WO2002035136A1

WO2002035136A1 - Pipe lining apparatus

Info

Publication number: WO2002035136A1
Application number: PCT/GB2001/004620
Authority: WO
Inventors: Terence Victor Manlow
Original assignee: Water Industry Standard Product Approvals Limited
Priority date: 2000-10-17
Filing date: 2001-10-17
Publication date: 2002-05-02
Also published as: GB0025425D0

Abstract

A pipe lining apparatus (2) for inserting a liner into a pipe or passageway, the apparatus comprising a chamber (4) including a liner inlet (6), a liner outlet (8) and a fluid inlet (19) for the input of a pressurized fluid into the chamber; the liner inlet including a valve (9) capable of being selectively opened to allow passage of a portion of a liner therethrough, or closed to prevent movement of the liner with respect to the liner inlet and to provide a substantially fluid-tight seal at the inlet of the chamber, the valve including a flexible valve body (26) and an operating means (14), wherein the operating means is mechanically engageable with the flexible body to close the valve.

Description

PIPE LINING APPARATUS

The present invention relates to an apparatus, and a method, for everting a liner or a flexible tube such as is employed in the lining of pipes, passageways and the like.

It is often inconvenient to replace a worn-out section of pipe such as a sewer pipe, since this often involves excavating a relatively large area in order to gain access to the old pipe, and allow it to be removed and replaced with a new pipe. Therefore, it has become common practice, where possible, simply to line the worn-out sections of such pipes.

One way of inserting a liner into the pipe is by everting it in response to fluid pressure exerted on the interior of the liner. Such a method is disclosed, for example, in US 4,064,211.

Conventionally, the fluid pressure required to evert the liner is generated using water at a suitable pressure. One way of generating the required water pressure is to use a column of water stored at a suitable height above the pipe to be lined. However, this often requires a head of water which is several metres in height and additional apparatus, e.g. scaffolding, is required to effect the lining of the pipe.

In order to overcome this problem, it has been proposed to use a pressurised everting fluid which passes into an eversion chamber including at least a portion of the liner to be everted. However, a problem with this type of method occurs when trying to seal the chamber where the everting fluid is introduced or pressurised. An example of such an apparatus is described in EP 0504343. The apparatus described in this document uses a sphincter valve which is controlled by fluid pressure in a chamber to provide a seal between two further chambers. However, since each of the three chambers separately may be pressurised, the apparatus requires a complicated arrangement of pipes and valves for controlling the pressure in each of the chambers. This type of complicated arrangement, as well as being difficult and costly to assemble, also has the problems that with so many components, there is a relatively high risk of one of these components failing, causing the apparatus to be off-line whilst being repaired. Thus, this type of apparatus also requires a relatively high degree of maintenance. Additionally, a great deal of skill is required to operate this apparatus, since the pressure in the chamber which controls the sphincter valve needs to be sufficient to provide an effective seal through which the liner can slide, but not so much that in passing through the seal, that the liner resin is stripped (or "milked") from the liner substraight Thus, too little pressure in that chamber and the seal will be poor, leading to the apparatus operating inefficiently, while too much pressure may damage the liner.

There is therefore a desire to provide a pipe lining apparatus which is relatively simple and cheap to manufacture, easy to operate, requires little in the way of maintenance and has a low risk of failure.

Thus, in accordance with a first aspect of the present invention there is provided a pipe lining apparatus for inserting a liner into a pipe or passageway, the apparatus comprising a chamber including a liner inlet, a liner outlet and a fluid inlet for the input of a pressurised fluid into the chamber; the liner inlet including a valve capable of being selectively opened to allow passage of a portion of a liner therethrough, or closed to prevent movement of the liner with respect to the liner inlet and to provide a substantially fluid-tight seal at the inlet of the chamber, the valve including a flexible valve body and an operating means, wherein the operating means is mechanically engageable with the flexible body to close the valve.

Preferably, the operating means includes a contact element operatively connected to a drive means whereby the contact element is engageable with the flexible body to open or close the valve.

The operating means preferably includes a pair of opposed contact elements. More preferably, each contact element is operatively connected to a respective drive means. In the alternative, one of the contact elements may be operatively connected to a respective drive means and the other of the contact elements may be fixed relative to the liner inlet.

Advantageously, the flexible valve body is a resilient element which may be deflected by the operating means, but which is biased to its original or non- deflected position. Thus, as the force exerted by the operating means on the valve body is reduced or removed, the valve will open. In a preferred embodiment, the flexible valve body has a generally oval-shaped cross section with a hollow core to allow a liner to pass therethrough.

A portion of the flexible valve body is preferably secured to a portion of the chamber by a securing means whereby a first portion of the flexible valve body is fixed and a second portion of the valve body is capable of being deflected by the operating means.

In the preferred embodiments where the operating means includes a drive means, the drive means may comprise a piston slidably mounted within a cylinder, the piston preferably being driven by a compressed fluid. Alternatively, the drive means may comprise a motor, preferably an electric motor, which is capable of inducing translational movement in the contact element connected thereto. As a further alternative, the drive means may comprise a lever which is manually operable by a user.

