Deep sea gate valve
By using airbags and cylinder balancers in deep-sea gate valves to achieve internal and external pressure balance, the pressure imbalance and corrosion problems of valve actuators in deep-sea environments are solved, product performance and life are improved, and manufacturing costs are reduced.
Patent Information
- Application Number
- CN202420935640.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-30
- Publication Date
- 2024-12-06
- Estimated Expiration
- 2034-04-30
AI Technical Summary
The deep-sea valve actuator reacts back pressure due to internal and external pressure imbalance in a high-pressure environment, which prevents the mechanism from operating, and directly introduces seawater into the internal chamber will cause corrosion, affecting product performance and life.
A balancer including airbags and cylinders is used to enter the airbags through seawater to expand them, compress the gas in the inner cavity of the transmission box, achieve internal and external pressure balance, avoid increasing the thickness and weight of the shell, and at the same time, use a sealing ring to improve sealing performance.
The internal and external pressure balance of the deep-sea gate valve actuator is achieved, the safety of the transmission box is ensured, the product volume and weight is reduced, the service life is extended, and the sealing performance is improved.
Smart Images
Figure CN222122286U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of valves, in particular to a deep-sea gate valve. Background Art
[0002] In recent years, some Chinese companies have carried out research on special technologies and products for offshore oil underwater equipment and have made great progress. In offshore underwater oil and gas, petroleum mining and production equipment, underwater valves and valve actuators are used, and the use and control of underwater valves can only be completed through valve actuators.
[0003] In land-based valve actuators, except for the pressure-control chamber that bears the operating hydraulic pressure or air pressure, the internal and external pressures of other internal chambers are generally atmospheric pressure. When designing the overall structural strength of the valve actuator, only the pressure-bearing strength and structural strength of the pressure-bearing chamber need to be considered. When the pressure and volume changes in the pressure-control chamber drive the actuator to move, the air pressure and volume in other chambers will also change. This change can be dynamically compensated through the guide holes between the chambers in the shell or the exhaust holes connected to the atmosphere.
[0004] For valve actuators used in the deep sea, in addition to the operating hydraulic pressure, the valve actuator housing also has to withstand the external water depth pressure. If the non-pressure-controlled chamber inside the actuator does not take pressure balance compensation, when the working pressure is introduced into the pressure-controlled chamber, the non-pressure-controlled chamber inside the actuator will produce a certain reaction back pressure due to the closed inner cavity, which will prevent the actuator from moving; at the same time, the housing will be subjected to unilateral pressure from the external water depth, resulting in inconsistent internal and external pressures, which has a tendency to crush the housing. In order to ensure the safety of the housing, the housing wall thickness needs to be increased, resulting in an increase in the overall size and weight, and an increase in manufacturing costs.
[0005] In order to achieve pressure balance and compensation, the deep-sea valve actuator is simply connected to the external seawater through the diversion (pressure) hole like the actuator on land, and the seawater is directly introduced into the internal chambers of the actuator. Although the internal and external pressure balance and compensation can be achieved, the seawater will corrode the internal parts of the valve actuator, seriously affecting the performance and life of the product. In order to achieve the internal and external pressure balance and effective volume compensation of the actuator, improve the performance and life of the product, and reduce the size and weight, it is necessary to conduct necessary research on this functional structure. Utility Model Content
[0006] The purpose of the utility model is to provide a deep-sea gate valve, which can achieve internal and external pressure balance of the deep-sea gate valve actuator, ensure the safety of the actuator transmission box, and improve the product performance and life.
