GB2599164A

GB2599164A - Pipe fitting

Info

Publication number: GB2599164A
Application number: GB2015378.9A
Authority: GB
Inventors: Welfare Andrew
Original assignee: Crane Ltd
Current assignee: Crane Ltd
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2022-03-30
Also published as: GB202015378D0

Abstract

There is provided a pipe entry 2 for delivering fluid through a building wall 4. The pipe entry comprises a pipe section 10 at least partially defining a conduit 18 for carrying a fluid. The pipe section defines a pipe outer diameter 66. The pipe entry further comprises a flange restraint 12 at least partially defining the conduit 18. The flange restraint comprises an engagement portion 44. The pipe entry further comprises a mounting flange 16 having a mounting formation 64 for connection with a downstream pipe section 65. The mounting flange is configured to engage the engagement portion to couple the flange restraint to the downstream pipe section. The flange restraint defines a flange restraint outer diameter that is substantially equal to or less than the pipe outer diameter. A method of installing a pipe entry through a wall. The engagement portion may comprise an engagement surface, such as a shoulder, onto which the flange can be seated. The flange restraint may be integrally formed with the pipe or may be attached by weldment.

Description

Pipe Fitting The present invention relates to a pipe entry for delivering fluid through a building wall and a method of installing the same.

Many buildings have a gas supply for heating the building and/or providing fuel for industrial or domestic devices contained within the building. Commonly, gas is supplied to the building by a network of underground pipes terminating in a riser that protrudes vertically above ground level. The riser is typically positioned outside of the building perimeter and as close to the building wall as possible so that any maintenance to the underground pipe network (for example the replacement of underground pipe components) can be completed without damage to the building's foundations. Accordingly, it is necessary for the gas supply to enter the building through one or more holes drilled formed in the external walls.

An pipe entry is a mechanical device that connects the external riser to a downstream pipe network positioned inside the building. Such pipe entries typically comprise a 90 ° elbow section connected directly to the top of the riser, and an elongate horizontal pipe section that passes through the hole in the wall of the building. The pipe section is typically contained within a protective sleeve to prevent damage and provide insulation from the wall. The end of the pipe section can be joined to the downstream pipe network in a number of ways, set out below.

In a first example, the pipe section may be formed from a plain-ended piece of tubular piping that is passed through the hole in the wall. Once the pipe section has been passed through the hole, a circumferentially extending flange having mounting holes is welded to the end of the pipe section. The mounting holes of the flange are then used to join the pipe section to the downstream pipe network, for example using fasteners to compress adjacent flanges together. A gasket may be positioned between the two flanges to provide sealing therebetween. Whilst such a method is an effective way of joining the pipe entry to the downstream pipe network, it has the disadvantage that the flange must be welded in place in-situ, and therefore requires the presence of welding equipment and specially trained welding personnel on site.

In a second example, the pipe section may comprise a radially extending ring that is welded onto the end of the pipe section in a factory, before the pipe section is brought to the building site. The radially extending ring defines a diameter that is larger than the outer diameter of the pipe. During installation, the pipe section is passed through the hole in the wall, and a split mounting flange is fitted over the pipe section between the radially extending ring and the interior wall. A split mounting flange is a mechanical device comprising two arcuate plates that can be assembled around the pipe section to form a circumferentially extending mounting flange. The split mounting flange typically defines a number of mounting holes for receiving fasteners in the same manner as the first example above. When tightened, the fasteners cause the split mounting flange to engage the radially extending ring so that the ring is compressed between the split mounting flange and the corresponding mounting flange of the downstream pipe network. The mounting flange grips the ring to couple the pipe section to the downstream pipe network. The use of a split mounting flange avoids the need to perform any welding on site. However, the split mounting flange cannot be used without the ring and therefore the hole in the building wall must be made larger to accommodate the external diameter of the ring so that the ring can pass through. It follows that there is often a very large clearance between the protective sleeve surrounding the pipe section and the hole in the wall. This clearance must then be filled with an insulative material, such as a bung or sealant, to seal any cavities inside the wall from the interior and exterior environments in case of gas leakage and to prevent heat escaping from the building.

It is an object of the invention to provide a pipe fitting assembly and method of joining adjacent pipe network components that obviates or mitigates one or more disadvantages of the prior art, whether identified herein or elsewhere. It is a further object of the invention to provide an improved or alternative version of the same.

