GB2555669A

GB2555669A - Duct and installation method

Info

Publication number: GB2555669A
Application number: GB1708489.8A
Authority: GB
Inventors: John Muckle Derek
Original assignee: Radius Systems Ltd
Current assignee: Radius Systems Ltd
Priority date: 2017-05-26
Filing date: 2017-05-26
Publication date: 2018-05-09
Anticipated expiration: 2037-05-26
Also published as: WO2018215790A1; GB2555669B; GB201708489D0

Abstract

A duct 100 for installation on the interior wall 9 of a non-man entry sewer pipe comprising a body 102 having a conduit there through and first 6a and a second 6b flexible tabs. The first and second flexible tabs are arranged on an outer surface of the body and flexible thereto. The first and second tabs and a section of the outer surface of the body there between define a sealing region 130 for sealing the duct to the interior wall. The first and second flexible tabs form first 10a and second 10b flow channels respectively. Also disclosed is a kit of parts, a method of manufacturing and an apparatus for installing the duct.

Description

(54) Title of the Invention: Duct and installation method Abstract Title: Duct and installation method (57) A duct 100 for installation on the interior wall 9 of a non-man entry sewer pipe comprising a body 102 having a conduit there through and first 6a and a second 6b flexible tabs. The first and second flexible tabs are arranged on an outer surface of the body and flexible thereto. The first and second tabs and a section of the outer surface of the body there between define a sealing region 130 for sealing the duct to the interior wall. The first and second flexible tabs form first 10a and second 10b flow channels respectively. Also disclosed is a kit of parts, a method of manufacturing and an apparatus for installing the duct.

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At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

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DUCT AND INSTALLATION METHOD

TECHNICAL FIELD

The present invention relates to a duct and to a method of installing a duct in a pipe. Particularly, but not exclusively, the invention relates to a duct for and to a method for installing a duct inside a sewer pipe, such as a non-man entry sewer pipe. Aspects and embodiments of the invention provide a duct, a kit, a method of manufacture, a method of installation and a system.

BACKGROUND

In many developed countries, installing additional underground infrastructure may be challenging, particularly when working with ground that is already congested with existing pipe and cable systems. Challenges may also be faced where restrictions on undertaking street works, particularly intrusive street works that involve excavation, apply. This prevents or at least delays a roll out of new infrastructure in some areas and is particularly acute for construction and installation of new optical fibre networks.

One opportunity that is available for installing an optical fibre network is to lease space in existing cable or pipe assets to install optical fibre ducts. This greatly reduces the intrusive nature of installing new underground assets. Such solutions have been proposed and tested in gas pipelines, water pipelines and sewers. Sewers may offer the best prospects for installing optical fibre ducts because they are least impacted in their operation by the inclusion of small optical fibre ducts affixed to some part of the pipe or sewer internal surface. Furthermore, in most urban areas, sewers are particularly abundant, often connecting many, if not all buildings that they pass.

It is known in the art to install optical fibre ducts in sewers or tunnels that are large enough for humans to enter. Such sewers and tunnels are known in the art as “man-entry sewers” and typically have a diameter greater than approximately 900mm. In man-entry sewers, an optical fibre duct is fixed to a wall or walls of the sewer or tunnel by a human installer entering the sewer and using mechanical fixings to hold the optical fibre duct in place. However, to date, there has been no significant application of this principle in sewers, such as clay sewer pipes, that are too small for a human installer to enter. Such sewers are known in the art as “non-man entry sewers” and typically have a diameter of less that approximately 900mm.

There have been a number of developments aimed at solving the problem of fitting optical fibre ducts in non-man entry sewers. One known method is to use one or more robots to install the optical fibre duct using mechanical fixings to hold the optical fibre duct against the wall of the sewer pipe. Some variations of this method comprise drilling a hole in the sewer pipe and using mechanical fixings. Such mechanical fixings may be very similar to those used in man-entry sewers and tunnels. Other variations of this method comprise using different mechanical fixings, such as expanding clamps which are jacked into a locking position and are distributed along a length of the installed optical fibre duct. However, such methods may not be cost effective for the installation process. Furthermore, for some sewer wall materials in particular (for example concrete), it is generally undesirable to drill into the wall as this increases the risk of damage to the infrastructure by cracks or fractures developing.

Another group of known methods comprise combining installation of the optical fibre duct with one or more common sewer renovation technologies, such as a technique known in the art as cured in place pipe (CIPP) lining. These methods comprise first inserting the optical fibre duct into the non-man entry sewer and subsequently inserting a composite liner. The liner is arranged to cover the ducts and the remaining internal surface area of the non-man entry sewer pipe. Finally, the CIPP liner is cured, for example using heat or ultra violet means. Curing changes the structure of the CIPP liner into a more rigid structure. When used in this way the optical fibre duct is concealed between the CIPP liner and the non-man entry sewer pipe. However, the CIPP method necessitates covering all existing connections in the wall of the sewer pipe with the liner. The subsequent redrilling of the connections makes CIPP a relatively expensive method.

Yet another group of known methods comprise bonding optical fibre ducts to the sewer using an adhesive. Typically, the ducts must be bonded to the bottom of the sewer pipe, known in the art as the “invert” of the non-man entry sewer pipe. This method typically comprises first laying optical fibre ducts to the invert of a sewer pipe and subsequently flooding the sewer with a resin or concrete adhesive to cover the ducts and to fill space between the ducts. Whilst the invert of a sewer pipe is not a logical place to fix an optical fibre duct, for many infrastructure owners it is the only practical option. This is most likely due to practices in some territories wherein lateral connections to the non-man entry sewer may be made at any position around the circumference of the pipe and not always connecting with the lateral invert at the same height as the main sewer to which it connects. It is not appropriate to place a duct directly across a lateral connection and thus for simplicity, only the invert is actually available for the purpose of routing an optical fibre duct through the sewer in many cases.

