Roller and method for compressing protective sheeting of polymer material around a pipeline

Abstract

A roller for compressing protective sheeting of polymer material around a pipeline rotates about a given or designated axis of rotation and has a shaft; and a first tubular portion which extends about the shaft and varies in elasticity along the given or designated axis of rotation; more specifically, the first tubular portion is of greater elasticity at the ends of the roller than at the center of the roller.

Claims

1. A pipeline protective sheeting compression roller comprising: a shaft configured to rotate about an axis of rotation; at least one first tubular portion which extends about the shaft and is configured to rotate about the axis of rotation, wherein the at least one first tubular portion varies in elasticity along the axis of rotation such that when the at least one first tubular portion compresses a protective sheeting of polymer material around a cutback of a pipeline including a raised portion, part of the at least one first tubular portion deforms for the raised portion of the pipeline to not alter a thickness of the protective sheeting; and a second tubular portion which is fitted about the first tubular portion and includes a plurality of cylindrical walls movable with respect to one another and arranged end to end along the axis of rotation.

2. The pipeline protective sheeting compression roller of claim 1, wherein the at least one first tubular portion includes a plurality of tubular members arranged end to end along the axis of rotation.

3. The pipeline protective sheeting compression roller of claim 2, wherein at least two of the adjacent tubular members differ in elasticity.

4. The pipeline protective sheeting compression roller of claim 2, wherein the tubular members include two lateral tubular members of greater elasticity than an adjacent tubular member.

5. The pipeline protective sheeting compression roller of claim 2, wherein each tubular member includes a tubular layer.

6. The pipeline protective sheeting compression roller of claim 5, wherein the tubular layer of each tubular member includes a layer of silicone.

7. The pipeline protective sheeting compression roller of claim 5, wherein each tubular layer defines a plurality of axial openings equally spaced about the axis of rotation.

8. The pipeline protective sheeting compression roller of claim 5, wherein each tubular member includes a sleeve supporting the tubular layer and fitted to the shaft.

9. The pipeline protective sheeting compression roller of claim 1, wherein the second tubular portion includes a central cylindrical wall defining a groove.

10. The pipeline protective sheeting compression roller of claim 9, wherein the second tubular portion includes two intermediate cylindrical walls located at opposite ends of the central cylindrical wall.

11. The pipeline protective sheeting compression roller of claim 1, wherein the second tubular portion includes a plurality of central cylindrical walls each radially slidable with reference to the axis of rotation with respect to adjacent cylindrical walls.

12. The pipeline protective sheeting compression roller of claim 11, wherein the second tubular portion includes two intermediate cylindrical walls located at opposite ends of the central cylindrical walls.

13. The pipeline protective sheeting compression roller of claim 1, wherein the second tubular portion includes a plurality of lateral cylindrical walls located at opposite ends of the roller.

14. The pipeline protective sheeting compression roller of claim 1, which includes a sheath of greater elasticity than the shaft and configured to define an outer surface configured to be positioned contacting the protective sheeting.

15. A roller comprising: a shaft; a first tubular portion which extends about the shaft and which varies in elasticity along an axis of rotation; a second tubular portion fitted about the first tubular portion and including: a plurality of central cylindrical walls arranged end to end along the axis of rotation, wherein each of the central cylindrical walls is radially slidable with reference to the axis of rotation with respect to at least an adjacent one of the cylindrical walls, and at least one of the plurality of central cylindrical walls defines a groove, and two intermediate cylindrical walls located at opposite ends of the plurality of central cylindrical walls; and a sheath configured to define an outer surface configured to be positioned contacting a protective sheeting of polymer material configured to be compressed around a cutback of a pipeline.

16. The roller of claim 15, wherein the first tubular portion includes a plurality of tubular members arranged end to end along the axis of rotation.

17. The roller of claim 16, wherein at least two of the adjacent tubular members differ in elasticity.

18. The roller of claim 16, wherein the tubular members include two lateral tubular members of greater elasticity than an adjacent tubular member.

