A main steam safety valve sealing plug disassembly and assembly device

Abstract

The present invention specifically relates to a main steam safety valve sealing plug disassembly and assembly device, comprising a connecting sleeve (8), a threaded cover (12), a screw rod (14), a bridge and a power device; the bridge is installed on the flange of the main steam safety valve; the bottom of the screw rod (14) passes through the center of the bridge and extends into the interior of the connecting sleeve (8); the threaded cover (12) is sleeved on the screw rod (14) and cooperates with the spherical surface of the upper end of the ball head (11); the screw rod (14) is connected to the power device, and the power device drives the screw rod (14) to rise and fall and transmits it to the sealing plug (3) through the threaded cover (12), the arc-shaped washer (9) and the connecting sleeve (8), thereby completing the disassembly and assembly of the main steam safety valve sealing plug. The main steam safety valve sealing plug disassembly and assembly device of the present invention can conveniently disassemble and assemble the main steam safety valve sealing plug, and at the same time can ensure that the O-ring is installed in place and is not damaged, thereby improving the working efficiency and quality of the main steam safety valve sealing plug disassembly and assembly.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear power plant maintenance, in particular to a main steam safety valve sealing plug disassembly and assembly device. Background Art

[0002] The main steam safety valve is one of the key equipment in a nuclear power plant and belongs to the secondary circuit pressure boundary. According to nuclear safety regulations and operating specifications, the secondary circuit pressure boundary, including the main steam safety valve, must be regularly subjected to hydrostatic tests to verify the integrity of the boundary containing radioactive materials. The secondary circuit hydrostatic test is the main line of work in the overhaul of a nuclear power plant. Before the project starts, it is necessary to plug the nozzle of the main steam safety valve that is being dismantled and overhauled, press a special sealing plug into the nozzle, and rely on the O-ring to achieve the seal between the nozzle and the plug. During the test, if a leak occurs, the test process will be rolled back and the sealing plug will be reinstalled, which will inevitably affect the overhaul plan and cause economic losses. The high pressure (10.2MPa) of the secondary circuit hydrostatic test causes the O-ring to have a large fit and tightening force, making it difficult to press the sealing plug into the nozzle by manpower. If a non-standard tool is used to force the sealing plug into the nozzle, it is easy to damage the O-ring or even damage the nozzle sealing ring, causing leakage and forcing the hydrostatic test to terminate. In addition, due to the tight fit of the O-ring, it is also extremely difficult to pull out the sealing plug, and forced operation is likely to damage the equipment. Summary of the invention

[0003] Based on this, it is necessary to provide a main steam safety valve sealing plug disassembly and assembly device to address the problem that existing tools cannot meet the installation and removal requirements of the main steam safety valve sealing plug. The device can conveniently disassemble and assemble the main steam safety valve sealing plug, and at the same time ensure that the O-ring is installed in place and not damaged, thereby improving the work efficiency and quality of the main steam safety valve sealing plug disassembly and assembly.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A main steam safety valve sealing plug disassembly and assembly device comprises a connecting sleeve, a screw rod, a threaded cover, a bridge and a power device; the bridge is installed on the flange of the main steam safety valve; the bottom of the screw rod passes through the center of the bridge and extends into the interior of the connecting sleeve; the threaded cover is sleeved on the screw rod and matched with the spherical surface of the upper end of the ball head;

[0006] The screw rod is connected to the power device, and the power device drives the screw rod to rise and fall and transmits the drive to the sealing plug through the threaded cover and the connecting sleeve, thereby completing the disassembly and assembly of the sealing plug of the main steam safety valve.

[0007] Furthermore, the main steam safety valve sealing plug disassembly and assembly device also includes an arc-shaped washer, and the ball head at the bottom of the screw rod passes through the center of the bridge to form a close contact with the threaded cover and the arc-shaped washer, so that the power is automatically aligned with the center of the main steam safety valve, eliminating the adverse effects caused by the uneven placement of the device and the sealing plug. The power device drives the screw rod to rise and fall and transmits it to the sealing plug through the threaded cover, the arc-shaped washer and the connecting sleeve to complete the disassembly and assembly of the main steam safety valve sealing plug.

