GB1603245A - Expansion joint for pipe lines - Google Patents

Abstract

The compensator consists of a bellows (2), segment-like discs (3) and connecting pieces (4). The connecting pieces (4) are pushed onto the bellows (2), during assembly of the compensator (1) so far that the segment-like discs (3) can be inserted into the respective outer inner corrugations (2a) of the bellows. In order to instal the expansion compensator (1) in a pipeline system, the connecting pieces (4) are pushed so far outwards on the bellows (2) that the segment-like discs (3) enter recesses (4a) in the ends of the connecting pieces (4) close to the bellows in a rotationally symmetrical manner. The connecting pieces (4) are then - expediently successively - screwed onto the pipelines which pass onwards, using the internal thread (4b) of said connecting pieces, the ends of said pipelines being provided with external threads corresponding thereto. The connecting pieces (4) are normally provided externally with a hexagon which, in conjunction with a spanner, ensures that the expansion compensator is connected to the pipelines which pass onwards in a pressure-tight and fluid-tight manner. <IMAGE>

Description

(54) EXPANSION JOINT FOR PIPE LINES (71) We, INDUSTRIE-WERKE KAR LSRUHE AUGSBURG A.G., a Joint Stock Company organised under the laws of Germany (Fed. Rep.) of Postfach 3409, 7500 Karlsruhe 1, Germany (Fed. Rep.) do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates to an expansion joint for a pipe line.

It is known to provide expansion joints in pipe lines, e.g. of heating installations, so as to compensate for changes in length of the pipe line. It has been previously proposed to provide such an expansion joint comprising an externally corrugated bellows member extending between connector elements adapted for connection on the one hand to the bellows member and on the other hand to the pipe line. The connector element may, for example, be a hose connector with split inserts and cones for clamping the metal braiding of the hose. Corrugations pressed against the bellows in conjunction with sealing discs serve as sealing surfaces in this case.

A disadvantage of such known constructions is that they are relatively complicated and there is a risk that the braiding of the hoses may slip so as no longer to be able to fulfil its function. On-site assembly is complicated and insufficient protection is afforded against corrosion because the flow medium, usually hot water or steam, is in close contact with steel parts which are liable to corrode.

In previously proposed constructions of expansion joint using a bellows member the connector elements are provided with internal or external screw-threading for releasable connection to a pipe line. During assembly the bellows member is therefore subjected to torsional stresses as the connector elements are screwed on to the pipe line. This may lead to fractures in the bellows member and consequent leakage of the pipe line in use.

An object of the present invention is to provide an expansion joint of relatively simple construction enabling the aforesaid disadvantages to be obviated or mitigated..

According to the present invention there is provided an expansion joint for a pipe line, comprising two connector elements, an externally corrugated bellows member extending between the connector elements, a clearance bore in each connector element enabling the connector element to be fitted onto a respective end of the bellows member, a screwthreaded section of said bore for attaching the connector element to the pipe line, and two annular inserts each seated in a corrugation at a respective end of the bellows member and extending outwardly therefrom for engagement by retaining means of the associated connector element, whereby, in use, tightening of the screw-threaded connection between the conector elements and the pipe line serves to clamp the inserts and hence the ends of the bellows member against the ends of the pipe line.

Preferably, each annular insert is in the form of a flat ring.

Each annular insert preferably comprises two semi-circular segments.

The retaining means preferably comprises a recess in the bore of the connector element.

The invention will now be further described by way of example only with reference to the accompanying drawing which is a vertical half section of one embodiment of expansion joint according to the invention.

Referring now to the drawing, the exemplary expansion joint indicated generally by reference numeral 1 comprises an externally corrugated bellows member 2, annular inserts in the form of flat rings 3, and connector elements 4. The bellows member 2 extends between the connector elements 4 each of which has a clearance bore enabling it to be fitted onto a respective end of the bellows member 2. During assembly of the expansion joint the connector elements 4 are moved towards each other away from the respective ends of the bellows member 2 so as to expose the respective terminal corrugation 2a. With the connector elements 4 in this position the flat rings 3 are inserted in the respective corrugations 2a whereupon the connector elements 4 are returned to their illustrated end positions.

The bore of each connector element 4 is provided with retaining means for the associ ated flat ring 3 and in the present embodi ment said retaining means comprises a recess 4a in the bore of the connector element 4.