Preferably the eversion fluid is water which may be pressurised by the addition of a pressurised gas, preferably compressed air. In such embodiments, the chamber may include a water (preferably cold water) inlet and a compressed gas inlet. Optionally, the chamber may also include a gas outlet valve to vent the compressed gas and de-presurise the chamber. Additionally or alternatively, the water may be pressurised before introduction into the eversion chamber.

The liner for use with the present apparatus is preferably a resin impregnated tube.

In accordance with a second aspect of the present invention, there is provided a method for inserting a liner into a pipe or passageway by eversion of the liner using the apparatus according to the first aspect of the present invention, the method including (i) feeding a leading end portion of the liner through the apparatus and securing it to the liner outlet of the chamber, (ii) feeding a first portion of the liner into the chamber, (iii) closing the valve, (iv) applying a fluid pressure via the fluid inlet to evert a length of the liner equal to the length of the first portion, (v) releasing the fluid pressure, (vi) opening the valve, and (vii) repeating steps (ii to vi) as many times as necessary to line the pipe or the passageway.

Thus, the liner is only fed into the eversion chamber when the valve is open and is only everted when the valve is closed, the valve being capable of alternating between open and closed configurations as required. The step of releasing the fluid pressure may be achieved by opening the valve. Thus, steps (v) and (vi) may be carried out simultaneously. Alternatively, the fluid pressure may be released via a release valve provided in the chamber of the apparatus and the steps may be carried out sequentially or simultaneously.

In a preferred embodiment, the step of closing the valve includes activating the operating means to engage the flexible valve body which is in turn urged into sealing contact with the liner. Similarly, the valve is opened by the operating means either retracting the flexible body away from the liner or allowing the flexible body to resiliently spring back away from the liner whereby the fluid-tight seal around the liner is released or broken.

In embodiments of the invention where the operating means includes a contact element operatively connected to a drive means, the method may further include the step of energising the drive means which in turn causes the contact element to engage the flexible valve body and urge it into sealing engagement with the liner.

The liner may be fed into the chamber manually by a user, or it may be fed in automatically via a suitable feeding apparatus mounted either externally of the chamber or within the chamber.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:-

Figure 1 shows a side elevational view of a pipe lining apparatus according to the first aspect of the present invention;

Figure 2 is a plan view from above of the apparatus shown in Figure 1; Figure 3 is a schematic drawing showing in more detail the liner inlet of the embodiment shown in Figure 1, with the inlet valve in an open configuration; and

Figure 4 is a schematic drawing showing the same portion of the apparatus as Figure 3, but with the valve in a closed configuration.

A pipe lining apparatus 2 is shown in the drawings which comprises an eversion chamber 4, a liner inlet 6 and a liner outlet 8.

The apparatus 2 is supported by four legs 22 and further includes a cold water inlet 18 and a compressed air inlet 19.

The liner inlet 6 includes a liner inlet valve 9 comprising a pair of hydraulic rams 10, a pair of contact elements 14 each of which is connected to a respective hydraulic ram 10 by a connecting rod 36, and a flexible valve body 26. The liner inlet valve 9 is carried by an upwardly facing support surface 49 of a top plate 48 of the chamber 4. The hydraulic rams 10 are mounted to the support surface 49 by respective ram support elements 16.

The flexible valve body 26 has a cross section which may be described as being generally oval in shape, and a correspondingly shaped clamp member 42, which is secured to the upwardly facing support surface 49, clamps a lower portion 40 of the valve body 26 to the chamber top plate 48. The remainder of the flexible valve body which is not rigidly held within the clamp 42 is free to move. However, the flexible valve body 26 is made from a resilient material such that it is biased towards the open position shown in Figure 3 and will return to this position if deflected and then released. In particular, the valve body is formed from a suitably shaped foamed polymer core and an outer layer comprising a polyester fabric coated with a polyurethene which is commercially available under the mark "XX067".

Each of the two hydraulic rams 10 is connected to a source of hydraulic fluid via respective hydraulic fluid pipes 12.

With the inlet valve 9 open, a liner 38 may be fed into the eversion chamber 4 through the liner inlet 6 and an aperture 50 centrally located through the top plate 48.

In use, the apparatus 2 is supported by supporting legs 22 in a desired position over an entry point, e.g. a vertical access point, of the pipe or passageway to be lined. The liner 38 to be everted is then fed manually by a user into the liner inlet 6, and through the eversion chamber 4, until its leading edge just protrudes out of the liner outlet 8. The leading end of the liner is then cuffed back over an outwardly facing surface 24 of the liner outlet 8 and secured thereto by any conventional method or apparatus commonly used in this art.

