WO2010102340A1

WO2010102340A1 - Tapping bands

Info

Publication number: WO2010102340A1
Application number: PCT/AU2010/000280
Authority: WO
Inventors: Raymond Rabanin; Anthony Favero
Original assignee: Raymond Rabanin; Anthony Favero
Priority date: 2009-03-12
Filing date: 2010-03-11
Publication date: 2010-09-16
Also published as: AU2010223854A1

Abstract

A tapping band for use in the tapping of a main pipe with a service pipe comprising first and second parts that each have a half-cylindrical shaped profile on their pipe facing surface, such that when used together, the parts form a band that surrounds the main pipe and grippingly engages with it, said parts being directly slidably engageable with respect to one another wherein the direction of sliding is along the longitudinal axis of the main pipe, and the first part has service pipe connecting means in the form of a boss extending outwardly from it.

Description

TAPPING BANDS

TECHNICAL FIELD

This invention relates to new types of tapping bands for use in connecting service pipes to main pipes so that fluid can flow therebetween, and to related methods.

BACKGROUND ART

It is a common requirement to connect a service pipe to a main pipe carrying a fluid, so that fluid can pass from the main pipe to the service pipe.

A particular example arises in the provision of water supplies to multiple properties from a water main. When for example an area is subdivided for new housing, a water main (pipe) may be laid under public land to supply water to numerous individual properties, before connection to those properties is required. When a property is to be connected to the main a service pipe for supplying water onto the property from the main is laid and a tapping (i.e. a hole) is made in the main and the service pipe connected.

This may be done using apparatus often referred to (because of its form) as a tapping band. An internally threaded boss in which the service pipe is threadably and sealingly received is positioned and held against a surface of the main and over the hole with a seal held between the boss and the wall surface of the pipe comprising the water main to prevent leakage. To hold the boss in position it is secured to a band or band-like apparatus that extends peripherally around the main. Figure 1 shows a portion of a main pipe 20, with one service pipe 21 connected thereto using a tapping band 22 and another service pipe 23 about to be screwed in to the boss 24 of another tapping band 25. Ih one type of tapping band, of which an example 1 is shown in Figure 2, the band is made in two approximately semicircular halves 2, 3 of which one half 2 is integral with the threaded boss 4. The two halves are held together on a main pipe 7 by nuts 5 and bolts 6. The band halves 2 and 3 may be made of metal or a suitable plastics material.

In another type of tapping band, of which an example 10 is shown in Figure 3, a band 11 (typically metallic) extends substantially around the main pipe 12 (shown in chain dotted lines) and a threaded stud 13 is arranged to be tightened whereby to in effect shorten the band 11 and so tighten it around the main pipe 12. A threaded boss 14 is secured to the band 11.

hi most tapping bands, including those shown in Figures 2 and 3, O-ring or lip-type seals may be used for sealing, as may generally saddle-shaped seals shaped to lie conformably against an outer surface wall of the main pipe 7 or 12. An O-ring seal 16 is shown in Figure 2, and is received in a recess 18 of boss 4, which itself is integrally formed as part of band half 2.

Problems are known with these and some other prior art tapping bands. They must be carefully and correctly tightened. If they are overtightened there may be excessive distortion and even damage such as cracking of the main pipe, leading to leakage from the main pipe or contamination of the water in it. Even distortion without cracking can lead to a degree of resistance to water flow in a main pipe.

Conversely, undertightening can lead to poor sealing with consequent water leakage past the seal.

It is common to specify that nuts be tightened on bolts to a specified torque value, but it is also not unknown for a torque wrench not to be used at all, thus leading to over- or undertightening. The difference between undertightening and overtightening, in terms of actual nut angle, may be quite small, exacerbating the difficulty of obtaining accurate torque. Multiple bolts or studs are commonly used (as in the examples of Figures 1 and 2) and unevenness between the degree of tightening of them can exacerbate the problems mentioned.

Another problem associated with using conventional tapping bands is that there is a large degree of tolerance in the actual outer diameter of pipes in various regions of the world, and from different manufacturers. Some pipes are manufactured with slightly smaller outer diameters, and others are manufactured slightly bigger. Tightening the bolts to the same degree when the band is used on a pipe with slightly bigger external diameter has the potential to cause the main pipe to distort or crack, conversely tightening the bolts to the same degree when the tapping band is used on a main pipe with smaller external diameter may not cause the tapping band to seal properly and as a consequence create a leak.

