GB2316144A - Assembly for coupling a plain-ended pipe to a flanged pipe - Google Patents

Abstract

The assembly comprises a sleeve 4 and a plurality e.g. two of separately formed flange segments 14,16, the flange segments 14,16 being arranged in use to encircle one end of the sleeve 4 so as to define a coupling flange for connection to the flange-ended pipe P1, the sleeve 4 being provided at the other end thereof with means 42,52 for connecting the adaptor 2 to the plain-ended pipe P2. The segments 14,16 overlap at certain bolt holes 22 and are retained by a sleeve groove 8. The segments 14,16 also have bolt holes for compression bolts 60 for axially drawing a flange to compress a gripping ring 42 around the plain-ended pipe P2.

Description

PIPE COUPLINGS This invention relates to pipe couplings and more particularly to pipe couplings of the kind adapted to connect together a flange-ended pipe to a plain-ended pipe.

It is to be understood that the expression "pipe" as used herein includes pipes and tubes as such and also pipe-like members and fittings for use in pipework such as bends, elbows, "T" connectors, flange adaptors and parts and devices adapted to be fitted to pipework such as valves and pumps. Such pipes may have a variety of end configurations, and may, for example, be plain-ended or flange-ended.

Flange adaptors commonly comprise an annular sleeve member having a coupling flange at one end which can be secured to the flange of a pipe or pipe fitting by means of flange bolts in known fashion. At the other end, the sleeve member is provided with means for connection to a plain-ended pipe. The connection means usually comprises an annular sealing gasket arranged about the plain-ended pipe, and an annular compression flange disposed about the end of the sleeve member and arranged to be drawn axially against the sealing gasket by tightening means to cause the sealing gasket to be forced into sealing contact between the sleeve member and the outer periphery of the plain-ended pipe located within the sleeve.

Such pipe couplings can be formed, for example, of malleable iron, steel, or plastics material, the gaskets being of an appropriate elastomeric material.

The compression flange for such couplings may be provided with tightening means connecting together the compression flange and the coupling flange. The tightening means may comprise bolts passing along the length of the sleeve and through apertures spaced around the outer radial extremities of the respective flanges, such bolts being provided with a head at one end and carrying a nut at the other so that the flanges are drawn together by tightening the nuts on the bolts. Alternatively, the compression flange may screw into or onto the ends of the sleeve.

In common use, flange adaptors are generally manufactured as all-cast or all-fabricated products in iron and steel respectively, although other materials can also be used. For flange adaptors up to 12" (25.4cm) nominal diameter, the most economical method of manufacture is by casting, after which point it becomes more economical to fabricate the adaptor from steel.

Increasingly, it has become necessary for flange adaptors to accommodate a wide range of pipe outside diameters (O.D.) in one nominal size. For adaptors intended to connect a flange-ended pipe to a plain-ended pipe, this has created a particular problem. The annular sleeve member is usually flared at one end so as to accommodate a range of different pipe OD's, the flared portion being sufficiently deep to accommodate the sealing gasket. The presence of the flared end means that if the adaptor is to be produced by a casting method, it is necessary to use not only top and bottom mould halves but also a core box. The need to use a core box means that the casting process is significantly more expensive than would be the case if only top and bottom mould halves were needed and can lead to increases in cost of approximately 30%.

It is an object of the present invention to overcome or at least alleviate the aforementioned problems and provide a flange adaptor which is easier and more economical to manufacture.

The present invention adopts the principle of using separate flange and sleeve components, in so doing allowing the sleeve to be made from thin steel and fabricated in a high volume manufacturing method, whilst allowing the flange to be made by casting. Another very substantial advantage of the adaptor of the invention is that it allows for the possibility of flanges and sleeves being interchangeable thereby reducing the need to create a new set of mould patterns for each type and size of adaptor.

Separate flanges have been used previously for pipes; indeed the present applicants have designed and sold split and hinged flanges which engage in grooves made in steel pipe. However, the applicants are not aware that separate flanges have previously been used for flange adaptors nor have the significant advantages that arise from such use been recognised.

Accordingly, the invention provides an adaptor for connecting together a flange-ended pipe to a plain-ended pipe, the adaptor comprising a sleeve and a pluraiity of separately formed flange segments, the flange segments being arranged in use to encircle one end of the sleeve so as to define a coupling flange for connection to the flange-ended pipe, the sleeve being provided at the other end thereof with means for connecting the adaptor to the plain-ended pipe.

Typically, two flange segments are employed. Preferably the two flange segments are of approximately equal size.

The flange segments can be provided at their circumferential ends with circumferentially overlapping formations enabling the segments to be secured together about the sleeve.

