GB2340570A

GB2340570A - Annular joint

Info

Publication number: GB2340570A
Application number: GB9917573A
Authority: GB
Inventors: Thierry Botrel
Original assignee: Elf Exploration Production SAS
Current assignee: Elf Exploration Production SAS
Priority date: 1998-07-30
Filing date: 1999-07-28
Publication date: 2000-02-23
Also published as: NO993700D0; NO993700L; FR2781859A1; GB9917573D0

Abstract

An annular joint includes internal and external faces 2, 3, a plane of symmetry (5, fig 2) passing through an axis 4, and includes first and second contact zones 6, 7 contained respectively in first and second planes 8, 9. The first and second planes intersect to form a dihedral having an edge perpendicular to the plane of symmetry, where the dihedral angle 11 is between 0.5 and 10 degrees. The joint may be made of steel, and may have a polygonal, isosceles trapezoidal (fig 3), rectangular trapezoidal (fig 1), symmetrical oval (fig 4), or asymmetrical oval cross section (fig 5). Preferably the joint is used to connect two ducting members 30, 31 provided with flanges 32, 33 at each end, so that the longitudinal axes 34, 35 of the ducting members are not aligned. The joint may be used in the production of a curved ducting, eg a riser, for connecting an equipment item installed on the sea bed with a drilling platform or oil production platform.

Description

t 11D 2340570

DESCRIPTION

TECHNICAL FIELD

The present invention relates to the connection of ducting members by means of two flat flanges fixedly mounted at their ends that are to be mutually connected.

It in applicable in all industries in which liquid or gaseous fluids, powders or granules are transported, in particular in the oil industry.

PRIOR ART is In riany installations in which fluids circulate under pressure, a widely used technique for connecting ducting members to each other or to apparatus in a leaktight manner comprises installing a flat flange fixedly or. each of the ends of the member6 to be connected, interposing a joint between the two flanges and holding the joint gripped between the two flanges by appropriate means, for example a set of nuts and bolts.

Joints of various shapes produced from materials of various types, selected as a function of the operating conditions and the nature of the fluids circulating in the members, are commercially available.

Among these types of jointi two are particularly widely used: joints of polygonal cross section and joints of substantially oval cross section. The joints known as flat joints of rectangular cross section, which are very widespread, are one particular case of joints of polygonal cross section.

All these joints of annular shape possess coaxial internal and external lateral faces which are cylinders of revolution. Another feature oú these joints is their constant thickness.

As a result of these features, these joints can be used only to ensure the leaktightness of connections 2 of ducting members by means of parallel and coaxial flat flanges.

When two non-coaxial ducting members having intersecting axes are to be connected by flanges, it is necessary to deform one of the two members so that the two connecting flanges are parallel.

If two non-coaxial ducting members having offset parallel axes are to be connected by flanges, it Js necessary to interpose, between the members to be connected, a specially shaped sleeve having two flanges at its ends which are respectively parallel to the flanges of the two members to be connected.

These solutions are difficult to implement, particularly on construction sites, because they require the use of members which have to be specially manufactured.

These solutions are specially costly for the production of ductings in curved formt whether flat or otherwise, from long lengths based on short standard members which are easy to transport and position.

DESCRIPTION OF THE INVENTION

The present invention has the specific object of remedying these disadvantages and providing a leaktight joint for connecting ducting members, fitted at their ends with flanges having non-parallel faces, to each other or to apparatus.

This joint can be used to. connect ducting members whose axes are not aligned without modification of the members, and also to connect members whose axes are parallel but whose flanges have planes which are not perpendicular to the axes.

By virtue of the joint according to the invention, it is possible to produce curved ductings, whether flat or otherwise, from rectilinear members of short length which are easy to manufacturer transport and install.

3 To this end, the present invention proposes an ternal and external annular joint having coaxial int lateral faces an d in the form of surfaces of revolution, a plane of symmetry passing through the axis of revolution of the said lateral faces and possessing first and second contact zones contained, respectively, in first and second planes, the said first and second planes intersecting to form a dihedral having an edge perpendicular to the p lane of symmetry, characterised in that the angle of. the dihedral is between 0.5 and 10 degrees and in that it is produced from dimensionally stable material.

According to another feature, the joint according to the invention has cross sections of oval shape in the planes passing through the axis of the lateral faces.

According to another feature, the joint according to the invention has cross sections of polygonal shape in the planes passing through the axis of the lateral faces.

According to another feature, the joint according to the invention has cross sections of trapezoidal shape in the planes passing through the axis of the lateral faces.

According to another feature, the joint according to the invention has cross sections of rectangular trapezoidal shape 'n the planes passing through the axis of the lateral faces.

The invention also relates to the use of the joint for the connection of two ducting members which are cylinders of revolution and each have an end fitted with a flat flange.

