WO1999050585A1

WO1999050585A1 - Calibration hose assembly and closure device and a method of conforming a tubular pipe liner

Info

Publication number: WO1999050585A1
Application number: PCT/GB1999/000823
Authority: WO
Inventors: Andrew Steven Mitchell
Original assignee: Texon Uk Limited; Texon Materiales, S.L.
Priority date: 1998-03-28
Filing date: 1999-03-17
Publication date: 1999-10-07
Also published as: GB9806620D0; AU2945399A

Abstract

A calibration hose assembly suitable for use in conforming a pipeliner (88) to the interior surface of a pipeline (74) to be renovated comprising a hose (42), a closure device (20) partially received in the interior of the hose (42) and projecting therefrom at a first end, and securing means (46) securing the closure device (20) to the hose (42) at the first end to create a fluid-tight seal preventing fluid passing between the interior of the hose (42) and the closure device (20) at said first end portion, the closure device (20) comprising attachment means for connecting the device to an article or articles. The closures device (20) has a hole (34) extending therethrough which is sealed by a method of conforming a pipeliner to release trapped air from the calibration hose.

Description

CALIBRATION HOSE ASSEMBLY AND CLOSURE DEVICE AND A METHOD OF CONFORMING A TUBULAR PIPE LINER

Technical Field This invention is concerned with a calibration hose assembly suitable for use in conforming a pipeline to the interior surface of the pipeline, a closure device suitable for use in closing an end portion of a hose and a method of conforming a tubular pipeline to the interior surface of the pipeline, especially in applying a renovated pipeliner to the interior surface of a pipeline.

Background Art

As pipeline networks age it becomes necessary either to replace or renovate sections of pipeline in order to maintain an efficient system. Different techniques of pipeline renovation have been proposed and one such technique involves use of a fabric tube impregnated with a curable resin, the tube being located within the pipeline to be renovated and then urged into engagement with the pipeline by inflation of a hose, commonly known as a calibration hose, within the tubular pipeline. Finally the resin with which the pipeline is impregnated is cured to create a substantially rigid tubular pipeline.

One known method of conforming a tubular pipeliner to the interior surface of a pipeline has involved the use of a scaffolding tower or other means of supporting a feed pipe extending from an entry to the pipeline upwardly for distance of about 14 feet to an inlet to the feed pipe. A calibration hose is turned partially inside out by passing a first end of the hose through the interior of the hose so that a pocket is formed at a leading portion of the hose. The second end of the hose which is not

1 turned inside out is secured at the inlet to the pipe with the leading portion of the hose extending through the feed pipe and projecting from- an outlet of the feed pipe and with the remainder of the hose still extending through the interior of the hose. The leading end which forms the pocket is then introduced into the tubular pipeliner at the entry of the pipeline to be lined. Water is then poured into the pocket at the inlet to the feed pipe and the water pressure is sufficient to force the leading portion of the hose through the tubular pipeliner urging it against the wall of the pipeline to be lined.

A length of calibration hose which is twice the total distance between the inlet to the feed pipe and the end of the tubular pipeliner which is being installed within the pipeline is required in order that the pocket can become sufficiently large to reach the end of the renovation pipeliner whilst still maintaining the head of water to the inlet of the feed pipe. This hydraulic pressure urges the tubular pipeliner into engagement with the interior surface of the pipe line until the resin impregnated into the pipeliner has cured, following which the water is released from the pocket and the calibration hose withdrawn. Some curable impregnants which are used in renovating pipelines will react and cure to a rigid condition at room temperature within an acceptable period of time. But for other curable resin systems, it is necessary to heat the resin eg by the introducing hot water in order to cause the necessary curing reaction to take place sufficiently rapidly.

Introducing hot water into the pocket of a calibration hose as described above can cause complications for example, if the water is too hot the calibration hose itself may be adversely effected and softened so that it no longer properly fulfils its function or may bust. Furthermore, it may be difficult to cause sufficiently hot water to reach the far end of the hose pocket and thus to activate the resin at the most remote region of the pipeliner, so that it is possible that the calibration hose may be withdrawn before the resin has been promptly cured thereby leading to a risk that the pipeliner may collapse away from the pipeline to be renovated. Furthermore, the method outlined above utilises a considerable length of calibration hose and it would be desirable to reduce the amount of calibration hose needed for renovating a length of pipeline, compared with the amount needed using the method outlined above.

