GB1562184A

GB1562184A - Pipe couplings

Info

Publication number: GB1562184A
Application number: GB3368375A
Authority: GB
Original assignee: Grace J C
Current assignee: Grace J C
Priority date: 1976-11-10
Filing date: 1976-11-10
Publication date: 1980-03-05

Description

(54) IMPROVEMENTS RELATING TO PIPE COUPLINGS (71) We, ROBERT JAMES WRIGHT, a British Subject of 54, Egerton Road, Streetly, in the County of Stafford and JOHN COLIN GRACE, a British Subject of 224A Hale Road, Hale in the County of Chester do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a coupling method and means for joining a branch pipe to a main pipe of greater diameter.

It is desirable, particularly in the joining up of domestic or industrial outlets to a liquid (e.g. water or oil) or gas main, to be able to join a branch pipe onto a main while the main is under pressure. In this way, the addition of a branch pipe to the main need not affect the flow of fluid through the main to other users.

In some methods used hitherto, it has been necessary to isolate the section of the main where the branch pipe is to be fitted because it has been essential to gain access to the interior of the main pipe in order to fit the branch connection.

It is an object of the present invention to provide a coupling method and means which enables a branch pipe to be coupled to a main whilst the main is under pressure or in use.

According to a first aspect, the invention provides a coupling method for coupling a branch pipe to a main pipe of greater diameter comprising taking a branch pipe fitting adapted to have a branch pipe secured thereto and also having a plain tubular portion of malleable material, surrounding said fitting with a saddle member adapted to conform sealingly with the external surface of the main pipe and of the fitting, forming a hole in the main pipe, passing the plain tubular portion through the hole, passing a swaging tool through the plain tubular portion, swaging the free end of the tubular portion into engagement with the interior of the wall of the main pipe surrounding the hole, withdrawing the swaging tool and clamping the saddle in sealing engagement with the main pipe and the fitting, and securing a branch pipe to the fitting.

The invention also provides a coupling means comprising a branch pipe fitting adapted to have a branch pipe secured thereto and also having an imperforate, cylindrical tubular portion of malleable material capable of being inserted into a suitably sized hole in a main pipe.

The fitting may be provided with external screw threads to receive a clamping nut adjacent to and surrounding the plain tubular portion. The fitting may also have screw threaded means capable of being used to secure the branch pipe thereto. The fitting may include mechanism for selectively opening and closing a portion of the fitting communicating with the branch pipe.

The invention will now be described in more detail by way of example only with reference to the accompanying informal drawing which shows, in transverse section, a portion of a main pipe and a fitting embodying the invention.

The pipe is generally indicated at 10 and may be of metal or plastics and adapted to carry any liquid or gaseous fluid, which can be supplied continuously throughout the fixing of the branch pipe, if desired.

A pipe fitting is generally indicated at 11 and is provided with a continuously screw threaded bore 12, and externally screw, threaded portions 13 and 14 adjacent its ends. The fitting also includes an imperforate cylindrical tube 25 of malleable material. As shown in the drawing, this tube is formed separately from the remainder of the fitting and may be of copper whilst the fitting may be of brass or gun metal. However, it is envisaged that the fitting may be formed in one piece and may consist throughout of a single material which has or can be caused to have properties of malleability. For example, this material may be a metal which is capable of being annealed at one end of the fitting so as to be malleable whilst the remainder of the fitting remains hard The upper part of the fitting is of generally known type and is shown to include a screw threaded plug 15 and one r more lateral openings 16 which will eventually communicate with a branch pipe. The plug 15, as shown, has a drive formation in the form of a non-circular socket, by means of which it is rotatable to move along the threaded bore 12.

A saddle 17 is provided which conforms to the outer surface of the pipe and is provided with suitable sealing means such as a resilient O-ring or may itself be of soft or resilient material having sealing properties. In the drawing the O-ring seal is shown at 18 and the saddle 17 is of a synthetic plastics material.

A clamping nut 19 is also provided which surrounds the fitting 11 and has a complementary internal screw thread which co-operates with the externally threaded portion 14 of the fitting.

The portion 20 of the fitting is of hexagonal or other non-circular cross-section so as to provide a wrench engageable portion.

The joining of a branch pipe to a main will now be described with reference to a water main.

Apparatus is known which is capable of being sealingly applied to the exterior of a water main and of carrying out a drilling and plugging operation without allowing escape of substantial quantities of water. Such a machine is desirably used to attach the fitting shown in the drawings.

Firstly, the fitting is assembled with the nut 19 abutting the part 20 of the fitting and with the saddle surrounding the lower end of the fitting. A hole is drilled at 21 into the pipe 10 and the plain tubular portion 25 of the fitting is passed through the hole 21 so as to communicate with the interior of the main.

The plug 15 is withdrawn from the bore 12 and a swaging tool is inserted. Such a tool may be of any known type which can be operated from the "blind side" of a workpiece and may be, for example, a ball swaging tool of generally known type. Such a tool comprises a cage within which a plurality of balls are disposed, a wedge being movable into a position between the balls so as to urge them radially outwardly from the cage and hence expand the periphery of the tool. The tool is inserted in non-operative condition and the wedge is then forced between the balls so as to urge them outwardly into engagement with the malleable tubular part 25 which is swaged outwardly as shown at 22, so as to abut closely against the interior of the wall of the main.

After swaging, the tool is withdrawn and the plug 15 reinserted. The nut 19 is then tightened down onto the saddle 17 so as to form a watertight joint. It will be appreciated that. at this stage. the interior of the main is sealed off from the exterior by virtue of the O-ring seal 18, further sealing means 23 between the saddle and the fitting, and the plug 15. Where the fitting has been applied by machine, the machine can be removed at this stage from sealing engagement with the main pipe.

