WO1983002990A1

WO1983002990A1 - Pipe tapping assembly

Info

Publication number: WO1983002990A1
Application number: PCT/AU1983/000025
Authority: WO
Inventors: Kemp & Co. Pty Ltd. James
Original assignee: James, Ian
Priority date: 1982-02-24
Filing date: 1983-02-24
Publication date: 1983-09-01
Also published as: DK485483D0; FI833880A; JPS59500380A; EP0101473A1; DK485483A; FI833880A0; EP0101473A4

Abstract

A pipe tapping assembly (10) for making a fluid connection with a pipe (12). The pipe tapping assembly (10) includes a mounting part (11) having a raised outlet housing (13). The mounting part is fixed to the pipe (12) and a detachable connector assembly (14) is supported by the mounting part in seal relationship with the pipe via a seal (8). The connector assembly may be non-removable and the seal may be integral with the connector assembly. To overcome problems of bimetallic corrosion the connector assembly (14) either may be coated with an elastomeric substance, or be formed of plastics material, or an elastomeric shroud (19) can be used to electrically isolate the mounting part (11) from the connector assembly (14). To overcome the problem of holding large stocks of mounting parts, a plurality of connector assemblies are provided so that different ferrule connections can be made.

Description

- PIPE TAPPING ASSEMBLY

- /-

THIS INVENTION relates to improvements in and relating to pipe tapping methods and means therefor.

One of the traditional methods of providing a side branch connection to a watermain is to fit and assemble a tapping band to the watermain and then fit a connecting ferrule or pipe to the tapping band. This method permits a connection to be made to an unpressurized watermain, or with suitable equipment, to a pressurized watermain. Whilst this system provides a cheap, effective method of connection it is possible that severe corrosion problems can develop under certain conditions due to the materials that are used in the various components and to environmental effects. Traditional materials used in the watermain structure include cast iron, steels and asbestos cement. Materials used in tapping bands are generally cast iron whilst the ferrules are most invariably manu¬ factured in gunmetal. It is the combination of the tapping band and ferrule materials that provide the bimetallic corrosion problem especially in the presence of ground water and stray D.C. electricity.

D.C. electricity has its major use in the traction purposes for tramways and railways and the like and special protection can be provided to underground pipe installations in those areas that may be subjected to stray D.C. currents. However the increased use in recent times of A.C. appliances with speed control or energy selection, especially with single diode control resulting in the production of D.C. electricity, is spreading the areas effected by stray D.C. electricity to encompass residential districts. Some of these areas affected may never have been previously subjected to D.C. electricity and so are inadequately protected. Of course the material selection of watermains and the like laid in such areas at an earlier date did not take the current situation into account and thus such watermains may not be adequately protected against those effects.

Another disadvantage of the presently available tapping bands is that each band includes an integral attachment portion which is apertured and internally

5 threaded to receive the externally threaded connecting ferrule for making the necessary side branch connection. Since various types and sizes of threads are required in use, it is necessary that stock supplies of the tapping bands be maintained with an assortment of the

10. various combinations of threads and pipe sizes. This greatly adds to the stock holdings of the manufacturers and other stockists and creates difficulty in the on-site selection of the appropriate tapping band for each installation.

15 it is an object of the present invention to provide a tapping method and means which will alleviate the above mentioned disadvantages and which will prove reliable and efficient in operation. Other objects and advantages of the present invention will hereinafter

20 become apparent.

With the foregoing and other objects in view, this invention in one aspect resides broadly in a pipe tapping assembly for making a fluid connection with a pipe, said pipe tapping assembly including a mounting

25 part adapted to be secured to a said pipe and a connector assembly adapted to be supported by said mounting part in operative sealed relationship with said pipe.

Preferably the aperture in the tapping assembly is non-circular so that the connector may be retained

30 non-rotatable therein but of course as desired the circular aperture could be provided and other locking means could be provided to prevent rotation of the connector within the tapping assembly. For example the connector could be provided with an outwardly projecting tab adapted to

35 be received in a corresponding slot associated with the tapping assembly. Alternatively the connector could be rotatably and sealably secured in said tapping assembly whereby it could be rotated for example for screw threaded engagement with a branch pipe. It is also preferred that the connector be provided with an enlarged base portion whereby it may be retained between the tapping assembly and the pipe to which it is to be connected. Alternatively the connector may be otherwise formed such as tapered, to achieve retention between said tapping assembly and the pipe.

In a further embodiment of the invention the connector is electrically insulated from the tapping assembly. This may be achieved for example, by coating the surface of the connector which would normally engage the tapping assembly with a non-conducting material such as an elastomeric substance. Alternatively, the connector itself may be formed of a non-conductive plastics or other suitable material. Preferably.the connector is detachably securable to the mounting part of said tapping assembly but of course it could be glued into position if desired or otherwise permanently secured in place.