The actual process of tapping with conventional tapping bands can also take significant time. This becomes important particularly when many tappings are to be made along a length of main pipe. The problem of tightening nuts correctly can be exacerbated by difficulties of access and assembly. It will be noted by reference to Figures 2 and 3 that in the usual situation where access to an end of a main pipe is not available, at least these prior art tapping bands have to be assembled by securing their constituent parts to each other around the main pipe. This can take a significant amount of time. It would be desirable to have a tapping band able to be very quickly assembled to a main pipe.

The cost of tapping bands can be considerable and stems partly from cost of assembly and the number of the various parts in conventional types.

The present invention addresses one or more of the aforesaid problems with tapping bands. DISCLOSURE OF INVENTION

The invention flows from the recognition that a particular way of securing cooperating parts around a structure such as a pipe has surprisingly great advantages in the tapping band application.

Accordingly, the invention provides in a first aspect a tapping band for use in the tapping of a main pipe with a service pipe comprising first and second parts that each have a half-cylindrical shaped profile on their pipe facing surface, such that when used together, the parts form a band that surrounds the main pipe and grippingly engages with it, said parts being directly slidably engageable with respect to one another wherein the direction of sliding is along the longitudinal axis of the main pipe, and the first part has service pipe connecting means in the form of a boss extending outwardly from it.

In particular the first and second parts comprise a pair of integrated elongate wedges that are slidably receivable within a pair of elongate channel shaped formations that are arranged to receive the wedges.

Each wedge on a first part and its corresponding elongate channel shaped formation on the second part is arranged such that the wedging action created when the two parts slidably engage with one another, causes the tapping band to constrict around and grip the main pipe.

Preferably at least one side of the first part comprises a facing surface that slides along a corresponding facing surface of the second part, when the two parts are slid together to form the tapping band, said facing surface on the first part includes at least a portion of the facing surface that is serrated, and the corresponding facing surface of the second part at least has a corresponding portion of serrations, such that when the first and second parts are slid together to form the tapping band, the corresponding portions of serrations engage one another and increase the resistance of the two parts from sliding out of engagement with each other. Optionally the service pipe connecting boss is either integrated into the first part, or alternatively, is an insert that is received into a corresponding recess in the first part.

The boss may comprise either a female or external thread for engagement with a corresponding thread on the service pipe.

Optionally the boss may comprise an insert that provides a female thread for engagement with the service pipe wherein the insert is made of metal.

When the pipe connecting boss is an insert, the insert is inserted into the first part from the pipe facing side, and has a corresponding part cylindrical profiled surface that closely matches the half-cylinder profile of the pipe facing side of the first part such that when the insert is fully inserted, the pipe facing side of the insert sits flush with the pipe facing side of the first part and maintains the half-cylinder shaped profile.

The insert may have sealing means between the pipe facing surface of the insert and the pipe so that when the first and second parts are slidably engaged, the constriction of the tapping band around the main pipe causes the sealing means to be compressed against the main pipe's outer wall and thereby provides suitable sealing.

Optionally the first and second parts and the insert are made of plastic or metal.

Advantageously, the two parts may be proportioned so that for a specified range of degrees of engagement of the two parts with each other a specified range of pipe sizes may be gripped with a specified force.

Other features inventive concepts and advantages are disclosed in the following description. In order that the invention can be better understood it will now be described non- limitingly by reference to preferred embodiments as shown in the attached Figures.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 is a plan view of a main pipe fitted with first and second tapping bands, and two service pipes, one connected to a first tapping band and the other being positioned for connection to a second tapping band;

Figure 2 is an end on view of a first prior art tapping band;

Figure 3 is a perspective view of a second prior art tapping band;

Figure 4 is a perspective view of a tapping band according to the invention in use on a main pipe;

Figure 5 is a perspective view of the tapping band shown in Figure 4, assembled;

Figure 6 is an exploded view of two parts of the tapping band shown in Figure

5;

Figure 7 comprises two perspective views of one part of the tapping band shown in Figure 5;

Figure 8 is a side view of the tapping band shown in Figure 5;

Figure 9 is a section through the tapping band shown in Figure 8, the section being taken at station 9 - 9;

Figure 10 is a perspective view of a seal comprised in the tapping band shown in Figure 5; Figure 11 comprises two perspective views of a part of a second embodiment of a tapping clamp according to the invention;

Figure 12 is an exploded perspective view of the part shown in Figure 11;

Figure 13 is a further exploded perspective view of the part shown in Figure 11 ;

Figure 14 is a schematic cross-sectional view of an insert that is an alternative to the insert shown in Figure 12, secured to a flanged fitting;

Figure 15 shows schematically and not to scale, a modified version of the tapping band shown in Figure 5 installed on (at (a) an undersize pipe and (at (b)) an oversize pipe.