19. The roller of claim 16, wherein each tubular member includes a tubular layer.

20. The roller of claim 19, wherein each tubular layer defines a plurality of axial openings equally spaced about the axis of rotation.

21. The roller of claim 19, wherein each tubular member includes a sleeve supporting the tubular layer and fitted to the shaft.

22. A roller comprising: a shaft; and a first tubular portion which extends about the shaft and which varies in elasticity along an axis of rotation; a second tubular portion fitted about the first tubular portion and including: a plurality of central cylindrical walls arranged end to end along the axis of rotation, two intermediate cylindrical walls located at opposite ends of the central cylindrical walls, and a plurality of lateral cylindrical walls located at opposite ends of the roller, wherein the central cylindrical walls are each radially slidable with reference to the axis of rotation with respect to adjacent cylindrical walls; and a sheath configured to define an outer surface configured to be positioned contacting a protective sheeting of polymer material configured to be compressed around a cutback of a pipeline.

23. The roller of claim 22, wherein the first tubular portion includes a plurality of tubular members arranged end to end along the axis of rotation.

24. The roller of claim 23, wherein at least two of the adjacent tubular members differ in elasticity.

25. The roller of claim 23, wherein the tubular members include two lateral tubular members of greater elasticity than an adjacent tubular member.

26. The roller of claim 23, wherein each tubular member includes a tubular layer.

27. The roller of claim 26, wherein each tubular layer defines a plurality of axial openings equally spaced about the axis of rotation.

28. The roller of claim 26, wherein each tubular member includes a sleeve supporting the tubular layer and fitted to the shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Certain embodiments of the present disclosure will be described by way of example with reference to the attached drawings, in which:

(2) FIG. 1 shows a partly exploded elevation, with parts removed for clarity, of the roller according to the present disclosure, the pipeline, and the protective sheeting;

(3) FIG. 2 shows a larger-scale longitudinal section, with parts removed for clarity, of the FIG. 1 roller;

(4) FIGS. 3 and 4 show cross sections, with parts removed for clarity, of the FIG. 2 roller along lines III-III and IV-IV respectively;

(5) FIG. 5 shows a cross section, with parts removed for clarity, of a variation of the roller according to the present disclosure;

(6) FIG. 6 shows a partly sectioned, larger-scale elevation, with parts removed for clarity, of a detail of the FIG. 2 roller when compressing the protective sheeting onto the pipeline; and

(7) FIG. 7 shows a partly sectioned, larger-scale elevation, with parts removed for clarity, of a variation of the roller according to the present disclosure when compressing the protective sheeting onto the pipeline.

DETAILED DESCRIPTION

(8) Referring now to the example embodiments of the present disclosure illustrated in FIGS. 1 to 7, number 1 in FIG. 1 indicates a pipeline composed of two pipes 2 joined by a weld, of which is shown an annular weld bead 3. Each pipe 2 comprises a metal cylinder 4; and a coating 5 of polymer material, normally polyethylene or polypropylene, for corrosion-proofing metal cylinder 4.

(9) Each pipe 2 has two opposite free ends 6 with no coatings 5. Each coating 5 has an end portion 7 including a bevel which reduces the thickness of coating 5 gradually to zero towards free end 6. Two pipes 2 welded together form a cutback 8, which extends along a longitudinal axis A1, between two end portions 7.

(10) In addition to welding metal cylinders 4, joining pipes 2 also comprises coating cutback 8. This comprises grit-blasting cutback 8; heating, such as via induction heating, cutback 8 to a temperature of 180? C.-250? C., and applying protective sheeting 9 of polymer material to cutback 8 to form a layer (not shown in FIG. 1). Coating cutback 8 normally comprises applying two relatively very thin layers of polymer materialthe first with anticorrosion and the second with adhesive propertiesto cutback 8 before applying protective sheeting 9.