Variations of the above method of placing ducts on the invert of a sewer and then flooding the invert to hold the ducts in place are known. One example of prior art includes NL1018324 in which a small robot is used to spread a protective layer of resin over the duct placed on the sewer invert. W02014068308 describes a further variation of this theme. However, one aspect in common with all of these methods is that after installation, the sewer invert effectively becomes flat rather than curved. This can have a negative effect on the operation of the sewer, particularly under conditions of low flow, and can lead to the deposit of silt in the base of the sewer which would not otherwise occur.

To overcome the problem of a resulting flat invert, some variations of this method comprise a first step of milling a groove in the invert into which the ducts can be laid. A resin or concrete filler material may then be used to cover the ducts and to fill space between the ducts. The filler material may finally be trimmed so that it is flush with the internal surface of the sewer and restores the original circular profile of the sewer. For example, DE19752424 describes a method comprising use of a robot to first mill a channel into the sewer invert, to which the ducts are inserted. A resin is subsequently used to fill the channel which is smooth. The resin is finally blended to restore the sewer’s original cross sectional shape. However, this solution is only suitable for sewers that are relatively thick walled in the first place and which can be warranted not to be structurally inferior after the works are undertaken. Many sewer asset owners are unwilling to permit leaseholders to install optical fibre ducts using a method that materially alters the existing sewer structure for fear of increasing risks of infiltration, exfiltration or simply collapse of the infrastructure. For these reasons the technique is not well known in practice.

Another problem with the method of laying ducts and flooding the invert with resin or concrete is that the optical fibre ducts are generally buoyant. Unless the ducts can be held in position sufficiently to resist the upwards thrust of the buoyant duct whilst the resin or concrete cures, the duct simply rises to the surface of the resin or concrete and sets at that position. This typically requires a second pass operation to apply a second layer to cover the duct entirely. Additionally, typical materials used for optical fibre ducts respond to temperature increases and have a relatively high coefficient of thermal expansion. Curing of two part resin adhesives such as epoxy, polyurethane or polyurea adhesives, which may be employed as the filler material generates exothermic reactions. Consequently, curing the resin may cause the ducts to increase in length. If the ducts are not sufficiently held in place until the filler material has cured, the ducts will take on a wavy appearance along the length of the sewer. The wavy appearance of the ducts is undesirable because it will be impractical for blowing optical fibres into the duct at a later date. The problem is exacerbated when relatively large volumes of resin are used, because this leads to significant heat generation.

It is an object of embodiments of the invention to at least mitigate one or more of the problems of the prior art.

BRIEF SUMMARY OF THE DISCLOSURE

Aspects and embodiments of the invention provide a duct, a kit, a method of manufacture, a method of installation and an apparatus, as claimed in the appended claims.

According to an aspect of the invention, there is provided a duct for installation on an invert of a non-man entry sewer pipe, the duct comprising:

a body having a conduit therethrough; and first and second flexible tabs arranged on an outer surface of said body and flexible with respect thereto, wherein the first and second tabs and a section of the outer surface of the body therebetween define a sealing region for sealing the duct to the invert and wherein, in use, first and second flow channels are defined by the first and second flexible tabs respectively.

Advantageously, the duct permits fluid flow via said flow channels, even in low flow conditions. The arrangement advantageously increases the velocity of water under low volumetric flow conditions, thereby providing a scouring or self-cleaning effect and to minimise silting within the flow channels.

In some embodiments, sealing the body and the first and second tabs to the invert creates a substantially fluid-tight sealed region, the first and second flow channels being outside said sealed region.

In some embodiments, the sealing region comprises a mechanical key profile. Advantageously, the mechanical key profile provides, in use, a mechanical anchor between the duct and, for example, an adhesive, thereby strengthening a join between the duct and the invert.

In some embodiments, the cross-sectional shape and/or material of the mechanical key profile is capable of providing sufficient tensile strength to resist a buoyancy effect of the duct when the duct is adhesively bonded to the invert. Advantageously, this helps to join the duct to the invert in a close fit.

Optionally, the mechanical key profile comprises one or more protrusions shaped so that when an adhesive is applied between the invert and the sealing region, the adhesive substantially surrounds the protrusions and provides a mechanical anchor between the duct and the invert. Advantageously, this improves joining the duct to the invert, providing a more robust joint.

Optionally, the one or more protrusions comprise one or more substantially T shaped or substantially bulbous protrusions. Advantageously, a T shaped or bulbous protrusion increases surface area of the mechanical key profile, thereby increasing an area for contacting an adhesive. This provides a stronger joint between the duct and the invert.

In some embodiments, the mechanical key profile is integrally formed with the body. The mechanical key profile may, in some embodiments, be axially extruded with the body.

In some embodiments, the first and second tabs are integrally formed with the body. The first and second tabs may, in some embodiments, be axially extruded with the body.

In some embodiments, the first and second tabs extend from the outer surface of the body, and movement of the first and second tabs relative to the body is substantially limited to conforming to a shape of a surface of the invert.

Alternatively, the first and second tabs are flexible from a first, storage position, in which the first and second tabs are substantially retracted to the body so as to minimise a footprint or profile of the duct, to a second, in use position, in which the first and second tabs are substantially extended from the body, in an anticipated installation orientation. Advantageously, this initially minimises a storage volume of the duct, thereby facilitating storage and transportation of the duct prior to installation.

In some embodiments, the first and second tabs include a substantially smooth upper surface. Advantageously, the smooth upper surfaces help to prevent catching of objects flowing in the non-man entry sewer pipe, thereby preventing or at least minimising occurrences of hang-ups and blockages forming in the non-man entry sewer pipe caused by said objects.

In some embodiments, the first and second tabs each include a concave surface.

In some embodiments, the first and second tabs comprise ends having a tapering thickness. Advantageously, this provides, in use, a smooth transition between the tabs and the invert surface. This helps to prevent catching of objects flowing in the non-man entry sewer pipe, thereby preventing or at least minimising occurrences of hang-ups and blockages forming in the non-man entry sewer pipe caused by said objects.

