WO1993022595A1

WO1993022595A1 - Means and procedure for pipeline tapping

Info

Publication number: WO1993022595A1
Application number: PCT/FI1992/000124
Authority: WO
Inventors: Rauno Kankaanranta
Original assignee: Oy Kwh Tech Ab
Priority date: 1990-12-10
Filing date: 1992-04-28
Publication date: 1993-11-11
Also published as: FI906063A; FI906063A0; FI90127B; FI90127C

Abstract

The invention concerns a procedure for tapping a pipeline, a globe valve (1) being welded to the pipeline (2) which is to be tapped and a hole being bored in the pipeline through said globe valve. As taught be the invention, on the open end (3) of the glove valve is affixed a boring device (4) by means of a sealing member (5) which is pressed in place in pressure-tight fashion by means of a tightening member (6) getting purchase on the other side of the glove valve. The invention also relates to a means for tapping a pipeline.

Description

MEANS AND PROCEDURE FOR PIPELINE TAPPING

The present invention concerns a procedure as defined in the preamble to Claim 1, and a means as de- fined in the preamble to Claim 2, for tapping a pipe¬ line.

Problems are at present encountered in tapping pipelines which carry pressure in such a way as to avoid interference with the process associated with the pipeline. In area heating lines, for instance, the pressure is within 10 to 20 bar and the temperature is 120 to 140°C. In such instances, when a tap is made on the line, the practice is to weld a boring shut-off piece to the side of the pipe, and it is generally necessary, in view of safety alone, to shut off and release the pressure in connection with the boring of said piece, whereafter a hole can be made in the pipe, through said boring shut-off piece, and whereupon, fur¬ thermore, a globe_shut-off valve is welded on, in ex- tension of the shut-off piece that was added.

The greatest problem in tapping area heating pipelines is posed by the interruptions thereby caused in the supply of heat to consumers, as well as the extra expense which the heating plant incurs because the hot water is let out of the pipelines.

Similar problems also occur in various pipe systems in the process industry in which high pressures and temperatures are used, because the operations of closing down and restarting the process usually take several hours or even days.

The object of the invention is to eliminate the drawbacks mentioned. It is particularly an object of the invention, to disclose a procedure, and a cor¬ responding means, enabling a tap to be made on a pipe- line, regardless of pressure and temperature, in a safe and swift manner and without disturbing the process associated with the pipeline, in any way whatsoever. Regarding the features which characterize the invention, reference is made to the claims section.

In the pipeline tapping procedure of the in- vention, a globe valve, that is one juncture tube thereof, is welded onto the pipeline that shall be tapped, whereafter a hole is bored in the pipeline, operating through the globe valve. As taught by the in¬ vention, a boring device is mounted on the free end of the globe valve, that is on its second juncture tube, together with a sealing member, which is pressed in pressure-tight fashion on the end of the juncture tube with the aid of a tightening member getting purchase on the other side of the globe valve.

Advantageously, said purchase of the tighten- ing member is gained immediately behind the round- shaped housing of the globe valve, around the juncture tube adjacent to the pipeline which is to be tapped. It is equally possible, within the scope of the present inventive idea, to provide purchase on the pipeline for the tightening member.

The means of the invention for tapping a pipe¬ line comprises a boring device which bores a hole in the pipeline, operating through the globe valve welded to the pipeline that is to be tapped. As taught by the invention, this device comprises a sealing member abut¬ ting on the open end of the globe valve, and a tighten¬ ing member extending across the globe valve to its side adjacent to the pipeline to be tapped and by the aid of which the tightening member and the boring device are held in pressure-tight contact against the open end of the globe valve. Hereby, the making of a hole in the pipeline to be tapped can be carried out through the globe valve, in a pressure-sealed space.

It is obvious to a person skilled in the art, of course, that although in this context we speak of welding a globe valve to the pipeline, the globe valve itself, which usually has a cast-iron housing, is not welded: it rather comprises, as essential components, steel tubes attached to its housing, and these tubes are weldable in standard manner.

The means of the invention advantageously com- prises a purchase member disposed to get purchase on the side of the globe valve adjacent to the pipeline to be tapped, against the valve's expanding outer housing, and the tightening members getting purchase thereon. It is equally conceivable that the purchase members get purchase on the pipeline to be tapped.

