WO1984000594A1

WO1984000594A1 - Articulated pipe coupling

Info

Publication number: WO1984000594A1
Application number: PCT/SE1982/000250
Authority: WO
Inventors: Stig S A Johansson
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-07-28
Filing date: 1982-07-28
Publication date: 1984-02-16
Anticipated expiration: 1985-01-28
Also published as: EP0116033A1; AU8738282A

Abstract

Articulated pipe coupling comprising a central spherically S-curved pipe bend (3) and on each side of said central pipe bend (3) a two-dimensionally curved pipe bend (4, 5) each rotatably connected to the central pipe bend (3), and whereby the two outer pipe bends (4, 5) are rotatable in planes perpendicular to each other. Sealings and guides between the pipe bends (3, 4 and 3, 5) can be provided externally of the pipe bends, and the mutual interconnection of the pipe bends (3, 4 and 3, 5) preferably is provided internally of the pipe bends and is at least somewhat resilient. The two outer pipe bends (4, 5) may be formed with a curvature of more than 90o so that the outlets (8, 9) of the articulated pipe coupling extend substantially on the same axial line.

Description

Articulated pipe coupling.

The present invention relates to an apparatus, called arti¬ culated pipe coupling, and which is^' intended for interconnection of tubes, pipes and other components and which is formed so that movements and strains, which may appear in the said pipes or simi¬ lar devices are received by. the articulated pipe coupling.

When laying pipe-lines comprising several interconnected pipes, tubes or other components strains or torques may appear in the pipes. The said strains and torques especially affect the connection points between the pipes. When laying such pipe-lines on a plane surface, whether on or above the earth or in the air or in the water small strains and torques normally are compensated by the pipes themselves.

In many cases, however, the pipes are laid on uneven ground, sometimes since the pipes^"must be brought to pass stone blocks, rocks and other elevated portions of the ground, whereby the pi¬ pes are heavily curved. The costs for. planning the substrate for the pipes by blasting, excavation etc are often so high that it should be advantageous to have the pipes follow the unevenesses instead. In order to eliminate the movements and the strains at blunt pipe connection at such unevenesses the invention foresees to use an articulated pipe coupling which is formed so that the movements, torques, strains etc. which tend to appear when laying the pipes are received only by the articulated pipe coupling. Therefore the coupling is formed with at least three pipe coupling portions which are rotatably connected to each other and which are formed so that the articulated pipe coupling as a whole can rotate in at least two directions which are perpendicular to each other, basically in the same way as a Cardan joint. Articulated pipe couplings of this type are known for in-

OMPI _.. stance from the US patent 622305. The known pipe coupling com¬ prises two joint halves which are interconnected by means of a joint which is actuatable from outside, and in which each joint half is provided with a preferably rotatably connected connection for a tube. The previously known pipe joint involves some essen¬ tial disadvantages. The joint means actuatable from outside may be damaged if the pipe joint moves, for instance if the pipe joint depending on frequent movements scrapes against some hard object on the ground, in the earth or at the bottom of the see. Since further the joint halves are formed for overlapping the flowing fluid has to be articulated twice each time at 90° when passing each joint, what limits the flow capacity, what is a risk for crea¬ ting of turbulent flows, which may create noice and which restricts the flow speed and can cause wear and tear of any parts included in the pipe joint.

Therefore the invention is concerned with an articulated pipe coupling which is formed for taking and eliminating movements, strains and torques etc. appearing in pipe-lines composed of seve¬ ral interconnected pipes, and in which the pipe coupling can take expansions, contractions and any other movements in the pipes, in which the pipe coupling as a whole has practically unrestricted flow area and the shortest possible bends, and in which the pipe coupling as a whole is formed with curved surfaces which both gi¬ ves a practically unreduced flow area through the entire coupling and allows a soft, 1aminary flow through the articulated pipe coup¬ ling.