With the liner inlet valve 9 still open a length of the liner 38 is fed manually by the user into the eversion chamber 4 through the liner inlet 6. The liner inlet valve 9 is then closed by applying pressurised hydraulic fluid through pipes 12 into a cyclinder 28 of each hydraulic ram 10, urging a piston 30 slidably mounted within the cylinder 28 to more axially within it towards the oppositely mounted hydraulic ram 10. This in turn causes each of the two contact elements 14 to be displaced towards one another, since each contact element 14 is connected to a respective hydraulic ram piston 30 via a connecting rod 36. The contact elements 14 engage the flexible valve body 26 and cause the valve to be pinched closed by urging the flexible body 26 into fluid-tight sealing engagement with the liner 38. Once the valve 9 has been closed, water 46 is pumped into the eversion chamber 4 through the water inlet valve 18 up to a desired level, the water being prevented from escaping from the outlet 8 of the eversion chamber 4 by the cuffed back liner 38. The level of the water is indicated to a user via a sight glass 32, and is controlled by a float (not shown) operatively connected to a solenoid (not shown) which in turn controls the water inlet valve 18. Once the desired amount of water 46 is present in the eversion chamber 4, compressed air is added to the eversion chamber 4 above the water level via the compressed gas inlet pipe 19 whereby a length of the liner 38 corresponding to the length of the liner 38 fed into the eversion chamber 4 is everted and extends out from the apparatus 2 through the liner outlet 8. The gas pressure is regulated by a pressure regulator in accordance with conventional techniques for such regulation.

Once a length of liner corresponding to that which was fed into the eversion chamber has been everted, the compressed air inlet is closed and the air pressure within the eversion chamber is released by exhausting the compressed gas back through the inlet pipe 19. The valve 9 is then opened by retracting the pistons back along their respective cyclinders, which in turn causes the contact elements 14 to move away from each other. The resilient nature of the flexible valve body 26 results in it springing away from the liner 38 and moving out of sealing engagement with it. With the valve 9 now in an open configuration, a further length of the liner 38 can be fed into the eversion chamber 4 and the above-described steps for everting the liner are repeated until the pipe or passageway is lined as desired.

After the eversion process has proceeded until the trailing end of the liner

38 is close to the liner inlet 6, the leading end of a flat hose (not shown), common within this art, is connected to the trailing end of the liner 38 in accordance with conventional methods and techniques. Accordingly, during the latter stages of the eversion process, the eversion of the trailing end of the liner will also cause the flat hose to be carried with it through the liner 38.

The liner 38 is a resin impregnated felt tube which is well known in this art and once fully everted and lining the pipe or passageway, a heated fluid, typically heated water, is introduced into the lined pipe or passageway via a hot water inlet pipe 20. The heated fluid urges the resin impregnated liner into intimate contact with the interior of the pipe or passageway to be lined and causes the resin of the liner to cure, thus securing the liner to the interior of the pipe or passageway.

Although only a single embodiment of the present invention has been specifically described herein, it will be apparent to those skilled in the art that variations may be made to the apparatus within the scope of the invention as defined in the following claims.

Claims

1. A pipe lining apparatus for inserting a liner into a pipe or passageway, the apparatus comprising a chamber including a liner inlet, a liner outlet and a fluid inlet for the input of a pressurised fluid into the chamber; the liner inlet including a valve capable of being selectively opened to allow passage of a portion of a liner therethrough, or closed to prevent movement of the liner with respect to the liner inlet and to provide a substantially fluid-tight seal at the inlet of the chamber, the valve including a flexible valve body and an operating means, wherein the operating means is mechanically engageable with the flexible body to close the valve.

2. A pipe lining apparatus according to claim 1, wherein the operating means includes a contact element operatively connected to a drive means wherein the contact element is engageable with the flexible body.

3. A pipe lining apparatus according to claim 2, wherein the apparatus includes a pair of opposed contact elements.

4. A pipe lining apparatus according to claim 3, wherein each contact element is operatively connected to a respective drive means.

5. A pipe lining apparatus according to claim 3, wherein one of the contact elements is operatively connected to a drive means and the other of the contact elements is fixed relative to the liner inlet.

6. A pipe lining apparatus according to any preceding claim, wherein the flexible valve body is a resilient element.

7. A pipe lining apparatus according to any preceding claim, wherein the flexible valve body has a generally oval-shaped cross-section.

8. A pipe lining apparatus according to any one claims 2 to 7, wherein the drive means comprises a piston slidably mounted within a cylinder.

9. A pipe lining apparatus according to any of the claims 2 to 7, wherein the drive means comprises an electric motor.

10. A method for inserting a liner into a pipe or passageway by eversion of the liner using an apparatus according to any preceding claim, the method including

(i) feeding a leading end portion of the liner through the apparatus and securing it to the liner outlet of the chamber,

(ii) feeding a first portion of the liner into the chamber,

(iii) closing the valve,

(iv) applying a fluid pressure via the fluid inlet to evert a length of the liner equal to the length of the first portion, (v) releasing the fluid pressure,

(vi) opening the valve, and

(vii) repeating steps (ii) to (vi) as many times as necessary to line the pipe or passageway.

11. A method according to claim 10, wherein the step of closing the valve includes causing the operating means to engage the flexible valve body which is urged into sealing contact with the liner.

12. A method according to claim 11, wherein the operating means of the apparatus includes a contact element operatively connected to a drive means and the step of closing the valve includes energising the drive means to cause the contact element to engage the flexible valve body and urging it into sealing engagement with the liner.

13. An apparatus substantially as herein described with reference to the accompanying drawings.

14. A method substantially as herein described with reference to the accompany drawings.