In a further aspect this invention resides broadly in a method of making a fluid connection with a pipe wherein there is provided a pipe mounting part having support means thereon for a detachable connector assembly and a plurality of connector assemblies, the method comprising the steps of:-

(a) selecting a suitable connector assembly; (b) securing said selected connector assembly to said mounting part, and

(c) securing said mounting part to said pipe so as to arrange said connector assembly for operative fluid communication with said pipe. Preferably the connector assembly is threaded to

v^ --- c-_ι receive a ferrule and the method further comprises the steps of;- (d) inserting said ferrule in said connector assembly, and

(e) fitting a branch pipe to said ferrule. In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate typical embodiments of the present invention, wherein:- FIG. 1 is a perspective view of a tapping band assembly of the type adapted to be connected to a pressurized watermain or the like;

FIG. 2 is a cross-sectional view taken along the lines 2-2 of Fig. 1;

FIG. 3 is a plan view of a further embodiment of the invention; and

FIG. 4 is a cross-sectional view taken along the lines 4-4 of Fig. 2.

Referring to Fig. 1, it will be seen that the tapping band assembly 10 includes a band-like mounting part 11 which is adapted to be clamped about a pipe or watermain 12 and having a raised outlet housing 13 which supports a connector assembly 14 adapted for connection to a ferrule whereby a branch connection may be made to the watermain 12. As can be seen in Fig. 2 the outlet housing 13 communicates with an aperture 9 in the pipe or watermain 12 and a sealing assembly 15 is interposed between the connector assembly 14 and the watermain 12 whereby the connector is disposed in operative sealed relationship with the pipe to permit a pressured connection to be made to the pipe 12 through the connector assembly 14. The sealing assembly 15 may be of the type more fully described in our Australian Patents Nos. 496,168; 505,509; and 506,839. Of course, other types of sealing arrangements for forming a pressured connection can be

C-'FI utilized as desired. Also the operative sealed connection between the connector assembly and the pipe may be formed in various manners as will become apparent.

The connector assembly 14 includes a body portion 16 formed of a selected material such as gunmetal and which is internally threaded at 17 for screw threaded connection to a ferrule (not shown) , while the outer face 18 thereof is hexagonal shaped so as to engage non-rotatably in a hexagonal shaped aperture 19 in the outer end portion of the raised outlet housing 13. The body portion 16 is suitably formed of a material which is electrically compatible with that of the ferrule. The lower end of the body portion 16 is provided with a radially extending flange 20 which is adapted to be retained behind a complementary shoulder 21 formed in the inner surface of the outlet housing 13. The shoulder 21 is disposed beneath the inner extremity of the hexagonal aperture 19. A locating lip 22 extends around the underside of the body portion 16. This lip in use engages with a recess in the sealing assembly 15 for locating the latter in its operative relationship as illustrated. The sealing assembly 15 includes a plurality of flexible sectoral leaves 8 which in their closed position abutt tightly against one another to form a seal but which may be parted to enable a drill or like tool to pass therethrough for drilling the aperture 9 in the pipe 12. An elastomeric covering or shroud 23 is interposed between the connector assembly 14 and the outlet housing 13 so that no direct metal to metal contact is made between the connector assembly 14 and the mounting portion 11 whereby the connector assembly 14 is electrically insulated from the mounting portion 11. It will be seen that the covering 23 extends about the hexagonal external face 18 and the flange 20. Thus corrosion resulting from the use of dissimilar materials for example, gunmetal for the connector assembly and cast iron for the mounting part 11, in a corrosive location will be greatly reduced. Preferably the cov¬ ering 23 is bonded to the body portion 16 or the connector assembly 14.

Since on-site installations of tapping bands are frequently performed subsequent to the watermain being placed in service, the installation has to be performed by a workman working within a narrow hole dug for the purpose of gaining access to the pipe. Thus all operat¬ ions associated with the installation of the pipe tapping band are difficult and in this respect a further feature of the present invention is that the elastomeric or other suitable covering for the body portion 16 suitably has a resilience which enables the connector assembly 14 to be forced into the aperture 19 by finger pressure in such a manner that it will remain in its operative position during further jostling or jolting of the components during assembly. In the embodiment illustrated in Figs. 3 and 4 it will be seen that the connector assembly 30 is not associ¬ ated with a seal of the type which permits a pressured connection to be formed, unless a special type of ferrule or connector is used. In this embodiment the connector assembly 30 is formed of a plastics or suitable elastomeric material. The connector assembly 30 includes a body portion 31 which is internally threaded and hexagonal shaped on the outside. A peripheral flange 32 is formed at the inner end of the hexagonal portion of the body and this flange 32 en¬ gages behind a corresponding shoulder 33 formed in the raised portion 38 of the pipe tapping band 34. The inner. portion of the connector assembly adjacent the pipe 36 is substantially frusto-conical shaped and has an annular base portion 35_.adapted to engage sealably with the pipe 36. For this purpose the body portion 31 is formed of material which may be compressed against the pipe 36 upon tightly ..securing the pipe tapping band to the pipe 36.