The articulated pipe coupling according to the invention com¬ prises a central spherically S-formed pipe bend which at each end has a coupling means in which a curved pipe bend is rotatably con- nected. The two curved pipe bends are rotatable in different pla¬ nes which are perpendicular to each other, for instance one pipe bend in the horizontal plane and the other pipe bend in the verti¬ cal plane, and the two curved pipe bends are connected to the S- formed central pipe bend by means of an inner screw joint. The in- ner screw joint may be formed so as to give a very little reduction of flow area through the articulated pipe coupling. Further characteristics and advantages of the invention will be evident from the following- detailed description in which refe¬ rence will be made to the accompanying drawings.

In the drawings Figure¹1 shows an articulated pipe coupling according to the invention having pipes connected at each end thereof, and Figure 2 shows a cross-section through the articula¬ ted pipe coupling according to Figure 1 along line II - II. Figure 3 is an enlarged cross-sectional view of an additional ar¬ ticulated pipe joint which can additionally be connected at any of the ends of the pipe coupling.

The articulated pipe coupling shown in Figures 1 and 2 is intended for interconnection of two pipes 1 and 2 so that move¬ ments of one pipe in relation to the other, strains in and between the pipes and torques between the pipes can be eliminated. This is made by the articulated pipe coupling, according to the invention which allows a rotation in all directions between the tubes 1 and 2.

The articulated pipe coupling^" comprises a spherically S- curved pipe bend 3 which at each end has a two-dimensionally curved pipe bend 4 and 5 rotatably connected thereto. For the connection of the central S-pipe bend 3 and the two outer pipe bends 4 and 5 respectively the pipe bends are formed with sealing swivel flanges 6 and 7 respectively. The two swivel flanges 6 and 7.are provided into planes perpendicular to each other, for instance one swivel flange 6 for rotation in a horizontal plane and the second swivel flange 7 for rotation in a vertical plane. Thereby the two outer pipe bends 4 and 5 and the pipes 1 and 2 connected thereto can be rotated in a Cardan-like way. Thereby the pipes 1 and 2 can be laid at any angle to each other, and by providing two articulated pipe couplings according to the invention on some distance from each other also longitudinal movements in the axial direction bet¬ ween the pipes can be overcome by the pipe coupling. The two outer pipe bends 4 and 5 are formed with coupling flanges 8 and 9 for connection of the pipes 1 and 2 respectively in a conventional way. For providing the largest possible flow area through the articulated pipe coupling the swivel flanges 6 and 7 between the

OMPI central pipe bend 3 and the two outer pipe bends 4 and 5 prefer¬ ably provided at the outside of the pipe bends in order not to occupy any portion of the total flow area. The pipe bends are formed with an even curved bend radius and thereby the pipe bends provide a smooth and even flow passageway which to a very small degree affects the flow through the pipes and the pipe bends and which gives an even and 1aminary flow-.

The swivel couplings 6 and 7 between the central pipe bend 3 and the outer pipe bends 4 and 5 may be formed in different ways. Preferably the connection, however, is made by an inner connection means which is shown in Figure 2. The central, spherically S- for ed pipe bend 3 is at each end formed with an outer slide ring half 10 extending round the entire pipe and having a male guide 11. The adherent outer pipe bend 4 (and 5 respectively) is at the end facing the central pipe bend 3 formed with a corresponding slide ring half 12 having a groove 13 for receiving the male guide 11 and on each side thereof a groove 14 and 15 for 0-ring seals 16 and 17. The said^" slide ring half 12 also can be formed with a cover flange 18 for the slide ring surfaces. For the connection of the central pipe bend 3 with the outer pipe bends 4 and 5 res¬ pectively is used an inner coupl ng means comprising a central coupling tube 19 which is centrally mounted at the end of the S-^" formed pipe bend 3 by means of four struts 20. The outer pipe bend 4 and 5 respectively is formed with a spring housing 21 which is mounted centrally at the end of the pipe bend 4 and 5 likewise by means of struts 22 and in a suitable location in relation to the coupling tube 19. In the spring housing 21 a spring .23 is mounted and the spring is supported by the bottom of the spring housing 21. The coupling tube 19 is formed with inner threads, and the pipe bends 3, 4 and 3, 5 respectively are kept together by means of a bolt 24 with a nut 25 butt screwed to the nut 26 of the coupling tube 19. The compression spring 23 which is acting between the nuts 25 and 26 on one hand and the bottom of the spring housing 21 on the other hand thereby receives all movements which may appear between the slide ring halves 10 and 12. For adapting the spring load between the pipe bends spacers 27 may be mounted between the