According to a first aspect of the invention, there is provided a pipe entry for delivering fluid through a building wall, the pipe entry comprising: a pipe section at least partially defining a conduit for carrying a fluid, the pipe section defining a pipe outer diameter; a flange restraint at least partially defining the conduit, the flange restraint comprising an engagement portion; and a mounting flange having a mounting formation for connection with a downstream pipe section and configured to engage the engagement portion to couple the flange restraint to the downstream pipe section; and wherein at least part of the engagement portion is positioned radially inwards of the pipe outer diameter relative to a central axis of the conduit Because at least part of the engagement portion is positioned radially inwards of the pipe outer diameter, the position at which the mounting flange engages the flange restraint is also radially inwards of the pipe outer diameter. As such, the flange restraint and the pipe section may pass as one piece through a hole in the building wall sized to receive the pipe section. That is to say, the engagement portion is defined radially inward of the outermost diameter of the pipe section and therefore, in contrast to prior art arrangements, the hole in the building wall does not need to be enlarged to accommodate a radially extending ring. The clearance between the hole in the building wall and the pipe entry can therefore be made smaller, and thus any thermal insulation placed within the clearance will be more effective and thermal losses through the clearance will be reduced. Additionally, the flange restraint can be coupled to the mounting flange without the need for any job-site welding.

The term "pipe section" encompasses the part of the pipe entry which passes through the wall and which carries fluid from an exterior side of the wall to an interior side of the wall. In this context, a "pipe section" may be considered distinct from an insulation sleeve or other component surrounding the pipe section in that such insulation sleeve or other components do not primarily function to carry fluid through the wall. The term "pipe outer dimeter" encompasses the maximum diameter of the pipe section relative to a central axis of the conduit.

The flange restraint may define a flange restraint outer diameter that is substantially equal to or less than the pipe outer diameter. When the flange restraint outer diameter is substantially equal to or less than the pipe outer diameter no part of the flange restraint is larger than the maximum diameter of the pipe section. As such, this enables the pipe section and the flange restraint to be passed through the same sized hole. The term "flange restraint outer diameter" encompasses the maximum diameter of the flange restraint relative to the central axis of the conduit. The term "substantially equal to or less than" encompasses that the flange restraint and the pipe may define approximately the same outer diameter or the flange restraint may define an outer diameter that is smaller than that of the pipe. It will be appreciated that in some embodiments whilst the pipe outer diameter and the flange restraint outer diameter are "substantially equal" there may be a minor variation between the two diameters. In this context a minor variation is a variation between the two diameters which enables the flange restraint to pass through a hole that has been sized to receive the pipe section. For example, the flange restraint outer diameter may be +/-10 %, +/-5 % or +/-1 % of the pipe outer diameter.

The flange restraint may comprise an external recess, and the engagement portion may be defined by an engagement surface of the external recess extending generally normal to a central axis of the conduit. When the engagement surface is generally normal to the central axis, the engagement surface is able to react any forces applied in the longitudinal direction by the mounting flange on the flange restraint. The reaction between the mounting flange and the engagement surface transfers any compressive (i.e. joining) force applied to the mounting flange to the flange restraint to couple the two together. The term "external recess" encompasses a radially inwardly extending formation defined by an external surface of the flange restraint. The term "generally normal" encompasses a surface that extends in a substantially normal direction, or which varies from normal by an immaterial amount, for example +/-10 °.

The external recess may define a recess inner diameter, and the recess inner diameter may be in the range of around 85 % to around 95 % of the flange restraint outer diameter. In alternative embodiments, the recess inner diameter may be in the range of around 87.5 % to around 91 % of the flange restraint outer diameter. When the inner diameter is in the ranges above, this provides sufficient overlap to allow forces acting in the longitudinal direction to be transferred from the mounting flange to the flange restraint, without overly narrowing the conduit. The term "inner diameter encompasses innermost diameter of the external recess.

The external recess may comprise a tapered surface at an opposite side of the external recess to the engagement surface relative to the central axis. The tapered surface may act as a guide to ensure that the mounting ring is received in the correct position within the external groove.

The flange restraint may be a generally cylindrical hollow tube, and the external recess may comprise a circumferentially extending groove. When the groove extends circumferentially, this ensures that that load applied on the external recess is distributed evenly around the flange restraint relative to the central axis.

The flange restraint and the pipe section may be integrally formed. That is to say, the flange restraint and the pipe section may be monolithically formed. When the flange restraint and the pipe section are integrally formed, no join is present between the two and therefore the possibility of mechanical failure between the flange restraint and the pipe section is greatly diminished.

The flange restraint may be formed from a separate component to the pipe section. It will be appreciated that because the engagement portion extends inwardly, the thickness of the flange restraint must be increased to compensate for the presence of the engagement portion. When the flange restraint is separately to the pipe section, only the flange restraint needs to be made with increased thickness. This therefore enables a thin-walled pipe section to be used.

The flange restraint may be joined to the pipe section by a weldment. Alternatively the flange restraint may be joined to the pipe section by adhesive, heat shrinking or the like.

The flange restraint may comprise a reduced diameter portion that is integrally formed with the pipe section. The flange restraint may also comprise a flange restraint ring. The flange restraint ring may be connected to the reduced diameter portion, for example by welding.

The flange restraint may comprises a stepped portion configured to be received within an end of the pipe section to join the flange restraint to the pipe section. When the flange restraint comprises a stepped portion, this ensures that there is some axial overlap between the pipe section and the flange restraint, thus ensuring the flange restraint is correctly seated relative to the stepped portion and improving the mechanical strength of the join therebetween.

