Collecting mechanism and Christmas tree

Abstract

The utility model discloses a collecting mechanism and a Christmas tree in the technical field of oil exploitation, which comprise a support plate, support legs arranged below the support plate, and a collecting component arranged on the support plate, the collecting component comprises a liquid inlet formed in one side of the upper portion of the supporting plate, a liquid outlet formed in the other side of the upper portion of the supporting plate, valve assemblies arranged on the liquid inlet and the liquid outlet, a flow channel assembly arranged between the two valve assemblies, a first filtering assembly arranged on the flow channel assembly and a second filtering assembly arranged on the flow channel assembly. According to the flow and the flow speed of fracturing fluid, communication and closing of the flow channel assembly are controlled through the valve assembly as required, operation stop caused by too large pipeline pressure is avoided, rock debris in the fracturing fluid is filtered in a layered mode through the first filtering assembly and the second filtering assembly, the filtering area is increased, and pipeline blockage is effectively avoided; meanwhile, the collecting box and the filter screen are convenient to detach, wash and replace.

Description

Technical Field

[0001] The utility model relates to the technical field of petroleum exploitation, in particular to a collection mechanism and an oil tree. Background Art

[0002] In the traditional oil extraction process, fracturing is a commonly used production-increasing measure. By injecting high-pressure fluid into the formation, cracks are created in the rock, thereby increasing the flow channel for oil and gas. However, a large amount of waste liquid is generated during the fracturing process. This waste liquid contains a variety of chemical additives and rock fragments. The rock fragments in the fracturing fluid can easily damage the pipes inside the Christmas tree. At the same time, due to the presence of rock fragments in the fracturing fluid, the pipes need to be disassembled and cleaned frequently. Repeated disassembly and installation actions can easily weaken the sealing effect of the sealing rings between the Christmas tree flanges. Utility Model Content

[0003] The purpose of this section is to summarize some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and utility model name of this application to avoid blurring the purpose of this section, specification abstract and utility model name, and such simplifications or omissions cannot be used to limit the scope of the utility model.

[0004] In view of the problem in the prior art that rock fragments easily damage the pipe inside the Christmas tree, the present utility model is proposed.

[0005] Therefore, the utility model aims to provide a collection mechanism, the purpose of which is to filter and collect rock debris in the fracturing fluid.

[0006] In order to solve the above technical problems, the utility model provides the following technical solutions: a collecting mechanism, comprising a support plate, a support leg arranged under the support plate, and a collecting component arranged on the support plate, the collecting component comprising a liquid inlet arranged on one side above the support plate, a liquid discharge port arranged on the other side above the support plate, a valve assembly arranged on the liquid inlet and the liquid discharge port, a flow channel assembly arranged between two groups of the valve assemblies, a first filter assembly arranged on the flow channel assembly, and a second filter assembly arranged on the flow channel assembly.

[0007] As a preferred solution of the collection mechanism described in the utility model, the valve assembly includes a first valve arranged on one side of the liquid inlet and the liquid outlet, a second valve arranged on one side of the first valve, and a third valve arranged on the other side of the first valve.

[0008] As a preferred solution of the collection mechanism described in the utility model, the flow channel assembly includes a first flow channel arranged between two groups of the first valves, a second flow channel arranged between two groups of the second valves, and a third flow channel arranged between two groups of the third valves, and the second flow channel and the third flow channel have the same size and structure.

[0009] As a preferred solution of the collection mechanism described in the utility model, the first filter assembly includes a first flow cavity arranged at the second flow channel close to the liquid inlet side and the output end of the third flow channel, a filter cover arranged in the first flow cavity, a connecting stud arranged on the first flow cavity, and a fastening nut arranged on the connecting stud.

[0010] As a preferred solution of the collection mechanism described in the utility model, the first flow chamber includes a connecting tube arranged on the support plate, a guide plate arranged in the connecting tube, and a clearing tooth column arranged in the connecting tube and cooperating with the filter cover.