OMFI ceiving access to the connection means the outer pipe bends 4 and 5 are formed with lids 28 which are sealingly mounted on the outer surface of the pipe bends. It is the intention to provide as straight flow line as pos¬ sible and for this purpose the outer pipe bends 4 and 5 are for¬ med as shown in Figure 2, whereby the coupling, flanges 8 and 9 are located substantially on the same axial line and whereby the pipes 1 and 2 in some positions of the articulated pipe coupling like- wise extend on the same axial line. Thereby an optimum straight and unrestricted flow movement of the flowing medium is obtained through the articulated pipe coupling. Each connected pipe, tube or other component can be rotated_^ in all directions without the risk of leakage of the passing liquid or gas fluid in the pipe coupling. The inner spring loaded screw joint gives a good sea¬ ling for the slide rings and by the double screw joint in the in-, ner screw connection means a large safety of τnaterial is obtained, and the short and compact coupling means are protected against outer damage. The articulated pipe coupling is suited also for connection to heavy pipes for instance pipes for the transporta¬ tion of gas and oil at the bottom of the see, and by the pipe coupling the pipes can be laid substantially freely, whereby the pipes depending on the pipe coupling will follow the contour of the bottom of the see, and still no tension, pressure and torques between the pipes appear. Any raised and lowered portions of the bottom of the see are automatically equalized when laying the pipe line.

In order to eliminate any rotating movements along the ax s of the pipes the separate axial slide coupling 29 shown in Figure 3 can be connected to the coupling flange 8 or 9 at the outer pipe bends 4 and.5. Thereby it is also possible to rotate each pipe 1 or 2 along the axial line in addition to the overall movement bet¬ ween two interconnected pipes.

OMPI

Claims

C 1 a i m s

1. Articulated pipe coupling having several pipe bends (3-5), in which the two outer pipe bends (4, 5) are formed for con- nection of pipes (1,.2), tubes or any other components in such a way that any movements and strains between the interconnected pi¬ pes, tubes or other components- are compensated and eliminated, c h a r a c t e r z e d in that the articulated pipe coupling comprises a central spherically S-curved pipe bend (3) and two outer mirror-symmetrically like two-dimensionally curved pipe bends (4, 5) which are rotatably connected to the central pipe bend (3) so as to be rotatable in two planes which are perpendicular to each other.

2. Articulated pipe coupling according to claim 1, c h a - r a c t e r i z e d in that swivel fTanges (6, 7) for mutual ro¬ tation of the three pipe bends (3, 4, 5) are provided at the out¬ side of each pipe bend and are formed as seal ng swivel-slide rings (10, 12).

3. Articulated pipe coupling according to claim 1 or 2, c h a r a c t e r i z e d^* in that the pipe bends (3,.4, 5) are mutually interconnected by inner screw connection means (19-27).

4. Articulated pipe coupling according to claim 3, c h a ¬ r a c t e i z e d in that the inner screw connection means com¬ prises a coupling tube (19) which is mounted in one pipe bend by means of struts (20) and a spring housing. (21) which is mounted in the adjacent pipe bend by means of struts (22) and a bolt means (24, 26) and a spring means (23) acting, between the coupling tube (19) and the spring housing (21) for resilient interconnection -of the pipe bends (3 - 5).

5. Articulated pipe coupling according to any of the prece¬ ding claims., c h a r a c t e r i z e d in that the outer two- dimensionally curved pipe bends (4, 5) provide a pipe bend of more than 90° and are formed so that coupling flanges (8, 9) at the out¬ lets of said two pipe bends (4, 5) are located on the same axial line, and whereby the flow of medium through the articulated pipe coupling is nearly axial.

6. Articulated pipe coupling according to any of the prece¬ ding claims, c h a r a c t e r i z e d in that a separate axial slide coupling (29) is connected to the outer end of at least one of the outer two-dimensionally curved pipe bends (4, 5) for allo¬ wing a rotation along an axial line of the two interconnected pipes (1, 2).