Summary of the Invention

It is an object of the invention to overcome one or more of the defects of the known method of inserting the calibration hose outlined above.

Another object of the invention is to provide an improved calibration hose assembly.

In one aspect the invention may be considered to provide a method of conforming a tubular pipeliner to the interior surface of a pipeline comprising the steps of:

(i) introducing a pipeliner into a length of pipeline to be lined at an entry to the pipeline;

(ii) supporting a feed pipe extending upwardly from an outlet adjacent the entry, to an inlet of the feed pipe; (iii) procuring a piece of calibration hose having a length which is the sum of the length of the pipeline to be lined, the distance between the entry of the pipeline to the outlet of the feed pipe, the length of the feed pipe between its inlet and outlet, and an excess sufficient to secure a first end of the calibration hose to a closure device and to secure the other, second end adjacent the inlet of the feed pipe;

(iv) turning a portion of the calibration hose inside out by passing the first end of the calibration hose through the interior of the hose to leave a leading portion of the hose adjacent the second end which is not turned inside out with the remainder of the hose still extending through the interior of the hose so that the leading portion forms a pocket;

(v) before or after step (iv) securing said first end of the calibration hose to a closure device according to any one of claims 12 to

17 to create a fluid tight seal between the hose and die closure device wid the attachment means of the device accessible after it has been turned inside out;

(vi) introducing said leading portion of the calibration hose into the inlet of the feed pipe and clamping a portion of the hose adjacent the second end or adjacent the inlet of the feed pipe; (vii) securing elongated flexible means to the attachment means;

(viii) feeding the leading portion of the hose through the feed pipe whilst keeping die second end secured at d e inlet end of die feed pipe dius drawing the part of the hose which was turned inside out back through the interior of the hose, until the leading portion reaches the entry to the pipeline;

(ix) introducing die leading portion of the hose into the tubular pipeliner at the entry;

(x) introducing liquid into the pocket formed at the leading portion whereby the pressure of liquid acts to propel die leading portion through die pipeline urging die pipeliner against the walls of the pipeline until the hose is turned back to its original condition widi the closure device at the end of the pipeline remote from the entry and wid the elongated flexible means extending mrough the hose from the closure device to and out of the inlet; (xi) thereafter withdrawing die hose from the pipeline and feed pipe.

In anomer aspect the invention may be considered to provide a calibration hose assembly suitable for use in conforming a pipeliner to the interior surface of a pipeline to be renovated comprising a hose, a closure device partially received in d e interior of die hose and projecting therefrom at a first end, and securing means securing the closure device to the hose at the first end to create a fluid-tight seal preventing fluid passing between the hose and the closure device at said first end, die closure device comprising attachment means for connecting the device to an article or articles. Preferably d e closure device comprises a body which is inserted into the interior of the hose.

In another aspect the invention may be considered to provide a closure device suitable for use in closing an end of a hose comprising a body adapted to be secured to an end of the hose into which the device is inserted, and attachment means by which the device can be attached to an article.

Preferably a closure device in accordance with die invention has a first hole in the body extending lengthwise therethrough from a first end portion of die body to a second end portion of die body and die device comprises a first releasable sealing means sealing the first hole and actuable from the first end portion of die body.

Suitably the attachment means is also disposed at the first end portion of the body; conveniently the attachment means may project lengthwise from the body at d e first end portion in d e form of a projection having a hole therein through which an article eg elongated flexible means to be attached to the closure device may be passed. A preferred closure 'device in accordance with the invention also has a second hole extending dirough die body from die first end portion to the second end portion and the device comprises second releasable sealing means which releasably seals die second hole. The first and second sealing means may be provided in any convenient manner and should seal die holes against passage of a fluid, bodi liquid or gas, under some pressure. One simple form of sealing means comprises a bolt screwed into a tapped end portion of the relevant one of the first and second holes so diat the bolt can be tightened to seal the hole or removed to open die hole. However, more sophisticated sealing means may be provided including sealing means which may be operated to open d e relevant hole remotely from me closure device.

A preferred closure device comprises first and second collars at die first and second end portions of the body and a waist portion between the collars. Conveniently in this case, d e means for securing die closure device to die hose in a calibration hose assembly in accordance with the invention may be provided by clamping means disposed on and extending around die waste portion. Suitably the clamping means may be a screw band clip of me type supplied under die trade name "Jubilee" .