[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a deep-sea gate valve, comprising a valve body, a valve cover, a bracket, an actuator, a valve stem and a gate plate, wherein the valve cover is mounted on the upper part of the valve body, the bracket is arranged on the valve cover, the actuator is arranged on the bracket, the valve stem sequentially passes through the bracket, the valve cover and the valve body, one end of the valve stem is linked to the output end of the actuator, and the other end of the valve stem is linked to the gate plate arranged inside the valve body, and valve seats for sealing with the gate plate when the valve is closed are respectively arranged at positions corresponding to both sides of the gate plate in the valve body; the actuator comprises a transmission box, a transmission shaft, a transmission rod, a connecting rod and a balancer, and the transmission rod is rotatably arranged in the transmission box The transmission shaft is installed at the upper end of the transmission box for linkage connection with an external actuator, and the lower end of the transmission shaft is linkage connection with the transmission rod. The connecting rod is vertically slidably arranged at the lower end of the transmission box for linkage connection with the valve stem, and the connecting rod is threadedly matched with the transmission rod; the balancer includes an oil inlet pipe, a steel cylinder and an air bag. The oil inlet pipe is arranged on the side of the transmission box, and one end of the oil inlet pipe is connected with the inner cavity of the transmission box, and the other end of the oil inlet pipe is connected with a plug. The two ends of the steel cylinder are respectively provided with an exchanger joint and a screw plug, and the screw plug is connected to the side of the oil inlet pipe. The air bag is arranged inside the steel cylinder and the inner end of the exchanger joint is connected to the inside of the air bag. A plurality of through holes are arranged on the exchanger joint.
[0008] By adopting the above technical solution, as the water depth increases, seawater enters the airbag, causing the airbag to expand, compressing the gas in the cylinder and the inner cavity of the actuator transmission box, thereby achieving internal and external pressure balance of the actuator and ensuring the safety of the actuator transmission box. There is no need to increase the thickness of the actuator transmission box, which not only reduces the volume and weight of the transmission box and reduces manufacturing costs, but also effectively improves the product performance and life.
[0009] The utility model is further configured such that a supporting flange extending inward is provided at the opening of the upper end of the steel cylinder, a mounting flange extending outward is provided at the upper end of the airbag, and a clamping nut is threadedly connected to the opening of the upper end of the steel cylinder, and the clamping nut presses the mounting flange onto the supporting flange.
[0010] By adopting the above technical solution, the locking installation of the airbag can be achieved, which is not only convenient for disassembly and assembly, but also has good reliability.
[0011] The utility model is further configured that a threaded sleeve is threadedly connected to the inner side of the clamping nut, and the lower end of the exchanger joint is threadedly connected to the threaded sleeve.
[0012] By adopting the above technical solution, the installation of the exchanger joint can be realized, the connection structure is simple and reliable, and the disassembly and assembly are very convenient.
[0013] The utility model is further configured that a plurality of guide racks are circumferentially arranged on the outer circumference of the connecting rod, the guide racks extend vertically, and a plurality of guide tooth grooves matching with the guide racks are arranged at the opening of the upper end of the bracket.
[0014] By adopting the above technical solution, the connecting rod can be limited circumferentially so that it can stably perform axial movement.
[0015] The utility model is further configured as follows: a limit drive rod is rotatably arranged in the transmission box, a guide groove is spirally arranged on the outer side of the limit drive rod, an indication shaft extending into the guide groove is arranged on the side of the connecting rod, a limit indication rod is arranged on the upper end of the limit drive rod, the upper end of the limit indication rod extends to the outside of the transmission box and is linked to an indication needle, and an opening indication plate and a closing indication plate are correspondingly arranged on the outer side of the transmission box.
[0016] By adopting the above technical solution, during the axial displacement of the connecting rod, when the indicating shaft on the connecting rod slides in the guide groove on the limit driving rod, the limit driving rod is driven to rotate, and the limit driving rod drives the limit indicating rod to rotate, thereby driving the indicating needle to rotate. When the indicating needle rotates to the open indicating plate, the valve is fully opened, and when the indicating needle rotates to the closed indicating plate, the valve is fully closed, so that the staff can judge the opening and closing status of the valve.
[0017] The utility model is further configured such that a limiting flange is provided on the outer periphery of the transmission rod, a supporting step is provided on the inner side of the transmission box, a pressure cover is threadedly connected inside the transmission box for limiting the limiting flange on the supporting step, and bearings are clamped between the pressure cover and the supporting flange, and between the supporting flange and the supporting step.
[0018] By adopting the above technical solution, the axial limitation of the transmission rod can be achieved, so that it can stably rotate in the circumferential direction, with small friction and stable transmission.
[0019] The utility model is further configured to include a connecting head, one end of which is provided with a connecting portion with a T-shaped cross-section, the connecting rod is provided with a connecting groove matching the connecting portion, the upper end of the valve stem is provided with a threaded section, and the lower end of the connecting head is provided with a threaded groove for the threaded section to be screwed into.
