CN112503274B

CN112503274B - Pipeline for aircraft fuel system and pipeline system

Info

Publication number: CN112503274B
Application number: CN202011349420.2A
Authority: CN
Inventors: 刘德刚; 高广拓; 黄晓霞; 赵士洋; 宋扬; 高和
Original assignee: Comac Shanghai Aircraft Design & Research Institute; Commercial Aircraft Corp of China Ltd
Current assignee: Comac Shanghai Aircraft Design & Research Institute; Commercial Aircraft Corp of China Ltd
Priority date: 2020-11-26
Filing date: 2020-11-26
Publication date: 2022-02-01
Anticipated expiration: 2040-11-26
Also published as: CN112503274A

Abstract

The invention relates to a pipeline for an aircraft fuel system and a pipeline system. The pipe end of the first pipe comprises an inner peripheral wall, a first groove and a protrusion. A first groove for accommodating the seal is provided on an end outer surface of the inner peripheral wall. The protrusion protrudes outward from the outer surface of the inner circumferential wall and forms an annular cavity around the outer surface of the pipe end, one end of the annular cavity is closed, the other end of the annular cavity is open towards the corresponding end of the pipe end, and a second groove is formed in the outer surface of the protrusion. The pipe connection mechanism can be sleeved on the adjacent end parts of the first pipe and the second pipe to be in sealing joint with the first pipe and the second pipe. The pipe system allows for no additional brackets at the locations where different pipes are butted up against each other.

Description

Pipeline for aircraft fuel system and pipeline system

Technical Field

The invention relates to the field of aircraft spare parts, in particular to a pipeline for an aircraft fuel system and a pipeline system.

Background

In order to reduce the difficulty of installing pipelines during aircraft manufacturing and to withstand the loads imposed on the pipelines by the deformation process of the wings and fuselage, the fuel system pipelines are generally segmented according to certain rules. The segmented pipelines are connected through joints.

However, because the diameter of the fuel system pipeline is larger and the rigidity is stronger, the deformation capacity of the fuel system pipeline is far smaller than that of the wings and the fuselage of the airplane in the flying process. The defect of small fuel pipeline deformation capacity easily causes the pipeline to bear larger local stress caused by the deformation of airplane wings and fuselage structural parts. For this reason, the existing fuel line systems are therefore generally subjected to a certain degree of deformation by the joints of the fuel line systems and can operate normally and reliably.

In the course of the daily operation of an aircraft, the pipes or the spaces in which the pipes are located inevitably generate currents due to factors such as friction. For this purpose, the fuel line is generally provided with a passage capable of transmitting an electric current for preventing the fuel inside the line from being ignited. A conventional fuel line 10 is shown in fig. 1, and the left and right lines are connected to each other by a joint 11. The pipelines on different sides are respectively provided with

lugs

12 and 13, and the two

lugs

12 and 13 are connected through a connecting belt 14. The pipelines on different sides are also respectively provided with a pipe hoop 15. The pipe clamp 15 is connected to the aircraft structural member by a bracket to support the pipeline. In the event of an electrical spark on the pipeline, the current is routed along the right pipeline lug 13, the connecting strip 14, the left pipeline lug 12, the left pipeline ferrule 15, the left pipeline support frame and the aircraft structural part to achieve the purpose of current bridging. As can be seen from fig. 1, when the current conduction cannot be achieved in the case of an accident occurring at the two

side lugs

12 and 13 or the connecting strap 14, the purpose of the current conduction cannot be achieved in the fuel pipe system 10, which may cause a greater fire risk to the fuel pipe system 10.

In addition, for the pipeline connection mode in the type, although the flexible joint connected between the pipelines can play a role in bearing deformation of the wing and the fuselage, the flexible joint is limited by the structural form of the flexible joint, and the flexible joint cannot bear large radial load, so that each pipeline needs to be provided with a support to bear the load of the pipeline. Due to the structural configuration of the aircraft structural member, the pipe clamps 21 on the pipes on both sides adjacent to the pipe joints need to be fixed on the same aircraft structural member. Referring to fig. 2A and 2B, the existing pipeline connection method requires that the bracket 22 and 22 'on at least one side of the pipeline needs to extend a certain distance along the axial direction of the pipeline, so that the pipeline bracket 22 and 22' on the side can be butted with the corresponding aircraft structural component 23. In the schematic block diagram of fig. 2, the supports 22, 22' have a generally zigzag-shaped framework. This form of stent has a long extension length and it should have a large resistance to shear, which can lead to the problem of a large weight of the stent 22, 22'.