The sealing member to be used consists advan¬ tageously of a plate-like flange with packing, abutting against the end of the juncture tube on the open end of the globe valve. It is conceivable that the boring de- vice, i.e., its boring chamber, and the sealing member constitute an integral entity. It is also conceivable that the sealing member and the boring chamber are joined with pressure-resistant junctures provided with packings. The purchase member to be used, getting pur¬ chase around the juncture tube of the globe valve, against the expanding housing of the globe valve, con¬ sists advantageously of a plate-like flange of which the inner diameter is substantially consistent with the outer diameter of the juncture tube.

Although in view of simplicity of manufactur¬ ing mainly plate-like flanges, e.g. round disks, are used for sealing members and purchase members, the de¬ sign of these members is not confined to such embodi- ments: within the scope of the design of the invention it is equally possible to use various rods, pins, cir¬ cles, and other purchase structures which are self-evi¬ dent to a person skilled in the art.

For tightening member connecting the sealing member and the purchase member, various threaded rods and bolts can be used, carrying on one or both ends nuts by which the tightening is accomplished. It is equally possible to use any other kind of tightening members by which adequate compression is achievable between the tightening member and the purchase member. Advantageously, adapter rings are provided on the purchase member and/or the tightening member, which enable one device to be used in installing globe valves with different diameters.

The boring device used in the invention con¬ sists of a boring chamber into which a shaft is carried through a stuffing box known in itself in the art, said shaft carrying on its end a bit for boring a hole in the pipeline to be tapped. Furthermore, an exhaust valve is provided on the boring chamber, this valve being opened after the hole has been bored and the globe valve closed, so that the pressure in the boring chamber can be released, whereafter the means of the invention can be dismounted from the globe valve.

The advantage over the state of art afforded by the procedure and means of the invention is that the pipeline tap made with its aid in no way interferes with the flow in the pipeline nor with the process therewith associated, and the juncture can be made safely with full assurance that no pressures or temper¬ atures, even if they are high, can gain access to the ambience when such a juncture is made.

In the following the invention is described in detail, referring to the attached drawing, wherein : - Fig. 1 presents, in perspective, a tapping device according to the invention, and Fig. 2 shows a sectional drawing of a means substan¬ tially consistent with that of Fig. 1.

A pipeline tapping device according to the invention, depicted in the drawing, comprises a circu¬ lar, plate-like bracing member 8 consisting of two halves 12 and 13 with semicircular shape which can be locked together with locking means 14, to become an annular entity. In the centre of said bracing means are provided four adapter rings 16, one within the other, which are arranged to rest on each other so that they constitute a rigid entity in one direction while in the other direction they can be disassembled and detached to be separate from each other. The design may for in¬ stance be implemented with the aid of conical surfaces, or with suitable flanges. The inner diameter of the smallest, or innermost, ring corresponds substantially to the outer diameter of the juncture tube 10 of the globe valve 1. The means likewise comprises a round, plate-like sealing member 6 resting against the open end 3 of the second juncture tube 9 of the globe valve, this sealing member comprising adapter rings corres¬ ponding to the adapter rings 16, though only on the side of the plate-like sealing member which is adjacent to the globe valve. Hereby the sealing member 5 and the adapter rings 15 with which it is provided constitute a well-fitting round-shaped aperture for the open end 3, this aperture moreover presenting packings for sealing the open end in pressure-tight fashion against the juncture tube 9 of the globe valve. The sealing member 5 and the bracing member 8 are connected with each other by a tightening member 6 consisting of two straight rods 11 running in parallel, on opposite sides of the globe valve, through the bracing member and the sealing member. The rods carry threads and nuts cooper¬ ating with these threads on their ends, tightening of these nuts enabling the sealing member and the bracing member to be urged towards each other. In the embodi- ment of Fig. 1 such threads have been provided on one end of the rods only, while an integral head has been provided on the other end.

Fixedly attached to the sealing member 5 is a boring device 4, consisting of a cylindrical boring chamber 17, at its extreme end a shaft 19 going through a bushing 20 into the boring chamber. On the end of this shaft, inside the boring chamber, a bit 18 is pro- vided for boring a hole in the pipeline 2 to be tapped. Furthermore, an exhaust valve 21 is attached to the envelope of the boring chamber 17.