In some embodiments, said body comprises an inner sheath. In some embodiments, the inner sheath may be arranged so as not to be in fluid contact with the sewer. The inner sheath may, in some embodiments, comprise one or more functional layers.

Optionally, the inner sheath comprises a moisture barrier layer.

In some embodiments, the inner sheath comprises a vapour trap layer.

In some embodiments, the inner sheath comprises a glass filled layer. Advantageously, a glass filled layer discourages sustained rodent attack to the duct.

In some embodiments, the inner sheath comprises a layer resistant to permeation.

In some embodiments, the inner sheath comprises a metallic layer, such as a metallic sheath. Optionally the metallic sheath comprises steel. Advantageously, a metallic layer provides armoured protection to resist rodent attack whilst still permitting forming of the duct, such as forming of bends along an installed length of the duct. A metallic layer also advantageously allows the duct to be formed to and to conform to a topography of the nonman entry sewer, to which it may later be bonded.

Optionally, the metallic layer comprises corrugations. Optionally, the corrugations are arranged so that the metallic layer comprises a substantially wavy profile. Advantageously, metallic layer comprising corrugations may be more easily coiled, for example onto a drum, without kinking and subsequently uncoiled. This facilitates installation. A metallic layer comprising corrugations also advantageously helps the duct to be easily formed to and to conform to a topography of the non-man entry sewer, to which it may later be bonded. This advantageously enables the duct to be maintained in place whilst the adhesive sets, encouraging the duct to blend with the sewer invert.

A metallic layer comprising corrugations may also advantageously improve overall strength of the duct. In some embodiments, the corrugations may comprise a profile of square, curved, circular or ovular shape, or any combination thereof.

In some embodiments, the body comprises an outer sheath. The outer sheath may be in fluid contact with the non-man entry sewer. Advantageously, an outer sheath provides protection to internal components. For example, when the body comprises an inner sheath comprising metal, the outer sheath protects the metallic layer from, for example, corrosion.

Optionally, the outer sheath comprises a polyolefin.

Optionally, the outer sheath is axially extruded.

In some embodiments, the duct comprises one or more micro-ducts within the body.

In some embodiments, the duct is an optical fibre duct, or is suitable for conveying optical fibres through said conduit.

According to another aspect of the invention, there is provided a kit comprising a duct as above described and an adhesive for sealing the duct to the non-man entry sewer pipe. Advantageously, this provides means for bonding the advantageous duct to the invert.

In some embodiments, the adhesive comprises a fast setting resin. Advantageously, a fast setting resin prevents or at least minimises movement of the duct during installation, preventing the duct from deviating from a preselected position during installation.

In some embodiments, said adhesive comprises a two part resin. Advantageously, this allows the resin parts to be stored separately and mixed on site when the duct is ready to be installed on the invert, thereby providing more control over curing the resin.

In some embodiments the resin comprises a filler material arranged to scavenge water from the invert without hindering development of a chemical bond between the invert and the duct.

According to another aspect of the invention, there is provided a method of manufacturing the duct as above described, the method comprising:

extruding said body; and coextruding the first and second tabs and the mechanical key profile with said outer sheath layer.

Advantageously, coextruding the first and second tabs and the mechanical key profile provides an integral, stable structure and omits the requirement for a second joining step to join tabs or a key profile to the outer sheath layer.

In some embodiments, when the body comprises an inner sheath and an outer sheath, said extruding the body may comprises extruding the outer sheath over the inner sheath.

In some embodiments, the first and second tabs are coextruded in a storage orientation, in which the first and second tabs are substantially retracted to the body so as to minimise a footprint or profile of the duct. Advantageously, this initially minimises a storage volume of the duct, thereby facilitating storage and transportation of the duct prior to installation.

According to another aspect of the invention, there is provided a method for installing a duct as above described, the method comprising:

arranging the duct along an invert of a non-man entry sewer pipe; and bonding the sealing region of the duct to the invert.

In some embodiments, the method comprises shaping the duct to substantially match a shape of the invert of the non-man entry sewer pipe. Advantageously, this facilitates installation of the duct.

Optionally, said shaping comprises drawing a guide tool over the duetto move the first and second tabs into a position to substantially match the shape of the invert of the non-man entry sewer pipe.

In some embodiments, the method comprises cleaning a surface of the invert prior to said arranging and said bonding. Advantageously, this provides a cleaner invert surface on which to bond the sealing region to, thereby providing a more robust joint therebetween.

In some embodiments, the method comprises roughening a surface of the invert prior to said arranging and said bonding. A roughened invert surface may function as a mechanical key, advantageously improving bonding between the sealing region and the invert.

In some embodiments, said bonding comprises applying a fast setting adhesive. Advantageously, a fast setting adhesive prevents or at least minimises movement of the duct during installation, preventing the duct from deviating from a preselected position during installation.

In some embodiments said bonding comprises applying a two part adhesive. Advantageously, this allows the adhesive parts to be stored separately and mixed on site when the duct is ready to be installed on the invert, thereby providing more control over curing the adhesive. Advantageously, a fast setting adhesive prevents or at least minimises movement of the duct during installation, preventing the duct from deviating from a preselected position during installation.

In some embodiments, said two part adhesive comprises a two part epoxy adhesive, a two part polyurethane adhesive or a two part polyurea adhesive. Optionally, said two part polyurethane adhesive is formed by reacting mono di-isocyanate (MDI) with a polyol in the presence of a catalyst.

In some embodiments, said adhesive comprises one or more hydroscopic fillers for drawing moisture from invert surface to dry sufficiently to enable bonding.

In some embodiments, said bonding comprises continuously dispensing said adhesive along the invert to adhesively bond the duct to the invert. Advantageously, this ensures that adhesive is applied to an entire length of the invert on which the duct is to be installed.

In some embodiments, said bonding comprises intermittently dispensing the adhesive along the length of the sealing region of the duct to form adhesive patches or spots. Advantageously, this conserves adhesive material, thereby reducing costs associated with installation of the duct.

