GB2036904A

GB2036904A - Pipe Fittings

Info

Publication number: GB2036904A
Application number: GB7846974A
Authority: GB
Original assignee: Glynwed Tubes and Fittings Ltd
Current assignee: Glynwed Tubes and Fittings Ltd
Priority date: 1978-12-02
Filing date: 1978-12-02
Publication date: 1980-07-02
Also published as: GB2036904B

Abstract

A pipe fitting comprises a body 10 having, at its end or each end, a socket 13 for receiving a pipe 12 to be connected to the fitting, this socket being formed with a flared bell-mouth 15. A nut 16 (which may be a cap nut as shown or may be a sleeve nut) is retained on the body 10 by the bell- mouth 15 and faces the latter by a flared face 18. A complementary nut 20 (which is shown as a sleeve nut, but will be a cap nut if a sleeve nut is used as the nut 16) and a deformable sealing ring 19 are provided for fitting to the pipe 12. Upon screwing together the two nuts 16, 20, the ring is deformed into the space between the bell mouth 15 and the flared face 21, and is compressed onto the pipe 12, and the bell-mouth 15 is forced tightly against flared face 18 of the nut 16. <IMAGE>

Description

SPECIFICATION Pipe Fittings This invention concerns pipe fittings, that is to say pipe couplings or connectors, elbows, teepieces and the like, employed to connect together pipe lengths, accessories and equipment, for example for the distribution of water and other fluids.

Two types of pipe fittings are generally available at the present time for use in connecting together copper pipes, these being solderable fittings and compression fittings respectively.

Solderable fittings generally require at least some skill for their proper installation; they generally comprise a copper body socketed at each end for receiving the ends of the pipes to be connected and may incorporate a solder ring which melts upon application of heat or may require application of solder from a separate source.

Obviously, such fittings cannot be used in environments where heat cannot be applied or to which ready access with a blowlamp or the like cannot be had.

Compression fittings, on the other hand, do not require the application of heat. They generally comprise a hot-stamped and machined brass body, screw-threaded at its ends to receive respective union nuts, the said ends and the nuts having oppositely-directed conical faces between which is disposed a relatively soft compression ring which, upon tightening up of the nut, is compressed onto the pipe extending into the respective end of the fitting. Although these compression fittings have the advantage over solderable fittings that they can be installed without the use of heat and can therefore more easily be used by persons not possessing specific plumbing training, they are susceptible to dezincificaton when used in water pipelines. The zinc present in the brass leaches out, the fitting corrodes, and failure can result.

This latter disadvantage is not present with the solderable copper fittings, of course, since there is no brass present to be contacted by the water; however, hitherto no practical copper compression fitting has been devised or made commercially available. An object of the present invention is to provide a form of compression fitting which those parts which are contacted by fluid can be made of copper, so that the inherent disadvantage of known compression fittings can be obviated.

With this object in view the present invention provides a pipe fitting comprising a hollow body having at one or each of its ends, a respective socket for receiving a respective pipe required to be connected to the fitting, characterised in that the or each said end is outwardly-flared to define a bell-mouth which serves to retain, on the said end, a first nut onto which fits a complementary nut which threadedly engages with the first nut and has a respective flared face, and a deformable sealing ring disposed between the nuts so that, in use, upon fitting of a pipe into the respective end of the body and tightening together of the nuts, the sealing ring will be forced into the bell-mouth and, by reaction against said bell-mouth and the flared face of the complementary nut, will be compressed onto the pipe, to seal the latter relative to the body.

Preferably the ends of the body are formed as sockets shaped to define specific depths of insertion of the respective pipes to be joined to the fitting.

The fitting of the invention may, for example, be in the form of a linear coupling or connector, an elbow, or a tee-piece.