[0020] By adopting the above technical solution, the connecting rod and the valve stem can be quickly connected through the connecting head, so that the valve stem can be driven to move axially through the connecting rod.
[0021] The utility model is further configured that the inner wall of the valve body is provided with a mounting groove, one end of the valve seat is embedded in the mounting groove, and the other end of the valve seat is tightly fitted with the gate plate.
[0022] By adopting the above technical solution, only one end of the valve seat needs to be set in the installation groove, and the two valve seats are against the two sides of the gate plate. The two sides of the gate plate can respectively limit the two valve seats, making the installation of the valve seat more stable and reliable, and reducing the difficulty of installing the valve seat.
[0023] The utility model is further configured as follows: a sealing groove is provided on one side of the valve seat close to the mounting groove, a sealing ring is embedded in the sealing groove, the sealing ring comprises a lip ring and a V-ring, an annular groove is provided in the middle of the lip ring, the V-ring is arranged in the annular groove, and a supporting convex edge is respectively provided at positions on both sides of the lip ring corresponding to the annular groove, the two ends of the V-ring are respectively pressed against the inner sides of the corresponding supporting convex edges, and an annular reinforcement portion extending outward is also provided in the middle of the V-ring.
[0024] By adopting the above technical solution, when the sealing ring is under pressure, the two ends of the V-ring will apply an outward pre-tightening force, causing the two sides of the lip ring to have a tendency to move outward, pressing against the contact surfaces on both sides, thereby improving the sealing performance of the valve seat installation under high-pressure environment. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 It is a schematic diagram of the overall structure of the utility model;
[0026] Figure 2 It is a structural schematic diagram of the actuator of the utility model;
[0027] Figure 3 This is a schematic diagram of the matching structure of the connecting rod and the limit driving rod of the utility model;
[0028] Figure 4 It is an exploded view of the connecting rod and the bracket of the utility model;
[0029] Figure 5 This is a schematic diagram of the installation structure of the valve seat of the utility model;
[0030] Figure 6 for Figure 5 Schematic diagram of the enlarged structure of part A in the middle.
[0031] In the figure: 1, valve body; 2, valve cover; 3, bracket; 4, actuator; 5, valve stem; 6, gate; 7, valve seat; 8, transmission box; 9, transmission shaft; 10, transmission rod; 11, connecting rod; 12, balancer; 13, oil inlet pipe; 14, cylinder; 15, air bag; 16, plug; 17, exchanger joint; 18, screw plug; 19, through hole; 20, support flange; 21, mounting flange; 22, compression nut; 23, screw sleeve; 24, guide rack; 25, guide tooth groove; 26, limit drive Moving rod; 27, guide groove; 28, indicator shaft; 29, limit indicator rod; 30, indicator needle; 31, open indicator plate; 32, close indicator plate; 33, limit flange; 34, support step; 35, pressure cover; 36, bearing; 37, connector; 38, connecting part; 39, connecting groove; 40, threaded section; 41, threaded groove; 42, mounting groove; 43, sealing groove; 44, sealing ring; 45, lip ring; 46, annular groove; 47, V-ring; 48, supporting convex edge; 49, annular reinforcement part. DETAILED DESCRIPTION
[0032] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0033] Example: As attached Figures 1 to 6A deep-sea gate valve shown in the figure comprises a valve body 1, a valve cover 2, a bracket 3, an actuator 4, a valve stem 5 and a gate plate 6, wherein the valve cover 2 is mounted on the upper part of the valve body 1, the bracket 3 is arranged on the valve cover 2, the actuator 4 is arranged on the bracket 3, the valve stem 5 sequentially passes through the bracket 3, the valve cover 2 and the valve body 1, one end of the valve stem 5 is linked to the output end of the actuator 4, and the other end of the valve stem 5 is linked to the gate plate 6 arranged inside the valve body 1, and valve seats 7 for forming a sealing fit with the gate plate 6 when the valve is closed are also respectively arranged at positions corresponding to both sides of the gate plate 6 in the valve body 1; the actuator 4 comprises a transmission box 8, a transmission shaft 9, a transmission rod 10, a connecting rod 11 and a balancer 12, the transmission rod 10 is rotatably arranged in the transmission box 8, the transmission shaft 9 is mounted on the upper end of the transmission