JPS6238593B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealed flexible pipe joint, and more particularly to a sealed flexible pipe joint that can withstand high pressure and maintain fluid tightness while allowing movement between fluid conduits. .

In recent years, exploration for oil, natural gas, etc. has extended to the ocean floor. As exploration expanded to the ocean floor, drilling techniques developed for land use were modified to suit the marine environment. Initially, a drilling platform was fixed on a tower built on the seabed, and excavation was carried out from that platform. Once an oil or natural gas field is ready for production, the oil or gas is sent via undersea pipelines to processing plants on land, rather than being lifted to the surface.

Exploration for oil and gas is currently extending deeper and deeper into the ocean. As exploration moved deeper into the ocean, it became economically and technically impossible to support the drilling platform with an underwater structure based on the seabed. Furthermore, as oil and gas fields are dug more than 1,000 meters below sea level, it has become economically and technically difficult to lay and maintain submarine pipelines. For this reason, there has recently been a trend to build floating platforms for excavation, and to install floating processing equipment to carry out preliminary processing. When using such floating equipment, a method is needed to stabilize the structure, and the conduits for excavation and product suction must be flexible enough to accommodate the sway of the floating platform. It becomes necessary to have it.

Although such a floating platform can be stabilized to a certain extent, it is inevitable that it will sway to some extent due to wave motion. Therefore, for example, excavation operations performed from the platform must be carried out while allowing the platform to oscillate in the horizontal and vertical directions. To allow such movement of the platform, pipes such as drill strings and suction pipes must have flexible joints in the middle, or the pipe itself must be sufficiently flexible so that the platform does not move. The pipe must be such that it cannot move or be destroyed by waves or currents acting on the pipe. The pipes used in drill strings are usually small enough in diameter to allow the platform to flex horizontally or vertically without breaking. On the other hand, water risers and suction pipes, for example, have a relatively large diameter and are less flexible than drill strings. Therefore, large-diameter riser pipes and suction pipes should be equipped with at least one flexible pipe joint that can easily bend to accommodate bending movements and that can withstand and seal against high internal and external pressures.
Must contain.

Some flexible pipe joints used in such water riser pipes, for example, consist of a spherical member having a precisely machined spherical surface and a socket member having a concave surface that slides into contact with the spherical surface. The joint is bendable by the articulation of the ball and socket members. The elastic O-ring also seals the interface between the two sliding surfaces.
However, when high pressure is applied to such a ball joint, relative movement between the two sliding surfaces becomes impossible. Furthermore, this ball joint has the problem that both sliding surfaces and the O-ring are worn out and deteriorated, requiring frequent repair or replacement.

Another method is to connect fluid conduits such as water risers by sandwiching an annular flexible elastic member between flanges provided at opposite ends of both conduits. The elastic member usually consists of alternating layers of non-stretchable material and layers of elastic material. The non-stretchable material layer is typically a metal and the elastic material layer is typically an elastomer. Each layer of the elastic member may be annular with a flat surface, as in the pipe fitting of Johnson, U.S. Pat. No. 3,168,334, or it may have a spherical surface, as in the flexible fitting of Harvard et al. It may have a ring shape. Such a laminated elastic member allows flexural movement of the joint and also functions as a seal. Since a joint using this laminated elastic member does not have a so-called "moving part", there is no problem of wear as in the ball joint. Examples of flexible pipe fittings using laminated elastic members are also described in Harvard et al., US Pat.

Flexible joints using such elastic members do not suffer from the wear problems of ball-and-socket type flexible joints that have a spherical member and a socket member, but they are subject to some axial loads and large pressure differences. If this occurs, there is a problem in that the laminated elastic member is likely to be destroyed. The elastomer layers of laminated elastic members can withstand fairly high compressive loads, but are relatively weak in tensile loads. Therefore, when a tensile load is applied to the laminated elastic member due to relative movement in the axial direction of the two conduits connected by the joint, the laminated elastic member is likely to be destroyed. One way to solve this problem is to use a tension bar that supports the tensile load before it is applied to the elastic member. Furthermore, multiple pairs of laminated elastic members may be used such that at least one elastic member is always compressed regardless of the direction of axial movement of both conduits. Furthermore, by bonding and integrating adjacent elastic members together, the tendency of the elastic members to break due to high pressure differences can be reduced. In addition, the shape of the elastic member is made into a wedge shape that is thicker on the high-pressure side and thinner on the low-pressure side.The wedge effect prevents the elastic member from protruding toward the low-pressure side due to pressure on the high-pressure side. U.S. Patent Application No. 621433 filed by the applicant is intended to withstand high pressure differences acting on the
has been proposed.