[0008] Furthermore, an arc is provided on the arc-shaped washer, and a ball head matching the arc is provided at the bottom of the screw rod; the ball head is in close contact with the arc, so that the power is automatically aligned with the center of the main steam safety valve, eliminating the adverse effects caused by the uneven placement of the sealing plug.

[0009] Furthermore, the ball head is matched with the arc of the threaded cover to ensure that the sealing plug is only subjected to upward force.

[0010] Furthermore, the bridge includes an installation bridge plate and a pull-out bridge plate; a threaded hole matching the screw rod is provided at the center of the installation bridge plate, and the bottom of the screw rod passes through the threaded hole in the center of the installation bridge plate to form a close contact with the arc-shaped washer, so that the pressure is automatically aligned with the center of the main steam safety valve, eliminating the adverse effects caused by the uneven placement of the sealing plug; a through hole with a diameter larger than the outer diameter of the screw rod is provided at the center of the pull-out bridge plate, and the bottom of the screw rod passes through the through hole in the center of the pull-out bridge plate to form a close contact with the threaded cover, so that the pulling force is automatically aligned with the center of the main steam safety valve, eliminating the adverse effects caused by the misalignment of the device.

[0011] Furthermore, the main steam safety valve sealing plug disassembly and assembly device also includes a thrust bearing, and the thrust bearing is installed at the bottom of the arc-shaped washer to prevent the connecting sleeve from rotating when the screw rod rotates, causing the sealing plug to rotate and damage the sealing ring.

[0012] Furthermore, the main steam safety valve sealing plug disassembly and assembly device also includes a nut matching the middle flange bolt, and bolt holes matching the middle flange bolts are provided at both ends of the bridge. The middle flange bolts of the main steam safety valve, one end away from the valve body, pass through the bolt holes at both ends of the bridge and are threadedly connected with the nuts.

[0013] Furthermore, the power device includes an installation power device and a removal power device; the installation power device is connected to the screw rod, driving the screw rod to rotate to generate downward pressure, and the pressure is transmitted to the sealing plug through the threaded cover, the arc-shaped washer and the connecting sleeve, pressing the sealing plug into the nozzle; the removal power device is respectively connected to the screw rod and the sealing plug, driving the screw rod to generate an upward pulling force, and the pulling force is transmitted to the sealing plug through the threaded cover, the connecting sleeve and the connecting pin, pulling the sealing plug out of the nozzle.

[0014] Furthermore, the installation power device is a ratchet wrench; the ratchet wrench matches the screw rod; the top of the screw rod is connected to the ratchet wrench, and the ratchet wrench is held to drive the screw rod to rotate, generating downward pressure, and the pressure is transmitted to the sealing plug through the arc washer, thrust bearing and connecting sleeve, pressing the sealing plug into the nozzle.

[0015] The manual ratchet wrench drives the screw to rotate, which can easily sense the changes in pressure. When the sealing plug is tilted or the O-ring is stuck, the operation can be stopped immediately to avoid irreversible damage to the equipment.

[0016] Furthermore, the removal power device includes a connecting pin, a hollow jack, a washer, a nut and a hydraulic pump; the bottom of the connecting sleeve is provided with a pin hole matching the pin hole of the sealing plug, and the connecting pin is respectively connected to the pin holes of the connecting sleeve and the sealing plug, so that the connecting sleeve and the sealing plug are connected as a whole; a hollow jack is installed on the pull-out bridge plate, and the left side of the hollow jack is connected to a hydraulic pump; the top of the screw rod passes through the hollow jack and is threadedly connected to the nut, and a washer is arranged between the hollow jack and the nut; the hydraulic pump applies a lifting force to the hollow jack, drives the screw rod to move upward, and the force is transmitted to the sealing plug through the threaded cover, the connecting sleeve and the connecting pin, and the sealing plug is pulled up from the nozzle. The hydraulic pressure can easily pull up the sealing plug.