The underside surface 37 of the peripheral base portion 35 may be patterned such as to provide areas of high pressure contact to ensure the formation of an effective seal between the connector assembly 30 and the pipe 36. In an alternate form the peripheral base portion 35 may be in the form of a pressure actuated seal of the type typified by an oil seal or the like and having a resilient lip adapted to bear tightly against the pipe and/or tapping band as fluid pressure is formed. Furthermore, the base portion could be a combination of the two systems described. In use, stock holdings of the pipe tapping bands of the present invention may be substantially reduced since a tapping band for a particular pipe size may include a hexagonal aperture which is common for ferrules of a range of types and sizes and varying threads which can be attached to the pipe tapping band, theuconnector assembly being selected to suit the particular application. Of course this feature of the invention can be utilized singularly where corrosion is not a problem such that a connector assembly could be formed wholly of metal as desired and connected directly to the tapping band such as by being threadedly engaged therewith. Alternatively a non-removable connector assembly with insulating properties could be used to advantage in selected operations.

In the embodiments described it is a simple operation to remove the complete insert prior to drilling a hole in a watermain if another thread size is required. If the new thread size is within the range accomodated by the original tapping band the latter may be re-used to minimize conversion costs.

Of course, while the above has been given by way of illustrative example of the invention, all such

cv:; modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the present invention as is defined in the appended claims.

o?

Claims

THE CLAIMS DEFINING THE IN -V1EN-TION ARE AS FOLLOWS:

1. A pipe tapping assembly for making a fluid connection with a pipe, said pipe tapping assembly including a mounting part adapted to be secured to said pipe and a connector assembly adapted to be supported by said mounting part in operative sealed relationship with said pipe.

2. A pipe tapping assembly according to Claim 1, wherein said connector assembly is detachably secured to said mounting part and includes connector means for connecting a branch pipe to said pipe tapping assembly.

3. A pipe tapping assembly according to Claim 2, wherein said mounting part includes a housing portion for supporting said connector assembly in fluid communication with said pipe.

4. A pipe tapping assembly according to Claim 3, wherein said connector assembly is electrically isolated from said mounting part and is supported thereby in spaced relationship with said pipe.

5. A pipe tapping assembly according to Claim 4, wherein said connector assembly is a metal insert and there is provided an electrically insulated shroud interposed between said insert and said mounting part and said connector means is constituted by an internally threaded bore of said insert.

6. A pipe tapping assembly according to Claim 4, wherein said connector assembly is an insert formed of electrically non-conductive material and said connector means is constituted by an internally threaded bore thereof.

7. A pipe tapping assembly according to Claim 6, wherein said insert is formed of an elastomeric material.

8. A pipe tapping assembly according to any one of Claims 5 to 7, wherein said insert has a locating portion engageable non-rotatably with said mounting part. - lQ-

9. A pipe tapping assembly according to any one of Claims 3 to 8, wherein there are provided sealing means for forming a fluid tight connection between said pipe and said connector means.

10. A pipe tapping assembly according to Claim 9, wherein said sealing means is constituted by- a sealing assembly having a base part adapted to sealably engage said pipe and an outer part adjacent said connector assembly having a plurality of flexible sectoral leaves movable between a sealing position and an open position to permit a drilling tool to be passed there¬ through.

11. A pipe tapping assembly according to Claim 1(1, wherein said connector assembly is provided with locating means engageable sealably with the outer end portion of said sealing assembly.

12. A pipe tapping assembly according to any one of Claims 6 to 8, wherein said sealing means is constituted by a portion of said insert arranged in abutting relationship with, said pipe.

13. A method of making a fluid connection with a pipe wherein there is provided a pipe mounting part having support means thereon for a detachable connector assembly and a plurality of connector assemblies, the method comprising the steps of;

(.a) selecting a suitable connector assembly (bl securing said selected connector assembly to said mounting part; and

Ccl securing said mounting part to said pipe so as to arrange said connector assembly for operative fluid communication with said pipe.

14. The method according to Clai_m 13, and wherein said connector assembly is threaded to receive a ferrule, the method further comprising the steps of;-*■*

Cd) inserting said ferrule in said connector

Q. 'Y -M- assembly; and

(e) fitting a branch pipe to said ferrule.

15. A pipe tapping assembly substantially as herein¬ before described with reference to the accompanying drawings.

16. A method substantially as hereinbefore described with reference to the accompanying drawings.