According to another feature of the invention, each flange being disposed perpendicularly to the axis of revolution of the member to which it belongs, the axes of revolution of the two ducting members form an angle of between 0.5 and 10 degrees.

According to another feature of the invention, the axes of revolution of the two ducting members being 4 aligned, at least one of the flanges forms an angle of between 0.5 and 10 degrees with the axis of revolution of the member to which it belongs.

According to another feature, the invention comprises connecting a plurality of rectilinear members to produce a curved ducting.

According to another feature of the invention, the flat flanges have opposite faces which possess means for the axial positioning of the joint.

According to another feature of the invention the means for the axial positioning of the joint are formed by two identical facing grooves obtained by machining on each flange a groove of revolution whose axis coincides with the axis of the ducting member on which each flange is arranged and which possesses at least one face on which the joint bears.

According to a final feature of the invention, the means for the axial positioning of the joint are formed by shoulders obtained by machining on each flange at least one shoulder of revolution whose axis coincides with the axis of the ducting member on which each flange is arranged. BRIEF DESCRIPTION OF THE DRAWINGS 25 The invention will be better understood from a reading of the description which follows, given in a non-limiting manner and with reference to the attached drawings, in which: 30 - Figure I shows a view in traverse section of a joint of rectangular trapezoidal cross section, according to the description of the invention, - Figure 2 shows the joint according to Figure 1 in a view from above, 35 - Figure 3 shows a view in transverse section of a joint of isosceles trapezoidal cross section, - Figure 4 shows a view in transverse section of a joint of symmetrical oval cross section,

Figure 5 shows a view in transverse section of a joint of asyrrinetrical oval cross section, - Figure 6 shows a sectional view of a joint arranged between two flanges mounted at the ends of two 5 ducting members.

- Figure 7 shows a sectional view of a joint arranged between two flanges provided with grooves, mounted at the ends of two ducting members, and Figure 8 shows a sectional view of a joint arranged between two flanges provided with shoulders, mounted at the ends of two ducting members.

DETAILED DESCRIPTION OF THE INVENTION is Figures 1 and 2 show a first form of embodiment of the annular Joint according to the invention, according to which the joint 1, produced from steel, possesses an inner lateral face 2 and an outer lateral face 3, which are surfaces of revolution about a common axis 4, and has a plane 5 of symmetry passing through the axis 4. It additionally comprises two contact zones which connect the lateral faces 2 and 3, a first contact zone 6 included in a first plane 8 and a second contact zone 7 included within a second plane 9 perpendicular to the plane 5 of symmetry.

The first plane 8 and the second plane 9 intersect and form a dihedral having an edge 10 perpendicular to the plane 5 of symmetry, the said edge being situated outside the outside lateral surface 3 of the jcint.

The angle 11 of the dihedral formed by the planes 8 and 9 is equal to 3 degrees.

The transverse sections of the.joint 1, through planes passing through the axis 4 of symmetry, have a rectangular trapezoid shape, in particular the cross sections 12 and 13 which correspond to the cross section of the joint through the plane 5 of symmetry.

6 Thus the joint 1 has the peculiarity of a thickness which is variable both radially and circularly.

Figure 3 shows a second form of embodiment according to which the annular joint according to the invention, produced from steel, possesses cross sections through planes passing through the axis 4 in the form of isosceles trapezoids and a plane 21 of symmetry perpendicular to the axis 4.

lhe first plane B and second plane 20 form a dihedral of angle ll.

Figure 4 shows a third form of embodiment, according to which the annular joint.according to the invention possesses cross sections through planes passing through the axis 4 of oval shape and a plane 26 of symmetry perpendicular to the axis 4.

A first contact zone 24 and a second contact zone 25 are containedo respectively, in a first plane 22 and a second plane 23, the said contact zones being reduced to curves of elliptical shape.

FL.gure 5 shows a third form of embodiment according to which the annular joint 'according to the invention possesses cross sections through planes passing through the axis 4 of asymmetrical oval shapes.

A first plane 22 and a second plane 27 form a dihedral of angle 11, the second plane 27 being perpendicular to the axis 4 of revolution.

Whatever the form of embodiment of the joint according to the invention, it is easy to machine.

Figure 6 Illustrates the use of an annular joint according to the first form of embodiment of the invention, as a sealing member in a flange-type connecting device for two duCting members 30 and 31.

The ducting members 30 and 31, which are cylinders of revolution about, respectively, axes 34 and 35, are provided at their ends with flanges 32 and 33 whose bearing faces 36 and 37 are respectively perpendicular to the axes 34 and 35.