[0011] As a preferred solution of the collection mechanism described in the utility model, the filter cover includes a fixed plate arranged on the connecting pipe, a collection box arranged on the fixed plate, an interception mesh plate arranged on one side of the collection box, a slider arranged on the interception mesh plate, a slide groove opened on the connecting pipe to cooperate with the slider, and a handle arranged on the fixed plate.

[0012] As a preferred solution of the collection mechanism described in the utility model, the second filter assembly includes a second flow chamber arranged on the second flow channel and the third flow channel, a cover plate arranged on the second flow chamber, a mounting piece arranged in the second flow chamber, and a filter screen arranged on the mounting piece.

[0013] As a preferred solution of a collecting mechanism described in the utility model, wherein: the cover plate includes a plate body arranged on the second flow chamber, a telescopic chamber opened in the plate body, a compression spring arranged in the telescopic chamber, a pressure plate arranged at the lower end of the compression spring, and a pressure groove opened on the second flow chamber to cooperate with the pressure plate, the mounting member includes a pull plate arranged in the second flow chamber, the upper part of the pull plate is clamped with the pressure groove, a first mounting block arranged at the lower part of the pull plate, a second mounting block arranged on one side of the first mounting block, a support shaft arranged between the first mounting block and the second mounting block, a first mounting groove arranged on the first mounting block, and a second mounting groove arranged on the second mounting block.

[0014] The beneficial effects of the utility model are as follows: according to the flow rate and flow velocity of the fracturing fluid, the connection and closing of the flow channel component are controlled by the valve component as required to avoid operation stop caused by excessive pipeline pressure; the rock fragments in the fracturing fluid are filtered in layers by the first filter component and the second filter component to increase the filtering area, effectively avoiding pipeline blockage, and facilitating the disassembly, cleaning and replacement of the collection box and the filter screen.

[0015] In view of the problem in the prior art that multiple disassembly and installation actions may easily cause the sealing effect of the sealing ring between the Christmas tree flanges to be weakened, the present utility model is proposed.

[0016] Therefore, the utility model aims to provide a Christmas tree, the purpose of which is to enhance the sealing performance of the flange sealing ring.

[0017] To solve the above technical problems, the utility model provides the following technical solutions: a Christmas tree, comprising a Christmas tree body arranged at one end of the liquid inlet, a side diameter arranged on one side of the Christmas tree body, a connecting flange arranged at one end of the side diameter, and a pump body arranged at one end of the connecting flange, wherein the pump body is connected to the liquid inlet.

[0018] As a preferred solution of the Christmas tree of the utility model, the connecting flange includes a flange plate arranged between the side passage and the pump body, connecting bolts arranged on the flange plate, a sealing groove opened in the flange plate, a sealing ring arranged in the sealing groove, and an expansion hole opened in the sealing ring.

[0019] The beneficial effects of the utility model are as follows: the expansion hole allows the sealing ring to deform in all directions when squeezed to fill the entire sealing groove, and as the fracturing operation proceeds, the high heat of the fracturing fluid is transferred to the inside of the expansion hole, causing the expansion hole to expand, thereby further improving the sealing performance of the connecting bolt. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0021] Figure 1 The utility model is a schematic diagram of the overall structure of an oil tree.

[0022] Figure 2 The utility model is a schematic diagram of the overall structure of a collecting mechanism.

[0023] Figure 3It is a structural schematic diagram of a first filtering component of a collecting mechanism of the utility model.

[0024] Figure 4 This is a schematic diagram of the internal structure of a first filtering component of a collecting mechanism of the utility model.

[0025] Figure 5 The utility model is a schematic diagram of the cross-sectional structure of a connecting pipe of a collecting mechanism.

[0026] Figure 6 It is a structural schematic diagram of a collection box of a collection mechanism of the utility model.

[0027] Figure 7 It is a schematic diagram of the cross-sectional structure of the second flow channel of a collecting mechanism of the utility model.

[0028] Figure 8 It is a schematic cross-sectional structure diagram of a second filter assembly of a collecting mechanism of the utility model.

