GB2202019A

GB2202019A - Flanged pipe couplings

Info

Publication number: GB2202019A
Application number: GB08706055A
Authority: GB
Inventors: Major Edward Athelstan Halford
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-03-13
Filing date: 1987-03-13
Publication date: 1988-09-14
Also published as: GB8706055D0

Abstract

A pipe coupling comprises a first flange member adapted to be mounted upon a first pipe element and a second flange member adapted to be mounted upon a second pipe element, one of said flange members including an axially extending projection and the other of said flange members including an axially extending recess, said projection being adapted to be a sealing fit within said recess and to seal said flange members together, said flange members being provided with means for securing the flange members together so as to locate said projection sealingly within said recess. Preferably the sealing fit between the axially extending projection and recess is a hard tap-fit and preferably the projection and the recess are provided with co-operating tapers to achieve satisfactory sealing. It is an important feature of the invention that no gasket is necessary to achieve sealing between the flange members. <IMAGE>

Description

DRAFT PIPE COUPLING This invention relates to a pipe coupling and is suitable for joining two pipes together or for joining a pipe e.g. to a tank or for joining fittings such as a tap or a valve to a pipe.

It is known to produce a coupling between lengths of piping wherein adjacent ends of the pipe are provided with flat annular flanges between which is located a sealing gasket. The flanges are then secured together e.g. by means of bolts passing through aligned apertures in said flanges. There are many cases on record where such known pipe couplings have failed, due to failure of the gasket. In cases where the pipe contains for example super-heated steam at high pressure or dangerous liquids, the consequences of such a coupling failure could be extremely serious.

It is an object of the present invention to provide a pipe coupling in which the possibility of coupling failure is reduced or minimised. According to the present invention there is provided a pipe coupling which comprises a first flange member adapted to be mounted upon a first pipe element and a second flange member adapted to be mounted upon a second pipe element, one of said flange members including an axially extending projection, and the other of said flange members including an axially extending recess, said projection being adapted to be a sealing fit within said recess and to seal said flange members together, said flange members being provided with means of securing the flange members together so as to locate said projection sealingly within said recess.

The term 'pipe element' is intended to cover not merely a pipe but also a fitting for a pipe, such as a tap or valve, as well as an article or piece of apparatus to which it may be desired to connect a pipe or pipe fitting.

Preferably the flange members are annular and are adapted to be secured together by means of bolts extending through corresponding apertures located respectively in each flange member.

Preferably each flange member is adapted to be welded to its associated pipe element. Alternatively a pipe element can be cold-shrunk into a said flange member or a flange member can be heat shrunk on to a said pipe element.

It is preferred that the material from which the said pipe elements, flange members and bolts (if present) is composed be the same for each component, so as to avoid differential expansion. Thus, for example, each of the pipe elements, flange members and connecting bolts may be composed of stainless steel, of copper, of brass, of bronze or of aluminium. Although it is generally preferred that the various components be of metal, it is envisaged that for specific applications, said components could be formed of a thermoplastic or thermosetting resin.

Preferably the pipe elements are fabricated e.g. by welding. The pipe elements can be moulded pr cast but this is not preferred because of possible porosity problems.

The sealing fit between said axially extending projection and the co-operating axially extending recess may be arranged to be a hard tap-fit and the projection and the recess may be provided with co-operating tapers in order to achieve satisfactory sealing.

It is an important feature of the present invention that no gasket is necessary to achieve sealing between the flange members; however if desired, a gasket can be located between the flange members to provide for additional security.

It is envisaged that the pipe coupling of the present invention may employ more than one co-operating axial projection and recess. For example one said flange member could include two co-axially arranged, axially extending annular projections whilst the other said flange member includes two co-axially arranged axially extending corresponding annular recesses.

Embodiments of pipe couplings according to the present invention will now be described, by way of example only, and by reference to the accompanying drawings, in which: Fig. 1 shows in longitudinal section a first embodiment of a pipe coupling according to the present invention and Fig. 2 is a longitudinal section of a second embodiment of a pipe coupling according to the present invention.

Referring firstly to Fig. 1 of the accompanying drawings, there is shown a pipe coupling 1 for coupling together two pipes 2, 3. The pipe coupling 1 comprises a pair of co-operating flange members 4,5, welded to respective pipes 2,3 by means of welds 6,7. Each flange member 4,5 includes a plurality of corresponding apertures 8', 8'', 9', 9'', etc. Each corresponding pair of apertures is adapted to receive bolts 10', 10", etc., secured in position by means of nuts 11', 11'', etc.