In order that the invention may be fully understood, it will be described further, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is an elevation of a linear coupling, of short axial length, conforming to the present invention, with its parts separated; Fig. 2 is a sectional elevation illustrating a pipe about to be connected to one end of the coupling of Fig. 1; Fig. 3 is a view comparable with Fig. 2, but showing the pipe connected; Fig. 4 is an elevation of an elbow conforming to the present invention; Fig. 5 is an elevation of a tee-piece conforming to the present invention; and Fig. 6 is a view comparable with Fig. 2, illustrating how the relative dispositions of the nuts can be reversed in each of the embodiments of the fitting of the invention.

In the various figures, similar parts have been allocated similar reference numerals.

Turning firstly to Figs. 1, 2 and 3 of the drawings a pipe fitting in the form of a simple linear pipe coupling or connector comprises a tubular body 10 of relatively short axial length. A middle portion 11 of the body has an internal diameter corresponding approximately to the internal diameter of pipes 12, of which one only is shown in Figs. 2 and 3, to be connected by the coupling, and at each end the body 10 is formed as a socket 13 of external diameter such that the respective pipes 12 to be connected by the fitting are a snug fit therein. The transitions between the inner ends of the sockets 13 and the middle portion 1 1 are, of course, such as to form shoulders 14 which define a maximum possible depth of insertion of the pipes 12.

As can be seen particularly from Fig. 2, the outer extremity of each socket 13 is outwardlyflared to form a bell-mouth 15, this flaring having been formed by any suitable operation, such as by swaging.

The bell-mouths 15 serve to retain, on the respective ends of the coupling, respective internally-threaded cap nuts 16, these each being formed, as can be seen particularly from Fig. 2, with an internal flange or lip 17 presenting a frusto-conical or flared face 1 8 towards the respective bell-mouth 15. It will readily be understood that the cap nuts 16 are slipped onto the body 10 prior to forming the bell-mouths, during the production of the coupling.

Provided for each cap nut 16 is a respective deformable sealing ring 19, made for example of soft metal, this being semi-elliptical in radial cross-section and being of an internal diameter such that it is a snug sliding fit on the pipe 12.

Additionally, each cap nut 16 is provided with a respective externally-threaded sleeve nut 20 which is a sliding clearance fit on the pipe 12 and which is provided, on its end which screws into the cap nut 16 and faces the bell-mouth 15, with a flared or frusto-conical end face 21.

The manner in which the coupling of Fig. 1 is employed for coupling together pipes will be readily understood from Figs. 2 and 3, which serve to illustrate the securement of the coupling onto one end of the pipe 1 2. The pipe 12 is firstly prepared by slipping onto it firstly the sleeve nut 20 and then the sealing ring 19 as shown in Fig.

2. Then, the pipe 12 is inserted into the socket 13 to its fullest extent until it abuts the shoulder 14, and the sealing ring 19 is then slid along the pipe 12 to abut the bell-mouth 15 with its corresponding edge entering into the gap between the bell-mouth 15 and the pipe.

Securement is then effected by appropriately securing the sleeve nut 20 into the cap nut 16. As will be evident from Fig. 3, as tightening progresses, the ring 19 is forced into the bellmouth 15, and is subject to cold flow deformation, as a result of which it assumes a configuration corresponding to and filling the eventual space remaining between the bellmouth 15, the flared face 21 of the sleeve nut 20 and the registering outer surface of the pipe 12.

The flared configurations of the face 21 and the bell-mouth 15 ensure, of course, that the ring 19 is contracted onto the pipe 12.

Furthermore, of course, by reaction the bellmouth 15 is caused to expand and deform slightly to abut firmly against the flared face 1 8 of the flange or lip 17, ensuring that the bell-mouth 1 5 is gripped firmly against the sealing ring 19 and is presented by the latter from flexing and ensuring that the cap nut 1 6 cannot ride over the bellmouth 1 5.

It will be appreciated that the fitting can be coupled onto the pipe 12 very quickly and easily, and the connection so made is achieved without the need for any particular plumbing skill. A particularly important advantage lies in the fact that, the pipe 12 and the body 10 of the fitting being made of copper, no de-zincification can take place, since fluid passing through the pipe 10 and the fitting can contact only the pipe 12, the body 10 and perhaps the sealing ring 19. The two nuts 1 6 and 20 can be made of brass if so desired, as they do not come into contact with the fluid passing through the coupling.