[0029] Fig. 9 It is a right side structural schematic diagram of a mounting part of a collecting mechanism of the utility model.

[0030] Fig.10 It is a left-side structural schematic diagram of a mounting component of a collecting mechanism of the utility model.

[0031] Fig.11 The utility model is a structural schematic diagram of a Christmas tree body of a Christmas tree.

[0032] Fig.12 It is a schematic diagram of the cross-sectional structure of a connecting flange of a collecting mechanism of the utility model. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0034] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0035] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0036] Secondly, the present invention is described in detail with reference to the schematic diagram. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0037] Example 1

[0038] Reference Figure 1-Figure 6 , which is the first embodiment of the utility model, provides a collection mechanism, which includes a support plate 100, which is used to cooperate with the support leg 200 to play a supporting role, the support leg 200 is arranged under the support plate 100, and a collection component 300 is arranged on the support plate 100, which is used to filter and collect rock fragments in the fracturing fluid.

[0039] The collecting component 300 includes a liquid inlet 301 arranged on one side above the support plate 100, for the entry of fracturing fluid, a liquid outlet 302 arranged on the other side above the support plate 100, for the outflow of fracturing fluid, a valve assembly 303 arranged on the liquid inlet 301 and the liquid outlet 302, for controlling the on-off of a flow channel assembly 304, a flow channel assembly 304 arranged between two sets of valve assemblies 303, for the flow of fracturing fluid, a first filter assembly 305 arranged on the flow channel assembly 304, for filtering and collecting large-volume rock fragments, and a second filter assembly 306 arranged on the flow channel assembly 304, for filtering and collecting small-particle rock fragments.

[0040] The valve assembly 303 includes a first valve 303a disposed on one side of the liquid inlet 301 and the liquid outlet 302, a second valve 303b disposed on one side of the first valve 303a, and a third valve 303c disposed on the other side of the first valve 303a.

[0041] Among them, the flow channel assembly 304 includes a first flow channel 304a arranged between two groups of first valves 303a, a second flow channel 304b arranged between two groups of second valves 303b, and a third flow channel 304c arranged between two groups of third valves 303c. The second flow channel 304b and the third flow channel 304c have the same size and structure. The first valve 303a is used to control the on-off of the first flow channel 304a, the second valve 303b is used to control the on-off of the second flow channel 304b, and the third valve 303c is used to control the on-off of the third flow channel 304c.

[0042] Among them, the first filter component 305 includes a first flow chamber 305a arranged at the output end of the second flow channel 304b and the third flow channel 304c on the side close to the liquid inlet 301, which is used to connect the second valve 303b and the second flow channel 304b, a filter cover 305b arranged in the first flow chamber 305a, which is used to filter large-volume debris, a connecting stud 305c arranged on the first flow chamber 305a, and a fastening nut 305d arranged on the connecting stud 305c, the connecting stud 305c is movable and passes through the filter cover 305b, and is used to cooperate with the connecting stud 305c to disassemble and assemble the filter cover 305b.

[0043] Among them, the first flow chamber 305a includes a connecting pipe 305a-1 arranged on the support plate 100, which is used for the flow of fracturing fluid, a guide plate 305a-2 arranged in the connecting pipe 305a-1, which is used to separate the connecting pipe 305a-1 and guide the fracturing fluid into the filter cover 305b, and a clearing tooth column 305a-3 rotatably arranged in the connecting pipe 305a-1 and cooperating with the filter cover 305b, which is used to clean the filter cover 305b.