In view of these circumstances, it is an object of the present invention to provide a sealed flexible pipe joint that can withstand extremely large pressure differences.

Furthermore, the present invention provides a highly reliable joint that has double fluid sealing using elastic members to ensure fluid sealing, so that even if one is damaged, the sealing performance of the other is not impaired. The purpose is to provide

The flexible pipe fitting of the present invention consists of a hollow annular housing and a tubular member having an outer diameter smaller than the maximum inner diameter of the housing. The housing has an opening at each end thereof and further includes a pair of annular flanges extending radially inwardly relative to a maximum inner diameter of the housing. The pair of flanges are spaced apart from each other in the length direction of the housing. An annular flange is provided adjacent one end of the tubular member and extending radially outwardly of the tubular member. The annular flange is positioned between a pair of annular flanges of the housing. The other end of the tubular member projects from the opening at one end of the housing to the outside of the housing and is adapted to be attached to one of the two fluid conduits to be connected. A pair of annular elastic members are arranged between one flange of the housing and the flange of the tubular member and between the other flange of the housing and the flange of the tubular member. Each elastic member includes at least one elastomeric body. One elastic member is disposed between the tubular member and the housing and includes at least one fluid-tight passageway connecting the tubular member and an opening at the one end of the housing from which the tubular member projects and an opening at the opposite end of the housing. forms part of it. Both elastic members are arranged within the housing so as to form, together with the housing, a fluid-tight annular space within the housing that is independent of the passageway thereof. One side of the one elastic member forming the passage faces the passage, and the other side faces the space. One side of the other elastic member faces the space and the other side faces the outside of the joint. Furthermore, the space is filled with a liquid that is almost incompressible.

The liquid transmits pressure between both elastic members. Both elastic members therefore act in series with each other to share the load due to the pressure difference between the fluid pressure in the passage and the external pressure. For example, when the internal pressure is higher than the external pressure, the elastic member facing the passage is pushed by the internal pressure and deforms. The deformation causes a load to be applied to the liquid, which in turn transmits the load to the other elastic member. Since the inner elastic member also has a certain degree of resistance to internal pressure, the pressure applied to the outer elastic member is reduced accordingly. In addition, the outer elastic member not only shares the load due to the pressure difference with the inner elastic member, but also backs up the load when the inner elastic member is destroyed for some reason, thereby sealing the fluid inside the joint. For this purpose, the outer elastic member must withstand the full load due to the difference between the internal and external pressures.

The joint of the present invention is somewhat similar in overall structure to the joint shown in the conventional patent, but the conventional joint has two elastic members connected in series to share the load due to the pressure difference between the internal and external pressures. There is no array arranged in .
For example, the aforementioned Harvard et al. U.S. Patent No. 3,680,895
No. 3,734,546, and No. 3,853,337 disclose a flexible joint comprising a pair of elastic members disposed within an annular housing. Each resilient member defines an annular space surrounding a fluid passageway through the joint.
However, in the three Harvard et al. patents mentioned above, both elastic members are not configured to share the load based on the pressure difference between them, and the pressure in the fluid passage and the pressure in the annular space surrounding the passage are are configured to be equal. Therefore, the joint is sealed only with the outer elastic member and is configured to withstand pressure differences. A joint constructed to equalize pressure is also shown in FIG. 4 of Harvard et al., US Pat. No. 3,390,899. Although this patent does not specifically mention the structure that equalizes pressure, which is clearly shown in the other three patents, this patent also includes the following:
There is no suggestion of a structure in which the annular space between both elastic members is filled with an almost incompressible liquid so that both elastic members share the load due to the pressure difference.

