PIPE ASSEMBLY

Abstract

Disclosed herein is a pipe assembly containing a pipe, an insulating jacket coupled to the pipe via an attachment base; and a tracer wire within the insulating jacket. The width of the attachment base is greater than width of the insulating jacket. Also disclosed herein are methods of locating a pipe concealed below a ground surface, and detecting the presence and the position of a leak in a pipe concealed below a ground surface.

Claims

1. A device comprising: a tube including a metal; a T-shape defined via an insulating jacket and a base such that the base is positioned between the tube and the insulating jacket; and a wire extending within the insulating jacket, wherein the base is positioned between the wire and the tube.

2. The device of claim 1, wherein the insulating jacket thins towards the base.

3. The device of claim 1, wherein the base has a width within a range of about 5 millimeters to about 8 millimeters.

4. The device of claim 1, further comprising: a signal generator coupled to the wire.

5. The device of claim 4, further comprising: an oscilloscope coupled to the wire.

6. The device of claim 1, further comprising: an oscilloscope coupled to the wire.

7. The device of claim 6, further comprising: a signal generator coupled to the wire.

8. The device of claim 1, wherein the tube is rectilinear.

9. The device of claim 1 wherein the tube includes a high-density polyethylene.

10. The device of claim 1, wherein the wire includes an electrically conductive material.

11. The device of claim 1, further comprising: a memory that stores a reflection representation.

12. The device of claim 1, wherein the tube is a first tube, and further comprising: a second tube butt welded to the first tube such that a continuous tube is formed.

13. The device of claim 12, wherein the wire is a first wire, wherein the second tube hosts a second wire, wherein the first wire and the second wire are joined via a flexible multi-strand cable.

14. The device of claim 13, wherein the first wire includes a first end portion, wherein the second wire includes a second end portion, wherein the flexible multi-strand cable includes a plurality of end portions hosting a plurality of tubular lugs that crimp and insulate the first end portion and the second end portion.

15. A method comprising: causing a signal source to be coupled to a wire extending within an insulating jacket, wherein the insulating jacket and a base define a T-shape, wherein the base is positioned between the insulating jacket and a tube concealed below a ground surface, wherein the base is positioned between the wire and the tube; causing a signal to be sent from the signal source through the wire; and causing the signal to be sensed via a sensor located above the ground surface.

16. The method of claim 16, further comprising: generating a representation of the tube concealed below the ground surface.

17. A method comprising: causing a signal source to be coupled to a wire extending within an insulating jacket, wherein the insulating jacket and a base define a T-shape, wherein the base is positioned between the insulating jacket and a tube concealed below a ground surface, wherein the base is positioned between the wire and the tube; causing a pulse to be sent from the signal source through the wire; receiving a reflection of the pulse via the wire; performing an analysis of the reflection; and determining a presence of a leak in the tube based on the analysis.

18. The method of claim 17, further comprising: determining a position of the leak based on the analysis.

19. A method comprising: causing a first end portion of a first wire to be exposed from a first insulation jacket, wherein the first insulation jacket and a first base define a first T-shape, wherein the first wire extends within the first insulation jacket, wherein the first base is positioned between the first insulation jacket and a tube, wherein the first base is positioned between the first wire and the tube; causing a second end portion of a second wire to be exposed from a second insulation jacket, wherein the second insulation jacket and a second base define a second T-shape, wherein the second wire extends within the second insulation jacket, wherein the second base is positioned between the second insulation jacket and a second tube, wherein the second base is positioned between the second wire and the second tube; causing the first end portion to be joined to a first lug; causing the second end portion to be joined to a second lug; causing the first lug and the second lug to be attached to a multi-strand insulated cable.

20. The method of claim 19, further comprising: causing an application of a heat shrinkage sleeve such that the heat shrinkage sleeve encompasses at least a portion of the multi-strand cable and the first lug and the second lug; causing the heat shrinkage sleeve to be heated such that a joint of the first wire and the second wire is created.

21. A device comprising: a tube including a non-metal; a T-shape defined via an insulating jacket and a base such that the base is positioned between the tube and the insulating jacket; and a wire extending within the insulating jacket, wherein the base is positioned between the wire and the tube.