The pipe entry may further comprise a restraining ring received over the flange restraint, the restraining ring may be configured to engage the mounting flange and the downstream pipe section so as to distribute a joining load when the flange restraint is coupled to the downstream pipe section. When a restraining ring is used, the restraining ring is able to share some of the load applied by the mounting flange on the flange restraint. This reduces the stress carried by the flange restraint and prevents bending, buckling, and component failure.

The engagement portion may defines a first engagement surface and the restraining ring may defines a second engagement surface. During use the first and second engagement surfaces may be aligned within a common plane normal to a central axis of the conduit such that the mounting flange engages the first engagement surface and the second engagement surface simultaneously. Where the first and second engagement surfaces are aligned within a common plane, this the mounting flange can engage both surfaces simultaneously so that any compressive (i.e. joining) force is spread over both surfaces.

The restraining ring may comprise a generally cylindrical plate defining a central bore.

The restraining ring may defines a restraining ring outer diameter, and the restraining ring outer diameter may be in the range of around 110 % to around 150 % of the flange restraint outer diameter. In alternative embodiments the restraining ring outer diameter may be in the range of around 120 % to around 130 % of the flange restraint outer diameter, or the restraining ring outer diameter may be in the range of around 125 % to around 126 % of the flange restraint outer diameter. When the restraining ring diameter is in the ranges above, the restraining ring is large enough to distribute the load from the mounting flange whilst remaining as compact as possible. The term "restraining ring outer diameter" encompasses the diameter of the radially outermost part of the restraining ring relative to the central axis of the conduit.

The restraining ring may comprise an o-ring received within a circumferentially extending groove. During use when the restraining ring is mounted to the flange restraint, the o-ring may be compressed to form a substantially fluid-tight seal between the restraining ring and the flange restraint. The seal may be, in particular, a gas-tight seal. The circumferentially extending groove may be a groove defined by an inner cylindrical face of the restraining ring. Additionally or alternatively, the circumferentially extending groove may be a groove that is defined by an annular surface of the restraining ring (for example a face extending generally normal to the central axis).

The restraining ring may define a stepped portion configured to receive an end of the flange restraint. When a stepped portion is used, the stepped portion helps to ensure that the restraining ring is correctly seated relative to the flange restraint. In addition, the stepped portion may limit movement of the restraining ring relative to the flange restraint.

The mounting flange may define a mounting flange inner diameter, and the mounting flange inner diameter may be smaller than the flange restraint outer diameter. When the mounting flange inner diameter is smaller than the flange restraint outer diameter, this ensures that the mounting flange will overlap the engagement portion in a radial direction relative to the central axis A. The term "mounting flange inner diameter' encompasses the innermost diameter of the mounting flange.

The mounting flange may comprise two or more relatively movable sections configured to permit assembly and disassembly of the mounting flange around the flange restraint in a plane normal to a central axis of the conduit. For example, the mounting flange may be a split flange comprising two arcuate sections hinged together at a common end and pivotable relative to one another to receive the flange restraint therebetween. Nevertheless, it will be appreciated that in alternative embodiments the mounting flange may have any suitable configuration such that it can engage the engagement surface. For example, the mounting flange may be a single integral piece composed of a flexible material such as rubber so that it can be received over the flange restraint parallel to the longitudinal direction.

The mounting formation may comprise one or more through holes each configured to receive a fastening element. The pipe entry may further comprise an insulation sleeve received over the pipe section configured to protect the pipe section from the hole in the building wall. The insulation sleeve may extend over at least a portion of the flange restraint. The pipe entry may further comprise a collar attachable to the wall of the building. The collar may define an axially and circumferentially extending lip configured to receive the flange restraint and the pipe section therethrough.

According to a second aspect of the invention, there is provided a method of installing a pipe entry for delivering fluid through a building wall, the method comprising: providing a pipe section at least partially defining a conduit for carrying a fluid, the pipe section defining a pipe outer diameter; providing a flange restraint at least partially defining the conduit, wherein the flange restraint comprises an engagement portion and wherein at least part of the engagement portion is positioned radially inwards of the pipe outer diameter relative to a central axis of the conduit; providing a mounting flange having a mounting formation for connection with a downstream pipe section; passing the flange restraint and the pipe section through a hole in the building wall; and engaging the mounting flange with the engagement portion to couple the flange restraint to the downstream pipe section.

The method of the second aspect of the invention may comprise any of the features of the pipe entry of the first aspect of the invention.

According to a third aspect of the invention, there is provided a pipe entry for delivering fluid through a building wall, the pipe entry comprising: a pipe section at least partially defining a conduit for carrying a fluid, the pipe section defining a pipe outer diameter; a flange restraint at least partially defining the conduit, the flange restraint comprising an engagement portion; and a mounting flange having a mounting formation for connection with a downstream pipe section and configured to engage the engagement portion to couple the flange restraint to the downstream pipe section; and wherein the flange restraint defines a flange restraint outer diameter that is substantially equal to or less than the pipe outer diameter. The pipe entry of the third aspect of the invention may comprise any of the optional features of the pipe entry of the first aspect of the invention.