[0017] Beneficial technical effects of the present invention:

[0018] The main steam safety valve sealing plug disassembly and assembly device of the present invention has an ingenious design, a simple and reliable structure, is easy to process, manufacture and use on site, can effectively improve the efficiency and quality of key work in a nuclear power plant, and has development and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a partial structural schematic diagram of the main steam safety valve sealing plug disassembly and assembly device of the present invention when the main steam safety valve sealing plug is extracted;

[0020] Figure 2 It is a structural schematic diagram of the main steam safety valve sealing plug disassembly and assembly device of the present invention when installing the main steam safety valve sealing plug;

[0021] Figure 3 Schematic diagram of the sealing plug structure of the main steam safety valve.

[0022] In the figure, 1. nozzle; 2. sealing ring; 3. sealing plug; 4. locking cap; 5. valve body; 6. middle flange bolt; 7. connecting pin; 8. connecting sleeve; 9. arc washer; 10. thrust bearing; 11. ball head; 12. threaded cover; 13. installation bridge plate; 14. screw rod; 15. ratchet wrench; 16. pull out bridge plate; 17. hollow jack; 18. washer; 19. nut; 20. hydraulic pump. DETAILED DESCRIPTION

[0023] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by terms such as "left side", "right side", "above", "below", "outside", "inside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0024] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] When plugging the nozzle of the main steam safety valve that is being dismantled for maintenance, it is necessary to press the main steam safety valve sealing plug 3 into the main steam safety valve nozzle 1, and rely on the O-ring 2 to achieve sealing between the main steam safety valve nozzle 1 and the main steam safety valve sealing plug 3.

[0026] See also Figure 1-3 The present invention provides a main steam safety valve sealing plug disassembly and assembly device, including a connecting pin 7, a connecting sleeve 8, an arc-shaped washer 9, a thrust bearing 10, a ball head 11, a threaded cover 12, a mounting bridge plate 13, a screw rod 14, a ratchet wrench 15, a pull-out plate bridge 16, a hollow jack 17, a washer 18, a nut 19 and a hydraulic pump 20.

[0027] The arc-shaped washer 9 is provided with an arc, and the bottom of the screw rod 14 is provided with a ball head 11 matching the arc. The ball head 11 is matched with the arc of the threaded cover 12 to ensure that the sealing plug 3 is only subjected to an upward force.

[0028] Bolt holes matching the middle flange bolts 6 are provided at both ends of the mounting bridge plate 13, and the middle flange of the main steam safety valve is installed with the mounting bridge plate 13 through the middle flange bolts 6 and the bolts and nuts; a threaded hole matching the screw rod 14 is provided at the center of the mounting bridge plate 13, and the bottom of the screw rod 14 passes through the threaded hole in the center of the mounting bridge plate 13 to form a close contact with the arc-shaped washer 9, so that the pressure is automatically aligned with the center of the main steam safety valve, eliminating the adverse effects caused by the uneven placement of the sealing plug 3.

[0029] Both ends of the pull-out bridge plate 16 are provided with bolt holes matching the middle flange bolts 6, and the middle flange of the main steam safety valve is installed with the pull-out bridge plate 16 through the bolts and nuts of the middle flange bolts 6; the center of the pull-out bridge plate 16 is provided with a through hole with a diameter greater than the outer diameter of the screw rod 14, and the bottom of the screw rod 14 passes through the through hole in the center of the pull-out bridge plate 16 to form a close contact with the threaded cover 12, so that the pulling force is automatically aligned with the center of the main steam safety valve, eliminating the adverse effects caused by the misalignment of the device.

[0030] A thrust bearing 10 is installed at the bottom of the arc-shaped washer 9 to prevent the connecting sleeve 8 from rotating when the screw rod 14 rotates, causing the sealing plug 3 to rotate and damage the sealing ring 2.

[0031] The threaded cover 12 is sleeved on the screw rod 14 and matches with the spherical surface of the upper end of the ball head 11 .