22. The device of claim 21, wherein the insulating jacket thins towards the base.

23. The device of claim 21, wherein the base has a width within a range of about 5 millimeters to about 8 millimeters.

24. The device of claim 21, further comprising: a signal generator coupled to the wire.

25. The device of claim 24, further comprising: an oscilloscope coupled to the wire.

26. The device of claim 21, further comprising: an oscilloscope coupled to the wire.

27. The device of claim 26, further comprising: a signal generator coupled to the wire.

28. The device of claim 21, wherein the tube is rectilinear.

29. The device of claim 21 wherein the tube includes a high-density polyethylene.

30. The device of claim 21, wherein the wire includes an electrically conductive material.

31. The device of claim 21, further comprising: a memory that stores a reflection representation.

32. The device of claim 21, wherein the tube is a first tube, and further comprising: a second tube butt welded to the first tube such that a continuous tube is formed.

33. The device of claim 22, wherein the wire is a first wire, wherein the second tube hosts a second wire, wherein the first wire and the second wire are joined via a flexible multi-strand cable.

34. The device of claim 23, wherein the first wire includes a first end portion, wherein the second wire includes a second end portion, wherein the flexible multi-strand cable includes a plurality of end portions hosting a plurality of tubular lugs that crimp and insulate the first end portion and the second end portion.

35. The device of claim 21, wherein the non-metal includes a polymer.

36. The device of claim 21, wherein the non-metal includes a polybutylene.

37. The device of claim 21, wherein the non-metal includes a polyvinylchloride.

38. The device of claim 21, wherein the non-metal includes a unplasticised polyvinylchloride.

39. The device of claim 21, wherein the non-metal includes a polyethylene.

40. The device of claim 21, wherein the non-metal includes a high density polyethylene.

41. The device of claim 21, wherein the non-metal includes a polypropylene.

42. The device of claim 21, wherein the non-metal includes a cross-linked polyethylene.

43. The device of claim 21, wherein the non-metal includes a plastic.

44. The device of claim 21, wherein the non-metal includes a fiberglass.

45. The device of claim 21, wherein the non-metal includes a concrete.

46. An assembly comprising: a pipe; an insulating jacket coupled to the pipe via an attachment base; and a tracer wire within the insulating jacket.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0013] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an implementation of the present invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings:

[0014] FIG. 1 depicts a cross sectional view of a pipe known in the art.

[0015] FIG. 2 depicts a sectional view of a duct body having a single tracer wire, according to an exemplary embodiment.

[0016] FIG. 3 depicts a sectional view of a duct body having a double tracer wire, according to an exemplary embodiment.

[0017] FIG. 4 depicts a system to determine leakage in a duct body, according to an exemplary embodiment.

[0018] FIG. 5 depicts a waveform, according to an exemplary embodiment.

[0019] FIGS. 6A and 6B depict the joining of tracer wires when connecting pipes, according to an exemplary embodiment.

DETAILED DESCRIPTION

[0020] In the following description of the illustrated embodiments, references are made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration, various embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural and functional changes may be made without departing from the scope of the inventions disclosed herein.

[0021] Referring to the accompanying drawings, FIG. 1 shows a cross sectional view of a pipe 100 with a pinpoint wire 102 encased in a protective insulation 104. The pinpoint wire 102 or its protective insulation 104 is coupled to the pipe 100 via a narrow base 106.

[0022] FIG. 2 shows a sectional view of a duct body 200 with a tracer wire 202 within an insulating jacket 204 and an attachment base 206. The duct body 200 is made of suitable polymer material such as polybutylene, unplasticised polyvinylchloride, polyethylene (PE or HDPE), polypropylene, cross-linked polyethylene, other plastics, or other pipe materials known in the art. The duct body has a tracer cable 202 along a portion of its length or its entire length encased in suitable polymer material that forms an insulating jacket 204. The insulating jacket is coupled to the duct body via an attachment base 206. The attachment base 206 has a shape that has a width x, which is greater than the width y of the insulating jacket, the width z of the insulating jacket and the tracer wire, or both. In an example, the shape of the attachment base 206 is rectangular or square. In an example, the width of the base x is in the range from and including 5 mm to 8 mm, both inclusive. In an embodiment the width of the base x is about 5 mm, about 6 mm, about 7 mm or about 8 mm.