box 8 for linkage connection with an external actuator, the external actuator can be a motor, and the lower end of the transmission shaft 9 is connected to the transmission rod 1 0 linkage connection, the connecting rod 11 is vertically slidably arranged at the lower end of the transmission box 8 for linkage connection with the valve stem 5, the connecting rod 11 is threadedly matched with the transmission rod 10, that is, the connecting rod 11 has an internal thread, and the transmission rod 10 has an external thread matched with the internal thread; the balancer 12 includes an oil inlet pipe 13, a steel cylinder 14 and an air bag 15, the oil inlet pipe 13 is arranged on the side of the transmission box 8, the oil inlet pipe 13 is a three-way pipe, and one end of the oil inlet pipe 13 is connected to the inner cavity of the transmission box 8, and the other end of the oil inlet pipe 13 is connected to a plug 16, the two ends of the steel cylinder 14 are respectively provided with an exchanger joint 17 and a screw plug 18, and the screw plug 18 is connected to the side of the oil inlet pipe 13, specifically, the screw plug 18 is welded on the side hole of the three-way pipe, the air bag 15 is arranged inside the steel cylinder 14 and the inner end of the exchanger joint 17 is connected to the inside of the air bag 15, and a plurality of through holes 19 are provided on the exchanger joint 17. As the water depth increases, seawater enters the airbag 15, causing the airbag 15 to expand, compressing the gas in the cylinder 14 and the inner cavity of the transmission box 8 of the actuator 4, achieving internal and external pressure balance of the actuator 4, ensuring the safety of the transmission box 8 of the actuator 4, and eliminating the need to increase the thickness of the transmission box 8 of the actuator 4. This not only reduces the volume and weight of the transmission box 8 and reduces manufacturing costs, but also effectively improves the product performance and lifespan.
[0034] As attached Figure 2 As shown, the upper opening of the steel cylinder 14 is provided with an inwardly extending support flange 20, the upper end of the airbag 15 is provided with an outwardly extending mounting flange 21, and the upper opening of the steel cylinder 14 is also threadedly connected with a clamping nut 22, and the clamping nut 22 presses the mounting flange 21 onto the support flange 20. This design can realize the locking installation of the airbag 15, which is not only convenient for disassembly and assembly, but also has good reliability.
[0035] As attached Figure 2As shown, the inner side of the compression nut 22 is threadedly connected with a screw sleeve 23, and the lower end of the exchanger joint 17 is threadedly connected in the screw sleeve 23. This design can realize the installation of the exchanger joint 17, the connection structure is simple and reliable, and the disassembly and assembly are very convenient.
[0036] As attached Figure 2 and attached Figure 4 As shown, the outer circumference of the connecting rod 11 is provided with a plurality of guide racks 24 along the circumferential direction, and the guide racks 24 extend vertically, and the upper opening of the bracket 3 is provided with a plurality of guide tooth grooves 25 matching the guide racks 24. This design can limit the circumferential position of the connecting rod 11, so that it can stably perform axial movement.
[0037] As attached Figure 2 and attached Figure 3 As shown, a limited driving rod 26 is also rotatably arranged in the transmission box 8, and a guide groove 27 is spirally arranged on the outer side of the limited driving rod 26. An indicating shaft 28 extending into the guide groove 27 is arranged on the side of the connecting rod 11, and a limited indicating rod 29 is arranged on the upper end of the limited driving rod 26. The upper end of the limited indicating rod 29 extends to the outside of the transmission box 8 and is linked to an indicating needle 30. An opening indicating plate 31 and a closing indicating plate 32 are correspondingly arranged on the outer side of the transmission box 8. During the axial displacement of the connecting rod 11, when the indicating shaft 28 on the connecting rod 11 slides in the guiding groove 27 on the limited driving rod 26, the limited driving rod 26 is driven to rotate, and the limited driving rod 26 drives the limited indicating rod 29 to rotate, and then drives the indicating needle 30 to rotate. When the indicating needle 30 rotates to the opening indicating plate 31, the valve is fully opened, and when the indicating needle 30 rotates to the closing indicating plate 32, the valve is fully closed, so that the staff can judge the opening and closing state of the valve.
