GB2356598A - Preparation tool for joining together pipes - Google Patents

Description

2356598 Page I Preparation Tool For Joining Together Pipes.

The invention relates particularly but not exclusively to a device for preparing the ends of certain types of pipes and/or fittings prior to them being joined together in a permanent or semi permanent manner by a jointing method which may be by thermal heating, chemical solvent welding or mechanical jointing.

In the distribution of certain volatile materials particularly but not exclusively liquid petroleum products, liquified petroleum gases and other flammable and or dangerous materials it is common to use ferrous pipes as the transportation medium. It is known that ferrous materials are subject to rusting and corrosion over a period of time and that they require regular painting or coating for protection. Where pipes require to be joined together or where it is necessary to make other types of connection for instance a branch or off-take then the joint must be welded together or a mechanical (screwed or flanged) connection used. Mechanical methods may leak if not made correctly and regularly inspected, welded joints require both special expertise and welding is not easily carried out in areas where flammable material is present. An alternative material for the production of pipes is the use of plastics, the advantages of use being well documented, however in the transportation of such materials as above or where pipelines carrying for instance non hazardous materials for instance potable water are to be routed underground through a hazardous or polluted area then it is known that certain volatile materials may in small quantities pass out through the plastic into the surrounding area as in the case of transported material or infact pass into the transported material from the Page 2 outside thereby causing non polluted material to become polluted. A method of preventing the above is to use a plastic pipe to utilise the advantages of plastic for instance corrosion resistance, lightness, ease ofjointing and to build into it a barrier to prevent the passing of material into and out of the pipe, the barrier being for instance an inner tube of thin wall or some other similar means. The production or use of this barrier not being within the scope of this document. As already stated plastic pipelines may be joined together by the known method of electroftision whereby the pipe ends are introduced into a coupler or sleeve containing internally wound heating wires and on application of electrical power the heating effect joins together the pipes and the sleeve to produce a joint. Where a barrier in the form of a thin walled tube forms part of the pipeline for the transportation of volatile materials, the joining together of the barrier to prevent leakage would be separate to the joining together of the plastic pipe. A method ofjoining together the barrier tube to maintain the integrity of the pipeline would be by as a for instance inserting into each end of the tube a ferrule or spool containing a sealing means for instance a series of rings which closely fit into the inner bore of the tube and the overall joint being completed by the outer plastic pipe being electrofused figure I being an embodiment of this process. This invention relates to a tool or series of tools to allow the ends of the inner tube to be initially flared or trumpeted out in a controlled manner to allow the spool connector to be inserted into the tube without damaging the sealing Page 3 means and that the circumference of the finished trumpeted end is perfectly round when viewed from the end and conical in section with all opposing points being of equal radius from a line drawn longitudinally down the centre of the tube. The tool or tools will then calibrate the section of tube into which the spool is to be insefted so that the internal dimensions are consistent with the limitations of the fit of the spool connector and parallel with the longitudinal centre line of the tube irrespective of any minor irregularity or variation in the thickness of the tube wall or ovality in cross section.

An embodiment of the invention will now be described by way of example and by reference to the accompanying drawings.

Figure I A view of the assembled joint with spool.

Figure 2 A view of the preparation tool.

Figure 3 A view of the dual cone pipe centring & clamping means.

Figure 4 & 4A A view of the tool trumpeting means.

Figure 5 & 5A A view of the tool calibrating means.

According to the following text and with reference to fig.2 there is a preparation tool consisting of a pipe clamping and centring means to correctly position the whole of the tool within the internal bore of the tube consisting of an expanding gripper (part 1) consisting of a series of tubular collet sections retained in position by flexible rings with outside dimensions slightly less that the bore of the tube and fixed between travesable cones, as the cones are drawn together by Page 4 a screw means (part 2 & 3) compressing the collets they are displaced outwards in a uniform manner. When the compression takes place in the bore of the tube the collets will grip the inner tube wall thereby fixing centrally the too] inside the tube. The handle (part 4) being an extension of the threaded tube (part 5) supporting the collets and retaining rings control the compression of the collets when the cones are drawn together. After the tool is fixed in position rotation of the feed handle (part 6),will traverse by means of an internal feed-nut situated inside the tool-holder (part 7) along the threaded tube (part 5)and thereby push the trumpeting or calibration tool (part 9) into the pipe bore. Figure 3 shows the expanding gripper means in close up detail. Part 10 being the expanding collets, Part I I being the retaining rings. Figure 4 shows the operation of forming the trumpet section with the forming Cone being pushed into the pipe end by rotation of the handle. Figure 4A shows the forming cone trumpeting the pipe end. Figure 5 shows the calibrating spherical ball being pushed into the pipe end. Figure 5A shows the calibrating spherical ball expanding the tube to the correct inside diameter.

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Claims (6)

1. I. A tool for the preparation of pipe ends prior to jointing together comprising of a means for firmly fixing the tool centrally in the bore of the pipe and then mechanically force feed into the bore by rotation of a feed-nut along a feedscrew a multiplicity of non rotating forming tools to form and calibrate the pipe bore.
2. 2. A tool as claimed in claim 1 wherein the method of fixing and locating the tool within the bore of the pipe is by moving away from each other or moving towards each other opposing cones between which are mounted collets and retaining rings that displace outwardly when the cones are moved towards each other thereby increasing their circumference and gripping onto the bore of the pipe.
3. 3. A tool as claimed in claim 1,2 wherein the forming tool when carried by the tool may be of conical or other shape requiring rotational movement to perform its design task.
4. 4. A tool as claimed in claimsl,2,3 wherein the calibration tool when carried by the tool may be a spherical ball or other shape.
5. 5. A tool asclaimed in claims l,2,3,4 wherein a single tool may be used on a number of pipe sizes.
6. 6. A tool as claimed in claims 1,2,3,4,5 wherein a single tool may not necessarily perform all the required operations and more than one tool may be required.