, characterized in that said clamping means includes means for clamping said half-cylindrical shells so tightly around said exterior tubes that the end portions of said exterior tubes are compressed to a reduced diameter.

Claim 6

A pipe system according to claim 4, characterized in that said exterior tubes are compressed such that both the inner and outer diameter of said end portions of said exterior tubes are reduced.

Claim 7

A pipe system according to claim 4, characterized in that the entire axial extent of the exterior tubes overlapped by said shells is compressed to a reduced diameter.

Claim 8

A pipe system according to claim 4, characterized in that the shells have an interior radius which is slightly smaller than the exterior radius of the protective tubes.

Claim 9

A pipe system according to claim 4, characterized in that the shells are provided with longitudinal, outwardly projecting tightening and sealing flanges along their joined edges.

Claim 10

A pipe system according to claim 4, characterized in that the shells are constructed of rigid plate material such as steel plate and in that means are provided for tightening the shells tightly around the ends of the exterior tubes.

Claim 11

A pipe system according to claim 4, characterized in that the shells are shaped with a bend so that in assembled condition they form a tube elbow covering correspondingly angled pipe units.

Claim 12

A pipe system according to claim 4, characterized in that the shells are provided with half-cylindrical branch portions in such a manner that in assembled condition they form a T-section.

Claim 13

A pipe system according to claim 3, characterized in that said tube casing means forms an axially rigid connection between the end portions of the exterior tubes.

Claim 14

A pipe system according to claim 3, wherein said clamping means extend through outwardly protruding flanges at said shells.

Claim 15

A pipe system according to claim 1, wherein said heat insulating material completely fills the space between said interior and exterior tubes.

Claim 16

A pipe system according to claim 14, characterized in that a combination adhesive and sealing compound is provided between the shells and the exterior tubes.

Claim 17

A pipe system according to claim 15, characterized in that said compound is Rubstick or the like.

Claim 18

A pipe system according to claim 15, further comprising flanges provided adjacent the joined edge portions of the shells, characterized in that a sealing compound is also interposed between said flanges.

Claim 19

A pipe system according to claim 14, further comprising a split reduction ring tightened in between said shells and said exterior tubes for accommodating clamping of exterior tubes of reduced diameter as compared to the inner dimensions of said shells.

Claim 20

A pipe system according to claim 14, characterized in that at least one of the shells is provided with inwardly protruding portions which are welded directly to the interior tube.

Claim 21

A pipe system according to claim 19, characterized in that said at least one shell is also provided with outwardly protruding anchoring portions for anchoring the joined pipe units to adjacent building structure and the like.

Claim 22

A pipe system according to claim 20, characterized in that said inwardly and outwardly protruding portions are formed as a single bar extending radially outwardly from the interior tube.

Claim 23

A pipe system according to claim 14, characterized in that said pipe units form part of a subterranean district heating tube system.

Claim 24

A pipe system according to claim 14, characterized in that each of said interior tubes are axially rigid at least along that portion of their length extending beyond the ends of the exterior tubes.

Claim 25

A pipe system according to claim 14, characterized in that each of said interior tubes are axially rigid throughout their length.

Claim 26

A pipe system according to claim 14, characterized in that said interior tubes have a diameter substantially less than said exterior tubes.

Claim 27

A pipe system according to claim 14, characterized in that the end portions of the interior tubes are joined by welding.

Claim 28

A pipe system according to claim 14, wherein said interior and exterior tubes are concentric to one another.

Claim 29

A pipe system according to claim 27, wherein said tube casing means comprises a plurality of part-cylindrical shells of rigid material.

Claim 30

A heat insulated pipe system such as a subterranean district heating tube system including a number of jointed insulated pipe units; each of said pipe units comprising at least one interior conductor tube, an exterior protective mantel tube of synthetic material, and a heat insulating material interposed between said exterior and interior tubes; said conductor tubes being exposed adjacent the ends of each pipe unit and being joined one to another by welding or otherwise, each joint between two respective pipe units being provided with a tube casing bridging the joint and overlapping the adjacent ends of the protective tubes in tight connection therewith, said tube casings comprising a pair of half-cylindrical shells of steel plate or similar rigid plate material, said shells having longitudinal outwardly projecting tightening and sealing flanges along their edges to be joined, means being provided for tightening said shells around the ends of the protective tubes to such an extent that these ends are compressed to a reduced diameter, said shells being provided with half-cylindrical branch portions in such a manner that in assembled condition they form a T-shaped structure, and wherein said branch portions adjacent their adjoining edges are provided with inwardly protruding edge flanges, the exterior surface of each of saiD branch portions being of unbroken cylindrical shape with half-circular cross section.