According to a fourth aspect of the invention, there is provided a method of installing a pipe entry for delivering fluid through a building wall, the method comprising: providing a pipe section at least partially defining a conduit for carrying a fluid, the pipe section defining a pipe outer diameter; providing a flange restraint at least partially defining the conduit, wherein the flange restraint comprises an engagement portion and wherein the flange restraint defines a flange restraint outer diameter that its substantially equal to or less than the pipe outer diameter; providing a mounting flange having a mounting formation for connection with a downstream pipe section; passing the flange restraint and the pipe section through a hole in the building wall; and engaging the mounting flange with the engagement portion to couple the flange restraint to the downstream pipe section. The method fourth aspect of the invention may comprise any of the optional features of the features of the pipe entry of the first aspect of the invention A detailed description of the invention will now be provided with reference to the accompanying drawings, in which: Figure 1 is a schematic cross-sectional view of a pipe entry according to a first embodiment of the present invention; Figure 2 is an enlarged schematic cross-sectional view of a portion of the pipe entry of Figure 1; Figure 3 is a schematic plan view of a mounting flange according to the present invention; and Figure 4 is a schematic cross-sectional view of a portion of a pipe entry according to a second embodiment of the present invention.

Figure 1 shows a cross-sectional view of a pipe entry 2 according to a first embodiment of the present invention for delivering fluid through a building wall 4. The pipe entry 2 comprises a riser 6, an elbow section 8, a pipe section 10, a flange restraint 12, a restraining ring 14 and a mounting flange 16. The riser 6, elbow section 8, pipe section 10, flange restraint 12, and restraining ring 14 are hollow and generally tubular in shape, such that they collectively define a conduit 18 for carrying a fluid, such as for example a domestic or industrial gas supply. The conduit 18 defines a central axis A. The riser 8 extends vertically upwards from the ground (not shown) on an exterior side 20 of the wall 4. The elbow section 8 comprises a connector 22 having a spigot 24 and a collar 26. The spigot 24 defines a number of circumferentially extending external groves and the riser 6 defines a corresponding series of internal grooves. The riser 6 is made from polymer, such that the riser 6 is flexibly compliant and is able to fit over the spigot 24. The riser 6 is compressed against the spigot 24 by a compression ring 28 which forces the groves of the spigot 24 to interdigitate with the corresponding grooves of the riser 6 to provide a substantially gas tight seal therebetween and to prevent separation of the riser 6 from the elbow section 8 in a vertical direction 0.e. along the central axis A). The spigot 24 is made from a stiff material such as metal, so as to be able to withstand the compressive force applied by the riser 6. To protect the compression ring 28, a protective outer sleeve 30 is fitted over the compression ring 28 at one end. An o-ring 32 is positioned between the outer sleeve 30 and the riser 6 to hold the protective sleeve in position during groundworks when the riser 6 is being buried. As an alternative to the o-ring 32, any suitable means of preventing the outer sleeve 30 from moving relative to the riser 6 may be used, for example a wedge shaped rubber ring or the like. The collar 26 is welded to one end of the elbow section 8, and the opposite end of the elbow section 8 is welded to the pipe section 10. The elbow section 8 and the pipe section 10 are made from metal. The elbow section 8 defines a substantially right-angled bend, and the pipe section 10 extends generally horizontally through a hole 34 formed in the wall 4 from the exterior side 22 of the wall 4 to an interior side 36.

Figure 2 shows an enlarged view of an end of the pipe section 10, the flange restraint 12, the restraining ring 14 and the mounting flange 16 of the pipe entry 2. The flange restraint 12 is a hollow generally cylindrical tube and comprises a stepped portion 38 that is received by the end of the pipe section 10. The stepped portion 38 defines an external diameter that is smaller than a corresponding internal diameter of the pipe section 10. The flange restraint 12 is made from metal. An opposite end of the pipe section 10 to the elbow section 8 is welded to the flange restraint 12, forming a weldment 40 extending circumferentially around the interface between the flange restraint 12 and the pipe section 10. The flange restraint 12 further comprises an external recess 42 is a circumferentially extending groove comprising a first engagement surface 44 and a tapered surface 48. The engagement surface 44 extends generally normal to the central axis A and defines an engagement portion configured to engage the mounting flange 16.

The restraining ring 14 is a generally cylindrical plate defining a central bore 50 and a stepped portion 52. The restraining ring 14 is made from metal. The stepped potion 52 is fitted over the end of the flange restraint 12 opposite the weldment 40. The stepped portion 52 comprises a circumferentially extending internal groove 54 that contains an o-ring 56. During use, when the restraining ring 14 is fitted to the end of the flange restraint 12 as shown in Figures 1 and 2, the o-ring 56 is compressed between flange restraint 12 and the restraining ring 14 to form a substantially gas-tight seal therebetween. The restraining ring 14 further defines a second engagement surface 58 which is approximately or substantially co-planar to the first engagement surface 44 when the restraining ring 14 is mounted to the flange restraint 12.