Therefore, there is a need for improvements in the form of piping connections and electrical lap joints for existing fuel piping systems.

Disclosure of Invention

In view of the above-mentioned situation of the fuel pipeline system, an object of the present invention is to provide a pipeline for an aircraft fuel system, which can provide two different current flow paths for current, thereby realizing multiple overlapping of the fuel pipeline system.

This object is achieved by the following form of the apparatus of the invention. Wherein at least one axial end of the pipeline is formed with a pipeline end head for engaging with other pipelines to realize fluid communication. The pipe end comprises an inner peripheral wall, a first groove and a protruding part. Wherein the inner circumferential wall defines an inner cavity of the conduit. A first groove is provided on an end outer surface of the inner circumferential wall, which is configured to accommodate a seal therein. The protrusion protrudes outward from the outer surface of the inner circumferential wall and forms an annular cavity around the outer surface of the pipe end, one end of the annular cavity is closed, the other end of the annular cavity is open to the corresponding end of the pipe end, and a second groove suitable for accommodating a sealing member is formed in the outer surface of the open end of the protrusion. Wherein the open end of the protrusion is a predetermined distance from the corresponding end of the pipe end.

When the pipeline is used, the pipe wall of the other pipeline can be lapped on the first groove of the pipeline, so that the pipeline and the other pipeline can form an inner peripheral wall-current path of the other pipeline. In addition, after the pipe is connected with another pipe through the pipe connecting mechanism, another current path of the protrusion part of the pipe, the pipe connecting mechanism and the other pipe can be formed, thereby the pipe can realize the aim of multiple overlapping.

According to a preferred embodiment of the invention, the line head is configured to conduct an electric current.

According to a preferred embodiment of the invention, said first and second grooves are formed by two projecting pipe annular projections, respectively.

According to a preferred embodiment of the invention, the inner surface of the conduit is a smooth continuous surface.

In addition, the invention also discloses a pipeline system comprising any one of the pipelines (the first pipeline), the second pipeline and the pipeline connecting mechanism. Wherein an inner surface of at least one axial end of the second pipe is capable of pressing a seal member placed in the first groove, and an outer surface is formed with a third groove for accommodating the seal member. The pipe connection mechanism can be sleeved on the adjacent end parts of the first pipe and the second pipe and can be configured to be pressed on the sealing elements arranged in the second groove and the third groove so as to be in sealing joint with the first pipe and the second pipe. The gravity of the first pipeline can act on the second pipeline through the pipeline connecting mechanism, or the second pipeline acts the gravity on the first pipeline. With this pipe system, at the position where the first and second pipes are joined to each other, a support structure may be provided only on one side of the first and second pipes, and therefore the pipe system may omit at least one bracket, which makes the overall weight of the pipe system light.

According to a preferred embodiment of the invention, the pipe system further comprises a pipe sleeve which can be brought into abutment against the second and third grooves simultaneously, wherein the pipe connection can press the pipe sleeve towards the second and third grooves when the pipe connection engages the first and second pipes.

According to a preferred embodiment of the invention, said third recess is formed by a protruding pipe annular protrusion.

According to a preferred embodiment of the invention, the two axial end portions of the line connection are formed with collar annular projections which form-fit with the line annular projections of the second and third recesses.

According to a preferred embodiment of the invention, the pipe sleeve is arranged to be able to abut directly against the second and third grooves, the outer surface of the pipe sleeve being provided with a conducting wire, so that the pipe system forms a current path through the first, pipe sleeve and second pipe in this order.

According to a preferred embodiment of the invention, the outer surface of the sleeve is provided with a recess for accommodating a wire.

According to a preferred embodiment of the invention, the pipe connection is configured to be able to directly contact the outer surfaces of the first and second pipes, such that the pipe system forms a current path through the first pipe, the pipe connection and the second pipe in this order.

According to a preferred embodiment of the present invention, the conduit connection means has disposed therein wires that are electrically connectable to the first conduit and the second conduit, respectively.

According to a preferred embodiment of the invention, at least one of the first and second conduits is provided with a support member extending outwardly and adapted to engage with a support member of the aircraft, the support member being axially adjacent to a respective axial end of the first conduit and an axial end of the second conduit.