A calibration hose assembly in accordance wid the invention preferably utilises a closure device in accordance widi die invention.

Preferably a calibration hose assembly in accordance wid d e invention comprises a rope attached to d e attachment means; conveniently the lengd of the rope exceeds diat of die calibration hose so that when die calibration hose is extended to its full length in carrying out a method in accordance widi die invention, die rope will extend beyond the inlet to die feed pipe. A preferred assembly in accordance wid die invention also comprises a feed hose attached to die attachment means, of a sufficient length, at least as long as the rope, the feed hose having an outlet end portion positioned adjacent d e closure device; suitably the inlet end portion of die feed hose is connected to a supply of hot water, the temperature of which may, conveniently, be varied. The preferred assembly in accordance widi the invention also includes a diermocouple adjacent die closure device.

Conveniently, in carrying out a memod in accordance widi die invention diere is used a calibration hose assembly in accordance widi die invention. In a preferred memod in accordance with the invention die assembly includes a feed hose wid the outlet portion adjacent die closure device and the preferred method comprises the step of supplying hot water dirough the feed hose into d e interior of the calibration hose. Conveniently in this memod a diermocouple is mounted adjacent to die closure device. In carrying out the preferred method after the leading portion has been introduced into die feed pipe d e leading portion of the hose is propelled through the pipeline. When the closure devices reaches die inlet to d e fee pipe, the first hole is opened by releasing die first sealing means, thus releasing trapped air. The first sealing means is closed before die closure device is fed down die feed pipe dirough die interior of die hose. In a preferred me od in accordance wid die invention d e closure device also includes a second hole extending through the closure device and the second sealing means is released to open d e second hole and allowed water to drain from within the calibration hose, after curing of the curable resin in the pipeliner and before die calibration hose is withdrawn from the

7 pipeliner, deflation of the calibration hose facilitating withdrawal of die hose from the interior of die pipeline.

Brief Description of the Drawings There now follows a detailed description to be read widi reference to the accompanying drawings of a me od of conforming a tubular pipeliner to the interior surface of a pipeline embodying die invention, a calibration hose assembly embodying me invention for use in the illustrative memod and a closure device embodying die invention which is included in the illustrative calibration assembly.

In the accompanying drawings:

Figure 1 is a side view showing a closure device embodying die invention; Figure 2 is a plan view from above of the closure device;

Figure 3 is a view of die closure device from underneadi;

Figure 4 is a perspective view of a calibration hose assembly embodying die invention;

Figure 5 is a diagrammatic perspective view showing installation of a mbular pipeliner carrying out a method generally embodying die invention;

Figures 6 - 9 are schematic views showing installation of a pipeliner in carrying out a method embodying the invention; and

Figure 10 is a diagrammatic view showing an inlet of a feed pipe and die illustrative calibration hose assembly, in carrying out a me od embodying the invention.

Modes of Carrying out the Invention

In carrying out the illustrative me od use is made of a closure device 20

8 (see Figure 1) consisting of a body 22 and attachment means provided by a bracket 24 projecting from a first end portion of d e body 22. A collar 26 extends around the body at die first end portion and a second collar 28 extends around die body at a second end portion. A waist portion 30 lies between the collars 26, 28. A hole 32 is formed in the bracket 24.

The closure device 20 is made from any suitable material which is denser dian water for example an aluminium alloy solid block or a suitable engineering plastic material.

A first lengthwise hole 34 extends dirough the body from the first end portion to die second end portion. The hole 34 has a direaded part at die first end portion of die body. A first sealing means is provided by a sealing bolt 38 which is screw-direaded and arranged to be screwed into the direaded portion 36 of d e hole 34 whereby to create a fluid tight seal. A second hole 40 also extends dirough die body 22 from the first end portion to die second end portion. The hole 40 is direaded at the second end portion and is adapted to receive a threaded bolt (not shown) siππlar to the bolt 38, to create a fluid tight seal of die second hole 40.