(11) In the example shown, protective sheeting 9 is configured to wind around cutback 8, is wider than cutback 8 (measured along longitudinal axis A1) so as to overlap end portions 7 of coatings 5 of the two joined pipes 2, and is long enough to wind completely around the perimeter of cutback 8.

(12) Protective sheeting 9 is extruded as protective sheeting is wound about pipeline 1, and is compressed onto pipeline 1 by a roller 10.

(13) Protective sheeting 9 is applied before the polymer is completely cross-linked, so protective sheeting is relatively highly flexible and adapts to the irregular shape of the part of pipeline 1 to which protective sheeting is applied. Roller 10 ensures protective sheeting 9 adheres to the surface of pipeline 1 to which protective sheeting is applied, and prevents the formation of air bubbles, without altering the thickness of protective sheeting 9 as protective sheeting is applied.

(14) Roller 10 rotates idly, or is powered to rotate, about an axis of rotation A2, and is pushed onto pipeline 1 by a supporting mechanism 11, of which only two supporting arms 12 are shown in FIG. 1.

(15) With reference to FIG. 2, roller 10 comprises a rigid supporting shaft 13; a flexible tubular portion 14 around shaft 13; and a rigid tubular portion 15 around tubular portion 14.

(16) In certain embodiments, roller 10 comprises an elastic sheath 16 covering tubular portion 15.

(17) Tubular portion 14 varies in elasticity along axis of rotation A2. More specifically, tubular portion 14 is of greater elasticity at the ends of roller 10 than at the center of roller 10. It should be appreciated that the more elastic part of tubular portion is located at the ends of roller 10 and configured to compress protective sheeting 9 onto end portions 7 of coatings 5.

(18) Tubular portion 14 comprises a plurality of tubular members 17, 18 arranged end to end along axis of rotation A2.

(19) In the example shown, tubular portion 14 has a central tubular member 17; and two lateral tubular members 18 of greater elasticity than central tubular member 17.

(20) Tubular members 17 and 18 comprise respective tubular layers 19 and 20 of elastic material, such as silicone.

(21) With reference to FIGS. 3 and 4, tubular layers 19 and 20 have axial openings 21 and 22, which, in the example shown, are defined by holes and equally spaced around axis of rotation A2. The degree of elasticity of tubular layers 19 and 20 depends on the elastic material used, the number or quantity of openings 21 and 22, and the shape and size of the cross section of openings 21 and 22.

(22) FIG. 5 shows a variation of roller 10 with a different distribution pattern of openings 21 and 22.

(23) Tubular members 17 and 18 comprise respective sleeves 23 and 24, which support respective tubular layers 19 and 20, and are fitted to shaft 13, such as locked by key couplings 25.

(24) In certain embodiments, tubular layers 19 and 20 are cured to respective sleeves 23 and 24, which are made of metal.

(25) Tubular portion 15 as a whole forms a cylindrical shell fitted around tubular portion 14, and comprises a plurality of rigid cylindrical walls 26, 27, 28 of the same outside diameter and thickness, and arranged end to end. In a variation not shown, cylindrical walls 26, 27, 28 are of different thicknesses.

(26) In the example shown, tubular portion 15 comprises a central cylindrical wall 26 with a groove 29; and two intermediate cylindrical walls 27 at opposite ends of central cylindrical wall 26.

(27) Central cylindrical wall 26 and intermediate cylindrical walls 27 are fitted to central tubular member 17.

(28) In a variation not shown, intermediate walls 27 are eliminated, and central wall 26 is the same axial length as central tubular member 17.

(29) Central wall 26 and the two intermediate walls 27 make roller 10 easier to assemble.

(30) Tubular portion 15 comprises a plurality of cylindrical end walls 28 fitted to lateral tubular members 18.

(31) Cylindrical walls 28 are much smaller axially than cylindrical walls 26 and 27, so much so as to actually define respective rings.

(32) Sheath 16 is fitted around tubular portion 15 and covers all of cylindrical walls 26, 27, 28.