According to a preferred embodiment of the present invention, the support member is a support plate.

According to a preferred embodiment of the invention, the support plate is provided with at least one through hole for cooperation with a bolt.

According to a preferred embodiment of the present invention, the axial length of the pipe connection mechanism is configured such that a gap is formed between the projection of the first pipe and the second pipe in the axial direction when the pipe connection mechanism engages the first pipe and the second pipe.

On the basis of the common general knowledge in the field, the preferred embodiments can be combined randomly to obtain the preferred examples of the invention. Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description and this summary, be within the scope of the invention, and be protected by the accompanying claims.

Drawings

For a better understanding of the above and other objects, features, advantages and functions of the present invention, reference should be made to the preferred embodiments illustrated in the accompanying drawings. Like reference numerals in the drawings refer to like parts. It will be appreciated by persons skilled in the art that the drawings are intended to illustrate preferred embodiments of the invention without any limiting effect on the scope of the invention, and that the various components in the drawings are not drawn to scale.

Fig. 1 is a schematic structural diagram of a piping system in the prior art, which shows a connection form of the piping system.

Fig. 2A and 2B are schematic structural diagrams of two piping systems in the prior art, which show two supporting mechanisms of the piping system.

FIG. 3 is an exploded view of a fuel piping system according to a preferred embodiment of the present invention.

Fig. 4 is a longitudinal sectional view of a fuel piping system according to a preferred embodiment of the present invention.

Fig. 5 is an enlarged view of a portion O of fig. 4.

Fig. 6 shows a front view of the line connection of fig. 3-5.

Fig. 7 shows a side view of the tubing connection mechanism of fig. 3-5.

Fig. 8 shows a transfer route diagram for radial loads of the fuel line system.

Detailed Description

The inventive concept of the present invention will be described in detail below with reference to the accompanying drawings. What has been described herein is merely a preferred embodiment in accordance with the present invention and other ways of practicing the invention will occur to those skilled in the art and are within the scope of the invention. In the following detailed description, directional terms, such as "upper", "lower", "inner", "outer", "longitudinal", "lateral", and the like, are used with reference to the orientation depicted in the accompanying drawings. Components of embodiments of the present invention can be positioned in a number of different orientations and the directional terminology is used for purposes of illustration and is in no way limiting.

Referring to the aircraft fuel piping system according to the present invention as shown in FIG. 3, an exploded view of the piping system is shown. Fig. 4 shows a longitudinal sectional view of the assembled pipe system. Referring to fig. 3 and 4, the piping system 100 of the present invention includes a first piping 110, a second piping 120, and a piping connection mechanism 130 connecting the first piping 110 and the second piping 120. The pipe system 100 is capable of conducting electrical current.

Referring to fig. 5, an enlarged view of the portion O of fig. 4 is shown. Referring to fig. 5 in conjunction with fig. 3 and 4, the right axial end of the first tube 110 is formed with a tube end a for engaging the second tube 120 for fluid communication.

The pipe end a and the main body portion of the first pipe 110 may be integrally formed by casting or the like, or may be formed by welding. The first conduit 110 is preferably made of a material that is lightweight and does not react readily with aircraft fuel, for example the first conduit 110 is made of aluminum.

Referring to fig. 5, the pipe end a includes an inner circumferential wall 112, a first groove 111, and a protrusion 114. Wherein the inner circumferential wall 112 defines an inner cavity of the first conduit 110. In the preferred embodiment shown in fig. 5, the inner surface of the inner peripheral wall 112 and the inner surface of the main portion of the first conduit 110 together define a smooth continuous surface of the first conduit 110 to avoid significant fluctuations in the aircraft fuel flowing through the first and

second conduits

110, 120.

The first groove 111 of the pipe end a is provided on the end outer surface of the inner peripheral wall 112, which is configured to accommodate the seal 150 therein. Specifically, the first groove 111 is formed by two protruding pipe annular protrusions 116. Alternatively, the first groove 111 may also be formed by being depressed in the outer surface of the inner peripheral wall 112.