PREFERRED EMBODIMENTS OF THE INVENTION

Figure 4 shows a first tapping band 50 according to the invention, assembled on a main pipe 52, and ready for a threaded end of a service pipe (not shown) to be screwed into a female thread 54 formed in a boss 56. Figure 5 shows the tapping band 50, again assembled from parts described below, but now with the main pipe 52 omitted.

Tapping band 50 includes first and second main parts 60 and 62 respectively that in use interlock with each other to form a structure which extends completely around, and grips, an external surface 64 of main pipe 52. Integrally formed as part of part 60 is the boss 56. Figure 6 shows parts 60 and 62 disassembled (i.e. in an exploded view). Parts 60 and 62 can be assembled to each other by moving part 62 in the direction shown by arrow 66 into co-operating engagement with part 60.

Main part 60 is generally saddle shaped, having a substantially half-cylindrical wall 67 with a concave inner surface 68 that in use of tapping band 50 abuts conformingly or lies closely adjacent to the cylindrical outer surface 64 of main pipe 52. Main part 60 includes boss 56 and female thread 54.

Figures 6 and 7 show main part 60, and in these Figures can best be seen elongate wedges 70 that protrude outwards from edges of half-cylindrical wall 67 and extend along the length of half-cylindrical wall 67. Wedges 70 increase progressively in thickness along the length of half-cylindrical wall 67, both having their maximum thickness at the same end thereof.

Figure 6 shows the other main part 62 separated from main part 60. Main part 62 is also generally saddle-shaped and includes a substantially half-cylindrical wall 72 having a concave surface 74 that in use of tapping band 50 abuts conformingly or lies closely adjacent to the cylindrical outer surface 64 of main pipe 52.

Extending along the length of half-cylindrical wall 72 at its opposing edges are elongate formations 76. As can be seen particularly in Figures 6 and 9, each of formations 76 is channel-shaped in cross-section, with a recess 78 extending along its length and sized and oriented to receive therein one of the wedges 70 of the first main part 60. The dimension "x" (see Figure 9) of each of the recesses 78 varies progressively along the recess's length, each in the same direction so that the largest value of "x" is at the same end of each recess 78.

It is possible also to make main part 60 entirely from one material, for example a suitable metal or (by injection moulding) a suitable plastics material. Where aplastics material is used, there is a danger that when a service pipe is screwed firmly into engagement with thread 54, particularly if the thread on the service pipe is a tapered thread, the boss 56 might split or crack or excessively deform. Referring to Figure 9, boss 56 is shown as having a metal insert 80 therein, insert 80 having the thread 54 formed in it. If the process used to form main part 60 is injection moulding of a suitable plastics material, a pre-made metallic insert 80 may be supported in the mould (not shown) so as to be moulded in to main part 60 and firmly retained there. Insert 8 can provide resistance to damage from a tightly screwed-in service pipe end. Main part 62 may be and preferably is made as a single piece of one material. This may be metal or a suitable plastics material.

Refer now to Figure 9, which shows tapping band 50 assembled (although not secured on pipe 52) and in cross-section through the boss 56. Below insert 80 there is provided a recess 82 in which is accommodated a seal 84. This is preferably formed from a suitable resilient elastomeric material, such as a vulcanized natural rubber or a synthetic rubber or rubber-like material.

The purpose of seal 84 is to sealingly abut outer wall 64 of main pipe 52 when tapping band 50 is secured thereon, and so allow water flow between main pipe 52 and the service pipe (not shown). Seal 84, shown separately in Figure 10, surrounds the hole (not shown) drilled into pipe 52 as part of the tapping process and through which fluid flows from main pipe 52 into the service pipe (not shown). Seal 84 is shaped to fit recess 82 (which can be seen also in Figure 7), and to protrude beyond surface 68 of main part 60 when the tapping band 50 is not installed on pipe 52, but when tapping band is so installed, to be compressed into recess 82 so that a surface 86 presses sealingly against pipe outer surface 64. Seal 84 is shown in Figure 9 as having a generally trapezoidal cross-sectional shape. However, other shapes and types may be used and are known in the tapping band art, including circular cross-section O- rings and lip-type seals.