In one embodiment of the present invention, at least one of the elastic members includes an elastomer body and a pair of rigid rings, and the elastomer body is disposed between the pair of rigid rings, and the elastomer body is disposed between the pair of rigid rings, and the elastomer body is disposed between the pair of rigid rings, and the elastomer body is disposed between the pair of rigid rings, and the elastomer body is disposed between the pair of rigid rings. closely engaged. With this configuration, an annular side surface of the elastomer body is formed between both rings, which becomes an exposed side surface of the elastic member. One of the rigid rings fluid-tightly engages a flange of the tubular member and the other rigid ring fluid-tightly engages a flange of the housing. In a preferred embodiment of the invention, each elastic member includes a plurality of non-extensible annular shims embedded within the elastomeric body at spaced intervals. The shim and elastomeric body are generally spherical rings. The shim improves the ability of the elastomeric body to withstand compressive loads and, when spherical, facilitates rocking of the tubular member relative to the housing about an axis perpendicular to the axis of the coupling.

Embodiments of the present invention will be described in detail below with reference to the drawings.

The drawing is a partial cross-sectional and side view of a flexible pipe joint according to an embodiment of the present invention. In the drawings, the joint 10 of this embodiment has its upper and lower ends fluid-tightly connected to fluid conduits 12 and 14, respectively. Any conventionally known method may be used for this connection. For example, conduits 12-14 and fitting 10
flanges are provided at mutually opposing ends, and bolts passing through both flanges are used to
You can also tighten it. Furthermore, both flanges may be welded. The conduits 12, 14 are designed to allow passage of fluids such as oil, natural gas, water, etc. in a completely sealed manner. fitting 10 and conduit 12,
14 are both used while submerged in a fluid (usually underwater). Of course, it may also be exposed to the air. The internal and external pressures of conduits 12, 14 and fitting 10 are typically different. Joint 1 as described later
0 has a structure that can withstand the pressure difference and connect both conduits 12 and 14 in a sealed manner. The fitting 10 is also adapted to permit relative rocking movement between the conduits 12, 14 about an axis perpendicular to the longitudinal axis 16 thereof.

Fitting 10 includes a hollow annular housing 18 made of an airtight material such as steel.
The housing 18 includes a generally tubular body 20 and first and second flanges 22, 24 extending radially inwardly from the body 20. The first flange 22 has an annular shape and is located at one end of the main body 20. Its first flange 22
has multiple bolts 2 near its outer edge.
6 to the main body portion 20. The bolt 26 has a plurality of holes 28 arranged in a circle near the outer edge of the first flange 22.
the main body part 2 so as to pass through the hole 28 and align with the hole 28.
It is screwed into a screw hole 30 carved in the end face of 0. The bolt 26 has a hexagonal recess (not shown) in the head so that it can be tightened with a hexagonal wrench.
It is equipped with First flange 22 and main body 20
Two O-rings 32, 34 are fitted on the axial protrusion of the first flange 22 to ensure fluid tightness therebetween. Both O-rings 32 and 34 are
The first flange 2 fitted into the main body 20
It is placed in two annular grooves carved parallel to the two axial projections. The O-rings 32 and 34 are
It is airtightly engaged with the inner wall of the main body part 20. Because the first flange 22 is annular, its end of the housing 18 is open.

The second flange 24 is integrally formed with the tubular body portion 20 . The second flange 24 is made considerably thicker than the main body 20 because a larger load than the main body 20 of the housing 18 is applied perpendicularly to most of its surface. The second flange 24 is annular and has a longitudinal axis 16.
It is spaced apart from the first flange 22 along. The second flange 24 has a downwardly extending tubular extension 36 to which the conduit 14 is connected.