The protrusion 114 protrudes outward from the outer surface of the inner circumferential wall 112 and forms an annular cavity S around the outer surface of the tip of the first pipe 110. The left end of the annular cavity S is closed and the right end is open towards the corresponding end of the pipe end a, corresponding to the orientation of the view in fig. 5. In the embodiment of fig. 5, the protrusion 114 extends radially outward from the inner circumferential wall 112 and then extends in a direction parallel to the inner circumferential wall 112 (i.e., the axial direction of the first pipeline 110). The extension distance L1 of the protrusion 114 in the axial direction (i.e., the depth of the annular cavity S) may be set in the range of 15mm to 40, and preferably, the extension distance L1 may be set to 19cm, 21cm, 22cm, or the like. The small extension distance L1 ensures that the protrusion 114 is not easily deformed when the pipe connection 130 applies pressure to the protrusion 114.

According to the present invention, the protrusion 114 extends a distance L1 such that the open end of the protrusion 114 is a predetermined distance L3 from the corresponding end of the tip of the first tubing 110. The predetermined distance L3 may alternatively be any value within the range of 16mm-21mm, such as 16.5mm, 18mm, 20mm, etc.

The outer surface of the open end of the protrusion 114 is provided with a second groove 113 adapted to receive the sealing member 150. The form of the second groove 113 may be generally similar to the form of the first groove 111, again formed by a pair of conduit annular projections 116.

The protrusions 114 protrude outwardly from the inner circumferential wall 112 by a small distance D2 (the distance D2 is the radial dimension of the annular cavity S), and the distance D2 may be set in the range of 1.7mm-3.3mm, e.g., 1.7mm, 2.3mm, 2.8mm, etc.

With continued reference to fig. 5 in conjunction with fig. 3 and 4, the inner surface of the left axial end of the second conduit 120 of the conduit system 100 is capable of compressing the seal 150 of the first groove 111 disposed on the first conduit 110, which may be accomplished by setting the inner cavity diameter of the second conduit 120 to be substantially equal to the outer diameter of the conduit annular protrusion 116 forming the first groove 111. To facilitate sealing engagement, the outer surface of the left axial end portion of the second pipe 120 is formed with a third groove 122 for accommodating a seal 150, similar to the first pipe 110. The third recess 122 is formed by a pair of pipe annular projections 126.

The seals 150 received by the first, second, and

third grooves

111, 113, 122 may be selected from conventional O-rings and the like.

Referring to fig. 6 and 7, a front view and a side view of a tubing connection 130 according to the present invention is shown. Wherein the placement of the line connection 130 in the front view shown in fig. 6 corresponds to the placement of the line connection 130 shown in fig. 3-5, fig. 6 is a left side view of fig. 7. The conduit connection 130 is a conduit clamp, and referring to fig. 7, the conduit connection 130 includes two semicircular ring portions 131 that are bisected. The first ends of the semicircular ring parts 131 are hinged together, the second end of one semicircular ring part 131 (the first semicircular ring part 131A) is provided with a rotatable hanging ring 135, and the second end of the other semicircular ring part 131 (the second semicircular ring part 131B) is provided with a clamping groove 136 for hanging and holding the hanging ring 135. When the hanging ring 135 of the first semicircular ring portion 131 is separated from the catching groove 136 of the second semicircular ring portion 131, the first semicircular ring portion 131 and the second semicircular ring portion 131 are separated from each other at the end, and the pipeline connecting mechanism 130 can be sleeved on the adjacent end portions of the first pipeline 110 and the second pipeline 120. Subsequently, the operator rotates the ring 135 to fit the ring 135 onto the groove 136, and the inner surfaces of the first and second

semi-circular ring portions

131 and 131 can be pressed against the sealing members 150 (O-rings) disposed in the second and

third grooves

113 and 122, thereby sealingly engaging the first and

second pipelines

110 and 120.

According to some preferred embodiments of the present invention, referring to fig. 5, the pipe system 100 further comprises a pipe sleeve 140 capable of simultaneously abutting against the second groove 113 and the third groove 122, wherein the pipe connection 130 is capable of pressing the pipe sleeve 140 towards the second groove 113 and the third groove 122 when the pipe connection 130 engages the first pipe 110 and the second pipe 120.

Understandably, a separate sleeve 140 is provided as a preferred embodiment, however, in other embodiments, the sleeve 140 may be integral to the inner surface of the line connection mechanism 130.