A locating formation 88 is shown in Figure 10, and may be provided to correctly locate the shaped seal 84 in recess 82 by being received in a corresponding recess (not shown) in a wall of recess 82.

The cooperating action of main parts 60 and 62 and the way they and seal 84 are assembled to main pipe 52, will now be described. First, main part 60, with seal 84 located in its recess 82, is placed against main pipe 52, in the desired position thereon. If the tapping hole (not shown) has been drilled already, seal 84 is of course located to surround the hole. If the hole is to be drilled later, main part 60 is located so that the centreline (not shown) of thread 54 corresponds with the intended position of the hole. Concave surface 68 at this stage lies conformably against or closely adjacent to surface 64 of pipe 52.

Next, the second main part 62 is moved towards first main part 60 from the opposite side of pipe 52, in such an orientation that the thinner ends of wedges 70 are positioned to enter the thicker ends of recesses 78. Finally, second main part 62 is moved lengthwise along the tube 52, i.e.. in the direction n of arrow 66, into engagement with first main part 60. Main parts 60 and 62 are pulled inward toward pipe 52 by the sliding of inclined surfaces 90 of wedges 70 against facing inclined surfaces 178 of recesses 78. This process continues until wedges 70 are firmly gripped in recesses 78, main parts 60 and 62 grip main pipe 52, and seal 84 is pressing sealingly against pipe outer surface 64. At this point, the surfaces 68 and 12 of main parts 60 and 62 respectively abut outer surface 64 of pipe 52 over part or all of the circumference, depending on the precise proportions of parts 60 and 62 and the actual size and shape of pipe 52. Tapping band 50 is then ready for use.

Co-operating sets of serrations 96 and 98 maybe provided on facing surfaces 100 and 102 of main parts 60 and 62 respectively. One purpose of these is to prevent or at least resist disengagement from each other of parts 60 and 62, by wedges 70 leaving recesses 78. This could happen in the event for example of vibrations in the system comprising main pipe 52 and its service pipes (not shown).

Obviously, parts 60 and 62 must be made to suit particular nominal main pipe 52 sizes, and in for example water main practice this means several sizes - for example water pipes likely to be tapped are available in nominal sizes from 50mm to over

300mm and the present invention is believed suitable for at least a proportion of such sizes, if not all of them, hi addition, a range of service pipe sizes must generally be provided for. These factors can mean a large number of sizes to be made. Figures 11 to 13 show a way in which the issue of multiple service pipe sizes (and thread types) can be accommodated, so as to limit the number of separate sizes required. Assembly 110 is a direct substitute for, and can be installed on a pipe 52 in exactly the same way as, main part 60 of tapping band 50. It differs in that instead of the integrally formed boss 56, assembly 110 has a boss 112, with internal thread 114 for a service pipe (not shown), that is a separate item from a generally saddle shaped component 116. Component 116 interlocks with a part such as main part 62 in exactly the same way as main part 60 does, having wedges 118 the same as wedges 70. It may also have serrations 120 corresponding including in function to serrations 96.

As best seen in Figures 12 and 13, boss 112 is an integrally formed part of an insert 122 that is received in a recess 130 in component 116 and extends through a hole 132.

An exterior formation 128 on component 116 provides room for recess 130. An optional metal insert 126 with thread 114 is shown that can be moulded into boss 112 just as insert 80 is moulded into main part 60, and may be provided for the same reason. Insert 122 has a recess 134 (corresponding to recess 82) for a seal 124 (corresponding to seal 84).

This arrangement allows a number of different service pipe sizes, thread types and/or sizes and materials to be accommodated, for one size of component 116. In this way, the number of separate designs required to provide a full size range can be somewhat limited.

Insert 122 may e of a different material from component 116, for example they may be of brass and plastics.

Other connection arrangements are facilitated by this arrangement. For example Figure 14 shows schematically an insert 141 corresponding in function to insert 122 that has an external (as opposed to internal thread 140 and a fitting 142 secured to thread 140 with a flange 144 that is suited to the installation of a valve or meter (not shown) for example.

In the Figures, main parts 60 and 62 are shown as aligning longitudinally with each other when wedges 70 are fully received in recesses 78. Forcing part 62 further in the direction of arrow 66 relative to main part 60 would require very high force, so such full engagement acts as an effective restraint to further movement. However, in practice it is possible to provide different arrangements, potentially with advantage.