One end of a tubular member 38 formed of a gas-tight material such as steel is inserted into the housing 18. The tubular member 38 projects outwardly through an opening in the housing 18 formed by the first flange 22. This tubular member 3
The conduit 12 is fluid-tightly connected to the outwardly projecting end of 8 . An annular flange 40 is disposed at the end of the tubular member 38 that is inserted into the housing 18 . The flange 40 extends radially outwardly from the body 42 of the tubular member 38. Further, the flange 40 is located between the first and second flanges 22 and 24 of the housing 18.
The flange 40 is a ring formed separately from the main body 42 of the tubular member 38 and fitted into an annular groove provided on the outer periphery of the main body 42.

between the first flange 22 of the housing 18 and the flange 40 of the tubular member 38 and the housing 18
annular first and second elastic members 46, 4 between the second flange 24 of the tubular member 38 and the flange 40 of the tubular member 38;
8 are arranged respectively. Each elastic member 46,4
8 includes an annular elastomer body. The elastomeric body of the first elastic member 46 is connected at one end to the first flange 22 and at the other end to an end plate 50 that serves as a rigid ring. This end plate 50
is a part of the first elastic member 46. End plate 50 is preferably formed of metal and is engaged with and supported by flange 40 of tubular member 38. An annular O-ring 52 is connected to the end plate 50.
and the tubular member 38 are fluid-tightly sealed.
First flange 22 of housing 18 and end plate 50
The surfaces facing each other are spherical. In this embodiment, the spherical surfaces on both sides rotate around an arc having a common center 54. However, the arcs forming the two spherical surfaces need not be concentric, but may be arcs of the same radius with centers at different positions along the axis 16. An elastomer body 56 is disposed between the first flange 22 having such opposing surfaces and the end plate 50, and both end surfaces of the elastomer body 56 are bonded to the opposing surfaces, respectively. The elastomeric body 56 is formed from a material that is less extensible than an elastomer and includes a plurality of annular shims embedded within the elastomeric body and spaced apart from one another. In other words, the structure disposed between the first flange 22 and the end plate 50 is comprised of a plurality of alternating layers of elastomeric material and non-stretchable material laminated and adhered to each other.

Preferably, shim 58 is formed of steel;
Preferably, the elastomeric body is formed from nitrile rubber. Nitrile rubber has excellent oil resistance. The shim and elastomeric body may be formed from suitable non-extensible and elastomeric materials other than steel and nitrile rubber. For example, other synthetic rubbers or natural rubbers may be used instead of nitrile rubber, and other metal fiberglass, reinforced plastics, high-tensile fiber reinforced resins, etc. may be used instead of steel. The shim 58 has a spherical surface having a common center with the inner surface of the first flange 22 and the outer spherical surface of the end plate 50. In this way, the first elastic member 46 has a spherical shape as a whole and functions like a universal joint. Relative rotational movement between members other than the elastomer body (ie, shim 58, first flange 22, end plate 50) is permitted by deformation of the elastomer body 56.

The second elastic member 48 has almost the same structure as the first elastic member 46. The second elastic member 48 has two annular end plates 60, 62 that serve as rigid rings having a relatively large mass and high rigidity. The two end plates 60, 62 are preferably formed of metal. The opposing surfaces of both end plates 60 and 62 form spherical surfaces having a common center. The common center is the first flange 22, the end plate 5
0 and the center 54 of the spherical surface of the shim 58. An annular elastomer body 64 has both end plates 6
0 and 62, and both end surfaces are bonded to the opposing spherical surfaces. An elastomer body 64 similar to the elastomer body 56 of the first elastic member 46
is formed from a material with little extensibility compared to the elastomer and includes a plurality of shims 66 embedded within the elastomer and spaced apart from one another. This shim 66 has an annular shape, and further has an arcuate cross section in the radial direction. The center of the arc coincides with the center of the arc serving as a reference for the spherical surfaces of the end plates 60, 62. Elastomeric body 64 and shim 66 of second elastic member 48 may be formed of the same material as elastomeric body 56 and shim 58 of first elastic member 46, respectively. However, the second elastic member 48 is configured to more easily deform under compressive loads than the first elastic member 46. This is the second elastic member 4
By forming the elastomer body 64 of No. 8 from a material softer than the material of the elastomer body 56 of the first elastic member 46, and by configuring the shim 66 so as to have a smaller influence on the shape of the elastomer body than the shim 58. It is possible.