Both axial ends of the pipe connection 130 are provided with inwardly projecting collar annular projections 132, which are adapted to the pipe

annular projections

116, 126 of the first and

second pipes

110, 120. After the pipe connection 130 is installed in place, it can prevent the first and

second pipes

110, 120 from being detached from each other by the axially limiting action of the clip annular projection 132 on the pipe

annular projections

116, 126 of the first and

second pipes

110, 120.

According to the above fuel pipe system 100, the first pipe 110 and the second pipe 120 are more reliably joined based on the abutting relationship between the inner surface of the second pipe 120 and the inner peripheral wall 112 of the first pipe 110, and the locking action of the pipe connecting mechanism 130 on the first pipe 110 and the second pipe 120. In the vicinity of the position where the first pipeline 110 and the second pipeline 120 are connected to each other, a designer may simply provide a support mechanism on a single pipeline (the first pipeline 110 or the second pipeline 120), and thus the zigzag bracket shown in fig. 2A and 2B may be omitted.

In the embodiment of fig. 3, 4, the designer only provides support members 124 in the second conduit 120 that extend outwardly and are adapted to engage with aircraft support members 124. The support member 124 is axially offset from and abuts corresponding axial ends of the first and

second conduits

110, 120. Preferably, the supporting member 124 is configured as a supporting plate 124 having a simple structure and easy integration of the second pipe 120. The support plate 124 is a flat plate structure having at least one through hole for engaging with a bolt. The distance D1 between the support member 124 and the axial end of the corresponding tube may be determined based on the distance between the connection of the first tube 110 and the second tube 120 (i.e., the location of the tube connection 130) and the aircraft structure that may be used as a support site. Typically, the distance D1 between the support member 124 and the axial end of the corresponding tube does not exceed 2 times the axial length L of the tube end a, e.g., the distance D1 may be 0.6, 1, 1.5 times L, etc.

Understandably, the support member 124 (support plate) of the second pipe 120 is disposed on the first pipe 110.

It should be noted that the above technical solution of the present invention does not exclude that the first pipeline 110 and the second pipeline 120 are provided with support structures at other positions. The above description is merely for the purpose of illustrating that the present invention can provide a single support structure near the region where the first and

second pipelines

110 and 120 are butted against each other, rather than providing support structures at both the first and

second pipelines

110 and 120 as shown in fig. 2A and 2B. Indeed, it will be appreciated that where the first or

second conduits

110, 120 have a relatively long length, the designer may provide the support structure at other locations of the first and

second conduits

110, 120 suitable for engaging structural members of the aircraft.

For the second pipeline 120 of the present invention, it may be made of the same material as the first pipeline 110, that is, the second pipeline 120 may be made of a material which is light and is not easily reactive with the aircraft fuel, for example, the first pipeline 110 may be made of aluminum.

With continued reference to fig. 5, in accordance with the present invention, the line connection 130 has a relatively long axial length that may cause a gap L2 to form between the protrusion 114 of the first line 110 and the second line 120 in the axial direction when the line connection 130 engages the first line 110 and the second line 120. The gap L2 allows the first and

second conduits

110, 120 to bend at a small angle and move a small distance relative to each other, which ensures that different conduit sections connected to different parts of different aircraft bodies can move or bend with the aircraft bodies under the condition that the aircraft bodies are slightly deformed due to factors such as airflow and unbalanced load, and thus the conduit system 100 is subjected to a small stress.

In the initial state where the aircraft is not deformed, the gap L2 between the first pipeline 110 and the second pipeline 120 in the axial direction can be set to any value less than 8.7mm, such as 3.6mm, 4mm, 4.3mm, etc., so as to limit the mutual bending angle and the mutual axial movement distance between the first pipeline 110 and the second pipeline 120 to a suitable area, and avoid the relative violent movement between the two, thereby affecting the firmness of the pipeline system 100.

To achieve multiple electrical overlap, and to ensure that in any accidental event, the first and

second conduits

110, 120 are able to form a current path, in some embodiments, the sleeve 140 is configured to abut directly against the second and

third grooves

113, 122. Specifically, the tube housing 140 is point-connected to the pipe

annular protrusions

116 and 126 and the band annular protrusion 132 of the second groove 113 by wires (not shown) fixed to the outer surface thereof, respectively, so that the pipe system 100 forms a first current path that sequentially flows through the first pipe 110, the tube housing 140, and the second pipe 120 as shown in fig. 4. Here, the lead wire is disposed on the outer surface of the tube housing 140 to prevent the lead wire from being corroded due to immersion in a fuel environment.