On flange member 5 there is formed an axially extending annular projection 12, and in flange 4 there is formed a recess 13. The projection (spigot) 12 in this particular embodiment is 1/8" long whilst the corresponding recess 13 is 3/16" deep. The projection or spigot 12 is adapted to be a hard tap-fit to the said recess 13.

In assembling the pipe coupling of the present invention, the flange member 4 is welded on to pipe 2 and flange member 5 is welded on to pipe 3. The projection 12 is forcibly inserted into recess 13 and the flange members 4,5 secured together by means of bolts 10 and nuts 11. If desired the heads of the bolts 10 can be welded to the flange member 4.

In this embodiment the pipes, flange members and the nuts and bolts are all composed of stainless steel and all the welds are argon-arc welds.

Referring now to Fig. 2 of the accompanying drawings there is shown a second embodiment of a pipe coupling according to the present invention, adapted for fixing e.g. in the wall of a tank. In Fig. 2 like parts to those of Fig. 1 are designated by like numerals. In general the components of the pipe coupling of Fig. 2 are very similar to those of the pipe coupling of Fig. 1 and insofar as this is the case they will not be redescribed.

Instead however of the flange member 4 being welded to the end of a pipe 2, in the present embodiment the flange member 4 is welded to the end of the stub pipe 17. An axially extending annular projection 14 is provided co-axially of flange member 4, whilst a co-axial recess IS is formed in flange member 5. The flange members 4 and S are so disposed relative to pipe 17 and pipe 3 that when the pipe coupling is assembled an end of pipe 3 extends into flange member 4. The extent to which the axially extending projection 14 projects from the end face of flange member 4 is such that a wall 16 of a tank can be secured between flange members 4 and 5. with projection 14 still forming a sealing engagement within recess 15.

Although in the embodiments so far described the axially extending projection and corresponding recess have been located radially inwardly of the flange members this is not necessary to the performance of the invention and the projection and recess can be formed on the flange members 4 and 5 at any suitable radial distance.

Likewise, and as has been previously mentioned, more than one pair of corresponding projections and recesses may be provided, further to seal the pipe coupling.

One of the advantages of the pipe coupling of the present invention is that there is no particular need for the securing means, e.g. the coupling bolts, to be of massive construction, since there is substantially no pressure between the flanges of the coupling elements.

It will be appreciated that the invention may be performed otherwise than as has been particularly described and it is to be understood that the present invention embraces all modifications, alterations and additions which would be apparent to one skilled in the art.

Claims

CLAIMS:

1. A pipe coupling which comprises a first flange member adapted to be mounted upon a first pipe element (as hereinbefore defined) and a second flange element adapted to be mounted upon a second pipe element (as hereinbefore defined), one of said flange members including an axially extending projection, and the other of said flange members including an axially extending recess, said projection being adapted to be a sealing fit within said recess and to seal said flange members together, said flange members being provided with means for securing the flange members together so as to locate said projection sealingly within said recess.

2. A pipe coupling according to Claim 1, wherein each flange member is annular.

3. A pipe coupling according to Claims 1 and 2 wherein said means for securing the flange members together comprise bolts extending through corresponding apertures located respectively in each flange member.

4. A pipe coupling according to any one of the preceding Claims, wherein each flange member is adapted to be welded to its associated pipe element.

5. A pipe coupling according to any of Claims 1-3 wherein each flange member is mounted upon its associated pipe element by means of a cold shrinking operation.

6. A pipe coupling according to any of Claims 1-3 wherein each flange member is mounted upon its associated pipe element by means of a heat-shrinking operation.

7. A pipe coupling according to any one of the preceding Claims and made of metal.

8. A pipe coupling according to Claim 7, wherein each component of the pipe coupling is composed of the same metal.

9. A pipe coupling according to any one of the preceding Claims wherein said axially extending projection and the co-operating axially extending recess are arranged to be a hard tap-fit.

10. A pipe coupling according to any one of the preceding Claims wherein said axially extending projection and said axially extending recess are provided with co-operating tapers.

11. A pipe coupling acording to any one of the preceding Claims which further includes a gasket adapted for location between the flange members.

12. A pipe coupling, substantially as hereinbefore described, with reference to Fig. 1 or Fig. 2 of the accompanying drawings.

13. The features hereinbefore disclosed, all their equivalents, in any novel selection.