In Figure 4 die illustrative closure device 20 is shown as part of a calibration hose assembly embodying die invention. As well as the closure device 20 die illustrative calibration hose assembly also includes a calibration hose 42. The closure device 20 is secured to die hose 42 at a first end 44 by securing means provided by clamping means comprising a pair of Jubilee clips 46. The Jubilee clips 46 are disposed on and extend around die waist portion 30 of d e closure device 20 and is secured by tightening the screws 48 in known manner. The closure device 20 is connected to a rope 50 by a D-shaped shackle 52 a part of which extends dirough the hole 32 in die bracket 24 to secure the shackle to die bracket 24. Also connected to the shackle 52 is a short length of rope 54 which itself is attached to an outlet rose 56 secured to at an outlet end portion 58 of a feed hose 60. The rose 56 has perforations 62 which are positioned generally to eject fluid from the hose 60 in a direction away from the closure device. A thermocouple 64 is also secured to die rope 50 adjacent die closure device 20 and die outlet 56 of die hose 60; die diermocouple 64 is disposed at die end of a communication wire 66 which is attached to die rope 50 and extends along die rope.

In carrying out the illustrative method, a scaffolding tower 68 is first erected adjacent a manhole 70 at the bottom of which is an entry 72 to a length of pipeline 74 which is to be lined; in Figure 5 die pipeline to be lined is shown extending from the entry 72 to a larger pipeline 76 into which the pipeline 74 to be lined empties. The tower 68 supports a feed pipe 78 having an inlet 80 near die top of the tower 68 and an outlet 82 adjacent the entry 72 to d e pipeline.

In further carrying out die illustrative method the length of die pipeline 74 to be lined (as far as die entry 72) is measured as is die distance between d e outlet 82 of die feed pipe 78 and die inlet 72 and also die lengdi of me feed pipe 78 is measured. A piece of calibration hose 42 is dien cut which is die same as these lengdis plus a small allowance for attachment to the closure device 20 and a small allowance for forming a cuff 84 at die inlet end of the feed pipe.

A portion of the calibration hose is then turned inside out by passing the first end of the calibration hose through the interior of die hose, leaving a leading portion of the hose adjacent the second end which is not turned

10 inside out, with the remainder of the hose still extending through die interior of die hose, so die leading portion forms a pocket 86.

After the hose has been partially turned inside out as discussed above, die rope 50 carrying the thermocouple 64 and die rope 54 attached to die feed hose 60 are secured to die bracket 24 of die closure device 20. Bodi die hose 60 and die rope 50 as well as die wire 66 connected to die diermocouple 64 are longer than die lengϋi of calibration hose.

The leading portion 86 of die hose 42 is dien introduced into die inlet end 80 of die feed pipe 78 and fed through die feed pipe 78 until it leaves the pipe at die outlet 82. A piece of tubular pipeliner (comprising a non- woven fabric impregnated with a curable resin) having die same length as die pipeline 74 to be lined is introduced into the pipeline 74. The leading portion 86 of the calibration hose 42 is then introduced into the pipeliner 88 at the entry 72 to the pipeline 74 (see essentially Figures 6 and 7.

After die leading portion 86 has been introduced into the pipeliner 88 as shown in Figure 7, and the cuff 84 has been secured to die feed pipe 78 adjacent die inlet 80 (suitably by a clamping band 90 around the feed pipe 78 see Figure 10) water 94 is introduced, for example through a hose 92 into die calibration hose 42 at die inlet 80 filling die pocket 86. The hydraulic pressure of the water 94 in the feed pipe 78 on die leading portion 86 causes the calibration hose to be forced along die pipeline 74 thus drawing the excess calibration hose 42 into die inlet 80 of die feed pipe 78 until the closure device 20 reaches approximately the position in which it is shown in Figure 10. As can be seen air which was trapped in the part of the hose which extended dirough the interior is all forced by the hydrostatic pressure towards die highest point and compressed against

11 the closure device 20. As will be realised, the pocket of air 96 creates a buoyancy which will militate against the drawing of the closure device 20 and die first end 44 of the calibration hose 42 into the feed pipe 78, even though die closure device itself may be more dense dian water. The first bolt 38 is therefore unscrewed and die trapped air escapes dirough die hole 34. After all or most of the trapped air has escaped, die sealing bolt 38 is replaced tightly to create a fluid tight seal and water continues to be introduced dirough die hose 92 to force me leading portion 86 towards die end of die pipeline 74. At this point, die rope 50 and hose 60 are drawn into the feed pipe 78 and die rope 50 is used to control the rate at which the closure device is allowed to proceed dirough d e feed pipe 78 and into e pipeline 74 (see Figures 8 and 9). Finally, as shown in Figure 9, die piece of calibration hose 42 is fully extended and die closure device 20 reaches die end of the pipeline 74. As can be seen viewing Figure 9, this time, the pipeliner 88 is firmly urged into conformity with the interior of the pipeline 74 and it remains to cure the curable resin.

