DE8804285U1 - Tapping fitting - Google Patents

Description

The invention relates to a tapping fitting with a tapping bridge that can be closed around a pipeline and a metal body that is inserted in a sealing manner with a connection piece into a connection socket made of plastic of the tapping bridge and is held in place by a screw connection.

Such drilling fittings have been known for a long time. They are used to drill into closed pipelines and to attach a valve, generally an angle valve, to the hole, for example to create a house connection.

For cost reasons, it is known to manufacture the tapping bridges, which have an inner radius adapted to the pipeline and are generally made in two parts so that they can be placed around the pipeline and closed there, from plastic. The connection socket is therefore also made from plastic. For reasons of stability and safety, the valve bodies are made from metal.

Theodor-Heuss-Siraße 2

' Telephone 0531-80079

Telex 0-952620 grams d

D-3300 Braunschweig Federal Republic of Germany j tetes» 0531-81297 (uui &igr; 24-üj

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In the cone, the connection of the metal valve body with the connecting pieces of the connection nozzle of the tapping bridge is achieved by a nozzle of the valve body provided with an external pipe thread being screwed sealingly into an internal thread of the connection nozzle of the tapping bridge.

A connection of both parts is also known in which the connection piece of the fitting body has a smooth outer wall with one or more grooves in which O-rings are inserted and is inserted into the connection socket of the tapping bridge. The connection is therefore also equipped with a union nut on the metal fitting body, which is screwed with its internal thread over an external thread of the connection piece of the tapping bridge in order to hold the fitting body and the tapping bridge together.

This screw connection is problematic, especially in the case of plastic screw connections, in the opinion of some experts, since a screw connection in plastic does not guarantee the desired safety of the connection between the tapping bridge, which is mounted on the pipeline, and the tapping fitting.

The use of plastic tapping bridges has therefore largely been avoided. With metal tapping bridges, the connection using the metal union nut is unproblematic. However, with gas lines there is sometimes a desire to create electrical insulation between the tapping bridge (i.e. the pipe) and the connection valve. The connection of a plastic tapping bridge that creates this insulation is not possible for the reasons mentioned above.

The invention is therefore based on the object of designing a tapping valve of the type mentioned at the beginning in such a way that a secure connection of the metal body with the tapping bridge is established, which enables both the use of plastic tapping bridges and insulation between a metal tapping bridge and the metal valve body.

This task is solved with a tapping fitting of the type mentioned at the beginning in that the connection piece of the metal body is provided with an internal thread into which a hollow metal bushing provided with a flange is screwed from the pipe side of the connection bushing, whereby the flange is supported on an edge of the connection bushing formed by a step-shaped extension.

According to the invention, the screw connection between the metal body and the drilling bridge is not made - as previously - or from the side of the metal body and on the outer circumference of the connection socket, but inside the connection piece from the pipe side of the connection socket. The screw connection is made using a hollow metal bushing with an external thread screwed into an internal thread of the connection piece from the pipe side, which is supported by a flange attached to the pipe-side end on an edge of the connection socket formed by a stepped extension. In this way, a plastic-compatible connection between the metal body and the drilling bridge, which may be made of plastic, is possible, since the flange is supported with a relatively large annular surface on the corresponding edge of the plastic drilling bridge, so that a thread formation in the plastic body is not required.

If the tapping bridge is made of metal, the connection between the tapping bridge and the metal body according to the invention can also be used to create complete insulation between the tapping bridge and the metal body. To do this, the metal connection socket is provided with an inserted plastic hollow cylinder into which the connection piece protrudes. The plastic hollow cylinder can, if necessary, be screwed into the metal connection socket, since this screw connection only serves to spatially fix the plastic hollow cylinder, but not to connect the metal body and the tapping bridge. To complete the insulation, there is a

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Insulating ring disk, which preferably rests on a shaped metal edge of the tapping bridge. The insulating ring disk can be inserted as a separate part. In a similar way, an insulating ring disk can be clamped between the free end of the connection socket and the metal body, through which the connection piece protrudes. This insulating ring disk can also be a separate part and thus easy to manufacture.

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The invention will be explained in more detail below using embodiments shown in the drawing. They show:

Figure 1 - a vertical section through a plastic tapping bridge with an inserted metal body

Figure 2 - a corresponding vertical section through a metallic tapping bridge and an inserted metal body, whereby the connection is designed to be insulating.

Figure 1 shows a drilling bridge 1, which is made of plastic and has an inner radius 2 adapted to the outer radius of a pipe. The drilling bridge 1 consists of two parts, of which only the upper part is shown. The two parts are held together by screws protruding through lugs 3 after assembly around a pipeline.