The bore of each connector element 4 also has a screw-threaded section 4b for attaching the connector element to a pipe line (not shown).

Each flat ring 3 comprises two semi-circular segments seated in the respective corrugation 2a.

The ends of the pipe line to which the expansion joint is to be fitted are externally screw-threaded to fit the threaded sections 4b of the connector elements 4. The expansion joint is connected to the pipe line by screwing the connector elements onto the threaded ends of the pipe line and then tightening the screw connection. The flat rings 3 are thus engaged by the recesses 4a and clamped, together with the ends of the bellows member, against the ends of the pipe line. The connector ele ments 4 are conveniently provided with a hexa gonal outer surface enabling it to be mani pulated by a spanner. A fluid-tight seal be tween the bellows member 2 and the pipe line is thus achieved with a relatively simple construction. It will be appreciated that the flat rings 3 are disposed externally of the seal between the bellows member 2 and the pipe line and are therefore not subject to the corro- sive action of the flow medium. The con struction also enables torsional stressing of the bellows member to be avoided.

WHAT WE CLAIM IS: 1. An expansion joint for a pipe line, com- prising two connector elements, an externally corrugated bellows member extending between the connector elements, a clearance bore in each connector element enabling the connector element to be fitted onto a respective end of the bellows member, a screw-threaded section of said bore for attaching the connector element to the pipe line, and two annular inserts each seated in a corrugation at a respective end of the bellows member and extending outwardly therefrom for engagement by retaining means of the associated connector element, whereby, in use, tightening of the screwthreaded connection between the connector elements and the pipe line serves to clamp the inserts and hence the ends of the bellows member against the ends of the pipe line.

2. An expansion joint as claimed in claim 1, wherein each annular insert is in the form of a flat ring.

3. An expansion joint as claimed in claim 1 or 2, wherein each annular insert comprises two semi-circular segments.

4. 4. An expansion joint as claimed in any one of the preceding claims, wherein the retaining means comprises an annular recess in the bore of the connector element.

5. An expansion joint for a pipe line, substantially as herein described with reference to and and as illustrated in the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. The bore of each connector element 4 is provided with retaining means for the associ ated flat ring 3 and in the present embodi ment said retaining means comprises a recess 4a in the bore of the connector element 4. The bore of each connector element 4 also has a screw-threaded section 4b for attaching the connector element to a pipe line (not shown). Each flat ring 3 comprises two semi-circular segments seated in the respective corrugation 2a. The ends of the pipe line to which the expansion joint is to be fitted are externally screw-threaded to fit the threaded sections 4b of the connector elements 4. The expansion joint is connected to the pipe line by screwing the connector elements onto the threaded ends of the pipe line and then tightening the screw connection. The flat rings 3 are thus engaged by the recesses 4a and clamped, together with the ends of the bellows member, against the ends of the pipe line. The connector ele ments 4 are conveniently provided with a hexa gonal outer surface enabling it to be mani pulated by a spanner. A fluid-tight seal be tween the bellows member 2 and the pipe line is thus achieved with a relatively simple construction. It will be appreciated that the flat rings 3 are disposed externally of the seal between the bellows member 2 and the pipe line and are therefore not subject to the corro- sive action of the flow medium. The con struction also enables torsional stressing of the bellows member to be avoided. WHAT WE CLAIM IS:

1. An expansion joint for a pipe line, com- prising two connector elements, an externally corrugated bellows member extending between the connector elements, a clearance bore in each connector element enabling the connector element to be fitted onto a respective end of the bellows member, a screw-threaded section of said bore for attaching the connector element to the pipe line, and two annular inserts each seated in a corrugation at a respective end of the bellows member and extending outwardly therefrom for engagement by retaining means of the associated connector element, whereby, in use, tightening of the screwthreaded connection between the connector elements and the pipe line serves to clamp the inserts and hence the ends of the bellows member against the ends of the pipe line.

2. An expansion joint as claimed in claim 1, wherein each annular insert is in the form of a flat ring.

3. An expansion joint as claimed in claim 1 or 2, wherein each annular insert comprises two semi-circular segments.

4. 4. An expansion joint as claimed in any one of the preceding claims, wherein the retaining means comprises an annular recess in the bore of the connector element.

5. An expansion joint for a pipe line, substantially as herein described with reference to and and as illustrated in the accompanying drawing.