Hot water from a source of hot water 98 is pumped through die feed hose 60 and ejected from the outlet rose 56 through the holes 62, dius displacing the cold water which was introduced dirough die pipe 92. The temperamre of me hot water adjacent die outlet rose 56 is detected by me thermocouple 64 and transmitted via the wire 66 to d e top of the tower 68 thus enabling the operator to control the temperamre of the water supplied from the hot water supply 98 to a suitable temperamre. The temperamre must be chosen such that it does not exceed die softening temperamre of the calibration hose (typically about 60°C) but is sufficient to accelerate the cure of the curable resin impregnant in the pipeliner. A suitable resin impregnant for which a heated curing system is suitable is an epoxy resin system but odier heat curable resin impregnant may be utilised.

12 Conveniently a second thermocouple (not shown) may detect die temperamre of the water being displaced from the top of die feed pipe at the inlet 80 so that it is possible for the operator to conveniently determine when the hole of the pipeliner will have been exposed to a sufficiently high curing temperamre to cure the resin and rigidify the pipeliner.

Once the curable resin has been cured, die calibration hose 42 must be withdrawn from the pipeline 74 and diis is achieved by pulling on the rope 50, die end portion of which still extends from the inlet 80 to die feed pipe 78 (see Figure 9). In order to readily remove the hose 42 it is necessary first to drain me water 94 from the interior of the hose and, to achieve mis, die second sealing bolt 39 is removed from the second end portion of die closure device 20 which is at diis time exposed at die end of the pipeline 74. Commonly, the end of die pipeline 74 will be accessible to an operator because the lengms of pipeline diat are to be installed are usually chosen to extend between adjacent manhole access points or between other points to which access can be gained. Following removal of the second bolt 39 the water 94 from the interior of die hose 42 drains through the second hole in die closure device 20 and can be allowed to run away, for example in the pipe 76. After all die water has been drained die second bolt 39 is replaced to again seal the second hole in the closure device 20.

The second bolt 39 could also, if desired be removed during curing as an aid to hot water introduction and control. For use in situations where the closure device 20 is not accessible, it may be provided widi a remotely operated releasable sealing means instead of die second bolt.

The closure device 20 is dien called back through the pipe 74 and d e feed

13 pipe 78 using the rope 50 and die hose 60 is also withdrawn simultaneous.

This illustrative method has been found to considerably improve the speed of installation of pipeliners by curing the curable resin promptly and also by making the draining of die water from the calibration hose 42 more convenient. The release of the trapped air from the air pocket 98 improves the controllability of the insertion of me calibration hose and, indeed, may be essential (if the trapped air is substantial) to counteract die buoyancy of die air which may otherwise prevent the calibration hose being fully drawn into the pipe by the hydraulic pressure. The controllability of the curing by use of the hot water feed hose 60 and die associated diermocouple 64 ensures that reliable curing of pipeliners can be achieved as rapidly as possible dierefore improving installation times.

14

Claims

1. A calibration hose assembly suitable for use in conforming a pipeliner to the interior surface of a pipeline to be renovated comprising a hose, a closure device partially received in d e interior of the hose and projecting merefrom at a first end, and securing means securing me closure device to die hose at die first end portion to create a fluid-tight seal preventing fluid passing between the hose and the closure device at said first end portion, die closure device comprising attachment means for connecting the device to an article or articles.

2. An assembly according to claim 1 wherein the closure device comprises a body inserted into the interior of die hose.

3. An assembly according to claim 2 in which the closure device has a first hole in the body extending lengdiwise dieredirough from a first end portion of d e body to a second end portion of die body and first releasable sealing means sealing the first hole.

4. An assembly according to claim 3 in which the closure device has a second hole extending dirough tihe body from the first end portion to die second end portion of d e body and second releasable sealing means sealing the second hole.

5. An assembly according to eidier one of claims 3 and 4 wherein the attachment means is disposed at d e first end portion of the body.

6. An assembly according to any one of die preceding claims comprising first and second collars at first and second end portions of the

15 body and a waist portion between die collars.

7. An assembly according to claim 6 wherein the securing means comprises clamping means extending around die end of die hose and clamping it to the waist portion of the body of die device.