[0023] In an example the attachment base 206 is secured to the duct body using any adhesive known to persons of ordinary skill in the art. The insulating jacket and the attachment base are made of materials suitable for the expected temperatures and pressures with no or minimal vulnerability to electrolytic corrosion. As the attachment base 206 has a width greater than at least the width of the insulating jacket 204, the insulating jacket is coupled to the duct body on a greater surface area of the duct body than the conventional art, thereby attaching the tracing wire more securely to the duct body. In certain embodiments, the attachment base and the insulating wire can be parts of a single unit. In certain embodiments, the attachment base and the insulating wire can be two separate units securely coupled to each other, through physical means or chemical adhesion means or combinations thereof. As a result, the tracing wire is coupled more securely to the duct body and less likely to be damaged or removed during transit or when the pipe is laid underground, thereby reducing the occurrences of an impedance irregularity caused by damaged tracing wires and the amount of false positives for pipe location and or damage detection. The attachment base can be part of the duct body, or can be securely coupled to the duct body, through physical means or chemical means or combinations thereof. Physical means include any means by which the attachment base can be securely coupled to the pipe or the duct, such as a slot/insert, protrusion/groove, nails, screws, or other mechanical fasteners, or where heat or pressure is applied to couple the attachment base to the pipe or the duct such as crimping, welding, soldering, brazing, or others known in the art. Chemical means include gluing, cementing, or the use of other adhesives.

[0024] FIG. 3 depicts a duct body 300 with two tracing wires 302 and 303 each of which are encased within insulating jackets 304 and 305, and coupled to the duct body 300 via attachment bases 306 and 307 respectively. In this example, the attachment bases 306 and 307 have widths greater than the widths of the insulating jackets 304 and 305, and the tracing wires 302 and 303, or both. When more than one tracing wire is attached to a duct body, the width of the attachment base can vary to accommodate different sized insulating jackets and tracing wires and the attachment bases can be the same or different from each other. While FIG. 3 depicts two tracing wires coupled to the duct body, three or four or more tracing wires may be coupled to the duct body using an insulating jacket and attachment base.

[0025] FIG. 4 depicts a pulse generator 401 or any other known signal generator coupled to a tracer wire 402 by means of a suitable isolation circuit 403. The isolation circuit may be a passive circuit or may be an active switching circuit that directs the pulse from the pulse generator to the cable when the pulse is present and directs any reflected wave from the cable to an analyzing device such as, for example, an oscilloscope 404. As the pulse propagates down the line, the voltage across the cable will be proportional to the characteristic impedance of the cable. After the pulse has been applied to the cable, there will be a signal present at the input of the cable until a reflected waveform is received. If the characteristic impedance of the cable is uniform and is matched to the pulse of the generator there will be no reflected wave received until the pulse propagates along the entire length of the cable and is reflected by the end of the cable that is normally open circuited. However, because the cables generally do not have characteristic impedance that is perfectly matched to the impedance of the pulse generator, reflections will occur when the pulse encounters such irregularities in impedance. The reflected waveform across the input to the cable would be similar to the waveform illustrated in FIG. 5, which is illustrative of the type of waveform that would be displayed on the oscilloscope 404. The reflected waveforms may be stored in a memory storage device.

[0026] Referring now to FIG. 5, the waveform has an essentially horizontal section 3 and an upwardly (or downwardly) extending section 2. The essentially horizontal section 3 is the result of reflection within the cable and is a function of the characteristic impedance along the length of the cable. Thus the amplitude of the reflected waveform will vary as the characteristic impedance of the cable varies. The upwardly extended portion of the waveform 2 is the result of the pulse being reflected from the open circuited end of the cable. If desired, the far end of the cable could be short-circuited thus resulting in a downwardly extending end reflection, or otherwise terminated. A pair of thresholds 4 and 6 frames the horizontal section 3 of the waveform. The thresholds 4 and 6 are separated from the horizontal section of the waveform by an amount sufficient to accommodate variations in the amplitude of the horizontal section 3 of the waveform caused by variations in the characteristic impedance of the cable. Thus, under normal circumstances, in the absence of any breaks or leaks the thresholds 4 and 6 would define the upper and lower changes in magnitude of the horizontal section of the waveform.

