Radiographic pipe inspection method and apparatus

Abstract

A method of inspecting a pipe includes locating a container around a pipe when the container is in an open position and moving the container from the open to a closed position. Then passing radiation through the container and at least a portion of the pipe substantially enclosed by the container. The distance between a source of the radiation and the at least a portion of the pipe being equal to or less than 300 mm. An apparatus comprising a container moveable between an open and a closed position. In the open position the container is locatable around a pipe and in the closed position the container substantially encloses at least a portion of the pipe. In the closed position the distance between a source of radiation enclosed in the container and the at least a portion of the pipe is equal to or less than 300 mm.

Claims

1. A method of inspecting a pipe, the method including the steps of: providing a container comprising a first portion and a second portion that form a chamber in a closed position; locating the container around a pipe when the container is in an open position; moving the container from the open position to the closed position, wherein in the closed position the container is located around the pipe and substantially encloses at least a portion of the pipe within the chamber; and passing a beam of radiation across the chamber of the container and through the at least a portion of the pipe when the container is in the closed position, wherein the container shields the beam of radiation, wherein a center of the beam of radiation is perpendicular to a longitudinal axis along a length of the pipe, a distance between a source of the radiation and the at least a portion of the pipe being equal to or less than 300 mm, wherein the container comprises a radiation detector attached to and movable with the second portion of the container, the radiation detector configured to determine a strength, quantity, and/or amount of radiation, wherein the radiation detector is located in the container opposite to the source of radiation when in the closed position.

2. A method according to claim 1, wherein the at least a portion of the pipe includes a pipe fitting.

3. A method according to claim 1, wherein the distance between the source of radiation and the at least a portion of the pipe is equal to or less than 100 mm.

4. A method according to claim 1, wherein the container further comprises a safety system to at least mitigate an emission of radiation from the source of radiation into the container, when the container is in the open position.

5. A method according to claim 1, wherein the source of radiation has a wavelength of equal to or less than 100 nanometers.

6. A method according to claim 1, wherein the source of radiation has a frequency of equal to or more than 310.sup.15 Hz.

7. A method according to claim 1, wherein the container totally shields the beam of radiation.

8. A method according to claim 2, wherein the method includes the step of comparing the strength of the radiation able to pass through the pipe and pipe fitting with the strength of the radiation able to pass across the container.

9. A method according to claim 4, wherein the safety system is a shield, the shield comprising the second portion of the container.

10. An apparatus comprising: a container comprising a first portion and a second portion, the container being moveable between an open and a closed position, wherein in the open position the container is locatable around a pipe and in the closed position the first portion and the second portion of the container form a chamber that substantially encloses at least a portion of the pipe within the chamber; a source of radiation enclosed in the container and positioned to pass a beam of radiation across the chamber of the container in the closed position, wherein the container shields the beam of radiation, wherein a center of the beam of radiation is perpendicular to a longitudinal axis along a length of the pipe; wherein in the closed position a distance between the source of radiation and the at least a portion of the pipe is equal to or less than 300 mm; and a radiation detector attached to and movable with the second portion of the container, the radiation detector configured to determine a strength, quantity, and/or amount of radiation, wherein the radiation detector is located in the container opposite to the source of radiation when in the closed position.

11. An apparatus according to claim 10, wherein the pipe has a pipe fitting at one end.

12. An apparatus according to claim 10, wherein the distance between the source of radiation and the at least a portion of the pipe is equal to or less than 100 mm.

13. An apparatus according to claim 10, wherein the apparatus further comprises a safety system to at least mitigate an emission of radiation from the source of radiation into the container, when the container is in the open position.

14. An apparatus according to claim 10, wherein the source of radiation has a wavelength of equal to or less than 100 nanometers.

15. An apparatus according to claim 10, wherein the source of radiation has a frequency of equal to or more than 310.sup.15 Hz.

16. An apparatus according to claim 10, wherein the container comprises a first container and a second container, the first container comprising the first portion and the second portion, the second container attachable to the first container, wherein the second container comprises the source of radiation.

17. An apparatus according to claim 11, wherein in the closed position the container substantially encloses the at least a portion of the pipe and the pipe fitting.

18. An apparatus according to claim 13, wherein the safety system is a shield, the shield comprising the second portion of the container.

19. An apparatus according to claim 16, wherein the first container has an aperture for communication with an aperture in the second container, and wherein the apertures are aligned in the closed position such that the source of radiation in the second container provides the source of radiation in the first container.

