GB2386166A

GB2386166A - Device for tapping a pipe, includes a valve and partially enclosed hole former

Info

Publication number: GB2386166A
Application number: GB0205239A
Authority: GB
Inventors: David Simon Astall
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-03-06
Filing date: 2002-03-06
Publication date: 2003-09-10
Also published as: GB0205239D0

Abstract

A passageway 26, 36 with a saddle 10, 12 at an open 20 end and a closure 38 at the other end is placed against a pipeline 14. A valve 48, 50 is located along the tube 26, 36. An aperture boring or cutting tool 42 can move along the tube 26, past the valve 48, 50. The valve 48, 50 may be closed while the tool is in the tube 26, 36. A shank 40 and closure 38 form a seal. Preferably the tool 42, 46 is a drill bit and the valve 48, 50 is a ball type valve. The tool 42 is accessible from outside the fitting, and is preferably removed with the closure 38 once the hole has been formed and the valve 48, 50 closed. The fitting is used for tapping a water supply.

Description

PIPELINE FITTINGS This invention relates to fittings for connection to pipelines to allow fluid (gas and/or liquid) flowing through the pipeline to be tapped off at selected locations. A typical application of the invention is the supply of potable water from a mains supply to households and/or business premises.

A known fitting for use with plastics and cementitious pipelines comprises a saddle assembly for coupling the fitting to a pipeline, a port provided in the saddle assembly, a housing defining a passageway in registry at one end with the port, and a cutting tool accommodated in the housing. The housing is provided with a lateral branch in communication with the passageway. The cutting tool is threadedly and sealingly engaged within the passageway and is movable, by rotation using a useroperated key, from a retracted position beyond the lateral branch to an extended position in which it contacts a pipe in the region of the port to cut a hole in the pipe wall. When the tool is retracted again past the lateral branch, communication is established, through the passageway, between the interior of the pipeline and the lateral branch. This known fitting is used for plastics and cement-based pipelines and makes possible tapping off possible without having to shut off the fluid flow through the pipeline.

In the case of steel and cast iron pipelines, the conventional practice is to use a special cutting appliance to form an opening in the pipeline and then threadedly engage an internally threaded insert or ferrule in the opening to enable a branch pipe to be fitted. In this case, it is not practicable to make the tapping off without first shutting off the fluid flow through the pipeline.

According to the present invention there is provided a fitting for connection to a pipeline, the fitting comprising a saddle assembly for coupling the fitting to a pipeline, a port provided in the saddle assembly, a passageway in registry at one end with the port, a closure member at the other end of the passageway, a valve member intermediate the port and the closure member for opening and closing the passageway, and an aperture-boring tool accessible externally of the fitting and movable along the passageway and through the open valve between a boring position and a retracted position in which the tool is clear of the valve member to allow closing operation of the latter.

The passageway may have a generally rectilinear longitudinal axis.

The valve member may be a ball-type valve in which the valve member has a bore through it and is angularly movable between a closed position in which the bore extends substantially transversely of the passageway and an open position in which the bore is substantially aligned with the passageway to allow the tool to pass through the bore.

The tool may be freely movable along the passageway, i. e. it need not be coupled to the passageway through interengaging screwthreads, thereby allowing the tool to be rapidly advanced and retracted along the passageway.

The tool may in conjunction with the closure member seals the other end of the passageway.

The tool may have a shank which extends through and is in sliding sealing engagement with the closure member, the shank being accessible in the vicinity of the closure member.

The tool may be adapted to be rotatably driven by a drilling device, e. g. a manually or power-operating drilling device, to effect penetration through the pipeline wall.

The tool may be in the form of a drill bit.

Means may be provided for preventing withdrawal of the tool through the closure member at least until the valve member has been operated to close the passageway.

The closure member and tool may be removable from the fitting so that, after the hole has been made in the pipeline and the valve closed, a connection to a branch pipeline can then be effected without having to shut off the main pipeline.

The invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 is partially-sectioned view of a pipeline fitting in accordance with the invention, the fitting being assembled to a pipeline and"ready for use" ; and Figures 2 to 6 show the fitting at various stages during and completion of tapping into a pipeline.

Referring now to the drawings, the fitting comprises a saddle assembly having upper and lower saddle parts 10,12 which in use are assembled around and clamped to the pipeline 14 at the desired point of tapping. Nuts and bolts 16,18 are used to clamp the saddle parts 10,12 to the pipeline 14 in the manner shown. The upper

saddle part 10 is formed with a port 20 which, in use, is to register with the tapped opening in the pipeline. The port 20 is encircled by a sealing ring 22 accommodated in a groove so that an effective seal is made around the port 20 following clamping of the saddle assembly to the pipeline. A tubuluar extension 26 projects upwardly from the upper saddle part 10 and the body 28 of a ball-type valve is secured to the extension 26 by means of a threaded insert 30 engaging in female threaded portions 32,34 of the extension and the lower part of the valve body 28.