[0038] As attached Figure 2 As shown, the outer periphery of the transmission rod 10 is provided with a limiting flange 33, the inner side of the transmission box 8 is provided with a supporting step 34, the transmission box 8 is internally threaded with a gland 35 for limiting the limiting flange 33 on the supporting step 34, and a bearing 36 is sandwiched between the gland 35 and the supporting flange 20, and between the supporting flange 20 and the supporting step 34. This design can realize the axial limiting of the transmission rod 10, so that it can stably rotate in the circumferential direction, with low friction and stable transmission.
[0039] As attached Figure 2As shown, it also includes a connector 37, one end of which is provided with a connecting portion 38 with a T-shaped cross section, the connecting rod 11 is provided with a connecting groove 39 matched with the connecting portion 38, the upper end of the valve stem 5 is provided with a threaded section 40, and the lower end of the connector 37 is provided with a threaded groove 41 for the threaded section 40 to be screwed into. The connecting rod 11 and the valve stem 5 can be quickly connected through the connector 37, so that the valve stem 5 can be driven to move axially through the connecting rod 11.
[0040] As attached Figure 1 and attached Figure 5 As shown, the inner wall of the valve body 1 is provided with a mounting groove 42, one end of the valve seat 7 is embedded in the mounting groove 42, and the other end of the valve seat 7 is tightly fitted with the gate plate 6. It is only necessary to set one end of the valve seat 7 in the mounting groove 42, and the two valve seats 7 are against the two sides of the gate plate 6. The two sides of the gate plate 6 can respectively limit the two valve seats 7, so that the installation of the valve seat 7 is more stable and reliable, and the installation difficulty of the valve seat 7 is also reduced.
[0041] As attached Figure 6 As shown, a sealing groove 43 is provided on one side of the valve seat 7 close to the installation groove 42, and a sealing ring 44 is embedded in the sealing groove 43. The sealing ring 44 includes a lip ring 45 and a V-ring 47. An annular groove 46 is provided in the middle of the lip ring 45, and the V-ring 47 is arranged in the annular groove 46. A supporting convex edge 48 is provided at the positions on both sides of the lip ring 45 corresponding to the annular groove 46, respectively. The two ends of the V-ring 47 are respectively pressed against the inner side of the corresponding supporting convex edge 48, and the middle of the V-ring 47 is also provided with an annular reinforcement portion 49 extending outward. When the sealing ring 44 is pressurized, the two ends of the V-ring 47 will apply an outward pre-tightening force, so that the two sides of the lip ring 45 have a tendency to move outward, pressing against the contact surfaces on both sides, thereby improving the sealing performance of the valve seat 7 installed under high pressure environment.
Claims
1. A deep-sea gate valve, comprising a valve body (1), a valve cover (2), a bracket (3), an actuator (4), a valve stem (5) and a gate plate (6), wherein the valve cover (2) is mounted on the upper part of the valve body (1), the bracket (3) is arranged on the valve cover (2), the actuator (4) is arranged on the bracket (3), the valve stem (5) sequentially penetrates the bracket (3), the valve cover (2) and the valve body (1), one end of the valve stem (5) is linked to the output end of the actuator (4), and the other end of the valve stem (5) is linked to the gate plate (6) arranged inside the valve body (1), and valve seats (7) for forming a sealing fit with the gate plate (6) when the valve is closed are respectively arranged at positions corresponding to both sides of the gate plate (6) in the valve body (1); characterized in that: The actuator (4) comprises a transmission box (8), a transmission shaft (9), a transmission rod (10), a connecting rod (11) and a balancer (12); the transmission rod (10) is rotatably arranged in the transmission box (8); the transmission shaft (9) is mounted on the upper end of the transmission box (8) for linkage connection with an external actuator, and the lower end of the transmission shaft (9) is linkage connected with the transmission rod (10); the connecting rod (11) is vertically slidably arranged at the lower end of the transmission box (8) for linkage connection with the valve stem (5); the connecting rod (11) and the transmission rod (10) are threadedly matched; the balancer (12) comprises an oil inlet pipe (13) , a steel cylinder (14) and an air bag (15), wherein the oil inlet pipe (13) is arranged on the side of a transmission case (8), and one end of the oil inlet pipe (13) is communicated with the inner cavity of the transmission case (8), and the other end of the oil inlet pipe (13) is connected with a plug (16), the two ends of the steel cylinder (14) are respectively provided with an exchanger joint (17) and a screw plug (18), and the screw plug (18) is connected to the side of the oil inlet pipe (13), the air bag (15) is arranged inside the steel cylinder (14), and the inner end of the exchanger joint (17) is communicated with the inside of the air bag (15), and the exchanger joint (17) is provided with a plurality of through holes (19).