Figure 3 shows a plan view of the mounting flange 16. The mounting flange 16 comprises a first arcuate section 60 and a second arcuate section 62 that are generally C-shaped. The arcuate sections 60, 62 are made from metal. The terminal ends of the arcuate sections 60, 62 have a reduced thickness equal to half of the maximum thickness of the arcuate sections 60, 62 such that when the two are brought together in the configuration shown in Figure 3, the terminal ends of the two arcuate sections 60, 62 are overlapped. When the arcuate sections are brought together in this way the arcuate sections 60, 62 form a circle extending circumferentially around the flange restraint 12. The first and second arcuate sections 60, 62 each comprise a number of mounting formations in the form of through holes 64. As shown in Figure 2, the through holes 64 of the terminal ends are collocated so that a fastening means, such as a bolt, may be received therethrough to join the arcuate sections 60, 62 together. With reference to Figure 1, during use the mounting flange 16 is used to connect a downstream pipe section 65 to the pipe entry 2 by passing bolts through holes 67 formed in a flange 69 of the downstream pipe section 65.

A gasket 71 is positioned between the restraining ring 14 and a flange 73 of the downstream pipe section 65, and is held in compression therebetween under the action of the bolts. The gasket 71 may be made from any suitable material, for example a polymer material, and acts to prevent leakage at the interface between the flange 73 of the downstream pipe section 65 and the restraining ring 14. The gasket 71 is preferably of a heat resistant type and preferably comprises flat surfaces to form a full face seal against the restraining ring 14 and the flange 73 of the downstream pipe section. However, it will be appreciated that in alternative embodiments the gasket 71 may have any suitable configuration. In some embodiments, the gasket 71 may be omitted With reference to Figure 2, the pipe section 10 defines a pipe outer diameter 66. The pipe outer diameter 66 is the outermost diameter of the pipe section 10 measured relative to the central axis A. The flange restraint 12 defines a flange restraint outer diameter 68. The flange restraint outer diameter 68 is the outermost diameter of the flange restraint 12 measured relative to the central axis A. The flange restraint outer diameter 68 is substantially equal to or less than the pipe outer diameter 66. In some embodiments whilst the pipe outer diameter 66 and the flange restraint outer diameter 68 are "substantially equal" there may be a minor variation between the two diameters. For example, the flange restraint outer diameter 68 may be +/-10 c/o, +/-5 % or +/-1 cro of the pipe outer diameter 66.

The external recess 42 defines a recess inner diameter 70. The recess inner diameter 70 is the innermost diameter of the external recess 42 relative to the central axis A. If the depth of the external recess 42 is increased, the flange restraint 12 must be made thicker to accommodate the increased depth. This would lead to the flow through the conduit 18 being choked or restricted. As such, it is preferable that the recess inner diameter 70 is in the range of around 85 % to around 95 % of the flange restraint outer diameter 68, and more preferably is in the range of around 87.5 % to around 91 c/o. The relative proportions of the recess inner diameter 70 and the flange restraint outer diameter 68 may be chosen in dependence upon any relevant standard. For example, it will be appreciated that the inside diameter of the flange restraint 12 may have a minimum permitted value governed by an applicable industrial standard, such as for example by the GIS/PL3:2014 standard. For example, the minimum permitted insider diameter of the flange restraint 12 may be some proportion of the diameter of the riser 6. The wall thickness of the flange restraint 12 may be chosen based this minimum dimension, and the recess inner diameter 70 may be arrived at accordingly. In alternative embodiments, the recess inner diameter 70 may be chose in substantially any suitable manner.

The restraining ring 14 defines a restraining ring outer diameter 72. The restraining ring outer diameter 72 is the outermost diameter of the restraining ring 72 relative to the central axis A. The restraining ring outer diameter 72 is in the range of around 110 % to around 150% of the flange restraint outer diameter 68, and more preferably is around 120 ID/0 to around 130%, or most preferably around 125 % to 126 %. The relative proportions of the restraining ring outer diameter 72 to the flange restraint outer diameter 68 may be chosen in dependence upon any relevant industrial standard. The mounting flange 16 defines a mounting flange inner diameter 73. The mounting flange inner diameter 73 is the innermost diameter of the mounting flange 16 relative to the central axis A. The mounting flange inner diameter 73 is smaller than the flange restraint outer diameter 68 but larger than the recess inner diameter 70. Preferably, the mounting flange inner diameter 73 is in the range of around 85 % to 95 % of the flange restraint outer diameter 68, and more preferably is in the range of around 89 % to around 94 % or most preferably around 92 % to around 93 %.