In one embodiment, the adaptor has at the end remote from the flange segments an enlarged diameter (e.g. flared) portion for receiving therein an end of the plain-ended pipe, a sealing gasket for disposing in the said enlarged diameter portion and for encircling the end of the plain-ended pipe, and annular compression means arranged to be drawn axially against the sealing gasket by tightening means to cause the sealing gasket to be forced into sealing contact between the sleeve and the outer periphery of the plainended pipe located within the sleeve.

The sleeve can be provided with retaining means for holding the flange in place against axial displacement with respect to the sleeve. For example, the sleeve can be provided with a radially outwardly extending lip at the axial end thereof against which in use axial faces of the flange segments abut to prevent axial displacement of the segments from the sleeve end. An axially inner abutment surface is preferably also provided for preventing the flange segments from being displaced axially towards the coupling flange. The radially outwardly extending lip and the axially inner abutment surface can form part of a circumferential channel for retaining the radially inner edges of the flange segments. The circumferential channel can be defined, for example, by a radially inwardly recessed portion of the wall of the sleeve adjacent the lip.

The flange segments can be formed from cast iron, whilst the sleeve can be fabricated from steel sheet, strip or tube. The fabrication method can involve, for example, fabricating a plain cylindrical blank from a flat blank strip and then deforming the plain cylindrical blank using an appropriate deforming tool.

The invention will now be illustrated by reference to one particular embodiment as shown in the accompanying drawings, in which: Figure 1 is a side sectional elevation according to one embodiment of the invention; Figure 2 is a side sectional elevation of a sleeve member generally similar to the sleeve member of Figure 1; and Figure 3 is a plan view of a flange segment for use in the embodiment of Figure 1.

Referring now to the drawings, a flange adaptor 2 according to one embodiment of the present invention comprises a generally cylindrical sleeve 4 which in this embodiment has been fabricated from steel, for example by forming a cylindrical blank from a blank strip and then deforming the cylindrical blank to the desired shape.

At a first end, the sleeve 4 is provided with an annular lip 6 and, axially inwardly of the lip 6, an annular recess 8. At the other end (the second end) of the sleeve 4 is a flared portion 10, the flared portion 10 and annular recess 8 being linked by a plain cylindrical portion 12.

A pair of flange segments 14 and 1 6 are disposed about the first end of the sleeve 4. One of the flange segments 14 is shown in Figure 3.

Flange segment 14 has an end 1 8 which is recessed on its underside and an end 20 which is recessed on its top surface, the two ends having slotted apertures 22 and 24 respectively through which flange bolts 62 can pass.

Segment 14 has three further slotted apertures 26a, 26b and 26c spaced at 45 degree intervals along its length, also for receiving flange bolts (not shown) of the type referred to above by the reference numerals 62. In addition to the slotted apertures, the flange segment 14 has a pair of circular apertures 28 for receiving compression flange bolts 60, the apertures 28 being approximately 90 degrees apart. One side of the flange segment 14, which in use is the axially outwardly facing side, has a recessed region 32, the depth of the recess corresponding to, or being less than, the thickness of the annular lip 6 of the sleeve 4, so that in use the lip 6 and the adjacent axial surfaces of the flange segments 1 4, 1 6 are flush with, or proud of, one another. The radially inner edge 34 of the flange segment 14 has a larger diameter portion 36, a smaller diameter portion 38 and an inclined portion 40. The other flange segment 16 in this embodiment is identical in form to flange segment 14. In use, the flange segments 14 and 16 are arranged about the first end of the sleeve 4 so that the smaller diameter portion 38 and the inclined portion 40 of the radially inner edge fit snugly into the annular recess 8 of the sleeve member 4, and the axial face of the recessed region 32 of the flange segment abuts against the annular lip 6. The recessed regions 18, 20 at the circumferential ends of the two segments 14,16 overlap, the flange bolts 62 serving to secure the two flange segments 14 and 16 together.

At the second wend of the sleeve member 4, an annular gasket 42 formed of a suitable elastomeric material is located within the flared end 1 0.

Annular gasket 42 has a radially inner pipe sealing surface 44 provided with a plurality of annular ribs 46, and a radially outer inclined surface 48. The axially outer end 50 of the gasket is received within an annular recess 54 of compression flange 52. Compression flange 52 is of conventional construction and has a radially outer flange 56 portion having four circular apertures 58 therein through which the shafts of compression flange bolts 60 pass. The apertures 58 in use are aligned with the apertures 28 in the flange segments 14 and 16. Compression flange 52 is typically formed from cast iron or fabricated steel.