In some embodiments, the method comprises thermally conditioning said adhesive prior to said applying. Advantageously, this improves properties of the adhesive, such as reduces the viscosity of the adhesive, thereby making the adhesive more workable.

According to yet another aspect of the invention, there is provided apparatus for installing the duct as above described, using said method for installing the duct as above described, the apparatus comprising:

a storage means for storing an adhesive; a heating means for heating the stored adhesive; and a hose for depositing said adhesive, wherein the hose is in fluid connection with said storage means.

Advantageously, said heating means enables viscosity of the adhesive to be reduced prior to depositing the adhesive.

In some embodiments, the apparatus comprises a drum around which said hose is windable and a means for rotatably driving the drum so as to wind the hose around the drum at a substantially constant speed. Advantageously, this enabled the hose to be drawn through the non-man entry sewer pipe, depositing adhesive at a substantially constant rate and therefore a substantially uniform thickness.

In some embodiments, the apparatus comprises a guide tool fixed to an end ofthe hose for guiding said depositing of said stored adhesive. Advantageously, this means that adhesive may be deposited by the apparatus more accurately.

In some embodiments, said adhesive is a two part resin and said storage means comprises two separate storage tanks, each tank for storing one part ofthe two part resin. Advantageously, this allows the resin parts to be stored separately and mixed on site when the duct is ready to be installed on the invert, thereby providing more control over curing the resin.

Optionally, the apparatus comprises means for mixing the separate parts of the two part resin.

Optionally, when the apparatus comprises a guide tool, said means for mixing may comprise a static impingement mixer in the guide tool. Advantageously, this enables mixing of the two part resin immediately before deposition of said two part resin, thereby minimising any undesired curing of the two part resin prior to deposition of the same.

In some embodiments, the apparatus may be provided on a mobile trailer. Advantageously, this enables portability of the apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

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

Figure 1 shows a duct according to an embodiment of the invention;

Figure 2 shows the duct of Figure 1 fitted to an invert of a non-man entry sewer pipe, according to an embodiment of the invention;

Figure 3 shows sectional views of a duct according to an embodiment of the invention; and

Figure 4 shows a method of installing a duct according to an embodiment of the invention.

DETAILED DESCRIPTION

Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of the words, for example “comprising” and “comprises”, means “including but not limited to”, and is not intended to (and does not) exclude other moieties, additives, components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.

In the present disclosure, the following terms may be understood in terms of the below explanations:

The term “invert” may refer to a lowermost point of an internal surface of a cross section of a non-vertical hollow structure, such as a sewer or a drain, at any given longitudinal point. The term “invert” may include a length connecting one or more of said lowermost points along said internal surface. The length may extend from an opening at a first end of in the hollow structure to a second opening at a second end of the hollow structure. The term “invert” may comprise an area extending equally either side of said length. The area may extend so as to define a lowermost substantially hemi-cylindrical area.

The term “duct” may refer to a conduit arranged to convey one or more components or substances therethrough. The one or more components or substances may comprise any of a wire, a cable, an optical fibre or bundle of optical fibres, a micro-duct and/or fluid. The duct may be arranged to provide protection to the one or more components or substances, such as rodent protection, for example.

The term “micro-duct” may refer to a conduit arranged to convey one or more components or substances therethrough. The one or more components or substances may comprise optical fibres, for example. The term “micro-duct” may refer to a conduit arranged to be conveyed within a duct, the duct having a relatively larger diameter than the micro-duct.

The term “flow channel” may refer to a region arranged to encourage, or at least permit, fluid flow therealong. The term “flow channel” may include a passage, an opening, a trench, ora groove. The term “flow channel” may include a passage having a substantially curved cross sectional shape, such as a circular, ovular, semi-circular or semi-ovular cross sectional shape, for example. The term “flow channel” may include channels which function to increase velocity of fluid flowing through a non-man entry sewer pipe under low volumetric flow conditions.

The term “mechanical key profile” may refer to a region or area comprising a nonhomogenous surface area and/or a non-uniform cross sectional shape arranged to improve grip between the mechanical key and an adhesive received thereon. A nonhomogenous surface area and/or non-uniform cross sectional shape may comprise one or more of: a roughened surface, an undulating surface, a protrusion or an extension, for example.

The term “fast setting adhesive” may refer to an adhesive substance arranged to bond two components together to substantially resist separation thereof, wherein a primary chemical reaction of said bonding is substantially completed within one minute, preferably, within 30 seconds, of application of the adhesive substance to the two components. The term “fast setting adhesive” may include a fast setting resin.

The term “fast setting resin” may refer to a curable resin based material arranged to bond two components together to substantially resist separation thereof, wherein a primary chemical reaction of curing the resin based material is substantially completed within one minute, preferably, within 30 seconds, of initiating said curing reaction. The term “fast setting resin” may include two part resin materials arranged to cure on mixing.

The term “sealing region” may refer to a region of a duct arranged to be bonded or at least joined to a substrate, such as an invert of a pipe, to create a substantially fluid-tight sealed region.

With reference to Figures 1 and 2, embodiments of the present invention provide a duct 100 for installation on an invert 9 of a non-man entry sewer pipe. In some embodiments, the duct 100 is an optical fibre duct, arranged to house optical fibres therein. The duct 100 comprises a body 102. In some embodiments, the body 102 comprises one or more microducts 1. In the embodiments illustrated by Figures 1 and 2, the body 102 comprises a plurality of the micro-ducts 1, referred to as a bundle of micro-ducts. The duct 100 comprises a first tab 6a and a second tab 6b, arranged on opposed sides of the body 102. The first and second tabs 6a, 6b each define first and second low flow channels 10a, 10b, respectively. The channels 10a, 10b may comprise a substantially curved cross sectional shape, such as a circular, ovular, semi-circular or semi-ovular cross sectional shape, for example. In use, the channels 10a, 10b function to increase velocity of fluid flowing through the non-man entry sewer pipe under low volumetric flow conditions. A sealing region 130 is provided between the first and second tabs 10a, 10b for sealing the body and the first and second tabs to the invert 9, for example by means of adhesive bonding. The sealing region 130 is defined by the underside of the body and the tabs, from the point at which tab 6a contacts the invert 9 to the point at which tab 6b contacts the invert 9. Once bonded to the invert, the sealed region directs the majority of fluid flowing in the non-man entry sewer pipe in low volumetric flow conditions through the low flow channels 10a, 10b. The sealed region itself need not necessarily be completely fluid tight in service.

