GB2443012A

GB2443012A - Method of isolating a hydrant and accessing a water main

Info

Publication number: GB2443012A
Application number: GB0615752A
Authority: GB
Inventors: John William Proctor; Simon Nicholas Barnes; Anthony Chantrey; Sean Anthony Chantrey
Original assignee: Yorkshire Water Services Ltd
Current assignee: Yorkshire Water Services Ltd
Priority date: 2006-08-09
Filing date: 2006-08-09
Publication date: 2008-04-23
Also published as: GB0615752D0

Abstract

A method of isolating a hydrant having a riser pipe 1 connected to a head 3, an outlet pipe 11 extending from the head, and a jumper 8 comprising a bonnet 5 and plug 7 which seals the outlet from said riser. The method comprises: attaching to the outlet a closure device comprising a cap 12 and sealing means 14, to securely close the outlet pipe; opening the jumper so that water may flow from the supply via the riser into the head; positioning the sealing means within the riser and activating the sealing means e.g. a bagging off inflatable bladder such that it extends across the riser pipe to close the supply to the hydrant head. The bonnet and plug may be removed for refurbishment or replaced with a deployment head 15 for introduction of e.g. a camera or hydrophone 16 to the main and the sealing means removed.

Description

)THOD ND APPARATUS The present invention relates to a method for

gaining access to the mains water supply and to an apparatus for use in such a method.

Access to the mains water supply is often needed, for example to carry out essential repairs or for routine maintenance work. Often, in order to carry out work on the mains water supply, it is necessary to isolate selected areas and cut the supply while the work is carried out. This can be expensive, time-consuming and inconvenient for consumers.

Further, in the case of, for example, a leak, it may not be known in advance where the leak is located and thus larger areas of supply may be disrupted unnecessarily.

One current method of detecting leaks in the mains water supply is to insert a remote controlled camera into the mains. Typically the cameras enter the mains through an inlet pipe which is inserted into the side of the mains pipe. In order to insert the inlet pipe a hole must be drilled into the mains supply. Although this can be done whilst the supply is live, there is a risk of leakage and the introduction of an additional point of weakness into the mains pipe. This process can also be costly and time-consuming.

The present invention seeks to overcome at least one of the disadvantages associated with current methods and apparatus for accessing the mains water supply.

By a method for accessing the mains water supply we refer to a method in which an item can be inserted into the mains pipe. The item may be, for example, a detecting device or a tool for carrying out repair or maintenance.

Along a mains water supply pipe there are typically Located hydrants at regular intervals, for example every 200m. A hydrant is a large tap apparatus which is already connected to the mains. These are sometimes used by the fire brigade or to connect standpipes. A typical hydrant is shown diagrammatically in Figure 1.

A riser pipe 1 may be connected directly to the mains water pipe 2 and water is able to flow up into the riser pipe. The riser pipe 1 is connected to a hydrant head portion 3 by a flange 4. Where the mains is shallow, it may not be necessary to use a rise pipe. In some embodiments, the hydrant can be connected directly to the mains. In the example of figure 1, the body of the hydrant head is a cylindrical pipe of a similar diameter to the riser pipe. The top of the hydrant head is sealed by a bonnet 5. Across a lower section of the hydrant head is a valve seat 6. Valve seat 6 extends across the hydrant head but has an aperture which can be sealed by a plug 7 of a jumper 8. The jumper 8 comprises the plug 7 and a shaft 9 which extends to handle 10. The shaft 9 is threaded and passes through the a threaded aperture in the bonnet 5. Rotation of the handle 10 causes the shaft 9 and plug 7 to move up and down, depending on the direction of rotation. Extending from the hydrant head at a position above valve seat 6 is an outlet pipe 11.

During normal operation of the hydrant, a hose may for example be fitted to outlet pipe 11. Once the hose is securely fastened, the handle 10 may be rotated to raise the plug 7, opening the aperture in valve seat 6, allowing water to flow from the mains and through the outlet pipe.

The hydrant shown in Figure 1 is merely an example and common variations are possible as will be well understood by those skilled in the art.

It is sometimes necessary to carry out repair and maintenance work on hydrants and old hydrants may need to be replaced. When this work is carried out, it is often necessary to turn off the water supply to that hydrant.

The present invention provides a method of isolating a hydrant so that cutting off supply to that whole area is unnecessary.

The present invention provides a method of isolating a hydrant, the hydrant comprising a riser pipe connected to a hydrant head, an outlet pipe extending from said hydrant head, and a jumper which seals said outlet pipe from said riser pipe, the method comprising: (a) attaching to the outlet pipe a closure device comprising a cap and sealing means, such that the cap securely closes the exit of the outlet pipe; (b) opening the jumper so that water may flow from the mains water supply via the riser pipe into the hydrant head; (c) positioning the sealing means within the riser pipe; and (d) activating the sealing means such that it extends across the riser pipe to close the supply to the hydrant head.

