GB2281947A

GB2281947A - Connection for high pressure pipes

Info

Publication number: GB2281947A
Application number: GB9416660A
Authority: GB
Inventors: Jacques Bodet
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-08-30
Filing date: 1994-08-17
Publication date: 1995-03-22
Anticipated expiration: 2014-08-17
Also published as: GB9416660D0; DE4429766A1; FR2709530A1; GB2281947B; FR2709530B1

Description

2281947 Connection for high pressure-pipes The present invention relates

to a new connection for high pressure pipes.

The connection of two high pressure pipes may be carried out by soldering or by a connection system made up of two parts, male and female, situated at the end of the pipes which are to be connected: they must form an integral part with these pipes in a very firm manner.

The connection is subjected to great pulling forces. Annular grooves are formed inside each connection part. These parts are mounted onto the corresponding pipe, which comes to conform externally to the internal shape of the annular grooves by any known method.

The parts, thus fixed, can not be pulled out. By screwing the two Parts together, the connection is thus effected. If such a connection is subjected to a torsion couple corresponding to the tightening of the nut, it has been noted that this connection tends to rotate. It is, in fact, only secure against longitudinal forces.

Some solutions have been proposed which are not totally satisfactory. For example, some small grooves are produced at the end of each part with the pipe and glue is deposited there at the time of mounting, but experience has shown that this adherence is quite problematical and costly.

One of the aims of the present invention is to obtain a connection for high pressure pipes which resists not only pulling f orces but also torsion stresses, f or example on tightening of these connections.

Another aim of the invention is to provide such a connection which is simple to produce and low-cost, and which is quick'and very simple to use.

These aims are addressed by a connection especially but not exclusively for high pressure pipes, comprising two parts each arranged at the end of a length of pipe and each having at least one annular groove to resist pulling forces, in which each part also has channels substantially parallel to the axis of-the said part spaced apart around the circumference of its internal face.

Advantageously, the channels are produced between the annular groove or grooves and the free end of the part.. They can extend between an annular groove called the disengagement groove, and an engagement groove situated at or close to this end.

According to a preferred form of embodiment, the channels have a width similar to that of the annular grooves, sides substantially perpendicular to the internal wall of the connection, and sharp edges.

Advantageously, the depth of these channels is slightly less than that of the annular grooves.

Preferably, each connection part has a si protuberance in the form of an exterior annular ring, situated at the position of the channels, with the aim of reinforcing the mouth of the part.

An example of a connection made in accordance with the present invention will now be described with reference to the accompanying drawing, in which:

Figure 1 shows an axial sectional view of a part of a connection which embodies the present invention; Figure 2 is a cross-sectional view taken in the plane indicated by line II-II in Figure 1; Figure 3 is a view of the detail within the imaginary circle III of Figure 2, on an enlarged scaled; Figure 4 shows the view shown in Figure 3 after a pipe has been introduced into the part of this connection; and Figure 5 shows an axial sectional view of a modified part of a connection which embodies the present invention, the modified part having. an engagement groove.

The illustrated connection comprises two parts, one male, the other female, which are each arranged at the end of a pipe and which are made integral or firmly fixed therewith.

Each part 1, male or female, comprises annular grooves 2 so as to resist pulling forces, as previously described.

In addition at the free end of this part 1, that is to say at the end further f rom that which cooperates with the other part to produce the connection, channels 3 which are parallel to the longitudinal axis of the part 1 and which are spaced apart around the circumference of the internal face 4 thereof, are provided.

As can be seen in Figures 1 and 3, these channels 3 have a width substantially equal to that of the annular grooves 2. They have sides 5 which are perpendicular to the internal wall 4 of the connection and sharp edges 7 which have in particular the aim of. permitting a better anchoring in the material. The depth of these channels 3 is substantially less than that of the annular grooves so as to permit an outlet there without a forming a burr.

The channels 3 are produced between the last annular groove and the f ree end of the part. In the Figure 5 embodiment, they are produced between an annular groove named the disengagement groove and an engagement groove 9 situated close to this f ree end. This permits this part of the connection to present a totally circular end, the deformations of the tube in the channels remaining confined to the interior of the part.

To make this part 1, as shown in the embodiment of Figure 1 or the embodiment of Figure 5, integral with or fixed to the end of a pipe 8, it is sufficient to slip the f ormer on the latter, and then, by means which will be familiar to a person of ordinary skill in the art, to inflate this pipe 8 so that it comes, not only to conform to the shape of the grooves 2, but also to that of the channels 3.

One thus creates on the external surface of the pipe 8 "male" teeth which conform as perfectly as possible to the "female" teeth of the part 1, as represented in Figure 4.

Furthermore, one can likewise provide each part 1, at the positions of the annular grooves 2 or channels 3, with a protuberance in the form of an external circular ring. This protuberance, in the case of intense pressures, acts like an external binding to hold the part 1 rigidly on the pipe 8.

Such a part resists the pulling forces and also torsion couples, exerted in particular upon engaging two parts of the same connection.

Such a connection is adapted for substantially any two lengths of pipe to be connected, but is especially adapted to lengths of pipe which are called high pressure pipes, whether the fluid circulating therein is liquid or gaseous.

For example, a connection for a tube of steel having an external diameter of 12.7 mm comprises four spaced apart channels 3 which have a length of 3 mm and a depth of 0.25 mm approximately. This resists a torque of up to 75 Nm for such a steel tube. The annular grooves 2, of this same connection, have a depth of approximately 0.26 MM. A

Claims

- 7 CLAIMS

1. A connection especially but not exclusively for high pressure pipes, comprising two parts each arranged at the end of a length of pipe and each having at least one annular groove to resist pulling force s, in which each part also has channels substantially parallel to the axis of the said part spaced apart around the circumference of its internal face.

2. A connection according to Claim 1, in which the spaced apart channels are produced between the annular groove or grooves and the free end of the part.

3. A connection according to Claim 2, in which the channels extend between an annular groove called the disengagement groove and an engagement groove situated at or close to this end.

4. A connection according to any preceding Claim, in which each part also has a protuberance in the form of an exterior annular ring, situated at the position of the channels.

5. A connection according to any preceding Claim, in which the channels have a width similar to that of the annular grooves. sides which are substantially perpendicular to the internal wall of the said connection, and sharp edges.

6. A connection according to any preceding Claim, in which the depth of the channels is slightly less than that of the annular grooves.

7. A connection comprising two parts each substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawing, with or without the modification shown in Figure 5.