[0044] The filter cover 305b includes a fixing plate 305b-1 disposed on the connecting pipe 305a-1, which is used to be fixed on the connecting pipe 305a-1 through a connecting stud 305c and a fastening nut 305d, a collecting box 305b-2 disposed on the fixing plate 305b-1, which is used to collect large volumes of rock debris, and an intercepting mesh plate 305b-3 disposed on one side of the collecting box 305b-2. Since the rock debris in the fracturing fluid is filtered out, the clearing tooth column 305a-3 fits with the intercepting mesh plate 305b-3. When the intercepting mesh plate 305b-3 is pulled -3, the intercepting mesh plate 305b-3 drives the clearing tooth column 305a-3 to rotate, and clears the holes on the intercepting mesh plate 305b-3, and the slider 305b-4 arranged on the intercepting mesh plate 305b-3, and the slide groove 305b-5 provided on the connecting tube 305a-1 to cooperate with the slider 305b-4, are used to cooperate with the slider 305b-4, so as to facilitate the limited sliding of the collecting box 305b-2 on the connecting tube 305a-1, and the handle 305b-6 arranged on the fixing plate 305b-1 is used for holding, so as to facilitate pushing and pulling.

[0045] During use, when the fracturing fluid enters the connecting pipe 305a-1, under the guidance of the collecting box 305b-2, the fracturing fluid can only flow away through the intercepting mesh plate 305b-3. At this time, a large volume of rock debris is intercepted by the intercepting mesh plate 305b-3 and enters the collecting box 305b-2, and the remaining fracturing fluid enters the next link through the intercepting mesh plate 305b-3. When the debris in the collecting box 305b-2 needs to be cleaned, the fastening nut 305d is screwed off. , pull out the collecting box 305b-2. During the process of pulling out the collecting box 305b-2, the intercepting mesh plate 305b-3 drives the clearing tooth column 305a-3 to rotate, and clears the holes on the intercepting mesh plate 305b-3. After the collecting box 305b-2 is completely taken out, the debris in it is cleaned out, and then the collecting box 305b-2 is reinserted into the connecting pipe 305a-1 through the slider 305b-4 and the slide groove 305b-5, and the fastening nut 305d is tightened to fix it.

[0046] Example 2

[0047] Reference Figure 1 , Figure 2 ,as well as Figure 7-Figure 10 , which is the second embodiment of the utility model. This embodiment is different from the first embodiment in that it filters smaller debris.

[0048] Compared with Example 1, further, the second filter component 306 includes a second flow chamber 306a arranged on the second flow channel 304b and the third flow channel 304c, which is used to facilitate the removal of the mounting member 306c, a cover plate 306b arranged on the second flow chamber 306a, and a mounting member 306c for sealing and arranged in the second flow chamber 306a, which is used to install a filter screen 306d, and a filter screen 306d arranged on the mounting member 306c, which is used to intercept and filter small particles of debris. The filter screen 306d is cylindrical in shape, and its cross-sectional area gradually decreases from the end close to the liquid inlet 301. The cross-section of the filter screen 306d is spiral, and the filter screen 306d is spread out into a fan shape.

[0049] The cover plate 306b includes a plate body 306b-1 disposed on the second flow chamber 306a, used to close the upper space of the second flow chamber 306a, so as to facilitate opening to disassemble, wash and replace the filter screen 306d, a telescopic chamber 306b-2 disposed in the plate body 306b-1, used for the telescopic movement of the compression spring 306b-3, a compression spring 306b-3 disposed in the telescopic chamber 306b-2, used to generate thrust when squeezed, a pressing plate 306b-4 disposed at the lower end of the compression spring 306b-3, used to cooperate with the compression spring 306b-3 to compress the mounting member 306c, and a pressing groove 306b-5 disposed on the second flow chamber 306a to cooperate with the pressing plate 306b-4, used to place the mounting member 306c.

[0050] The mounting member 306c includes a pull plate 306c-1 arranged in the second flow chamber 306a, which is used to fix the first mounting block 306c-2, the upper part of the pull plate 306c-1 is clamped with the pressing groove 306b-5, a first mounting block 306c-2 arranged at the lower part of the pull plate 306c-1, which is used to cooperate with the second mounting block 306c-3 to install the filter screen 306d, a second mounting block 306c-3 arranged on one side of the first mounting block 306c-2, a support shaft 306c-4 arranged between the first mounting block 306c-2 and the second mounting block 306c-3, which is used to support the filter screen 306d, a first mounting groove 306c-5 arranged on the first mounting block 306c-2, and a second mounting groove 306c-6 arranged on the second mounting block 306c-3, which is used to cooperate with the first mounting groove 306c-5 to install the filter screen 306d.