Once the hydrant has been isolated in this way, it is possible to carry out repair and maintenance work. For example, a new jumper could be fitted.

The method may further include a method of accessing the mains water supply and may comprise the additional steps of: (e) removing the jumper from said hydrant head; (f) attaching a deployment head to said hydrant head; (g) deactivating the sealing means; and (h) moving a deployment device from the deployment head through the riser pipe and into the mains supply.

Optionally after step (g), the sealing means may be withdrawn from the riser pipe into the outlet pipe or into the cap.

The method may involve using a deployment device in the form of a sensor which may for example be used to detect a leak, measure dimensions of a pipe, measure water pressure or temperature or search for potential flaws.

Alternatively and/or additionally the method may involve using a deployment device in the form of a tool to carry out repair or maintenance work.

The present invention also provides apparatus for use, in isolating a hydrant, the hydrant comprising a riser pipe connected to a hydrant head, an outlet pipe extending from said hydrant head, and a jumper which seals said outlet pipe from said riser pipe, the apparatus comprising: (a) a closure device comprising a cap and sealing means, the closure device being attachable to the outiet pipe such that the cap securely closes the exit of the outlet pipe; (b) means for positioning the sealing means within the riser pipe after the jumper has been opened; and (c) means for activating the sealing means such that it extends across the riser pipe to close the supply to the hydrant head.

The cap may be threaded and may screw onto the exit of the outlet pipe. Alternatively, the cap may be adapted to be clamped over the exit of the outlet pipe.

The sealing means is suitably such that it is able to fit through an aperture in a valve seat of the hydrant.

Preferably the sealing means is expandable. The sealing means may, for example, comprise folded or layered parts which can extend across the diameter of the rise pipe and seal it.

Preferably the sealing means is inflatable. For example it may comprise an inflatable bag which can be pumped full of water or other fluid. Thus, in the method of the present invention, a deflated bag may be released from the S closure device once the cap has been fitted over the exit of the outlet pipe. The bag is positioned within the riser pipe and then inflated to fill all of the space across a diameter of the riser pipe thus sealing the hydrant head from the mains supply.

The closure device of the apparatus may further comprise connecting means which connect the cap and the sealing means. The connecting means may comprise any suitable form. Preferably the connecting means are extendable and may be used to direct the sealing means within the riser pipe and may be withdrawn fully into the cap of the closure device at the end of the operation. When the sealing means comprises an inflatable bag, the connecting means preferably comprises a passageway through which a fluid, for example water, may be pumped.

The apparatus may further comprise control means to direct the positioning and operation of the sealing means.

In some embodiments the apparatus may further comprise a deployment head. The deployment head is suitably adapted to enable it to fit securely onto the hydrant head in place of the bonnet and jumper. It may be adapted to be screwed or clamped into position.

Associated with the deployment head is a deployment device. The deployment device may comprise a sensor, for example a camera or a hydrophone; or it may comprise a tool suitable for carrying out repair and maintenance Any suitable deployment device may be used and tools and sensors currently used in the field are within the scope of the invention.

The deployment device may be remote controlled, or it may be connected to the deployment device, for example by a positioning lead. Suitably the positioning lead, when present, extends from a deployment head and may be retracted within it at the end of an operation.

One embodiment of the method and apparatus of the present invention will now be further described by way of example, with reference to the accompanying drawings in which: Figure 1 shows a hydrant in a closed position; Figure 2 shows the hydrant in which a closure device is fitted over the exit of the outlet pipe of the hydrant and the jumper is in an opened position; Figure 3 shows the hydrant after sealing means of the apparatus has been positioned in the riser pipe; Figure 4 shows the hydrant after the sealing means has been activated to close the supply to the riser pipe; Figure 5 shows how the bonnet and jumper of the hydrant have been replaced by a deployment head of the apparatus; Figure 6 shows the hydrant in which the deployment head is fitted and the sealing means has been deactivated; Figure 7 shows the hydrant in which the deployment head is fitted and the sealing means has been withdrawn to within a cap of the closure device; Figure 8 shows the hydrant when a device of the apparatus has been pushed down from the deployment head into the mains water supply pipe.

According to the present invention, a closure device is fitted to the exit of outlet pipe 11. In Figure 2, the closure device fitted is a "bagging off" device and comprises a cap 12, extension lead 13 and inflatable bag 14. Cap 12 is threaded and screws tightly onto the outlet pipe 11 (also threaded) to provide a secure fit. Cap 12 comprises a housing in which is located control means which direct the operation of extension lead 13.

Alternatively, extension lead 13 may be directed by external control means. Suitably the control means comprises a computing device which may be programmed to manipulate the extension lead as required.

Following attachment of the bagging off device, handle 10 is rotated to move plug 7 of jumper 8 upwards to expose the aperture in valve seat 6. Water flows from the mains into the hydrant head.

Extension lead 13 is initially retained within the housing of cap 12. The lead typically comprises an outer plastic coating and supporting metal core and has a -9 -passageway running therethrough. The extension lead is extended in order to position the inflatable bag 14 within the riser pipe as shown in Figure 3.