The first and second tabs 6a, 6b are shaped to prevent catching of objects flowing in the non-man entry sewer pipe. This may be achieved by one or more of: the tabs 6a, 6b being provided with substantially smooth surfaces, the tabs being provided with concave surfaces and the tabs being provided with ends having a tapering thickness, for example. The smooth surfaces of the tabs 6a, 6b conveniently cover any roughness of the underlying adhesive which is typically applied in “blobs” having rough peripheral edges that could otherwise interfere with flow in the sewer pipe.

The first and second tabs 6a, 6b may initially be formed relative to the body 102 in an anticipated installation orientation such that movement of the first and second tabs 6a, 6b is substantially limited to conforming to a shape of a surface 9’ of the invert 9. Alternatively, as illustrated by Figures 1 and 2, the first and second tabs 6a, 6b may be moveable, at least from a first, storage position (shown in Figure 1), in which the first and second tabs 6a, 6b are arranged tight to the body 102, to a second, use position (shown in Figure 2), in which the first and second tabs 6a, 6b are arranged, relative to the body 102, in an anticipated installation orientation. Movement of the tabs 6a, 6b relative to the body 102 is a result of a degree of flexibility in the material of the tabs.

The body 102 may comprise an inner sheath layer 2. The inner sheath layer 2 houses the micro-duct 1 or micro-duct bundles and functions to protect the same. With particular reference to Figure 3, the inner sheath layer 2 may comprise one or more layers having one or more functional properties. In the embodiments shown in Figure 3, three inner sheath layers 2, 3, 4 are provided, although it will be appreciated that fewer or more inner sheath layers may be provided. In the illustrated embodiment, an optional innermost sheath layer 2 encloses the micro-duct 1 or micro-duct bundles, a moisture barrier 3 may be provided for providing protection to the micro-duct 1 or micro-duct bundles from ingress of moisture and a corrugated metal sheath 4 may be provided for providing armoured protection to the duct 100 from, for example, rodents and weathering. The corrugated metal sheath allows the duct 100 to be formed to and to conform to a topography of the non-man entry sewer to which it is bonded. The corrugations also allow the duct 100 to be coiled to drums without kinking, and to be uncoiled, inserted and formed to match the topography of the non-man entry sewer. In some embodiments, the corrugated metal sheath may be of a square or curved profile to facilitate bending of the duct 100. An outer sheath 5, comprising, for example, a polyolefin, may also be provided to protect the inner sheath layers, including the inner sheath 2, the moisture barrier 3 and the corrugated metal sheath 4, as well as the micro-duct 1 or micro-duct bundles. The first and second tabs 6a, 6b may form an integral part of the outer sheath 5. For example, the first and second tabs 6a, 6b may be axially extruded profiles of the outer sheath 5.

The duct 100 is bondable to the surface 9’ of the invert 9 by means of an adhesive 8, such as a resin. The resin 8 may be a fast setting resin which may be designed so that a primary chemical reaction of the curing process is completed within one minute. In some embodiments, a two part resin that cures upon mixing of the two parts is used to bond the duct 100 to the surface 9’ of the invert 9. The resin 8 is suitable for application to damp surfaces without hindering the development of an adhesive bond between the duct 100 and the surface 9’ of the invert 9. To be compatible with damp surfaces, the resin, in some embodiments, comprises a hydroscopic filler material. The filler material is arranged to scavenge water from a substrate, such as the surface 9’ of the invert 9, without hindering the development of a chemical bond thereto.

In some embodiments, the sealing region 130 includes a mechanical key profile. The mechanical key profile is arranged so as to provide sufficient tensile strength to resist a buoyancy effect of the duct 100 when the adhesive 8 is used to bond the duct 100 to the invert 9. This may comprise one or both of using appropriate material selection for the mechanical key profile and providing the mechanical key profile with a suitable crosssectional shape. In some embodiments, such as the embodiments illustrated in Figures 1 and 2, the mechanical key profile comprises one or more protrusions 7 extending radially from the outer sheath 5. The protrusions 7 may form an integral part of the outer sheath 5, for example, the protrusions 7 may be axially extruded profiles of the outer sheath 5. The one or more protrusions 7 may comprise one or both of substantially T shaped protrusions and substantially bulbous protrusions. In this way, when the adhesive 8 is applied between the invert 9 and the fixing region 130, the adhesive 8 will envelop the mechanical key profile and will set to provide a mechanical anchor between the duct 100 and the invert 9.

Figure 2 shows the duct 100 according to an embodiment, installed on the invert 9 of the non-man entry sewer pipe. The first and second tabs 6a, 6b are at least partially deformable to allow for the duct 100 to be installed on the invert 9. In use, the tabs 6a, 6b are extendable in situ to form the low flow channels 10a, 10b either side of the body 102 of the duct 100. The tabs 6a, 6b extend out from the body 102 and abut the surface 9’ of the sewer invert 9. The protrusions 7 are pressed into and enveloped by the adhesive 8, which may be a two part fast setting adhesive, for example. The adhesive 8 is bonded to the surface 9’ of the invert 9 and to the sealing region 130 of the duct 100. When installed on the invert, the tabs 6a, 6b flex to conform to the shape of the surface 9’ of the invert 9 and define the low flow channels 10a, 10b, arranged on either side of the body 102 of the bonded duct 100.