Fig. 4 illustrates a pipe fitting in accordance with the invention, which is in the form of an elbow. As has already been mentioned, similar reference numerals have been allocated to similar parts throughout the drawings, so most of the parts of this fitting have been described already.

The fitting differs from that of Fig. 1 in that instead of having the short tubular middle portion 11, it has a somewhat longer curved middle portion 30 which provides for the two sockets 13 to be substantially at right angles, to permit the coupling together of two pipes 12 at right angles to one another. Of course, the curved portion can be greater than or less than a right angle in extent to provide for the sockets to be at corresponding angles as may be desired.

Fig. 5 illustrates a fitting according to the invention in the form of a tee-piece. This embodiment therefore has a relatively long middle portion 40 to which connects a side arm 41 which is provided with its respective socket 13, cap nut 16, sealing ring 19 and sleeve nut 20.

Finally, Fig. 6 illustrates the fact that it is not essential to the invention that the cap nut should be provided on the fitting, and that the sleeve nut should be separate, and that a reverse arrangement is possible. Thus, as shown, in this case a sleeve nut 50 is provided on the socket 13 and a corresponding cap nut 51 is provided for slipping onto the pipe 12. Flange or lip 52 of the cap nut must, of course, be of slightly greater radial extent than the flange or lip 17 in the previously-described embodiments, since it has to provide for the fact that the outside diameter of the pipe 12 is slightly smaller than the outside diameter of the socket 13. Of course, in this instance, the bell-mouth 15 of the fitting is claimed between flared face 53 of the sleeve nut 50 and the sealing ring 19.

Other modifications are, of course, possible within the scope of the following claims.

Claims

Claims

1. A pipe fitting comprising a hollow body having, at one or each of its ends, a respective socket for receiving a respective pipe required to be connected to the fitting, characterised in that the or each said end is outwardly-flared to define a bell-mouth which serves to retain, on the said end, a first nut onto which fits a complementary nut which threadedly engages with the first nut and has a respective flared face, and a deformable sealing ring disposed between the nuts so that, in use, upon fitting a pipe into the respective end of the body and tightening together of the nuts, the sealing ring will be forced into the bell-mouth, and by reaction against said bell-mouth and the flared face of the complementary nut, will be compressed onto the pipe, to seal the latter relative to the body.

2. A pipe fitting as claimed in claim 1 wherein the ends of the body are formed as sockets shaped to define specific depths of insertion of the respective pipes.

3. A pipe fitting as claimed in claim 1 to 2 wherein the body is linear, the fitting being a simple coupling.

4. A pipe fitting as claimed in claim 1 or 2 wherein the body is linear and has a lateral side arm, the fitting being a tee-piece.

5. A pipe fitting as claimed in claim 1 or 2 wherein the body is curved, the fitting being an elbow.

6. A pipe fitting as claimed in any preceding claim wherein the first nut is a cap nut and the complementary nut is a sleeve nut.

7. A pipe fitting substantially as hereinbefore described with reference to and as illustrated in Figs. 1, 2 and 3, in Fig. 4, in Fig. 5 or Fig. 6 of the accompanying drawings.

New Claims or Amendments to Claims filed on 1 May 1 979.

Superseded Claims 1.

New or Amended Claims:~

1. A pipe fitting comprising a hollow body having, at one or each of its ends, a respective socket for receiving a respective pipe required to be connected to the fitting, characterised in that the or each said end is outwardly-flared to define a bell-mouth which serves to retain, on the said end, a first nut which has formed directly thereon a respective flared face for abutment against said bell mouth, and onto which fits a complementary nut which threadedly engages with the first nut and has a respective flared face, and a deformable sealing ring disposed between the nuts so that, in use, upon fitting a pipe into the respective end of the body and tightening together of the nuts, the sealing ring will be forced into the bell-mouth, and by reaction against said bell-mouth, and the flared face of the complementary nut, will be compressed onto the pipe, to seal the latter relative to the body.