[0051] During use, when the fracturing fluid enters the second flow channel 304b, the fracturing fluid passes through the filter 306d, and the small particles and debris therein are intercepted and deposited in the filter 306d. When the small particles and debris need to be cleaned, the plate body 306b-1 is opened, and the entire mounting piece 306c is taken out by pulling the plate 306c-1, and then the filter 306d is pulled out through the first mounting groove 306c-5 and the second mounting groove 306c-6, and cleaned or replaced, and the new filter 306d is rolled on the outside of the support shaft 306c-4 according to the first mounting groove 306c-5 and the second mounting groove 306c-6. At this time, the entire mounting piece 306c is placed into the second flow channel 304b through the pulling plate 306c-1, and the plate body 306b-1 is covered again and tightened again. At this time, the pressing plate 306b-4 is squeezed onto the pulling plate 306c-1 to fix the position of the second filter assembly 306.

[0052] The remaining structures are the same as those of Example 1.

[0053] Example 3

[0054] Reference Figure 1 , Fig.11 ,as well as Fig.12 , which is the third embodiment of the utility model. This embodiment is different from the second embodiment in that the sealing performance of the flange sealing ring is increased.

[0055] Compared with Example 2, further, a Christmas tree comprises a Christmas tree body 400 disposed at one end of a liquid inlet 301, a side passage 500 disposed at one side of the Christmas tree body 400, used for fracturing fluid to flow out of the Christmas tree body 400, a connecting flange 600 disposed at one end of the side passage 500, which can be used for connection and fixation at various parts of the device, and a pump body 700 disposed at one end of the connecting flange 600, used for pumping out fracturing fluid, and the pump body 700 is connected to the liquid inlet 301.

[0056] Among them, the connecting flange 600 includes a flange plate 601 arranged between the side diameter 500 and the pump body 700. The flange plate 601 is a split design and is used for fastening through connecting bolts 602, connecting bolts 602 arranged on the flange plate 601, a sealing groove 603 opened in the flange plate 601, used to prevent the sealing ring 604, a sealing ring 604 arranged in the sealing groove 603, used for sealing, and an expansion hole 605 opened in the sealing ring 604, used to strengthen the sealing.

[0057] During use, when the device needs to be installed as a whole or in part, the sealing ring 604 is placed in the sealing groove 603, the flange 601 is aligned, and then the connecting bolts 602 are tightened. When the two sets of flanges 601 are about to touch, the sealing ring 604 abuts against the flanges 601 on both sides. At this time, the connecting bolts 602 are tightened. The two sets of flanges 601 are close to squeeze the sealing ring 604. The sealing ring 604 is deformed through the expansion hole 605, the middle part shrinks, and the outer side is squeezed around to improve the sealing performance. As the fracturing operation proceeds, the high heat of the fracturing fluid is transferred to the inside of the expansion hole 605, causing the expansion hole 605 to expand, which further improves the sealing performance of the connecting bolts 602.

[0058] The remaining structure is the same as that of Example 2.

[0059] It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A collection mechanism, characterized in that: It comprises a support plate (100), a support leg (200) arranged under the support plate (100), and a collecting component (300) arranged on the support plate (100). The collecting component (300) comprises a liquid inlet (301) arranged on one side above the support plate (100), a liquid discharge port (302) arranged on the other side above the support plate (100), a valve assembly (303) arranged on the liquid inlet (301) and the liquid discharge port (302), a flow channel assembly (304) arranged between two groups of the valve assemblies (303), a first filter assembly (305) arranged on the flow channel assembly (304), and a second filter assembly (306) arranged on the flow channel assembly (304).

2. The collecting mechanism according to claim 1, characterized in that: The valve assembly (303) comprises a first valve (303a) arranged on one side of the liquid inlet (301) and the liquid outlet (302), a second valve (303b) arranged on one side of the first valve (303a), and a third valve (303c) arranged on the other side of the first valve (303a).