20. An apparatus comprising: a container comprising a first portion and a second portion, the container being moveable between an open and a closed position, wherein in the open position the container is locatable around a pipe and in the closed position the first portion and the second portion of the container form a chamber that substantially encloses at least a portion of the pipe within the chamber; a source of radiation enclosed in the container and positioned to pass a beam of radiation across the chamber of the container in the closed position, wherein the container shields the beam of radiation; and a radiation detector attached to and movable with the second portion of the container, the radiation detector configured to determine a strength, quantity, and/or amount of radiation, wherein the radiation detector is located in the container opposite to the source of radiation when in the closed position.

21. An apparatus according to claim 20, wherein the container comprises a first container and a second container, the first container comprising the first portion and the second portion, the second container attachable to the first container, wherein the second container comprises the source of radiation.

22. An apparatus according to claim 20, wherein in the closed position a distance between the source of radiation and the at least a portion of the pipe is equal to or less than 300 mm.

23. An apparatus according to claim 21, wherein the first container has an aperture for communication with an aperture in the second container, and wherein the apertures are aligned in the closed position such that the source of radiation in the second container provides the source of radiation in the first container.

Description

(1) Embodiments of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which:

(2) FIG. 1 is a cross-sectional view of a first embodiment of the apparatus according to the present invention;

(3) FIG. 2 is a cross-sectional view of a second embodiment of the apparatus;

(4) FIG. 3 is a cross-sectional view of a third embodiment of the apparatus in an open configuration;

(5) FIG. 4 is a cross-sectional view of the third embodiment of the apparatus in a closed configuration;

(6) FIGS. 5 and 6 show a beam of radiation passing through a pipe and pipe fitting; and

(7) FIGS. 7A and 7B show radiographic images of a pipe and pipe fitting fitted together correctly (A) and incorrectly (B).

(8) FIG. 1 shows a cross-sectional view of the apparatus 10 according to the present invention. The apparatus 10 includes a container comprising first 12 and second 14 portions. The container 12, 14 is moveable between an open and a closed position.

(9) The source of radiation 16 is enclosed in the container 12, 14. In the open position the container 12, 14 is locatable around a pipe 18 and in a closed position the container 12, 14 substantially encloses at least a portion of the pipe 18.

(10) The pipe 18 has a pipe fitting (not shown) at one end. In the closed position the container, as shown in FIG. 1, substantially encloses the least a portion of the pipe 18 and the pipe fitting (not shown).

(11) The first 12 and second 14 portions of the container are connectable such that when the first and second portions are connected they form the container and a chamber 20 of the container. The first 12 and second 14 portions are separable.

(12) The apparatus 10 also includes a second container 22 or x-ray generator (not shown). The second container 22 or x-ray generator (not shown) is attached to the first portion 12 of the container. The source of radiation 16 is housed in the second container 22 or x-ray generator (not shown).

(13) The first portion of the container 12 has an aperture 26 for communication with an aperture 24 in the second container 22 or x-ray generator (not shown). The apertures 24, 26 are aligned such that the source of radiation 16 in the second container 22 or x-ray generator (not shown) provides the radiation in the container 12, 14 and therefore also the chamber 20.

(14) In use, the source of radiation 16 emits a beam of radiation 28.

(15) The container 12, 14 houses a radiation detector 30. The detector 30 is used to determine the strength or amount of radiation.

(16) FIG. 2 shows a cross-sectional view of a second embodiment of apparatus 10, also referred to as a two piece container. One side of the first 12 and second 14 portions of the container are connected by a hinge 32. The other side of the first 12 and second 14 portions of the container are connected by a pin 34. Other features of the apparatus 10 shown in FIG. 2 that are also shown in FIG. 1 have been labelled with the same reference numbers.

(17) FIGS. 3 and 4 show cross-sectional views of a third embodiment of the apparatus 10 in an open and a closed configuration respectively. The first 12 and second 14 portions of the apparatus 10 are rotatable relative to one another. FIG. 3 shows the apparatus 10 in the open position and FIG. 4 shows the apparatus 10 in the closed position.

(18) The first 12 and second 14 portions of the container are semicircular in shape. The diameter of the second portion 14 is smaller than that of the first portion 12. The gap 38 in the second portion 14 is such that the pipe 18 can pass through the gap 38 into the chamber 20. The second portion 14 is then moveable relative to the first portion 12 to enclose a portion of the pipe 18, as shown in FIG. 4.