7 The joint 1 is placed between the flanges 32 and 33 so that its contact zones 6 and 7 are respectively In contact with the bearing faces 36 and 37 of the flanges 32 and 33, the axis 4 of the joint 1 coinciding with the axis 35 of the ducting member 31 and the axis 34 of the ducting member 30 passing substantially through the point C defined by the intersection of the axis 4 with the plane 8.

Thus, the bearing surface 36 for the flange 32 on the first contact zone 6 of the joint 1 is contained in the first plane 8 and the bearing surface 37 for the flange 33 on the second contact zone 7 of the joint 1 is contained In the second plane 9.

The flanges 32 and 33 being mounted, respectively, perpendicularly to the axes 34 and 35 of the ductings 30 and 31, respectively, the resultof these arrangements is that the anale formed by the two axes 34 and 35 is equal to the angle 11 of the dihedral form.ed by the planes 8 and 9.

The flanges 32, 33 and joint 1 are held in contact by known gripping means (not shown in Figure 6) which exercise the necessary and sufficient forces for leaktightness to be ensured between the interior and the exterior of the ducting members 30 and 31.

By way of example of gripping means, mention nay be made of a plurality of spherical -headed screw bolts and washers, flange 32 being provided with a plurality of holes 38 and the flange 33 with a f holes 39 opposite the abovementioned holes plurality of for the passage of the said screws; mention may also be made of clamping collars.

To facilitate the axial positioning of the joint 1 relative to the flanges 32 and 33, the flanges may compr'se axial positioning means such as grooves and shoulders produced on the bearing.faces 36 and 37, as shown in Figures 7 and 8 respectively.

By virtue of the invention, it is possible to connect rectilinear ducting members in a simple and economic manner such that their longitudinal axes are - a - not aligned, the angle formed by the said axes being determined by the joint used.

Furthermore, the disalig=ent of the axes of the rectilinear members can be modified by simply 5 changing the joint.

By virtue of the invention, it is also possible to produce economically a curved ducting of great th by assembling rectilinear members of short lengs. length relative to the length of the ducting.

The application of the joints according to the invention is particularly useful for the economical production of a curved ducting, known as a riser, to connect an equipment item installed on the sea bed with a drilling platform or oil production platform on the surface of the sea, the said platform not being vertically above the submerged equipment item.

Claims

9 CLAIMS

1. Annular joint (1) having coaxial internal and external lateral faces (2) and (3) in the form of surfaces of revolution, a plane (5) of symmetry passing through the axis (4) of revolution of the said lateral faces (2) and (3), and possessing first and second centact zones (6) and (7) contained, respectively, in first and second planes (8) and (9), the said first and second planes (8) and (9) Intersecting to form a dihedral having an edge (10) perpendicular to the plane (5) of symmetry, characterized in that the angle (11) of the dihedral is between 0.5 and 10 degrees and in rhat it is produced from dimensionally stable material.

2. JoJnt according to Claim 1, characterized in z5 that it possesses cross sections of oval shape In the planes passing through the axis (4) of the lateral faces (2) and (3).

3. Joint according to Claim 1, characterized in 20 that it possesses cross sections of polygonal shape in the planes passing through the axis (4) of the lateral faces (2) and (3).

4. Joint according to Claim 3, characterized in that the shape of the cross sections in the planes passing through the axis (4) of the lateral faces is trapezoidal.

5. Joint according to Claim (4), characterized in that the shape of the cross sections in the planes passing through the axis (4) of the lateral faces is that of a rectangular trapezoid.

6. Use of the joint according to one of Claims 1 to 5 for the connection of two ducting members (30) and (31) which are cylinders of revolution and each have an end fitted with a flat flange.

7. Use according to Claim 6, characterized in that each flange (32) and (33) being disposed perpendicularly to the axis of revolution of the member to which it belongs, the axes (34) and (35) of revolution of the two ducting members (30) and (31) form an angle of between 0.5 and 10 degrees.

8. Use according to Claim 6, characterized in that the axes (34) and (35) of revolution of the two ducting members (30) and (31) being aligned, at least one of the flanges (32) or (33) forms an angle of between 0.5 and 10 degrees with the axis of revolution of the member to which it belongs.

9. Use according to Claim 6 or 7, characterized in 10 that it comprises connecting a plurality of rectilinear members to produce a curved ducting.

10. Use according to one of Claims 6 to 9, characterized in that the flat flanges have opposite faces (36) and (37) which possess means for the axial positioning of the joint.

11. Use according to Claim 10, characterized in that the means for the axial position ing of the joint are formed by two identical facing grooves obtained by machining on each flange a groove of revolution whose axis coincides with the axis of the ducting member on which each flange is arranged and which possesses at least one face on which the joint bears.

12. Use according to Claim 10, characterized in that the means for the axial positioning of the joint are formed by shoulders obtained by machining on each flange at least one shoulder of revolution whose axis coincides with the axis of the ducting member on which each flange is arranged.