(33) Cylindrical walls 27 may be connected to tubular member 17 by fastening members 30 (e.g., screws).

(34) Roller 10 may be idle, or powered by a reversible actuator 31.

(35) In actual use, and as shown in FIG. 6, protective sheeting 9 is compressed slightly between roller 10 and pipeline 1 at cutback 8. Roller 10 is sized and positioned axially so that groove 29 is located at weld bead 3, and lateral tubular members 18 are located at end portions 7 of coatings 5. The pressure exerted by roller 10 must be such as not to alter the thickness of protective sheeting 9. For this reason, a compressive force configured not to alter the thickness of protective sheeting 9 has been determined, and roller 10 is configured to yield easily where projecting parts are expected.

(36) At end portions 7 of coatings 5, roller 10 deforms considerably. More specifically, elastic deformation occurs at tubular layer 20, and cylindrical walls 28 move radially with respect to axis of rotation A2. More specifically, cylindrical walls 28 at the bevel slide radially with respect to one another to substantially match the shape of the bevel. Sheath 16 deforms elastically and imparts to roller 10 a smooth, continuous outer surface, regardless of the position of cylindrical walls 26, 27, 28. More specifically, relative radial slide of cylindrical walls 26, 27, 28 forms steps, but these do not alter the surface of protective sheeting 9, on account of cylindrical walls 26, 27, 28 being enclosed in sheath 16.

(37) The elasticity of tubular layers 19 and 20 is determined experimentally, by selecting the type of material and the number or quantity, shape, and size of openings 21, 22 on the basis of the thickness of coatings 5, and so as to exert substantially even pressure over the full width of protective sheeting 9.

(38) When tubular portion 14 deforms, tubular portion 15 maintains its circular cross section, so the contact area between roller 10 and protective sheeting 9 is independent of the degree of deformation of roller 10.

(39) Number 32 in the FIG. 7 variation indicates a roller which differs from roller 10 in FIGS. 1-6 by having a different central structure. More specifically, the central cylindrical wall 26 of roller 10 (FIG. 6) is replaced with a plurality of rigid central cylindrical walls 33 which, in the FIG. 7 example, are identical to cylindrical end walls 28. Each central cylindrical wall 33 is relatively very small and, in the FIG. 7 example, is roughly the same size as central cylindrical wall 33.

(40) Each central cylindrical wall 33 is slidable radially, with reference to axis A2, with respect to the adjacent central cylindrical walls 33 and intermediate cylindrical walls 27.

(41) Roller 32 also differs from roller 10 by central tubular member 17 in FIG. 6 being replaced with a central tubular member 34, and two intermediate tubular members 35 located at opposite ends of central tubular member 34 and at intermediate cylindrical walls 27. Tubular members 34, 35 comprise respective tubular layers 36, 37 of elastic material, such as silicone, and have axial openings 38 and 39. The degree of elasticity of tubular layers 36 and 37 depends on the elastic material used, the number or quantity of axial openings 38 and 39, and the shape and size of the cross section of openings 38 and 39.

(42) Tubular members 34, 35 comprise respective sleeves 40, 41 supporting respective tubular layers 36, 37.

(43) In certain embodiments, tubular layers 36, 37 are cured to respective sleeves 40, 41, which are made of metal.

(44) The other structural parts of roller 32 are identical to those of roller 10, and are indicated using the same reference numbers.

(45) In the variation described, roller 32 is able to deform sufficiently at weld bead 3 to leave the thickness of protective sheeting 9 unchanged.

(46) Also, the axial size of the center portion of roller 32 (i.e., the portion occupied by central cylindrical walls 33) is such as to even allow errors in the axial position of roller 32 with respect to weld bead 3.

(47) Clearly, changes may be made to the embodiment of the present disclosure described with reference to the attached drawings without, however, departing from the protective scope of the accompanying Claims. For example, in a variation not shown, the second tubular portion and/or the sheath are/is omitted. Accordingly, various changes and modifications to the presently disclosed embodiments will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.