Figure 15 shows (schematically) a tapping band 50a similar to tapping band 50 and with components 70a, 76a, 60a and 62a that correspond in function to components 70, 76, 60 and 62 respectively of tapping band 50. However, part 60a can move further longitudinally into engagement with part 62a than 60 into 62, before wedges 70a "jam" in the recesses (not shown) of parts 76a. The purpose is to increase the range of pipe diameters - above and below the nominal size that can be accommodated without such "jamming". Then for pipe sizes within the likely size tolerance range, the extent of engagement of wedges 70a in formations 76a allows close control of the force with which the tapping band 50a grips pipe 52a. The wedges (having a convergence angle for example of about 3 degrees, although other values are possible) allow for a significant degree of longitudinal movement to correspond to a quite small amount of increase in clamping force. This close control of clamping force may be achievable simply by choice of the degree of engagement between parts 60a and 62a. No torque spanner or the like is needed. It is possible to provide guide marks on the parts 60a and/or 62a to assist in the process of adjustment of clamping force.

Serrations (not shown in Figure 15, but the same as serrations 96 and 98 of tapping band 50) may be used also to assist in achieving controlled clamping force as well as avoiding inadvertent separation of the two halves 60a and 62a. For example, it maybe provided that a user engages parts 60a and 62a until resistance to further engagement noticeably increase as the pipe is gripped, and then advances part 62a onto part 62a by a set number of "clicks" of the serrations or a marked longitudinal distance, to get the correct amount of clamping force. The position of full engagement of wedges 70a in the recesses in formations 76a may be used to provide an absolute limit to the compression achievable, and so limit the potential for damage to or excessive deformation of pipe 52a. In this specification, the word "comprise" (or any of its derivatives, e.g. "comprising") when used in relation to integers elements or items of a system method apparatus or device is to be taken not to preclude, the possibility that other integers elements or items are present in the device method or system being described.

Claims

1. A tapping band for use in the tapping of a main pipe with a service pipe comprising first and second parts that each have a half-cylindrical shaped profile on their pipe facing surface, such that when used together, the parts form a band that surrounds the main pipe and grippingly engages with it, said parts being directly slidably engageable with respect to one another wherein the direction of sliding is along the longitudinal axis of the main pipe, and the first part has service pipe connecting means in the form of a boss extending outwardly from it.

2. A tapping band as defined in claim 1 wherein the first and second parts comprise a pair of integrated elongate wedges slidably receivable within a pair of elongate channel shaped formations arranged to receive the wedges.

3. A tapping band as defined in claim 2 wherein each wedge on a first part and its corresponding elongate channel shaped formation on the second part is arranged such that the wedging action created when the two parts slidably engage with one another, causes the tapping band to constrict around and grip the main pipe.

4. A tapping band as defined in claim 3 wherein at least one side of the first part comprises a facing surface that slides along a corresponding facing surface of the second part when the two parts are slid together to form the tapping band; said facing surface on the first part includes at least a portion of the facing surface that is serrated, and the corresponding facing surface of the second part at least has a corresponding portion of serrations, such that when the first and second parts are slid together to form the tapping band, the corresponding portions of serrations engage one another and increase the resistance of the two parts from sliding out of engagement with each other.

5. A tapping band as defined in any previous claim wherein the service pipe connecting boss is either integrated into the first part, or alternatively, is an insert that is received into a corresponding recess in the first part.

6. A tapping band as defined in claim 5 wherein the boss comprises either a female oorr eexxtteernrnaall tthhrreeaadd for engagement with a corresponding thread on the service pipe

7. A tapping band as defined in claim 6 wherein the boss comprises an insert that provides a female thread for engagement with the service pipe.

8. A tapping band as defined in claim 7 wherein the insert is made of metal.

9. A tapping band as defined in claim 5 wherein the insert is inserted into the first part from the pipe facing side, and has a corresponding part cylindrical profiled surface that closely matches the half-cylinder profile of the pipe facing side of the first part such that when the insert is fully inserted, the pipe facing side of the insert sits flush with the pipe facing side of the first part and maintains the half-cylinder shaped profile.

10. A tapping band as defined in claim 9 wherein the insert has sealing means between the pipe facing surface of the insert and the pipe so that when the first and second parts are slidably engaged, the constriction of the tapping band around the main pipe causes the sealing means to be compressed against the main pipe's outer wall and thereby provides suitable sealing.

11. A tapping band as defined in any preceding claim wherein the first and second parts and the insert are made of plastic or metal.