The surface of the end plate 60 opposite to the surface to which the elastomer body 64 is bonded is the lower surface of the end plate 50 of the first elastic member 46, the annular flange 40 of the tubular member 38, and the main body of the tubular member 38. 42. The end plates 50 and 60 have mating surfaces that closely fit each other so that relative radial movement between the end plates 50 and 60 is minimized, if not completely prevented. Two O-rings 68, 70 are placed in annular grooves cut into the engagement surfaces of end plates 50 to provide a fluid-tight seal between end plates 50 and 60. Similarly, two O-rings 7
2 and 74 are placed in an annular groove carved in the engagement surface of the tubular member 38, and the end plate 60 and the tubular member 3
8 is fluid-tightly sealed. These seals effectively prevent the flange 40 of the tubular member 38 from fluid contact even though the flange 40 is not itself in sealing engagement with any other member.

The other end plate 62 of the second elastic member 48 is in close contact with and supported by the second flange 24 of the housing 18. 2 O-rings 76,
78 are received within two annular grooves cut into the end plate 62 to provide a seal between the end plate 62 and the flange 24. An annular projection 80 of end plate 62 extends along the length of housing 18 and fits into an annular recess cut adjacent the inner periphery of second flange 24 . This prevents movement of the end plate 62 in the radial direction of the housing 18 and along the axis 16 in the direction of the conduit 14. Additionally, a thin film of elastomer covers the inner surface of the end plate 62 to prevent corrosion of the end plate 62.

In the assembled state of the joint 10 as shown in the figure,
A fluid-tight passageway is formed through the fitting 10.
A portion of the wall of the passageway is formed by the annular side surface 84 of the second resilient member 48 . Additionally, an annular fluid-tight space 82 is formed within the housing 18 surrounding the passageway and independent of the passageway.
The space 82 includes the inner surface of the main body 20 of the housing 18, the inner surface of the second flange 24, the other side surface 86 of the second elastic member 48, and the first elastic member 4.
6 is formed by one side 88 of 6. This space 82 is filled with a nearly incompressible liquid 90 such as water, mineral oil, or a mixture of water and ethylene glycol. This liquid 90 is introduced into the space 82 through a through hole 92 formed in the main body 20 of the housing 18 . The through hole 92 has a plug 9 with a thread.
4 and an O-ring 96.

A conduit 12 is fluid-tightly connected to the projecting end of the tubular member 38 and a conduit 14 is fluid-tightly connected to the tubular extension 36 of the second flange 24 . A pressurized fluid such as oil or natural gas flows between the conduits 12 and 14. In oil and gas well drilling equipment, both conduits 12 and 14 are typically under tension throughout their length. Tension on the joint 10 is supported by compressing the first elastic member 46. Since the elastomer body 56 deforms when a compressive load is applied to the first elastic member 46,
Both the end plate 50 and the flange 40 of the tubular member 38 tend to move away from the end plate 60 of the second resilient member 48 . To prevent such relative movement from destroying the seal between end plates 50, 60 and between end plate 60 and tubular member 38, both resilient members 46, 48 are used during assembly of the fitting. , the first and second flanges 2 of the housing 18
It has been compressed and deformed between 2 and 24 in advance. As mentioned above, since the second elastic member 48 is more easily deformed by compression than the first elastic member 46, the pre-compression causes the second elastic member 48 to deform more easily than the first elastic member. It is deformed more than 46. Therefore, even if the first elastic member 46 is compressed by the tension applied to both conduits 12 and 14, the deformation of the first elastic member 46 due to the compression will cause the second elastic member 4 to deform.
Not enough to completely release 8. For example, O
Rings 70, 74, 76 remain compressed. Furthermore, the pre-compression prevents relative movement between adjacent metal members, thereby limiting the friction of the abutment surfaces of those members.