3. The collection mechanism according to claim 2, characterized in that: The flow channel assembly (304) comprises a first flow channel (304a) arranged between two groups of the first valves (303a), a second flow channel (304b) arranged between two groups of the second valves (303b), and a third flow channel (304c) arranged between two groups of the third valves (303c); the second flow channel (304b) and the third flow channel (304c) have the same size and structure.

4. The collecting mechanism according to claim 3, characterized in that: The first filter assembly (305) comprises a first flow chamber (305a) arranged at the output end of the second flow channel (304b) and the third flow channel (304c) on a side close to the liquid inlet (301), a filter cover (305b) arranged in the first flow chamber (305a), a connecting stud (305c) arranged on the first flow chamber (305a), and a fastening nut (305d) arranged on the connecting stud (305c).

5. The collecting mechanism according to claim 4, characterized in that: The first flow chamber (305a) comprises a connecting tube (305a-1) arranged on the support plate (100), a guide plate (305a-2) arranged in the connecting tube (305a-1), and a clearing tooth column (305a-3) arranged in the connecting tube (305a-1) and cooperating with the filter cover (305b).

6. The collecting mechanism according to claim 5, characterized in that: The filter cover (305b) includes a fixing plate (305b-1) arranged on the connecting tube (305a-1), a collecting box (305b-2) arranged on the fixing plate (305b-1), an intercepting mesh plate (305b-3) arranged on one side of the collecting box (305b-2), a sliding block (305b-4) arranged on the intercepting mesh plate (305b-3), a sliding groove (305b-5) opened on the connecting tube (305a-1) and cooperating with the sliding block (305b-4), and a handle (305b-6) arranged on the fixing plate (305b-1).

7. The collecting mechanism according to claim 6, characterized in that: The second filter assembly (306) includes a second flow chamber (306a) disposed on the second flow channel (304b) and the third flow channel (304c), a cover plate (306b) disposed on the second flow chamber (306a), a mounting member (306c) disposed in the second flow chamber (306a), and a filter screen (306d) disposed on the mounting member (306c).

8. The collecting mechanism according to claim 7, characterized in that: The cover plate (306b) comprises a plate body (306b-1) arranged on the second flow chamber (306a), a telescopic chamber (306b-2) opened in the plate body (306b-1), a compression spring (306b-3) arranged in the telescopic chamber (306b-2), a pressure plate (306b-4) arranged at the lower end of the compression spring (306b-3), and a pressure groove (306b-5) opened on the second flow chamber (306a) and matched with the pressure plate (306b-4). The mounting member (306c) includes a pull plate (306c-1) arranged in the second flow chamber (306a), the upper part of the pull plate (306c-1) is clamped with the pressing groove (306b-5), a first mounting block (306c-2) arranged at the lower part of the pull plate (306c-1), a second mounting block (306c-3) arranged on one side of the first mounting block (306c-2), a support shaft (306c-4) arranged between the first mounting block (306c-2) and the second mounting block (306c-3), a first mounting groove (306c-5) arranged on the first mounting block (306c-2), and a second mounting groove (306c-6) arranged on the second mounting block (306c-3).

9. A Christmas tree, characterized in that: The method comprises the collecting mechanism as claimed in claim 8, and further comprises a Christmas tree body (400) arranged at one end of the liquid inlet (301), a side passage (500) arranged on one side of the Christmas tree body (400), a connecting flange (600) arranged at one end of the side passage (500), and a pump body (700) arranged at one end of the connecting flange (600), wherein the pump body (700) is connected to the liquid inlet (301).

10. The Christmas tree according to claim 9, characterized in that: The connecting flange (600) includes a flange (601) arranged between the side passage (500) and the pump body (700), connecting bolts (602) arranged on the flange (601), a sealing groove (603) opened in the flange (601), a sealing ring (604) arranged in the sealing groove (603), and an expansion hole (605) opened in the sealing ring (604).

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