Once the bag 14 is in position within the riser pipe water is pumped into it via the passageway in the extension lead. The bag expands to fit across the whole of the riser pipe and seal the mains supply from the hydrant head as shown in figure 4. Thus the hydrant is isolated. The bag is made from a strong elastic material for example a synthetic polymeric material Once the hydrant is isolated, it can be maintained or repaired, for example by fitting a new bonnet and/or jumper.

Alternatively further steps may be taken to provide access to the mains supply, for example to detect a leak.

When the inflated bag is in position, bonnet 5 and jumper 8 can be removed, without water leaking from the mains.

In figure 5, a deployment head 15 has been fitted in place of bonnet 5. The deployment head fits securely across the top of the hydrant. It may for example be screwed or clamped in place. Fitted to or within or extending from the deployment head is a deployment device in the form of a sensor 16 via attachment to positioning lead 17.

After the deployment head has been fitted in place of the bonnet, water is released from the inflatable bag.

Once the bag is fully deflated (see figure 6), it is retracted by manipulation of the extension lead to within the housing of cap 12, as shown in figure 7. It is now possible to directly access the mains pipe through the aperture in valve seat 6. In figure 8 positioning lead 17 has been pushed down through the hydrant to position the sensor within the mains pipe. From this position it maybe manoeuvred in either direction along the mains. The sensor may comprise a camera or other device able to detect a leak or monitor the condition of the pipe. The device may be a listening device such as a hydrophone.

Alternatively or additionally, the positioning lead may carry a deployment device in the form of a tool, for example to carry out repairs by remote control. The apparatus may for example be used to fill a hole or crack in the mains pipe.

Once the purpose for accessing the mains has been achieved, the deployment device is once again withdrawn into or through the deployment head.

To return the hydrant to its normal operating moie, the reverse process is followed. After withdrawal of the sensor, the inflatable bag is repositioned within the riser pipe and inflated to seal the pipe. The deployment head is removed and the bonnet and jumper replaced. The bag is then deflated and withdrawn into the cap. The jumper is repositioned such that the plug closes the cavity in the valve seat and seals the hydrant from the mains. The bagging off' device is then removed from the outlet pipe.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such featu:es and/or steps are mutually exclusive.

Each feature disclosed in this specification

(including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s) . The invention extends to any novel one, or any novel combination, of the features

disclosed in this specification (including any

accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

Claims 1. A method of isolating a hydrant, the hydrant comprising a

riser pipe connected to a hydrant head, an outlet pipe extending from said hydrant head, and a jumper which seals said outlet pipe from said riser pipe, the method comprising: (a) attaching to the outlet pipe a closure device comprising a cap and sealing means, such that the cap securely closes the exit of the outlet pipe; (b) opening the jumper so that water may flow from the mains water supply via the riser pipe into the hydrant head; (C) positioning the sealing means within the riser pipe; and (d) activating the sealing means such that it extends across the riser pipe to close the supply to the hydrant head. * * * **S.
2. A method of accessing the mains water supply which method comprises the method of isolating a hydrant of claim 1 and the additional steps of: *..

(e) removing the jumper from said hydrant head; * * (f) attaching a deployment head to said hydrant head; (g) deactivating the sealing means; and (h) moving a deployment device from the deployment head through the riser pipe and into the mains supply.
3. A method according to claim 2 wherein the sealing means are withdrawn from the riser pipe into the outlet pipe or into the cap after step (g)
4. A method according to claim 2 or claim 3 wherein the deployment device comprises a sensor.
5. A method according to any of claims 2 to 4 wherein the deployment device comprises a tool.
6. Apparatus for use in isolating a hydrant, the hydrant comprising a riser pipe connected to a hydrant head, an outlet pipe extending from said hydrant head, and a jumper which seals said outlet pipe from said riser pipe, the apparatus comprising: (a) a closure device comprising a cap and sealing means, the closure device being attachable to the outlet pipe such that the cap securely closes the exit of the : outlet pipe; ***.

(b) means for positioning the sealing means within the * riser pipe after the jumper has been opened; and *. ** : * *. (c) means for activating the sealing means such that it extends across the riser pipe to close the supply to the hydrant head.
7. Apparatus according to claim 6 wherein the sealing means is expandable.
8. Apparatus according to claim 7 wherein the sealing

means is inflatable.
9. Apparatus according to any of claims 6 to 8 wherein the closure device further comprises connecting means which connects the cap and the sealing means.
10. Apparatus according to claim 9 wherein the connecting means is extendable and may be used to direct the sealing means within the riser pipe and may be withdrawn fully into the cap of the closure device.
11. Apparatus according to any of claims 6 to 10 which further comprises a deployment head having a deployment device associated therewith.
12. A method or apparatus substantially as herein before described with reference to figures 1 to 8. * * * *Se. *a,. ** * S * 55, *

S *S ** * S

S *

*SSS*a * *