Claim 31

A heat insulated pipe system such as a subterranean district heating tube system including a number of jointed insulated pipe units; each of said pipe units comprising at least one interior conductor tube, an exterior protective mantel tube of synthetic material, and a heat insulating material interposed between said exterior and interior tubes; said conductor tubes being exposed adjacent the ends of each pipe unit and being joined one to another by welding or otherwise, each joint between two respective pipe units being provided with a tube casing bridging the joint and overlapping the adjacent ends of the protective tubes in tight connection therewith, said tube casings comprising a pair of half-cylindrical shells of steel plate or similar rigid plate material, said shells having longitudinal outwardly projecting tightening and sealing flanges along their edges to be joined, means being provided for tightening said shells around the ends of the protective tubes to such an extent that these ends are compressed to a reduced diameter, said shells being provided with half-cylindrical branch portions in such a manner that in assembled condition they form a T-shaped structure, and wherein said branch portions adjacent their adjoining edges are provided with inwardly protruding edge flanges, the exterior surface of each of saiD branch portions being of unbroken cylindrical shape with half-circular cross section.

Claim 32

A pipe system according to claim 29, in which the outer radius of the branch portions are approximately equal to the interior radius of the ends of tube casings of an immediately adjacent one of said pipe units.

Claim 33

A pipe system according to claim 29, further comprising a split reduction ring to be tightened in between the casing and a protective tube of reduced diameter.

Claim 34

A pipe system according to claim 29, in which at least one of the shells is provided with outwardly protruding anchoring portions and with inwardly protruding portions adapted to be welded to the conductor tube passing through the respective associated casing.

Claim 35

A pipe system according to claim 1, wherein said interior and exterior tubes are concentric to one another.

Claim 38

A heat insulated pipe system comprising: a plurality of insulated pipe units; each pipe unit including an axially rigid interior conductor tube, an exterior protective mantle tube of relatively rigid material, and a heat insulating material interposed between said interior and exterior tubes; each of said conductor tubes having an end portion extending beyond the end of the corresponding exterior tube of the respective pipe unit, the end portion of one conductor tube being axially rigidly joined with the end portion of another conductor tube to form a conductor tube joint, tube casing means for bridging the conductor tube joint and overlapping adjacent end portions of the exterior tubes, and clamping means for rigidly and sealingly clamping said tube casing means around the end portions of the exterior tubes, wherein the conductor tubes which are joined at a respective conductor tube joint are constructed such that axial movements of said conductor tubes with respect to one another are precluded at least in the area of said conductor tube joints, and wherein the tube casing means, clamping means, and the exterior tubes overlapped by said tube casing means are constructed such that axial movements of said exterior tubes with respect to one another are precluded at least in the area of said conductor tube joints each that, during use of the system with a fluid medium flowing through said coNductor tubes at a different temperature than the medium surrounding the exterior tubes, thermally induced relative axial movements of the conductor tubes with respect to one another and thermally induced relative axial movements of the exterior tubes with respect to one another in the area of said conductor tube joints are precluded.

Claim 39

A heat insulated pipe system comprising: a plurality of insulated pipe units; each pipe unit including an axially rigid interior conductor tube, an exterior protective mantle tube of relatively rigid material, and a heat insulating material interposed between said interior and exterior tubes; each of said conductor tubes having an end portion extending beyond the end of the corresponding exterior tube of the respective pipe unit, the end portion of one conductor tube being axially rigidly joined with the end portion of another conductor tube to form a conductor tube joint, tube casing means for bridging the conductor tube joint and overlapping adjacent end portions of the exterior tubes, and clamping means for rigidly and sealingly clamping said tube casing means around the end portions of the exterior tubes, wherein the conductor tubes which are joined at a respective conductor tube joint are constructed such that axial movements of said conductor tubes with respect to one another are precluded at least in the area of said conductor tube joints, and wherein the tube casing means, clamping means, and the exterior tubes overlapped by said tube casing means are constructed such that axial movements of said exterior tubes with respect to one another are precluded at least in the area of said conductor tube joints each that, during use of the system with a fluid medium flowing through said coNductor tubes at a different temperature than the medium surrounding the exterior tubes, thermally induced relative axial movements of the conductor tubes with respect to one another and thermally induced relative axial movements of the exterior tubes with respect to one another in the area of said conductor tube joints are precluded.

Claim 40

A pipe system according to claim 35, wherein said tube casing means comprises a plurality of part-cylindrical shells of rigid material.

Claim 41

A pipe system according to claim 36, wherein said plurality of part-cylindrical shells includes two half-cylindrical shells.

Claim 42

A pipe system according to claim 37, characterized in that said clamping means includes means for clamping said half-cylindrical shells so tightly around said exterior tubes that the end portions of said exterior tubes are compressed to a reduced diameter.