Identification of hidden pipes etc.

This invention relates to a system of identifying and providing information concerning hidden pipelines, cables, ducts, passages etc. hereinafter referred to directly as "pipelines and the like".

One of the problems in dealing with hidden (e.g. underground) pipelines or the like is to identify the location of the pipe, cable etc., the position at which bends occur, the position at which branches occur, and features such as the nature of the material from which the pipeline, or the like, is made, the contents of the pipe, the size of the pipe, the pressure of the fluid in the pipe and the nature of the fluid in the pipe.

An object of the present invention is to provide a system for identifying a pipeline or the like and for providing information dealing with the factors mentioned, by way of example, and other matters.

In accordance with the present invention a pipeline or the like is provided with a series of interrogatable information containing elements located at intervals along the pipeline and adapted to indicate the position of the pipeline, and other information relating to the pipeline.

Preferably the interrogatable elements are either self-­powered, or they have no power source within themselves but will respond to interrogation by an electromagnetic signal, such as an RF signal, and will produce an answering signal to convey the desired information.

The interrogatable elements may for instance be snap fitted into recesses in the surfaces of the pipe or they may be buried in the material of the pipe or they may be attached for example by use of clips or straps.

Preferably the information containing elements are located at specific points on the pipeline for example at a junction, at a bend, at a point where the service is taken off the pipeline, at a blind end of the pipe and so on.

The information containing elements when interrogated may also provide information concerning the nature of the material of the pipe, the nature of the fluid conveyed by the pipe e.g. gas, water, chemicals etc. Other information may include the date of installation of the pipe and its depth below ground for example.

The device for interrogating the pipe preferably comprises a transmitter/receiver which feeds a signal, such as an RF signal, to an antenna which may be at the end of a flexible cable or rod so that it may be located close to the ground. The transmitter receiver may have attached to it a power supply and also a decoder and recorder so that information received from the information containing elements on the pipeline may be decoded and recorded for future use. There may also be a display on the transmitter receiver which will display information received from the pipeline.

One embodiment of the invention is illustrated in the accompanying drawing in which:- <ul id="ul0001" list-style="none"><li>Figure 1 shows, diagrammatically, a section of a pipeline and the apparatus used to interrogate the information containing element on the pipeline; and</li><li>Figure 2 shows diagrammatically in plan a complicated pipeline with information containing elements capable of being interrogated located at intervals along the pipeline.</li></ul>

In Figure 1 a pipeline 10 is located below ground level 11 and has on it an information containing element which is interrogatable. The information containing element is shown as clipped into a recess 13 in the pipe although it may be, as mentioned above, attached by any other means.

One alternative is to have the element in the form of an inertly packaged coded tag 12A attached to the pipe by straps as seen in Figure 1.

The apparatus for interrogating the pipeline comprises a transmitter/receiver 14 connected by a flexible cable 15 to an antenna 16. The transmitter receiver has a power supply 17 and display 18 on which information received from the pipeline may be displayed. Connected to the transmitter receiver 14 is a decoder 19 and a recorder 20 which may for instance be a simple tape recorder. On interrogation of the pipeline by the transmitter receiver the transmitted RF signal causes the interrogatable element 12 to respond and return a signal which is picked up by the antenna 16 and supplied to the transmitter receiver 14 where it is decoded and recorded and also displayed on the display 18. Information displayed may for instance provide details as to depth and direction of alignment of the pipe 10, the material of which it is made, the fluid which is flowing through it etc.

The usefulness of this invention can be particularly seen in relation to Figure 2 which shows a complicated pipe run in plan. The pipe run is assumed to be buried underground at varying depths and at each point where information is relevant one of the information containing elements 12 is buried in the pipe 10 or is attached to the pipe 10. For example element 12A is adjacent to the joint in the pipeline. 12B is adjacent the point where a branch pipe 21 is taken off. 12C is at a point where the pipe 10 forms two branches 22 and 23. 12D is at a point where the pipe 22 bends. 12E is at a point where a branch pipe 24 goes off. 12F is at a bend and 12G is at a blanked off end of a branch of the pipe.

There will be on long straight lengths of the pipe information containing elements at intervals of say 5 metres which will enable the position of the long straight pipe to be located and information to be obtained from it. The invention may be applied to all kinds of pipes whether they are carrying gas, water, chemicals, telephone or electric cables etc.

The invention could also be applied to tunnels and underground passages for example to the channel tunnel so that in the event of external repairs to the tunnel being required it could easily be located on or below the sea bed.