With reference to Figure 1, the pipe entry 2 further comprises an insulation sleeve 74, a cosmetic ring 76, and a mounting collar 78. The pipe section 10 is received within the insulation sleeve 74 and extends through the entirety of the hole 34 from the exterior side 20 to the interior side 36 of the wall 4. In some embodiments, the insulation sleeve 74 may extend over the weldment 40 and along a portion of the flange restraint 12. The insulation sleeve 74 is made from a polymer material, such as polyethylene, to provide thermal and mechanical protection for the pipe section 10, and in particular to protect the pipe section 10 from being damaged by the wall 4. The insulation sleeve 74 ensures that if the pipe section is perforated, any gas escaping the pipe section 10 will not accumulate in any wall cavities but will instead either enter into the building on the interior side 36 of the wall 4 where the leak can be detected by small or will escape the building on the exterior side 20 of the wall 4 where the leak can also be detected. In addition, the insulation sleeve 74 provides corrosion resistance and thermal insulation for the pipe section 10.

The cosmetic ring 76 fits over the pipe section 10 on the exterior side 20 of the wall 4 so that the entrance to the hole 34 is not visible. The collar 78 comprises an axially extending lip 80 and a radially extending flange 82, both of which extend circumferentially around the central axis A. The collar 78 is fixed to the interior side 36 of the wall 4 via the radial flange 82, and the insulation sleeve 74 and the pipe section 10 are received within an aperture defined by the lip 80. Although not show, when viewed along the central axis A the collar 78 is generally C-shaped and defines two terminal ends in close proximity to one another. The terminal ends comprise tensioning formations 84 which enable the terminal ends to be brought into closer contact, and thereby control the size of the aperture. When tightened, the tensioning formations 84 enable the collar 78 to grip the outside of the insulation sleeve 74 to prevent movement of the pipe section 10 and the remainder of the pipe entry 2 relative to the wall 4.

The installation of the pipe entry 2 will now be described. First, the riser is connected to an underground pipe network positioned on the exterior side 20 of the wall 4. Next, the flange restraint 12, the pipe section 10 and the insulation sleeve 74 are passed through the hole 34 to the position shown in Figure 1, such that the flange restraint 12 is positioned on the interior side 36 of the wall 4. Subsequently, the restraining ring 14 is fitted over the end of the flange restraint 12, such that the first and second engagement surfaces 44, 58 are coplanar. The two arcuate sections 60, 62 of the mounting flange 16 are then fitted around the flange restraint 12. The gasket 71 is then placed between the restraining ring 14 and the flange 73 of the downstream pipe section 65. Finally, the mounting flange 16 is connected to the downstream pipe section 65 by passing fixtures, such as bolts, through the mounting holes 67 of the downstream pipe section 65 and into the mounting holes 64 of the mounting flange 16.

When the bolts are tightened, the mounting flange 16 is urged into contact with the first and second engagement surfaces 44, 58 of the flange restraint 12 and the restraining ring 14. The first and second engagement surfaces 44, 58 react the compressive force applied by the bolts. Because the mounting flange inner diameter 73 is less than the flange restraint outer diameter 68, the mounting flange 16 and the first engagement surface 44 overlap one another in the radial direction relative to the central axis A. The radial overlap ensures that the mounting flange 16 will engage the first engagement surface 44 when the bolts are tightened, causing the mounting flange to effectively "grip" the flange restraint 12 and thereby prevent the mounting flange 16 from being removed in an axial direction relative to the central axis A. The mounting flange 16 therefore effectively forms a radial extension to the flange restraint 12 so that the mounting holes 64 can be positioned at a diameter wider than the flange restraint 12 to enable connection to the downstream pipe section 65.

Because the flange restraint outer diameter 68 is substantially equal to or less than the pipe outer diameter 66, the flange restraint 12 can pass through the same sized hole as the pipe section 10. As such, the hole 34 in the wall 4 can be sized to match the pipe section 10 and/or the insulation sleeve 74, and does not need to be enlarged. As a result, the clearance between the inside of the hole 34 and the outside of the insulation sleeve 74 is narrower, resulting in less heat loss through the hole 34 from the interior of the building to the exterior of the building. Furthermore, the flange restraint 12 can be welded to the pipe section 10 prior to being brought to the site, for example in a factory, thus avoiding the need for any welding equipment on-site.

Tightening the bolts applies a joining load to the mounting flange 12. As the bolts are tightened the restraining ring 14 is compressed between the flange 69 of the downstream pipe section 65 and the mounting flange 16. The restraining ring 14 therefore acts to spread the load applied by the bolts, and ensures that the mounting flange 16 does not buckle or bend. As shown in Figure 2, the radial overlap between the mounting flange 16 and the first engagement surface 44 is relatively small and therefore it is preferable that the pipe entry 2 comprises the restraining ring 14. However, it will be appreciated that the restraining ring 14 is not essential. For example, the geometry of the restraining ring 14 could be incorporated into the end of the downstream pipe section 65. Alternatively, the invention would still function if the restraining ring 14 was omitted completely, however in such embodiments the interface between the first engagement surface 44 and the mounting flange 16 would be subject to relatively high stress.