8. An assembly according to any one of the preceding claims comprising a rope attached to die attachment means.

9. An assembly according to any one of die preceding claims comprising a hose attached to die attachment means, the hose having an outlet end portion positioned adjacent die closure device.

10. An assembly according to any one of the preceding claims having a thermocouple adjacent die closure device.

11. A closure device suitable for use in closing an end portion of a hose comprising a body adapted to be secured to an end of die hose into which the device is inserted, and attachment means by which the device can be attached to an article.

12. A closure device according to claim 11 having a first hole in the body extending lengthwise dieredirough from a first end portion of the body to a second end portion of die body and first releasable sealing means sealing the first hole.

13. A closure device according to claim 12 having a second hole extending through the body from the first end portion to die second end portion and comprising second releasable sealing means sealing the second

16 hole.

14. A closure device according to eidier one of claims 12 and 13 wherein the attachment means is disposed at d e first end portion of me body.

15. A closure device according to any one of claims 11 to 14 comprising first and second collars at first and second end portions of die body, and a waist portion between the collars.

16. A closure device according to claim 15 having clamping means disposed on and extending around die waist portion.

17. A method of conforming a tubular pipeliner to the interior surface of a pipeline comprising the steps of:

(i) introducing a pipeliner into a lengm of pipeline to be lined at an entry to the pipeline;

(ii) supporting a feed pipe extending upwardly from an outlet adjacent the entry, to an inlet of the feed pipe; (iii) procuring a piece of calibration hose having a length which is me sum of the lengdi of the pipeline to be lined, the distance between the entry of the pipeline to die oudet of die feed pipe, die length of d e feed pipe between its inlet and outlet, and an excess sufficient to secure a first end of the calibration hose to a closure device and to secure die odier, second end adjacent die inlet of the feed pipe;

(iv) turning a portion of the calibration hose inside out by passing the first end of die calibration hose dirough die interior of the hose to leave a leading portion of the hose adjacent d e second end which is not turned inside out widi the remainder of the hose still extending through die

17 interior of the hose so that the leading portion forms a pocket;

(v) before or after step (iv) securing said first end of the calibration hose to a closure device according to any one of claims 11 to

16 to create a fluid tight seal between die hose and die closure device widi the attachment means of the device accessible after it has been mrned inside out;

(vi) introducing said leading portion of the calibration hose into the inlet of the feed pipe and clamping a portion of the base adjacent die second end to or adjacent die inlet of the feed pipe; (vii) securing elongated flexible means to the attachment means;

(viii) feeding the leading portion of the hose dirough the feed pipe whilst keeping the second end secured at the inlet end of die feed pipe thus drawing die part of die hose which was mrned inside out back dirough die interior of the hose, until die leading portion reaches the entry to die pipeline;

(ix) introducing die leading portion of d e hose into the tubular pipeliner at the entry;

(x) introducing liquid into the pocket formed at die leading portion whereby the pressure of liquid acts to propel the leading portion through the pipeline urging the pipeliner against the walls of the pipeline until the hose is mrned back to its original condition wid die closure device at the end of the pipeline remote from the entry and widi die elongated flexible means extending through the hose from the closure device to and out of the inlet to die feed pipe; (xi) thereafter wididrawing the hose from the pipeline and feed pipe.

18. A method according to claim 17 wherein the elongated flexible means includes a rope by which the closure device can be retracted thus to

18 withdraw the hose.

19. A memod according to eidier one of claims 17 and 18 wherein die elongated flexible means includes a feed hose having an outlet portion adjacent die closure device, d e method further comprising the step of supplying hot water dirough die feed hose into the interior of me calibration hose.

20. A method according to claim 19 wherein a diermocouple is positioned adjacent die closure device to detect die temperature of me water in the calibration hose adjacent die outlet of the feed hose, and die temperamre of hot water supplied dirough the feed hose is adjusted to achieve a desired temperamre reading from the diermocouple.

21. A memod according to any one of claims 17 to 20 using a closure device according to claim 15 wherein, in carrying out step (x), when the closure device approaches the inlet to the feed pipe as die leading portion of the hose is propelled through the pipeline, the first hole is opened by releasing the first sealing means and trapped air is released, die first sealing means being closed before the closure device is fed down die feed pipe.

22. A method according to claim 21 using a closure device according to claim 13 wherein after completion of step (x) and before step (xi), the second sealing means is released to open die second hole and allow water to drain from within the calibration hose.

19