To manufacture the duct 100, the inner sheath layer 2, which may comprise the corrugated metal sheath 4, is first wrapped around a micro-duct 1 or a micro-duct bundle. The sheath layer may be formed having a substantially circular cross sectional shape. The outer sheath 5 is subsequently formed over the inner sheath layer 2. The outer sheath 5 may be coextruded over the inner sheath layer 2 to provide the tabs 6a, 6b and optionally, the mechanical key profile. The tabs 6a, 6b may be extruded as illustrated in Figure 1, such that they are initially tight to the body 102 of the duct 100 to facilitate coiling of long lengths of the duct 100 for storage and transportation. The tabs 6a, 6b may be deformable or flexible to an extent that at least permits movement of the tabs 6a, 6b to a position suitable for engaging with the invert 9 of the non-man entry sewer pipe. Alternatively, the tabs 6a, 6b may be extruded closer to their final form illustrated in Figure 2, with only minimal deformability or flexibility required to enable the tabs 6a, 6b to conform to a shape of the surface 9’ of the invert 9.

With reference to Figure 4, to install the duct 100 on an invert 9 of a non-man entry sewer pipe 18, the non-man entry sewer pipe 18 is first temporarily stoppered so that a section of the pipe can be isolated, for laying the duct 100 therein. Optionally, the surface 9’ of the invert 9 may be roughened prior to installation of the duct 100. Depending on a condition of the temporarily isolated section of pipe, the invert 9 may subsequently be cleaned using, for example, high pressure water jetting, to remove any silt, slime or tree roots that may be present on the invert 9. The duct 100 is then pulled through an access point, such as a manhole 13, until it reaches an exit point, such as an exit manhole. The duct 100 may be held in place by temporarily clamping the duct 100 at the access point 13. Alternatively or additionally, the duct 100 is temporarily fixed to the sewer 19 at an end 20 of the isolated section distal from the access point 13.

Adhesive 8 is then injected between the surface 9’ of the invert 9 and the duct 100. The adhesive 8 may be injected between the surface 9’ of the invert 9 and the sealing region 130 of the duct 100. The adhesive 8 may be continuously dispensed along the invert 9. Alternatively, or additionally, the adhesive 8 may be intermittently dispensed along the length of the sealing region 130 of the duct 100 to form adhesive patches or spots. The duct 100 may then be pressed into the invert 9 and the tabs 6a, 6b may be flexed against the invert 9 to define low flow channels 10a, 10b, respectively. The adhesive 8 forms a chemical bond between the surface 9’ of the invert 9 and the sealing region 130 of the duct 100.

With reference again to Figure 4 a system according to some embodiments of the invention may be supplied to a construction site, for example, on a mobile trailer 11. The system comprises a storage tank for storing the adhesive 8, and optionally a heating means for thermally conditioning the adhesive 8 by warming the adhesive 8 in the storage tank prior to application, to reduce the viscosity of said adhesive 8. Where the adhesive 8 comprises a two part resin, the adhesive storage tank may comprise two separate chambers, one chamber for each component of the two part resin. Each of the separate chambers may be heatable by the optional heating means to thermally condition each of the two components of the two part adhesive prior to application of the same.

The system also comprises a hose 12 in fluid communication with the storage tank and windable about a rotatable drum. The hose 12 may have a length of between 100 and 200 metres, for example. The system also comprises a means for rotatably driving the drum to pull the hose 12 through the non-man entry sewer pipe 18 at a substantially constant speed and a pumping means for pumping heated adhesive 8 from the storage tank through the hose 12.

In use, after the duct 100 has been pulled through the temporarily isolated part of the nonman entry sewer pipe 18 and arranged in position, the hose 12, is pulled from the rotatable drum through the sewer pipe 18 to a start position at or substantially proximal to the distal end 20 of the temporarily isolated section of the sewer pipe 18. The adhesive storage tank is optionally heated prior to deployment of the hose 12 to thermally condition the adhesive prior 8. Adhesive is applied to the surface 9’ of the invert 9 by pumping adhesive from the storage tank through the hose 12 whilst the drum is rotated at a substantially constant speed to draw the hose 12 back through the temporarily isolated section of sewer pie 18 from the distal end 20 towards the access manhole 13 at a substantially constant speed.

In some embodiments, a guide tool 15 is provided to an end of the hose 12. The guide tool 15 comprises an application head 16 for guiding the duct 100 into conformance with a shape of the sewer invert 9. The application head 16 may additionally be arranged for forming or shaping the tabs 6a, 6b against the surface 9’ of the invert 9, thereby forming the low flow channels 10a, 10b. As the duct 100 is pressed towards the surface 9’ of the invert 9, the adhesive 8 is injected between the surface 9’ and the sealing region 130 of the duct 100. The guide tool 15 is drawn from the distal end 20 through the non-man entry sewer pipe 18 with the hose 12 until the guide tool 15 arrives at the access point 13 adjacent to the machine 11. The guide tool 15 may additionally comprise a static impingement mixer for combining two components of a two part resin into one mixture, thereby initiating a curing reaction, immediately prior to ejection of the combined two part resin mixture. The resin mixture 8 then solidifies around the mechanical key features of the duct 100.

To install duct 100 having a length greater than the length of the hose 12, of the system, the trailer 11 must repositioned and the installation process restarted from the previous finishing point until the full length of the duct 100 has been bonded to the invert 9 of the non-man entry sewer pipe 18.

Claims

1. A duct for installation on an invert of a non-man entry sewer pipe, the duct comprising:

2. A duct according to claim 1 wherein the sealing region comprises a mechanical key profile.

3. A duct according to claim 2, wherein the cross-sectional shape and/or material of the mechanical key profile is capable of providing sufficient tensile strength to resist a buoyancy effect of the duct when the duct is adhesively bonded to the invert.

4. A duct according to claim 3, wherein the mechanical key profile comprises one or more protrusions shaped so that when an adhesive is applied between the invert and the sealing region, the adhesive substantially surrounds the protrusions and provides a mechanical anchor between the duct and the invert.