(19) The detector 30 is attached to the second portion 14 of the container and moves with the second portion 14. When the second portion 14 is moved such that the container is in the closed position, as shown in FIG. 4, the detector is located under the pipe, opposite to the source of radiation 16. The beam of radiation 28 is therefore able to pass through a cross-section of the pipe 18 and contact the detector 30. The beam of radiation 28 is emitted by the source of radiation 16 in the second container 22 or x-ray generator (not shown), passing through apertures 24, 26 and into the chamber 20 of the container.

(20) FIGS. 5 and 6 show a beam of radiation 28 passing through a pipe 18 and pipe fitting 40a and through a pipe fitting 40b respectively.

(21) FIG. 5 shows a pipe fitting 40a where an end or an end face of the pipe 18 abuts an internal mating surface 42 of the pipe fitting 40a. FIG. 6 shows a pipe fitting 40b where the end or the end face the pipe 18 is spaced apart from the internal mating surface 42 of the pipe fitting to leave a gap 44.

(22) The amount or strength of radiation, shown as the beam of radiation 28, passing through the pipe 18 and pipe fitting 40a, as shown in FIG. 5 is less than the amount or strength of radiation, shown by the beam of radiation 28, passing through only the pipe fitting 40b, as shown in FIG. 6. This difference can be used to determine if the pipe 18 and pipe fitting 40a, 40b have been correctly connected together, as shown in FIG. 5, or incorrectly connected together, as shown in FIG. 6. The radiation emitted by the source of radiation 16, passing through the pipe 18 and pipe fitting 40a or just the pipe fitting 40b is detected by the detector 30.

(23) FIGS. 7A and 7B show radiographic images of a pipe and pipe fitting fitted together correctly (A) and incorrectly (B).

(24) FIG. 7A is a radiograph of the pipe 18 and a typical pipe fitting 40a shown in FIG. 5. FIG. 7B is a radiograph of the pipe 18 and a typical pipe fitting 40b shown in FIG. 6. FIG. 7B shows a typical gap 44, also shown in FIG. 6.

(25) The boxed section in FIG. 7A shows a miss-fitted back ferrule and FIG. 7B shows a correctly fitted back ferrule,

(26) The method of inspecting a pipe involves locating the first portion 12 and second portion 14 of the first container around a pipe 18 when the first container is in an open position. The first container 12, 14 is then moved from the open position to a closed position, wherein in the closed position the container 12, 14 is located around the pipe 18 and at least substantially encloses at least a portion of the pipe 18. In use, the pipe 18 typically passes through the centre of the container 12, 14. Once the container 12, 14 is in the closed position as shown in FIGS. 1, 2 and 4, radiation is emitted from the source 16 of radiation enclosed in the second container 22 or from the x-ray generator (not shown).

(27) In use, the source of radiation 16 emits a beam of radiation 28. The radiation is ionising radiation with a wavelength of equal to or less than 100 nanometers and a frequency of equal to or more than 310.sup.15 hertz.

(28) The step of emitting radiation includes emitting the radiation through the container 12, 14 and/or through the at least a portion of the pipe 18 and a pipe fitting (not shown) via apertures 24, 26 which provide communication between the container 12, 14 and the second container 22 or x-ray generator (not shown). The radiation is subsequently detected by the radiation detector 30 in the second portion 14 of the container.

(29) In use, the method includes the step of comparing the strength of the radiation able to pass through the pipe 18 and/or pipe fitting with the strength of the radiation able to pass through the container 12, 14 and/or the strength of the radiation able to pass through only the pipe fitting.

(30) When there is a gap 44 between the pipe 18 and the pipe fitting 40b as shown in FIG. 6, the amount of radiation detected by the detector 30 is more than the amount of radiation detected by the detector 30 when the pipe 18 and the pipe fitting 40b are correctly connected or joined together, as shown in FIG. 5.

(31) The amount of radiation able to pass through a section or portion of pipe 18 where the thickness of the wall of the pipe has been reduced, by for example corrosion, is more than the amount of radiation able to pass through an un-corroded portion of the same pipe 18. Blockages in the pipe 18 or pipe fitting 40a will cause less radiation to pass through to the detector 30 in comparison to an unblocked pipe or fitting

(32) Modifications and improvements can be incorporated herein without departing from the scope of the invention.