The tapping bridge has a connection socket 4 that is open at the top and has a smooth inner wall 5. The smooth inner wall 5 is limited on the pipe side by an annular web 6 that causes a narrowing and that forms an annular edge 7 on the pipe side by means of a step-like widening. A smooth outer wall of a connection socket 8 is inserted in pairs into the smooth wall 5 of the connection socket 4 and sealed by O-rings 9 inserted into the outer wall. The connection socket 8 is part of a metal body 10 of a shut-off valve, which has a connection 11 for a house connection line and a connection 12 for a tapping tool and, if necessary, later a shut-off valve upper part.

A firm connection between the metal body 10 and the drilling bridge 1 is made by a metal hollow sleeve 13, which has an external thread in an internal thread of the metal

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The hollow metal bushing 13 is screwed on from the pipe-side end of the connection bushing 4. At the pipe-side end of the connection bushing 4, the hollow metal bushing 13 is closed off with an outwardly projecting flange 14, which rests on the edge 7 of the connection bushing 4 and thus pulls an annular shoulder 15 of the connection block 8 against the free front side 16 of the connection bushing 4. The force that creates the connection is applied with a high degree of safety by the relatively large-area annular contact of the flange 14 with the plastic edge 7, in a plastic-friendly manner, and not by a less durable and therefore unsafe plastic thread.

Figure 2 shows an embodiment in which the connecting piece 8 extends into a metal connecting bushing 4' of a metal tapping bridge 1*, which is lined with a plastic hollow cylinder 17 or with another insulating material. The hollow cylinder 17 can be pressed into the metal connecting bushing 4', screwed with a thread 17' or inserted in some other way. The metal connecting bushing 4' has a shoulder 7' approximately at the level of the pipe-side end of the plastic hollow cylinder 17. The connecting piece 8 is inserted with its O-rings 9 into the plastic hollow cylinder 17 and has - as in Figure 1 - an internal thread 8'. The external thread of the metal hollow bushing 13, which is also used here for fastening, is screwed into the internal thread 8'. The flange 14 of the hollow metal socket does not lie directly on the shoulder 7', but rather via an intermediate insulating ring disk 18. The flange 14 can have a smaller diameter than the insulating ring disk 16 and can be inserted into a corresponding ring-shaped recess 19 of the hollow metal ring disk 18, so that the insulation between the flange 14 and the metal 1 drilling bridge 1' is ensured. A further insulating ring disk 20 is placed on the front side 16 of the connection socket 4', through which the connection nozzle 8 protrudes and whose inner diameter corresponds to the outer diameter of the connection nozzle 8.

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One of the two ring disks 18,20 can be connected in one piece to the plastic hollow cylinder 17. However, the manufacture of the hollow cylinder 17 should be simplified if the insulating ring disks 18,20 are separate parts.

Li/bk/eru.

Claims (1)

1. Fitting with a tapping bridge (1) that can be closed around a pipeline and a metal body (10) that is inserted in a sealing manner with a connecting piece (8) into a plastic connecting bush (4,17) of the tapping bridge (1,1') and is held in place by a screw connection, characterized in that the connecting piece of the metal body is provided with an internal thread into which a hollow metal bush (13) provided with a flange (14) is screwed from the pipeline side of the connecting bush (4; 4',17), the flange (14) being supported on an edge (7,7*) of the connecting bush (4; 4*,17) formed by a step-shaped extension. 2. Tapping fitting according to claim 1, characterized in that the connection socket (4) is designed as part of a tapping bridge (1) made of plastic. 3* Tapping fitting according to claim 1, characterized in that the connecting bush (4*, 17) has an inserted plastic hollow cylinder (17) into which the connecting piece (&thetas;) projects. TteodoMHeues-Straße2 *..··..··..· : .:.. · D-WOO Braunschweig Federal Republic of Germany Telephone 0531-80079 Telex 0-9 52620 gramm d Fax 0531-81297 (CCfTT 2+3) &bull; t t I I· ti tltS ti &Igr;· ttt ·· t »t·· to tt I SI It It It* I ItI SI t llll till lilt I It I· ■ > S ■&Tgr; J-^tttlttttg 4. Tapping fitting according to claim 3, characterized in that an insulating ring disk (18) is located between the flange (14) and the hollow plastic cylinder (17). 5. Tapping fitting according to claim 4, characterized in that the insulating ring disk (18) is inserted as a separate part. 6. Tapping fitting according to one of claims 3 to 5, characterized in that an insulating ring disk (20) is clamped between the front end (16) of the connection socket (4; 4', 17) and the metal body (10), through which the connection piece (8) projects. 7. Tapping fitting according to claim 6, characterized in that the insulating ring disk (20) is a separate part. Patent attorneys
Gram + Line
Li/bk/Gru.