The globe valve 1 proper consists of a spheri- cal envelope 7, a circular shut-off member 22 within this envelope, with a hole 23 passing therethrough, an operating handle 24 external to the envelope and af¬ fixed to the shut-off member, and juncture tubes 9 and 10 extending from the envelope 7 in opposite direc- tions.

The means of the invention is used as follows. The globe valve 1 is welded, 25, onto the pipeline 2 to be tapped. The sealing member 5 and bracing member 8 are adjusted, with the adapter rings 15 and 16, to con- form with their inner diameters to the outer diameters of the juncture tubes 9 and 10. The sealing member 5 is then braced against the open end of the juncture tube 9, and the bracing member 8 is affixed immediately behind the envelope 7 of the globe valve, in the direc- tion from the globe valve towards the pipeline 2. The nuts of the tightening members 6 are then tightened to press the sealing member 5 tight against the open end 3 of the juncture tube 9, the anchoring point for this pressure being located beyond the envelope 7 of the globe valve. Since the boring device 4 is affixed to the sealing member 5, the boring device will also be sealed in pressure-tight fashion to constitute an en¬ tity with the globe valve.

The next step is opening of the globe valve and pushing the shaft 19 with its bit 18 through the hole 23 in the shut-off member 22 of the globe valve, and boring a hole in the pipeline 2.

The pressure present in the pipeline can dis¬ charge into the globe valve and the boring chamber 17, whereby the boring residue will also be driven into the boring chamber 17. When the shaft 19 and bit 18 are retracted back into the boring chamber 17, the globe valve is subsequently closed, whereafter the exhaust valve 21 is opened, letting the pressure accrued in the boring chamber 17 discharge into ambience. The means may thereafter be dismounted from the globe valve, and such pipes as may be desired can be connected to its juncture tube 9.

In the foregoing the invention has been de¬ scribed by way of example with the aid of the attached drawing, while different embodiments of the invention are feasible within the scope of the inventive idea delimited by the claims.

Claims

1. A procedure for tapping a pipeline, in said procedure a globe valve (1) being welded to the pipeline (2) which is to be tapped and a hole being bored in the pipeline through said globe valve, charac¬ terized in that on the open end (3) of the globe valve (1) is affixed a boring device (4) by means of a seal¬ ing member (5) which is pressed in place in pressure- tight fashion by means of a tightening member (6) get¬ ting purchase on the other side of the globe valve.

2. Procedure according to claim 1, charac¬ terized in that the tightening member (6) is braced immediately behind the globe valve (1) , against the expanding envelope (7) thereof, by means of a bracing member (8) getting purchase on said envelope.

3. A means for tapping a pipeline, comprising a boring device (4) boring a hole in the pipeline, operating through a globe valve (1) welded to the pipe- line (2) to be tapped, characterized in that the means comprises a sealing member (5) braced against the open end of the globe valve (1) and a tightening member (6) getting purchase across the globe valve on the other side thereof, for bracing the boring device (4) in pressure-tight fashion against the open end (3) of the globe valve.

4. Means according to claim 3, characterized in that the means comprises a bracing member (8) which gets purchase on the side of the globe valve (1) adja- cent to the pipeline (2) to be tapped, on the expanding outer envelope (7) of the globe valve.

5. Means according to claim 3, characterized in that the sealing member (5) consists of a flange, with packing, braced against the end of the juncture tube (9) on the open end (3) of the globe valve (1).

6. Means according to claim 3, characterized in that the bracing member (8) consists of a bracing flange disposed around the juncture tube (10) of the globe valve (1) adjacent to the pipeline (2) and of which the inner diameter is substantially consistent with the outer diameter of said juncture tube (10).

7. Means according to claim 6, characterized in that the bracing flange (8) consists of two parts (12,13) which are lockable onto each other by the aid of locking means, to encircle the juncture tube (10).

8. Means according to any one of claims 3-7, characterized in that the tightening member (6) con¬ sists of at least two rods (11) joining together the sealing member (5) and the bracing member (8).

9. Means according to any one of claims 3-8, characterized in that the sealing member (5) and/or the bracing member (8) comprises adapter rings (15,16) for adapting the means to fit around juncture tubes (9,10) with various diameters.

10. Means according to any one of claims 3-9, in which the boring device (4) comprises a boring cham- ber (17) with bit (18) and with a shaft (19) entering through a bushing (20), characterized in that the boring chamber (17) includes an exhaust valve (21) for letting escape the pressures produced in the boring operation.