2. A deep sea gate valve according to claim 1, characterized in that: The upper opening of the steel cylinder (14) is provided with a supporting flange (20) extending inwards, the upper end of the airbag (15) is provided with a mounting flange (21) extending outwards, and the upper opening of the steel cylinder (14) is also threadedly connected with a clamping nut (22), and the clamping nut (22) presses the mounting flange (21) onto the supporting flange (20).
3. A deep sea gate valve according to claim 2, characterized in that: The inner side of the compression nut (22) is threadedly connected with a threaded sleeve (23), and the lower end of the exchanger joint (17) is threadedly connected in the threaded sleeve (23).
4. A deep sea gate valve according to claim 1, characterized in that: The outer periphery of the connecting rod (11) is provided with a plurality of guide racks (24) along the circumferential direction. The guide racks (24) extend vertically. The upper opening of the bracket (3) is provided with a plurality of guide tooth grooves (25) matching with the guide racks (24).
5. A deep sea gate valve according to claim 1, characterized in that: A limit drive rod (26) is rotatably arranged in the transmission box (8), a guide groove (27) is spirally arranged on the outer side of the limit drive rod (26), an indication shaft (28) extending into the guide groove (27) is arranged on the side of the connecting rod (11), a limit indication rod (29) is arranged at the upper end of the limit drive rod (26), the upper end of the limit indication rod (29) extends to the outside of the transmission box (8) and is linked to an indication needle (30), and an opening indication plate (31) and a closing indication plate (32) are correspondingly arranged on the outer side of the transmission box (8).
6. A deep sea gate valve according to claim 1, characterized in that: A limiting flange (33) is arranged on the outer periphery of the transmission rod (10), a supporting step (34) is arranged on the inner side of the transmission box (8), a pressure cover (35) for limiting the limiting flange (33) on the supporting step (34) is connected to the inner thread of the transmission box (8), and bearings (36) are sandwiched between the pressure cover (35) and the supporting flange (20), and between the supporting flange (20) and the supporting step (34).
7. A deep sea gate valve according to claim 1, characterized in that: It also includes a connecting head (37), one end of which is provided with a connecting portion (38) with a T-shaped cross-section, the connecting rod (11) is provided with a connecting groove (39) that matches the connecting portion (38), the upper end of the valve stem (5) is provided with a threaded section (40), and the lower end of the connecting head (37) is provided with a threaded groove (41) for the threaded section (40) to be screwed into.
8. A deep sea gate valve according to claim 1, characterized in that: The inner wall of the valve body (1) is provided with a mounting groove (42), one end of the valve seat (7) is embedded in the mounting groove (42), and the other end of the valve seat (7) is tightly fitted with the gate plate (6).
9. A deep sea gate valve according to claim 8, characterized in that: A sealing groove (43) is provided on one side of the valve seat (7) close to the mounting groove (42), and a sealing ring (44) is embedded in the sealing groove (43). The sealing ring (44) includes a lip ring (45) and a V-shaped ring (47). An annular groove (46) is provided in the middle of the lip ring (45), and the V-shaped ring (47) is arranged in the annular groove (46). The lip ring (45) is provided with a supporting convex edge (48) at positions on both sides of the annular groove (46), respectively. The two ends of the V-shaped ring (47) are respectively pressed against the inner side of the corresponding supporting convex edge (48), and the middle of the V-shaped ring (47) is also provided with an outwardly extending annular reinforcement portion (49).