Figure 4 shows a schematic cross-sectional view of a second embodiment of a pipe entry 2 according to the present invention. In Figure 4, like reference numerals are used to refer to corresponding features to the first embodiment as shown in Figures 1 and 2. The second embodiment of the pipe entry 2 is substantially the same as the first embodiment, and differs only in the construction of the flange restraint 12'. In particular, the flange restraint 12' of the second embodiment is defined by two components, namely the pipe section 10' and a flange restraint ring 86. The terminal end of the pipe section 10' comprises a tapered portion 90 and a reduced diameter section 92. The tapered portion 90 defines an external tapered surface 48' equivalent to the tapered surface 48 of the first embodiment above. The reduced diameter section 92 defines an outside diameter that is narrower than the pipe section outer diameter 66. The reduced diameter section 92 defines a recess between the tapered surface 48' and the flange restraint ring 86 and is therefore equivalent to the external recess 42 of the first embodiment of the invention above. In particular, the outside diameter of the reduced diameter section 92 may be considered to define the recess inner diameter 70 and may have the same relationship to the pipe outer diameter 66 as set out with reference to the first embodiment.

The flange restraint ring 86 is a circumferentially extending ring that is permanently connected to the terminal end of the reduced diameter section 92, for example by welding. The flange restraint ring 86 extends radially outwards relative to the longitudinal axis A and defines a first annular surface 94 which extends generally normal to the central axis and faces towards the tapered surface 48'. The annular surface 94 may be considered equivalent to the engagement surface 44 of the external recess 42 of the first embodiment, and therefore embodies an engagement portion of the flange restraint 12'. The flange restraint ring 86 further defines a second annular surface 44 on an opposing side of the flange restraint ring 86 to the first annular surface 94. The restraining ring 14' comprises a circumferentially extending groove 54' having containing an o-ring. The circumferentially extending groove 54' is defined by an annular surface of the restraining ring 14' opposite to and configured to engage with the second annular surface 96 of the flange restraint ring 86. As such, the o-ring of the second embodiment forms a face-seal with the flange restraint ring 86.

As shown in Figure 4, the flange restraint ring 86 defines an outer diameter that is slightly larger than the pipe outer diameter 66. However, the outer diameter of the flange restraint ring 86 is only larger than the pipe outer diameter 70 by a small amount, and in particular is typically less than 10 %, 5 % or 1 % larger than the piper outer diameter. In alternative embodiments, the outer diameter of the flange restraint ring 86 may be substantially equal to or less than the pipe outer diameter 70.

The flange restraint ring 86 may extend circumferentially around the entire circumference of the reduced diameter portion 92, or in alternative embodiments may extend along only a section of the reduced diameter portion 92. In yet further embodiments, the flange restraint ring may be integrally formed with the pipe section 10.

Although the engagement portion described above is embodied as a radially extending engagement surface 44 of an external recess 42, it will be appreciated that in alternative embodiments the engagement portion may have substantially any suitable configuration. For example, the engagement portion may comprise a spring-loaded clip configured to actuate radially outwardly to engage the mounting flange 16.

Furthermore, although the external recess 42 extends circumferentially around the flange restraint 12, it will be appreciated that in alternative embodiments the flange restraint 12 may comprise multiple external recess 42 spaced at discrete points around the circumference of the flange restraint 12. Further still, the external recess 42 may extend along only a portion of the circumference of the flange restraint 12.

Although the mounting flange 16 comprises two arcuate sections 60, 62, it will be appreciated that in alternative embodiments the mounting flange 16 may have substantially any suitable configuration. For example, the mounting flange 16 may comprise more than two sections. Alternatively, the mounting flange 16 may comprise a single arcuate section that is clipped to the flange restraint 12 by a resilient member.

Although the flange restraint 12 and the pipe section 10 are embodied above as separate components that are welded together, it will be appreciated that in alternative embodiments the flange restraint 12 may be integrally formed with the pipe section 10.

This reduces the chance of mechanical failure and/or leakage at the interface between the flange restraint 12 and the pipe section 10.