The spherical surfaces of the non-extensible components of both elastic members 46, 48 permit angular displacement of the fitting 10 of the conduits 12, 14 in either direction. The relative rotation of the inextensible members of each elastic member 46, 48 and the deformation of the elastomers 56, 64 permit the conduits 12, 14 to be positioned at an angle to each other. Relative rotation of the non-extensible members occurs about the common center 54.
Even in the deformed state, both elastic members 46, 48 seal the fluid flowing within the joint 10. Fitting 1
Since there is almost always a difference between the pressure of the fluid flowing through the fitting 10 and the environmental pressure of the fitting 10, both elastic members tend to deform due to the pressure difference. For example, joint 1
Assuming that the pressure of the fluid within 0 is higher than the environmental pressure, the second elastic member 48 expands toward the outer surface 86 due to the pressure exerted on the inner surface 84 thereof. The liquid 90 in the annular space 82 is thereby pushed by the outer surface 86 of the second elastic member. Since this liquid 90 has almost no compressibility, the pressing force on its outer surface is transmitted to the side surface 88 of the first elastic member 46 on the space 82 side with almost no attenuation. The load applied to this side surface 88 is absorbed by the first elastic member 46.

Elastomer body 56 of both elastic members 46, 48,
64 are each connected to an end plate and therefore provide resistance to pressure.

Therefore, whenever the elastomeric bodies 56, 64 transmit pressure from one side to the other, there is a pressure attenuation. each elastomer body 56,
Because of the embedded shims 58, 64 within 64, a significant portion of the pressure is absorbed within each elastomer. The pressure exerted by the second resilient member 48 on the liquid in the space 82 is therefore considerably less than the pressure exerted by the fluid in the fitting 10 on the first resilient member 46. Therefore, the pressure applied to the first elastic member 46 is considerably attenuated. In this way, the difference between the internal pressure and the external pressure is absorbed by both elastic members 46 and 48 in a divided manner. The amount of pressure applied to each elastic member 46, 48 depends on factors such as the specific surface area of the portion of the elastic member 46, 48 exposed to pressure and the relative flexibility of the elastomeric body used in the elastic member. . The proportion of the total pressure difference absorbed by each elastic member 46, 48 can also be adjusted by initially subjecting the liquid in space 82 to a pressure somewhat above normal atmospheric pressure. In the joint 10 of this embodiment, both elastic members act in series to withstand the difference between the pressure of the fluid inside the joint 10 and the external pressure, so there is a double seal in the joint 10. I will do it. The second seal acts as the primary seal.
Even if the first elastic member 48 is destroyed for some reason, the first elastic member 46 can prevent the fluid inside the joint 10 from flowing out. Such features are particularly important when the fluid flowing through the joint 10 is one that pollutes the environment, such as petroleum. In order for the first elastic member 46 to function as a safety seal in this manner, the first elastic member 46 must be able to independently withstand the entire load due to the pressure difference between the internal pressure and the external pressure.

To enhance the utility of fitting 10 as a dual seal, a pressure transducer 100 is disposed within housing 18 and is adapted to sense the pressure of liquid 90 within space 82. This transducer 100 is conveniently located at the inlet portion of the hole 92 used to fill the space 82 with liquid 90. A lead wire 102 extends through a small hole (not shown) through the plug 94 to a remote display device so that the pressure within the space 82 can be monitored. By reading the pressure in the space 82 transmitted by this transducer 100, it is immediately possible to know if either one of the elastic members is destroyed, and the other elastic member is not destroyed. Since the joint can be repaired immediately, there is no need for emergency repairs, and leakage of fluid within the joint can be prevented.

The joint of the above embodiment can be modified in various ways without affecting its function. For example, the elastomer body of the second elastic member 48 does not necessarily have to be the shim 6.
6 may not be included. This is because, unlike the first elastic member 46, a large compressive load is not applied to the second elastic member 48. Also, the body 42, flange 40, end plate 50, and end plate 60 of the tubular member 38 can be, and sometimes convenient, formed as one piece. The first flange 22 of the housing 18 may be attached to the main body part 20 by a method other than bolting, for example, the first flange 22 of the housing 18 may be attached to the main body part 20 by threads that are threaded into each other. Further, the second flange 24 may be separate from the housing. Only the flange 40 is integrated with the main body portion 42 of the tubular member 38, and the end plate 5
0 and 60 may be separate bodies. Alternatively, the tubular extension 36 of the second flange 24 may be removed to connect the conduit 14 directly to the second flange 24. Furthermore, the first elastic member may be coupled to the first flange 22 via another end plate member. Also, the shims in the elastic member need not necessarily have a uniform thickness, but may be tapered when measured radially from the center 54. First,
As a modification of the second elastic members 46 and 48, as shown in FIG. 3 of U.S. Pat. It may be possible to expose it.

