Method of Manufacturing Reinforced Pipe

Abstract

A method of manufacturing a reinforced pipe (7) comprising: wrapping a pipe (1) in reinforcing tape (2) to form a wrapped pipe having an outer circumference consisting of a first circumferential portion (4) and a second circumferential portion (6); and passing the first circumferential portion (4) over one or more heating elements (3) to fuse the reinforcing tape (2) of said first circumferential portion (4); wherein: the first circumferential portion (4) is between 1% and 50% of the outer circumference; and the second circumferential portion (6) is not passed over a heating element (3) and is not fused. The method is advantageous in that it can provide reinforced pipes (7) in a simpler and cheaper way because it is not essential that the entirety of the outer circumference of the reinforced pipe (7) is fused. A reinforced pipe (7) produced according to the method of the present invention is also provided.

Claims

1. A method of manufacturing a reinforced pipe comprising: wrapping a pipe in reinforcing tape to form a wrapped pipe having an outer circumference consisting of a first circumferential portion and a second circumferential portion; and passing the first circumferential portion over one or more heating elements to fuse the reinforcing tape of said first circumferential portion; wherein: the first circumferential portion is between 1% and 50% of the outer circumference; and the second circumferential portion is not passed over a heating element and is not fused.

2. The method according to claim 1, wherein the pipe is wrapped in a single layer of reinforcing tape.

3. The method according to claim 1, wherein the pipe is wrapped in two or more layers of reinforcing tape.

4. The method according to claim 3, wherein the first circumferential portion is passed over the one or more heating elements only after the pipe has been wrapped in all of the two or more layers of reinforcing tape.

5. The method according to claim 3, wherein the first circumferential portion is passed over the one or more heating elements between wrapping the pipe in successive layers of reinforcing tape.

6. The method according to claim 3, wherein adjacent layers of reinforcing tape are wrapped around the pipe in different directions.

7. The method according to any preceding claim 1 in which the first circumferential portion consists of more than 10% of the outer circumference of the wrapped pipe, preferably more than 20%, and even more preferably more than 30%.

8. The method according to any preceding claim 1, wherein the first circumferential portion is passed over a single heating element.

9. The method according to claim 1, wherein the first circumferential portion is passed over two or more heating elements.

10. The method according to any preceding claim 1, wherein the pipe is not axially rotated relative to the one or more heating elements as the first circumferential portion is passed over said one or more heating elements.

11. The method according to claim 1, wherein the pipe is axially rotated relative to the one or more heating elements as the first circumferential portion is passed over said one or more heating elements.

12. The method according to claim 11, wherein the pipe is axially rotated and the one or more heating elements are not rotated.

13. The method according to claim 11, wherein the pipe is not rotated and the one or more heating elements are rotated about the axis of the pipe.

14. (canceled)

15. The method according to claim 1, wherein the first circumferential portion is a single circumferentially continuous portion.

16. The method according to claim 1, wherein, wherein the first circumferential portion consists of two or more circumferentially separated portions and the two or more circumferentially separated portions are equally spaced about the outer circumference.

17. (canceled)

18. A reinforced pipe consisting of an inner pipe that is wrapped in reinforcing tape, the reinforced pipe having an outer circumference consisting of a first circumferential portion and a second circumferential portion; wherein the reinforcing tape of the first circumferential portion has been heated and fused; the reinforcing tape of the second circumferential portion is not fused; and the first circumferential portion is between 5% and 50% of the outer circumference.

19. The reinforced pipe according to claim 18, wherein the inner pipe is wrapped in a single layer of reinforcing tape.

20. The reinforced pipe according to claim 18, wherein the inner pipe is wrapped in two or more layers of reinforcing tape.

21. The reinforced pipe according to claim 20, wherein adjacent layers of reinforcing tape are wrapped around the inner pipe in different and non-parallel directions.

22. (canceled)

23. (canceled)

24. The reinforced pipe according to claim 18, wherein the first circumferential portion consists of two or more circumferentially separated portions and the two or more circumferentially separated portions are equally circumferentially spaced about the outer circumference of the pipe.

25. (canceled)

Description

DRAWINGS

[0033] FIG. 1 shows an inner pipe wrapped with reinforcing tape prior to fusing;

[0034] FIG. 2 shows the wrapped pipe of FIG. 1 passing over a heating element to form a reinforced pipe having a first circumferential portion in accordance with a first embodiment of a method of the present invention; and

[0035] FIG. 3 shows the wrapped pipe of FIG. 1 passing over a heating element to form a reinforced pipe having a first circumferential portion in accordance with a second embodiment of a method of the present invention.

[0036] FIG. 1 shows an inner pipe 1 that has been wrapped in a single layer of reinforcing tape 2, prior to undergoing any fusing, in accordance with an initial step of a method according to the present invention. The reinforcing tape 2 has been wrapped around the inner pipe 1 in a spiral such that it completely covers the inner pipe. The inner pipe 1 is formed of HDPE and the reinforcing tape 2 is Celstran® CFR-TP.

[0037] In a subsequent step of a first embodiment of a method according to the present invention the inner pipe 1 wrapped in the single layer of reinforcing tape 2 is moved past a heating element 3 in the direction A, as shown in FIG. 2. The heating element 3 acts to heat a first circumferential portion 4 of the inner pipe 1 wrapped in the single layer of reinforcing tape 2. in order to fuse the reinforcing tape 2 of said first circumferential portion 4. As the inner pipe I wrapped in the single layer of reinforcing tape 2 is passed over the heating element 3 the inner pipe 2 is not axially rotated relative to the heating element 3. As a result, edges 5 of the first circumferential portion 4 are substantially parallel to a longitudinal axis of the inner pipe 1. The first circumferential portion 4 extends about approximately 20% of an outer circumference of the inner pipe 1 wrapped in the reinforcing tape 2. A second circumferential portion 6 extends around the remaining approximately 80% of the outer circumference of the inner pipe 1 wrapped in the reinforcing tape 2. The reinforcing tape 2 of the second circumferential portion 6 has not passed the heating element 3, has not been significantly heated, and is not fused.

[0038] The part of the inner pipe 1 wrapped in the reinforcing tape 2 that has passed the heating element and has a first circumferential portion 4 and a second circumferential portion is a reinforced pipe 7 according to the present invention. After the whole length of the inner pipe 1 wrapped in reinforcing tape 2 has passed the heating element 4 a complete length of reinforced pipe 7 according to the present invention is formed.

[0039] FIG. 3 shows a reinforced pipe 7 being formed using a second embodiment of a method according to the present invention. The second embodiment is substantially in accordance with the first embodiment of the method of the present invention described in relation to FIG. 2 above, with the exception that the inner pipe 1 wrapped in reinforcing tape 2 is rotated in direction B as the inner pipe 1 wrapped in reinforcing tape 2 is passed past the heating element 3 in direction A. As a result of this rotation in direction B, the first circumferential portion of the reinforced pipe 7 spirals around an outer circumference of the reinforced pipe and its edges 5 are not parallel to the longitudinal axis of the inner pipe 1. Nevertheless, as for the embodiment of FIG. 2, due to the size of the heating element 3 the first circumferential portion 4 still extends about approximately 20% of an outer circumference of the reinforced pipe 7 and the second circumferential portion 6 extends around the remaining approximately 80% of the outer circumference of the reinforced pipe 7. That is, for any given circumference of the reinforced pipe 1, approximately 80% will be part of the second circumferential portion 6 and approximately 20% will be part of the first circumferential portion 4.

[0040] It is to be understood that the embodiments shown in the Figures are illustrative only and are shown to aid understanding of the invention.