The valve body 28 defines a passageway 36 extending from the lower end of the valve to its upper end which receives a closure member 38. The closure member 38 together with a shank 40 of drill bit 42 seals the upper end of the valve body by sealing contact of the shank 40 with a pair of sealing rings 44. The shank 40 extends through the passageway 36 and terminates at its lower end in a cutting portion 46. The shank also extends through the through-opening 48 in a ball-type valve 50 by means of which fluid flow through the passage 36 can be cut-off in the absence of the shank 40 by rotating it from the position shown in Figure I to 3 through 90 degrees to the position shown in Figures 4 to 6. Rotation is effected by actuator 52 which may be in the form of a lever. The upper end of the shank 40 is fitted with a protective cap 54 which is removed when tapping is to be carried out.

The saddle assembly is first clamped on to the pipeline with the port 20 in the desired tapping position. The protective cap 54 is then removed and the upper end of the shank 40 is introduced into the chuck 56 of a power or hand drill and the chuck is tightened (see Figure 2). Drilling of the pipeline wall is then commenced until breakthrough is felt (see Figure 3). At this point, undue penetration of the drill bit 42 into the pipeline is prevented by contact of the chuck 56 with the top of the closure member 38.

Upon production of a suitable tapping aperture 60, the drill is raised with the bit 42 still located within the fitting and hence still making sealing contact with the seals 44 (see

Figure 4). Withdrawal of the bit 42 from the fitting is prevented by suitable means, e. g. by engagement of a shoulder 62 with the underside of the closure member 38. No water or gas can escape during this operation because of this sealing arrangement. Typically the drill bit has a cutting portion which is about 30 mm long while the remaining shank may be about 130 nun long. At this point, the drill bit 42 has been drawn completely clear of the through-opening in the ball-type valve 50 so that this can then be closed to seal off the aperture 60 and the lower portion of the passageway 36 (see Figures 4 and 5).

Once the ball-type valve 50 has been moved to its closed condition, the closure member 38 and the drill bit 42 may be removed and any debris may be washed out simply by opening the valve slightly to purge it out. In the case where the pipeline conducts a gas, clearing of the fitting may be done manually. With the closure member 38 and the drill bit 42 removed, a suitable fitting 66 (see Figure 6) may be connected to the upper female threaded outlet 68 of the valve body according to the user's requirements, e. g. supply pipework to a household. In this way, a"live"connection can be made to an iron or steel pipe without having to shut off the fluid-flow through the pipeline.

Following removal, the closure member and drilling bit assembly may be re-used repeatedly with the sealing rings 44 being replaced as and when needed. It will be seen that the system shown is simple to operate by untrained personnel and obviates the need for special equipment such as a drilling and tapping machine. Typical applications include venting, pressure guage fitting and water or gas supply connections.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance, it should be

understood that the Applicant claims protection in respect of any patentable feature or combination of features disclosed herein and/or shown in the drawings whether or not particular emphasis has been placed on such feature or features.

Claims

CLAIMS 1. A fitting for connection to a pipeline, the fitting comprising a saddle assembly for coupling the fitting to a pipeline, a port provided in the saddle assembly, a passageway in registry at one end with the port, a closure member at the other end of the passageway, a valve member intermediate the port and the closure member for opening and closing the passageway, and an aperture-boring tool accessible externally of the fitting and movable along the passageway and through the open valve between a boring position and a retracted position in which the tool is clear of the valve member to allow closing operation of the latter.
2. A fitting as claimed in Claim 1 in which the passageway has a generally rectilinear longitudinal axis.
3. A fitting as claimed in Claim 1 or 2 in which the valve member is a balltype valve in which the valve member has a bore through it and is angularly movable between a closed position in which the bore extends substantially transversely of the passageway and an open position in which the bore is substantially aligned with the passageway to allow the tool to pass through the bore.
4. A fitting as claimed in Claim 1,2 or 3 in which the tool is freely movable along the passageway.
5. A fitting as claimed in any one of the preceding claims in which the tool in conjunction with the closure member seals the other end of the passageway.
6. A fitting as claimed in any one of the preceding claims in which the tool has a shank which extends through and is in sliding sealing engagement with the

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closure member, the shank being externally accessible in the vicinity of the closure member.
7. A fitting as claimed in any one of the preceding claims in which the tool is adapted to be rotatably driven by a drilling device to effect penetration through the pipeline wall.
8. A fitting as claimed in any one of the preceding claims in which the tool is in the form of a drill bit.
9. A fitting as claimed in any one of the preceding claims in which means is provided for preventing withdrawal of the tool through the closure member at least until the valve member has been operated to close the passageway.
10. A fitting as claimed in any one of the preceding claims in which the closure member and tool are removable from the fitting so that, after the hole has been made in the pipeline and the valve closed, a connection to a branch pipeline can then be effected without having to shut off the main pipeline.
11. An assembly comprising a valve having a passage extending from one end of the valve to the other, a closure member at one end and a cutting tool extending through the passage and effecting a seal with the closure member.
12. An assembly as claimed in Claim 11 in which the closure member is coupled to the valve through a screw-threaded connection.
13. A fitting or assembly substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.