[Brief explanation of the drawing]

The drawing is a partially sectional side view of a flexible joint according to an embodiment of the present invention. 18... Housing, 20... Main body, 22,
24... flange, 38... tubular member, 40...
Flange, 46, 48...elastic member, 82...space, 90...liquid.

Claims (1)

[Scope of Claims] 1. A pipe joint for connecting two conduits through which a fluid having a pressure different from an external pressure is passed, which includes a through hole penetrating from one end to the other end and spaced apart from each other in the length direction of the through hole. a hollow annular housing comprising first and second radially inwardly extending annular flange means having an annular shape, the first annular flange means being closer to the one end than the second annular flange means; an annular flange means having an outer diameter smaller than the maximum diameter of the through hole of the housing and extending radially outward at one end;
said annular flange means being a first of said housing;
a second annular flange means, the second annular flange means being inserted into the through hole such that the other end thereof projects outwardly from the one end of the through hole of the housing, and one conduit is connected to the other projecting end of the through hole; a tubular member adapted to be connected, the tubular member having at least one elastomeric body and a pair of annular side surfaces between the first annular flange means of the housing and the annular flange means of the tubular member; a first elastic member disposed within the through hole to surround the tubular member; and at least one elastomer body and a pair of annular side surfaces, and a second annular flange means of the housing. a second elastic member disposed between the annular flange means of the tubular member and forming at least a portion of a fluid-tight passage connecting the tubular member and the other end of the through hole; The housing and both elastic members form a fluid-tight annular space in the housing that is independent of the fluid-tight passage, one side of the first elastic member facing the external pressure side and the other side facing the external pressure side. The second elastic member faces the annular space, one side of the second elastic member faces the fluid-tight passage, and the other side faces the annular space. a liquid that transmits pressure between the other side of the first elastic member and the other side of the second elastic member;
A sealed flexible pipe joint, characterized in that both elastic members are adapted to share with each other the loads resulting from the pressure difference between the pressure within the fluid-tight passageway and the external pressure. 2. At least one of the first and second elastic members includes a pair of rigid rings arranged at a distance from each other, and the elastomer body of the elastic member is arranged between the two rings, and the elastic member is arranged between the two rings. fluid-tightly engaged with mutually opposing surfaces of the elastomeric member, the annular sides of the elastomeric body forming exposed sides of the elastic member. pipe fittings. 3. One of the pairs of rings is fluid-tightly engaged with the tubular member, and the other is fluid-tightly engaged with one of the first and second flanges of the housing. Claim 2
Pipe fittings listed in section. 4. The pipe joint according to claim 2, wherein the elastomer body is bonded to each of the rings. 5. The method of claim 1, wherein each of the elastic members includes a plurality of non-stretchable shims embedded at intervals within the elastomer body and bonded to the elastomer body. pipe fittings. 6. The pipe joint according to claim 5, wherein each of the shims and the elastomer body is a substantially spherical ring. 7. Claims characterized in that when the external pressure and the pressure in the fluid-tight passage are equal to standard atmospheric pressure, the liquid in the space is pressurized to have a pressure higher than standard atmospheric pressure. The pipe joint described in paragraph 1. 8 said second elastic member is responsive to a compressive load applied by said tubular member flange means and a housing second flange means; Claim 1 characterized in that it resists less and is more easily deformed than to a compressive load of equal magnitude applied by the flange means of.
Pipe fittings listed in section. 9. The pipe joint according to claim 1, wherein the housing has a sealable hole that communicates the annular space with the outside. 10. The pipe joint according to claim 1, wherein the second flange of the housing is formed integrally with the main body.