Claims

CLAIMS: 1. A pipe entry (2) for delivering fluid through a building wall (4), the pipe entry (2) comprising: a pipe section (10) at least partially defining a conduit (18) for carrying a fluid, the pipe section (10) defining a pipe outer diameter (66); a flange restraint (12) at least partially defining the conduit (18), the flange restraint (12) comprising an engagement portion (44); and a mounting flange (16) having a mounting formation (64) for connection with a downstream pipe section (65) and configured to engage the engagement portion (44) to couple the flange restraint (12) to the downstream pipe section (65); and wherein at least part of the engagement portion (44) is positioned radially inwards of the pipe outer diameter (66) relative to a central axis (A) of the conduit (18).
2. A pipe entry (2) according to claim 1, wherein the flange restraint (12) defines a flange restraint outer diameter (68) that is substantially equal to or less than the pipe outer diameter (66).
3. A pipe entry (2) according to any preceding claim, wherein the flange restraint (12) comprises an external recess (42), and wherein the engagement portion (44) is defined by an engagement surface (44) of the external recess (42) extending generally normal to the central axis (A) of the conduit (18).
4. A pipe entry (2) according to claim 3, wherein the external recess (42) defines a recess inner diameter (70), and wherein the recess inner diameter (70) is in the range of around 85 % to around 95 % of the flange restraint outer diameter (68).
5. A pipe entry (2) according to claims 3 or 4, wherein the external recess (42) comprises a tapered surface (48) at an opposite side of the external recess (42) to the engagement surface (44) relative to the central axis (A).
6. A pipe entry (2) according to any of claims 3 to 5, wherein the flange restraint (12) is a generally cylindrical hollow tube, and wherein the external recess (42) comprises a circumferentially extending groove.
7. A pipe entry (2) according to any preceding claim, wherein the flange restraint (12) and the pipe section (10) are integrally formed.
8. A pipe entry (2) according to any of claims 1 to 6, wherein the flange restraint (12) is formed from a separate component to the pipe section (10).
9. A pipe entry (2) according to claim 8, wherein the flange restraint (12) is joined to the pipe section by a weldment (40).
10. A pipe entry (2) according to any of claims 1 to 6, wherein the flange restraint (12') comprises a reduced diameter portion (92) that is integrally formed with the pipe section (10') and a flange restraint ring (86) that is connected to the reduced diameter portion (92).
11. A pipe entry (2) according to any preceding claim, wherein the flange restraint (12) comprises a stepped portion (38) configured to be received within an end of the pipe section (10) to join the flange restraint (12) to the pipe section (10).
12. A pipe entry (2) according to any preceding claim, further comprising a restraining ring (14) received over the flange restraint (12), the restraining ring (14) being configured to engage the mounting flange (16) and the downstream pipe section (65) so as to distribute a joining load when the flange restraint (12) is coupled to the downstream pipe section (65).
13. A pipe entry (2) according to claim 12, wherein the engagement portion (44) defines a first engagement surface (44) and wherein the restraining ring (14) defines a second engagement surface (58), and wherein during use the first and second engagement surfaces (44, 58) are aligned within a common plane normal to the central axis (A) of the conduit (18) such that the mounting flange (16) engages the first engagement surface (44) and the second engagement surface (58) simultaneously.
14. A pipe entry (2) according to claim 12 or 13, wherein the restraining ring (14) comprises a generally cylindrical plate defining a central bore (50).
15. A pipe entry (2) according to any of claims 12 to 14, wherein the restraining ring (14) defines a restraining ring outer diameter (72), and wherein the restraining ring outer diameter (72) is in the range of around 110% to around 150% of the flange restraint outer diameter (68).
16. A pipe entry (2) according to any of claims 12 to 11, wherein the restraining ring (14) comprises an o-ring received within a circumferentially extending groove (54), and wherein during use when the restraining ring (14) is mounted to the flange restraint (12) the o-ring is compressed to form a substantially fluid-tight seal between the restraining ring (14) and the flange restraint (12).
17. A pipe entry (2) according to any of claims 12 to 16, wherein the restraining ring (14) defines a stepped portion (52) configured to receive an end of the flange restraint (12)
18. A pipe entry (2) according to any preceding claim, wherein the mounting flange (16) defines a mounting flange inner diameter (73), and wherein the mounting flange inner diameter (73) is smaller than the flange restraint outer diameter (68).
19. A pipe entry (2) according to any preceding claim, wherein the mounting flange (16) comprises two or more relatively movable sections (60, 62) configured to permit assembly and disassembly of the mounting flange (16) around the flange restraint (12) in a plane normal to a central axis (A) of the conduit (18).
20. A pipe entry (2) according to any preceding claim, wherein the mounting formation (64) comprises one or more through holes (64) each configured to receive a fastening element.
21. A pipe entry (2) according to any preceding claim, further comprising an insulation sleeve (74) received over the pipe section (10) configured to protect the pipe section (10) from the hole (34) in the building wall (4).
22. A pipe entry (2) according to claim 21, wherein the insulation sleeve (74) extends over at least a portion of the flange restraint (12).
23. A pipe entry (2) according to any preceding claim, further comprising a collar (78) attachable to the wall (4) of the building, wherein the collar (78) defines an axially and circumferentially extending lip (80) configured to receive the flange restraint (12) and the pipe section (10) therethrough
24. A method of installing a pipe entry (2) for delivering fluid through a building wall (4), the method comprising: providing a pipe section (10) at least partially defining a conduit (18) for carrying a fluid, the pipe section (10) defining a pipe outer diameter (66); providing a flange restraint (12) at least partially defining the conduit (18), wherein the flange restraint (12) comprises an engagement portion (44) and wherein at least part of the engagement portion (44) is positioned radially inwards of the pipe outer diameter (66) relative to a central axis (A) of the conduit (18); providing a mounting flange (16) having a mounting formation (64) for connection with a downstream pipe section (65); passing the flange restraint (12) and the pipe section (10) through a hole (34) in the building wall (4); and engaging the mounting flange (16) with the engagement portion (44) to couple the flange restraint (12) to the downstream pipe section (65).