The wires on the tube housing 140 may be secured by depressions provided on the outer surface thereof.

Piping system 100 may further form a second current path through first piping 110, piping connection 130, and second piping 120 in that order as shown in fig. 4. This may be accomplished by placing tubing connection 130 in direct contact with the outer surfaces of first tubing 110 and second tubing 120. Specifically, a wire 134 capable of electrically connecting with the first pipe 110 and the second pipe 120, respectively, may be disposed inside the pipe connection mechanism 130. When the conduit connection 130 engages the first conduit 110 and the second conduit 120, the wire 134 contacts the outer surface of the protrusion 114 of the first conduit 110 and the outer surface of the second conduit 120. It is understood that at this time, the lead wires 134 disposed at the pipe connection mechanism 130 do not contact the pipe

annular protrusions

116, 126 of the first and

second pipes

110, 120, thereby allowing the pipe system 100 to form a second current path different from the first current path.

Furthermore, the abutting relationship of the inner circumferential wall 112 to the inner surface of the second tube 120 causes the tube system 100 to form a third current path leading directly from the first tube 110 to the second tube 120.

By the above form, the pipe system 100 forms a triple electrically overlapped current path, which is enough to ensure that the pipe system 100 can achieve the purpose of current conduction under any condition.

Note that, in the above embodiment, one axial end portion of the first pipe 110 is provided with the pipe end a composed of the inner circumferential wall 112 and the protrusion 114, and in fact, both axial end portions of the first pipe 110 may also be provided with the pipe ends a, respectively. In addition, in the specific case where the aircraft structural component allows the first and

second pipelines

110 and 120 to have supporting structures on both sides, the supporting members 124 (supporting plates) can be set on the first and

second pipelines

110 and 120 at the same time, and the two supporting members 124 are respectively butted against the corresponding aircraft structural component. It should be noted that, in this case, the piping system 100 still does not need to be provided with an additional support bracket.

Referring to fig. 5 in conjunction with fig. 3 and 4, during installation, a sealing member 150 is first placed on the first groove 111, the second groove 113 and the third groove 122 of each

pipe

110 and 120. The sleeve 140 is then placed over a conduit, for example, the sleeve 140 is placed over the first conduit 110, such that the sleeve 140 compresses the seal 150 on the second groove 113. The operator then moves the second pipe 120 into the space defined by the sleeve 140 and the inner peripheral wall 112 of the first pipe 110 such that the seal 150 within the third groove 122 of the sleeve 140 is compressed by the sleeve 140 while the inner surface of the second pipe 120 compresses the seal 150 within the first groove 111. Finally, the pipe connecting mechanism 130 is inserted into a position where the first pipe 110 and the second pipe 120 are connected to each other, and the hanging ring 135 is inserted into the catching groove 136, thereby completing the installation process of the pipe system 100.

It can be understood that, referring to fig. 5, the operator can also first sleeve the pipe sleeve 140 on the second pipeline 120, and then move the first pipeline 110 along the axial direction of the second pipeline 120, so that the first groove 111 abuts against the inner surface of the second pipeline 120, and the second groove 113 abuts against the inner surface of the pipe sleeve 140. Finally, the operator completes the work of fixing the pipeline connecting mechanism 130.

In embodiments where the sleeve 140 is provided integral with the conduit connection 130, an operator may directly move the inner peripheral wall 112 of the first conduit 110 into the inner surface of the second conduit 120, causing the inner surface of the second conduit 120 to abut the first groove 111. Finally, the operator completes the work of fixing the pipeline connecting mechanism 130.

Referring to the embodiment of fig. 3-5, as shown in fig. 8, a shear load transfer path of the pipe system 100 is shown. When the first pipeline 110 is subjected to an externally applied shear load, the shear load is transferred to the second pipeline 120 through the inner peripheral wall 112 and is transferred to the aircraft structural member through the support plate of the second pipeline 120, so that the pipeline system 100 is not subjected to the shear load. After the first and

second pipelines

110 and 120 of the pipeline system 100 are subjected to an axial load, the axial gap L2 between the first and

second pipelines

110 and 120 allows them to move a certain distance in the axial direction, thereby overcoming the axial load.