The branch pipe can then be attached to the fitting in generally known manner so as to communicate with the bore 12 via the apertures 16 and, finally, the plug 15 can be withdrawn above the apertures 16 so as to allow fluid to flow into the branch pipe. The methods of making such a connection are generally known and form no part of the present invention.

WHAT WE CLAIM IS: 1. A method of coupling a branch pipe to a main pipe of greater diameter comprising taking a branch pipe fitting adapted to have a branch pipe secured thereto and also having a plain tubular portion of malleable material, surrounding said fitting with a saddle member adapted to conform sealingly with the external surface of the main pipe and of the fitting, forming a hole in the main pipe, passing the plain tubular portion through the hole, passing a swaging tool through the plain tubular portion, swaging the free end of the tubular portion into engagement with the interior of the wall of the main pipe surrounding the hole, withdrawing the swaging tool and clamping the saddle in sealing engagement with the main pipe and the fitting, and securing a branch pipe to the fitting.

2. A coupling means for use in coupling a branch pipe to a main pipe of greater diameter, the coupling means comprising a branch pipe fitting adapted to have a branch pipe secured thereto and also having an imperforate, cylindrical tubular portion of malleable material capable of being inserted into a suitably sized hole in a main pipe.

3. A fitting according to Claim 2 wherein external screw threads are provided adjacent and surrounding said plain tubular portion and adapted to receive a clamping nut.

4. A fitting according to Claim 2 or Claim 3 wherein screw threaded means are provided which are capable of being used to secure the branch pipe to the fitting.

5. A fitting according to any one of Claims 2 to 4 wherein a mechanism is provided for selectively opening and closing a portion of the fitting communicating with a branch pipe secured thereto.

6. A fitting according to Claim 5 when appendant to Claim 4 wherein said mechanism comprises a plug having an

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. openings 16 which will eventually communicate with a branch pipe. The plug 15, as shown, has a drive formation in the form of a non-circular socket, by means of which it is rotatable to move along the threaded bore 12. A saddle 17 is provided which conforms to the outer surface of the pipe and is provided with suitable sealing means such as a resilient O-ring or may itself be of soft or resilient material having sealing properties. In the drawing the O-ring seal is shown at 18 and the saddle 17 is of a synthetic plastics material. A clamping nut 19 is also provided which surrounds the fitting 11 and has a complementary internal screw thread which co-operates with the externally threaded portion 14 of the fitting. The portion 20 of the fitting is of hexagonal or other non-circular cross-section so as to provide a wrench engageable portion. The joining of a branch pipe to a main will now be described with reference to a water main. Apparatus is known which is capable of being sealingly applied to the exterior of a water main and of carrying out a drilling and plugging operation without allowing escape of substantial quantities of water. Such a machine is desirably used to attach the fitting shown in the drawings. Firstly, the fitting is assembled with the nut 19 abutting the part 20 of the fitting and with the saddle surrounding the lower end of the fitting. A hole is drilled at 21 into the pipe 10 and the plain tubular portion 25 of the fitting is passed through the hole 21 so as to communicate with the interior of the main. The plug 15 is withdrawn from the bore 12 and a swaging tool is inserted. Such a tool may be of any known type which can be operated from the "blind side" of a workpiece and may be, for example, a ball swaging tool of generally known type. Such a tool comprises a cage within which a plurality of balls are disposed, a wedge being movable into a position between the balls so as to urge them radially outwardly from the cage and hence expand the periphery of the tool. The tool is inserted in non-operative condition and the wedge is then forced between the balls so as to urge them outwardly into engagement with the malleable tubular part 25 which is swaged outwardly as shown at 22, so as to abut closely against the interior of the wall of the main. After swaging, the tool is withdrawn and the plug 15 reinserted. The nut 19 is then tightened down onto the saddle 17 so as to form a watertight joint. It will be appreciated that. at this stage. the interior of the main is sealed off from the exterior by virtue of the O-ring seal 18, further sealing means 23 between the saddle and the fitting, and the plug 15. Where the fitting has been applied by machine, the machine can be removed at this stage from sealing engagement with the main pipe. The branch pipe can then be attached to the fitting in generally known manner so as to communicate with the bore 12 via the apertures 16 and, finally, the plug 15 can be withdrawn above the apertures 16 so as to allow fluid to flow into the branch pipe. The methods of making such a connection are generally known and form no part of the present invention. WHAT WE CLAIM IS:

1. A method of coupling a branch pipe to a main pipe of greater diameter comprising taking a branch pipe fitting adapted to have a branch pipe secured thereto and also having a plain tubular portion of malleable material, surrounding said fitting with a saddle member adapted to conform sealingly with the external surface of the main pipe and of the fitting, forming a hole in the main pipe, passing the plain tubular portion through the hole, passing a swaging tool through the plain tubular portion, swaging the free end of the tubular portion into engagement with the interior of the wall of the main pipe surrounding the hole, withdrawing the swaging tool and clamping the saddle in sealing engagement with the main pipe and the fitting, and securing a branch pipe to the fitting.

external screw thread engageable with said screw threaded means and having a drive formation whereby it is rotatable, the fitting having ports adapted to communicate with the branch pipe and capable of being isolated from the remainder of the fitting by means of the screw threaded plug.

7. A fitting substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

8. A method of coupling a branch pipe to a main pipe of greater diameter according to Claim 1 and substantially as hereinbefore described.