5. A duct according to claim 4, wherein the one or more protrusions comprise one or more substantially T shaped or substantially bulbous protrusions.

6. A duct according to any of claims 2 to 5, wherein the mechanical key profile is integrally formed with the body.

7. A duct according to any of the preceding claims, wherein the first and second tabs are integrally formed with the body.

8. A duct according to any of the preceding claims, wherein the first and second tabs extend from an outer surface of the body, and wherein movement of the first and second tabs relative to the body is substantially limited to conforming to a shape of a surface of the invert.

9. A duct according to any of claims 1 to 7, wherein the first and second tabs are flexible from a first, storage position, in which the first and second tabs are substantially retracted to the body so as to minimise a footprint or profile of the duct, to a second, in use position, in which the first and second tabs are substantially extended from the body, in an anticipated installation orientation.

10. A duct according to any preceding claim, wherein the first and second tabs each include a substantially smooth upper surface.

11. A duct according to any preceding claim, wherein the first and second tabs each include a concave surface.

12. A duct according to any preceding claim, wherein the first and second tabs comprise ends having a tapering thickness.

13. A duct according to any of the preceding claims, wherein the body comprises an inner sheath.

14. A duct according to claim 13, wherein the inner sheath comprises one or more functional layers.

15. A duct according to claim 14, wherein the one or more functional layers comprises one or both of a moisture barrier layer and a metal sheath layer.

16. A duct according to any of the preceding claims, wherein the body comprises an outer sheath.

17. A duct according to claim 16, wherein the outer sheath comprises a polyolefin.

18. A duct according to claim 16 or claim 17, wherein the outer sheath is axially extruded.

19. A duct according to any preceding claim, comprising one or more micro-ducts within the body.

20. A duct according to any preceding claim, wherein the duct is an optical fibre duct.

21. A kit comprising:

a duct according to any of the preceding claims; and an adhesive for sealing the duct to the non-man entry sewer pipe.

22. A kit according to claim 21, wherein said adhesive comprises a fast setting resin.

23. A kit according to claim 21 or claim 22, wherein said adhesive comprises a two part resin.

24. A kit according to any of claims 21 to 23, wherein the resin comprises a filler material arranged to scavenge water from the invert without hindering development of a chemical bond between the invert and the duct.

25. A method of manufacturing the duct of any of claims 1 to 20, the method comprising:

26. A method according to claim 25, when dependent on claims 13 and 16, wherein said extruding the body comprises extruding the outer sheath over the inner sheath layer.

27. A method according to claim 25 or claim 26, wherein the first and second tabs are coextruded in a storage orientation, in which the first and second tabs are substantially retracted to the body so as to minimise a footprint or profile of the duct.

28. A method for installing the duct of any of claims 1 to 20, the method comprising:

29. A method according to claim 28, comprising shaping the duct to substantially match a shape of the invert of the non-man entry sewer pipe.

30. A method according to claim 29, wherein said shaping comprises drawing a guide tool over the duct to move the first and second tabs into a position to substantially match the shape of the invert of the non-man entry sewer pipe.

31. A method according to any of claims 28 to 30, comprising cleaning a surface of the invert prior to said arranging and said bonding.

32. A method according to any of claims 28 to 31, comprising roughening a surface of the invert prior to said arranging and said bonding.

33. A method according to any of claims 28 to 32, wherein said bonding comprises applying a fast setting adhesive.

34. A method according to any of claims 28 to 33, wherein said bonding comprises applying a two part adhesive.

35. A method according to claim 34, wherein said two part adhesive comprises a two part epoxy adhesive, a two part polyurethane adhesive or a two part polyurea adhesive.

36. A method according to claim 35, wherein said two part polyurethane adhesive is formed by reacting mono di-isocyanate (MDI) with a polyol in the presence of a catalyst.

37. A method according to any of claims 33 to 36, wherein said adhesive comprises one or more hydroscopic fillers for drawing moisture from invert surface to dry sufficiently to enable bonding.

38. A method according to any of claims 33 to 37, wherein said bonding comprises continuously dispensing said adhesive along the invert to adhesively bond the duct to the invert.

39. A method according to any of claims 33 to 38, wherein said bonding comprises intermittently dispensing the adhesive along the length of the sealing region of the duct to form adhesive patches or spots.

40. A method according to any of claims 33 to 39, comprising thermally conditioning said adhesive prior to said applying.

41. Apparatus for installing the duct of any of claims 1 to 20, using the method of any of claims 28 to 40, the apparatus comprising:

42. Apparatus according to claim 41, comprising a drum around which said hose is 5 windable and a means for rotatably driving the drum so as to wind the hose around the drum at a substantially constant speed.

43. Apparatus according to claim 41 or claim 42, comprising a guide tool fixed to an end of the hose for guiding said depositing of said stored adhesive.

44. Apparatus according to any of claims 41 to 43, wherein said adhesive is a two part resin and said storage means comprises two separate storage tanks, each tank for storing one part of the two part resin.

15

45. Apparatus according to claim 44, comprising means for mixing the separate parts of the two part resin.

46. Apparatus according to any of claims 40 to 45, provided on a mobile trailer.

26 03 18

Intellectual

Property

Office

Application No: GB1708489.8 Examiner: Mr James Walker

46. Apparatus according to claim 45, when dependent on claim 43, wherein said means for mixing comprises a static impingement mixer in the guide tool

47. Apparatus according to any of claims 41 to 46, provided on a mobile trailer.

26 03 18

Amendments to the Claims have been filed as follows:CLAIMS

a body having a conduit therethrough; and

5 first and second flexible tabs arranged on an outer surface of said body and flexible with respect thereto, wherein the first and second tabs and a section of the outer surface of the body therebetween define a sealing region for sealing the duct to the invert, the sealing region comprising a mechanical key profile, and

10 wherein, in use, first and second flow channels are defined by the first and second flexible tabs respectively.