The scope of the invention is limited only by the claims. Persons of ordinary skill in the art, having benefit of the teachings of the present invention, will readily appreciate that alternative structures to the structures disclosed herein are possible alternative embodiments, and that combinations of the disclosed embodiments may be made to create new embodiments, which also fall within the scope of the appended claims.

Description of reference numerals:

a pipeline system: 100.

a first pipeline: 110.

a second pipeline: 120.

pipeline coupling mechanism: 130.

pipe sleeve: 140.

sealing element: 150.

a first groove: 111.

inner peripheral wall: 112.

a second groove: 113.

a protrusion portion: 114.

the annular projection of the pipeline: 116. 126.

A third groove: 122.

a support member: 124.

semicircular ring part: 131. 131A, 131B.

The hoop annular is protruding: 132.

conducting wires: 134.

hanging a ring: 135.

a clamping groove: 136.

Claims

1. a piping system for an aircraft fuel system, characterized in that the piping system comprises:

a first tube having at least one axial end formed with a tube tip for engaging with another tube for fluid communication, wherein the tube tip comprises:

an inner circumferential wall defining an inner cavity of the conduit;

a first groove provided on an end outer surface of the inner circumferential wall, configured to accommodate a seal therein; and

a protrusion protruding outward from an outer surface of the inner circumferential wall and forming an annular cavity around an outer surface of the pipe end, one end of the annular cavity being closed and the other end being open toward a corresponding end of the pipe end, and a second groove adapted to receive a sealing member being provided on an outer surface of an open end of the protrusion,

wherein the open end of the protrusion is a predetermined distance from the corresponding end of the pipe end,

a second pipe having an inner surface capable of pressing the seal member placed in the first groove at least one axial end portion thereof and an outer surface formed with a third groove for receiving the seal member, an

And the pipeline connecting mechanism can be sleeved on the adjacent end parts of the first pipeline and the second pipeline and can be configured to be pressed on the sealing elements arranged in the second groove and the third groove so as to be in sealing joint with the first pipeline and the second pipeline.

2. The conduit system of claim 1, further comprising a sleeve configured to simultaneously abut the second and third grooves, wherein the conduit connection is configured to press the sleeve toward the second and third grooves when the conduit connection engages the first and second conduits.

3. The conduit system of claim 2, wherein the third groove is formed by a protruding conduit annular protrusion.

4. Pipeline system according to claim 3, wherein the two axial end portions of the pipeline connecting means are formed with collar annular projections form-fitting with the pipeline annular projections of the second and third recesses.

5. The conduit system of claim 2, wherein the sleeve is configured to directly abut the second and third grooves, an outer surface of the sleeve being provided with a conductive wire such that the conduit system forms a current path through the first, sleeve and second conduits in sequence.

6. Pipeline system according to claim 5, characterized in that the outer surface of the pipe sleeve is provided with a recess for accommodating a wire.

7. The conduit system of claim 3, wherein the conduit connection is configured to directly contact an outer surface of the first and second conduits such that the conduit system forms a current path through the first conduit, the conduit connection, and the second conduit in sequence.

8. Pipeline system according to claim 7, characterized in that wires are arranged in the pipeline connection means, which wires can be electrically connected to the first pipeline and the second pipeline, respectively.

9. The conduit system of claim 1, wherein at least one of the first and second conduits is provided with a support member extending outwardly and adapted to engage a support member of the aircraft axially adjacent the corresponding axial end of the first conduit and the axial end of the second conduit.

10. The conduit system of claim 9, wherein the support member is a support plate.

11. Pipeline system according to claim 10, wherein the support plate is provided with at least one through hole for cooperation with a bolt.

12. The conduit system of any one of claims 1-11, wherein the axial length of the conduit connection is configured such that when the conduit connection engages a first conduit and a second conduit, a gap is formed between the protrusion of the first conduit and the second conduit in the axial direction.

13. The conduit system of any one of claims 1-11, wherein the conduit end is configured to conduct electrical current.

14. Pipeline system according to any one of claims 1 to 11, wherein the first and second grooves are each formed by two protruding pipeline annular projections.

15. The conduit system of any one of claims 1-11, wherein the inner surface of the first conduit is a smooth continuous surface.

16. A pipeline system according to any of claims 1-11, wherein the predetermined distance is selected from any value in the range 16mm-21 mm.