[0027] In the event of a leak, the characteristic impedance of the transmission line will change. In most cases, this change is a decrease in characteristic impedance that occurs in the proximity of the leak or break, resulting in a dip 8 in the waveform. If the dip 8 is of sufficient magnitude to cross the threshold value, an alarm indicating a leak is sounded and the approximate position of the leak is determined from the position of the dip 8 in the waveform. Similarly, in the event of a break in the cable, a new end echo 9 resulting from the reflection at the break in the cable occurs. If this end echo 9 is of sufficient magnitude to cross the threshold, such as the upper threshold 4, an alarm is also sounded. Various other known leak detection means may also be used. As the tracer wire 202 is coupled to the duct body via the attachment base 206, it is less likely that an irregularity in the impedance is caused by damage to the tracing wire. The tracing wire is coupled more securely to the duct body, thus reducing the likelihood that the tracing wire is dislodged or damaged.

[0028] In another embodiment, a co-axial cable may be used as the tracer wire. The co-axial is co-extruded along the entire length of the non-metallic pipe using an insulating jacket and attachment base as described in the above embodiments.

[0029] Certain embodiments include a method of detecting a leak in a concealed pipe. The method includes the steps of providing a pipe assembly containing a pipe, an insulating jacket coupled to the pipe via an attachment base, and a tracer wire within the insulating jacket; connecting the tracer wire on the pipe to a pulse generator; passing pulses through the tracer wire by the pulse generator; receiving reflections of the pulses from the cable; and analyzing the reflections to determine presence of leak and its position. The pipe assembly further includes the attachment base with a width greater than a width of the insulating jacket.

[0030] Certain embodiments include a method of joining two non-metallic pipes with co-extruded tracer cables. The method includes the steps of peeling a tracer cable from the insulation jacket from pipes to be joined together; inserting the peeled off tracer cable into a heat shrinkage sleeve; joining the two ends of peeled off tracer cable to the lugs of a multi-strand insulated wire; and heating the heat shrinkage sleeve to seal the joint. The tracer cables are attached to the pipes via attachment bases, having a width greater than the width of the insulating jacket.

[0031] When a plurality of pipe assemblies are joined, one or more means of welding them can be utilized, for example butt welding or fillet welding. FIG. 6A and FIG. 6B show a method of joining two tracer wires on adjacent pipes. As shown in FIG. 6A, the pipes 601 and 602 are laid end-to-end and welded to form a leak proof joint 603, such as by butt welding. Tracer wires 604 and 605 are peeled off from ends of both the pipes and passed through a heat shrinkage sleeve 606. FIG. 6B shows the method in greater detail. Tracer wires 604 and 605 are connected to multi-strand flexible cable 607 through tubular metal lugs 608 and 609 for crimping that cover the joints of the tracer wires 604 and 605 and the multi-strand flexible cable 607. Heat is then applied to the components 610 and 611 of the heat shrinkage sleeve and the whole joining assembly is sealed.

[0032] The tracer wire is made of an electrically conductive material. Examples of materials for the trace wire include copper, aluminum, tungsten, zinc, nickel, iron, steel, or combinations thereof. In an embodiment, the tracer wire is made of high-grade 99.95% pure copper wire of specified thickness to provide the desired conductivity for carrying the tracer and leak detection signal. In an embodiment, the exact location of the duct body with co-extruded tracer wire is carried out with a multiple frequency locator. This equipment broadly consists of a transmitter and a receiver. The transmitter sends an electrical signal to the tracer wire coupled to the pipe being traced, while the receiver picks up that signal, allowing the trace of the signal's path and follow the pipe under detection. When the tracer wire is energized, a sensing device on the surface coupled to the receiver can pick up the signals and thus, the exact location of the underground pipe can be determined.

[0033] While various embodiments of the present invention have been described, it will be apparent to those of skill in the art that many more embodiments and implementations are possible that are within the scope of this invention. Accordingly, the present invention is not to be restricted except in light of the attached claims and their equivalents.