2. A duct according to claim 1, wherein the cross-sectional shape and/or material of the mechanical key profile is capable of providing sufficient tensile strength to resist a

15 buoyancy effect of the duct when the duct is adhesively bonded to the invert.

3. A duct according to claim 1 or 2, wherein the mechanical key profile comprises one or more protrusions shaped so that when an adhesive is applied between the invert and the sealing region, the adhesive substantially surrounds the protrusions and provides a

20 mechanical anchor between the duct and the invert.

4. A duct according to claim 3, wherein the one or more protrusions comprise one or more substantially T shaped or substantially bulbous protrusions.

25 5. A duct according to any of the preceding claims, wherein the mechanical key profile is integrally formed with the body.

6. A duct according to any of the preceding claims, wherein the first and second tabs are integrally formed with the body.

7. A duct according to any of the preceding claims, wherein the first and second tabs extend from an outer surface of the body, and wherein movement of the first and second tabs relative to the body is substantially limited to conforming to a shape of a surface of the invert.

8. A duct according to any of claims 1 to 7, wherein the first and second tabs are flexible from a first, storage position, in which the first and second tabs are substantially retracted

26 03 18 to the body so as to minimise a footprint or profile of the duct, to a second, in use position, in which the first and second tabs are substantially extended from the body, in an anticipated installation orientation.

5 9. A duct according to any preceding claim, wherein the first and second tabs each include a substantially smooth upper surface.

10. A duct according to any preceding claim, wherein the first and second tabs each include a concave surface.

11. A duct according to any preceding claim, wherein the first and second tabs comprise ends having a tapering thickness.

12. A duct according to any of the preceding claims, wherein the body comprises an inner

15 sheath.

13. A duct according to claim 12, wherein the inner sheath comprises one or more functional layers.

20 14. A duct according to claim 13, wherein the one or more functional layers comprises one or both of a moisture barrier layer and a metal sheath layer.

15. A duct according to any of the preceding claims, wherein the body comprises an outer sheath.

16. A duct according to claim 15, wherein the outer sheath comprises a polyolefin.

17. A duct according to claim 15 or claim 16, wherein the outer sheath is axially extruded.

30 18. A duct according to any preceding claim, comprising one or more micro-ducts within the body.

19. A duct according to any preceding claim, wherein the duct is an optical fibre duct.

35 20. A kit comprising:

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21. A kit according to claim 20, wherein said adhesive comprises a fast setting resin.

22. A kit according to claim 20 or claim 21, wherein said adhesive comprises a two part 5 resin.

23. A kit according to any of claims 20 to 22, wherein the resin comprises a filler material arranged to scavenge water from the invert without hindering development of a chemical bond between the invert and the duct.

24. A method of manufacturing the duct of any of claims 1 to 19, the method comprising:

25. A method according to claim 24, when dependent on claims 12 and 15, wherein said extruding the body comprises extruding the outer sheath over the inner sheath layer.

26. A method according to claim 24 or claim 25, wherein the first and second tabs are

20 coextruded in a storage orientation, in which the first and second tabs are substantially retracted to the body so as to minimise a footprint or profile of the duct.

27. A method for installing the duct of any of claims 1 to 19, the method comprising:

arranging the duct along an invert of a non-man entry sewer pipe; and

25 bonding the sealing region of the duct to the invert.

28. A method according to claim 27, comprising shaping the duct to substantially match a shape of the invert of the non-man entry sewer pipe.

30 29. A method according to claim 28, wherein said shaping comprises drawing a guide tool over the duct to move the first and second tabs into a position to substantially match the shape of the invert of the non-man entry sewer pipe.

30. A method according to any of claims 27 to 29, comprising cleaning a surface of the

35 invert prior to said arranging and said bonding.

26 03 18

31. A method according to any of claims 27 to 30, comprising roughening a surface of the invert prior to said arranging and said bonding.

32. A method according to any of claims 27 to 31, wherein said bonding comprises 5 applying a fast setting adhesive.

33. A method according to any of claims 27 to 32, wherein said bonding comprises applying a two part adhesive.

10 34. A method according to claim 33, wherein said two part adhesive comprises a two part epoxy adhesive, a two part polyurethane adhesive or a two part polyurea adhesive.

35. A method according to claim 34, wherein said two part polyurethane adhesive is formed by reacting mono di-isocyanate (MDI) with a polyol in the presence of a catalyst.

36. A method according to any of claims 32 to 35, wherein said adhesive comprises one or more hydroscopic fillers for drawing moisture from invert surface to dry sufficiently to enable bonding.

20 37. A method according to any of claims 32 to 36, wherein said bonding comprises continuously dispensing said adhesive along the invert to adhesively bond the duct to the invert.

38. A method according to any of claims 32 to 37, wherein said bonding comprises

25 intermittently dispensing the adhesive along the length of the sealing region of the duct to form adhesive patches or spots.

39. A method according to any of claims 32 to 38, comprising thermally conditioning said adhesive prior to said applying.

40. Apparatus for performing the method of any of claims 28 to 40, the apparatus comprising:

the duct of any of claims 1 to 19;

a storage means for storing an adhesive;

35 a heating means for heating the stored adhesive; and a hose for depositing said adhesive, wherein the hose is in fluid connection with said storage means.

41. Apparatus according to claim 40, comprising a drum around which said hose is windable and a means for rotatably driving the drum so as to wind the hose around the drum at a substantially constant speed.

42. Apparatus according to claim 40or claim 41, comprising a guide tool fixed to an end of the hose for guiding said depositing of said stored adhesive.

43. Apparatus according to any of claims 40 to 42, wherein said adhesive is a two part 10 resin and said storage means comprises two separate storage tanks, each tank for storing one part of the two part resin.

44. Apparatus according to claim 43, comprising means for mixing the separate parts of the two part resin.

45. Apparatus according to claim 44, when dependent on claim 42, wherein said means for mixing comprises a static impingement mixer in the guide tool