In use, the flange adaptor 2 is used to couple together a flange-ended pipe or pipe fitting P1 and a plain-ended pipe or pipe fitting P2. The flange F of the pipe or pipe fitting P1 is connected to the coupling flange constituted by flange segments 14 and 16 of the adaptor 2 by means of the flange bolts 62, a sealing gasket 64 providing an end face seal between the abutting flange F and the annular lip 6. At the other (second) end of the adaptor 2, the end of pipe or pipe fitting P2 is inserted into the sleeve member 4 and through the gasket 42. The inner diameter of the sleeve member 4 in this embodiment is larger than the nominal outer diameter of the pipe or pipe fitting P2 such that in this case there is an annular gap or clearance C between the outer periphery of P2 and the sleeve 4. By making the inner diameter of the sleeve 4 larger than the nominal OD of P2, the adaptor can accommodate the range of variations typically encountered in practice for a given nominal pipe OD. A seal between the pipe or pipe fitting P2 is provided by the gasket 42 which is compressed against the wall of the pipe or pipe fitting P2 by tightening the compression flange bolts 60 such that the compression flange 52 is drawn towards the coupling flange constituted by flange segments 14, 16, thereby urging the inclined portion 48 of the gasket against the inclined wall of the flared portion 10 of the sleeve 4 so as to deform the gasket radially inwardly against the wall of pipe or pipe fitting P2.

An advantage of the adaptor of the present invention is that the sleeve member 4 can be formed in a simple fabrication process from steel tube or strip, whereas the flange segments 1 4, 1 6 can be formed by casting using much simpler mouids than would be required if the entire adaptor were to be cast. A further and most significant advantage is that the flange segments can be used interchangeably with sleeve members of different dimensions to allow a range of adaptors to be constructed using a minimal number of mould patterns and moulds.

It will readily be apparent that numerous modifications and alterations could be made to the flange adaptor illustrated in the accompanying drawings without departing from the principles underlying this invention. All such modifications and alterations are intended to be embraced by this application.

Claims (14)

1. An adaptor for connecting together a flange-ended pipe to a plain ended pipe, the adaptor comprising a sleeve and a plurality of separately formed flange segments, the flange segments being arranged in use to encircle one end of the sleeve so as to define a coupling flange for connection to the flange-ended pipe, the sleeve being provided at the other end thereof with means for connecting the adaptor to the plain-ended pipe.

2. An adaptor according to claim 1 wherein two flange segments are employed.

3. An adaptor according to claim 2 wherein the two flange segments are of approximately equal size.

4. An adaptor according to any one of the preceding claims wherein the flange segments are provided at their circumferential ends with circumferentially overlapping formations enabling the segments to be secured together about the sleeve.

5. An adaptor according to any one of the preceding claims wherein the adaptor has at the end remote from the flange segments an enlarged diameter (e.g. flared) portion for receiving therein an end of the plain ended pipe, a sealing gasket for disposing in the said enlarged diameter portion and for encircling the end of the plain-ended pipe, and annular compression means arranged to be drawn axially against the sealing gasket by tightening means to cause the sealing gasket to be forced into sealing contact between the sleeve and the outer periphery of the plain-ended pipe located within the sleeve.

6. An adaptor according to any one of the preceding claims wherein the sleeve is provided with retaining means for holding the flange in place against axial displacement with respect to the sleeve.

7. An adaptor according to claim 6 wherein the sleeve is provided with a radially outwardly extending lip at the axial end thereof against which in use axial faces of the flange segments abut to prevent axial displacement of the segments from the sleeve end.

8. An adaptor according to claim 7 wherein an axially inner abutment surface is also provided for preventing the flange segments from being displaced axially towards the coupling flange.

9. An adaptor according to claim 8 wherein the radially outwardly extending lip and the axially inner abutment surface form part of a circumferential channel for retaining the radially inner edges of the flange segments.

1 0. An adaptor according to claim 9 wherein the circumferential channel is defined by a radially inwardly recessed portion of the wall of the sleeve adjacent the lip.

11. An adaptor according to any one of the preceding claims wherein the flange segments are formed from cast iron, and the sleeve is fabricated from steel sheet, strip or tube.

1 2. An adaptor according to claim 11 wherein the sleeve has been formed by fabricating a plain cylindrical blank from a flat blank strip and then deforming the plain cylindrical blank using an appropriate deforming tool.

1 3. An adaptor substantially as described herein with reference to the accompanying drawings.

14. A method of coupling a flange-ended pipe to a plain-ended pipe using an adaptor as defined in any one of the preceding claims.