[0032] The ratchet wrench 15 matches the screw rod 14; the top of the screw rod 14 is connected to the ratchet wrench 15, and the hand-held ratchet wrench 15 drives the screw rod 14 to rotate, generating downward pressure, which is transmitted to the sealing plug 3 through the arc-shaped washer 9, the thrust bearing 10 and the connecting sleeve 8, pressing the sealing plug 3 into the nozzle 1. The manual ratchet wrench 15 drives the screw rod 14 to rotate, and the pressure change can be easily sensed. When the sealing plug 3 is tilted or the O-ring 2 is blocked, the operation can be stopped immediately to avoid irreversible damage to the equipment.

[0033] The bottom of the connecting sleeve 8 is provided with a pin hole matching the pin hole of the sealing plug 3, and the connecting pin 7 is connected to the pin holes of the connecting sleeve 8 and the sealing plug 3 respectively, so that the connecting sleeve 8 and the sealing plug 3 are connected as a whole; the hollow jack 17 is installed on the pull-out bridge plate 16, and the left side of the hollow jack 17 is connected to the hydraulic pump 20; the top of the screw rod 14 passes through the hollow jack 17 and is threadedly connected to the nut 19, and a washer 18 is arranged between the hollow jack 17 and the nut 19; the hydraulic pump 20 applies a lifting force to the hollow jack 17, driving the screw rod 14 to move upward, and the force is transmitted to the sealing plug 3 through the threaded cover 12, the connecting sleeve 8 and the connecting pin 7, and the sealing plug 3 is pulled up from the nozzle 1. The hydraulic pressure can easily pull up the sealing plug 3.

[0034] First, when the main steam safety valve sealing plug disassembly and assembly device is used to install the main steam safety valve sealing plug, the following steps are included:

[0035] 1. Put the sealing ring 2 on the sealing plug 3, and then place the sealing plug 3 flat on the nozzle 1;

[0036] 2. Place the thrust bearing 10 and the arc-shaped washer 9 in the connecting sleeve 8 in sequence;

[0037] 3. Put the threaded cover 12 on the screw rod 14, screw them into the connecting sleeve 8 together, and shake them appropriately to confirm that they are installed in place and the spherical surface fits smoothly;

[0038] 4. Rotate the mounting bridge plate 13 to the center of the screw rod 14;

[0039] 5. Place the connecting sleeve 8, arc-shaped washer 9, thrust bearing 10, ball head 11, threaded cover 12, mounting bridge plate 13 and screw rod 14 on the flange of the main steam safety valve;

[0040] 6. Install the middle flange bolts and nuts 6 to fix the bridge plate 13;

[0041] 7. Use the ratchet wrench 15 to rotate the screw rod 14 to gradually lower the connecting sleeve 8 until it contacts the sealing plug 3;

[0042] 8. Observe the sealing ring 2 and confirm that there is no abnormality. Then continue to rotate the screw 14 to press the sealing plug 3 into the nozzle 1;

[0043] 9. When you hear a "pop" sound, it means that the sealing ring 2 has completely entered the nozzle 1. Then observe and confirm that the sealing plug 3 is in contact with the inner inclined surface of the nozzle 1, and the installation of the sealing plug 3 is completed.

[0044] Then remove the sealing plug of the main steam safety valve, including the following steps:

[0045] 1. Remove the flange bolts 6 in the flange and unscrew the mounting bridge plate 13;

[0046] 2. Install the pull-out bridge plate 16 and secure it with the middle flange bolts 6 and nuts;

[0047] 3. Install the hollow jack 17, washer 18 and nut 19 on the pull-out bridge plate 16;

[0048] 4. Rotate the connecting sleeve 8 to align the pin hole with the sealing plug 3, and insert the connecting pin 7;

[0049] 5. Connect the oil pump 20 and the hollow jack 17;

[0050] 6. The hollow jack 17 is driven upward by the oil pump to apply an upward pulling force to the screw rod; the pulling force is transmitted to the sealing plug 3 by the threaded cover 12, the connecting sleeve 8 and the connecting pin 7. As the oil pump 20 is pressurized, the sealing plug 3 will be gradually pulled out.

[0051] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A main steam safety valve sealing plug disassembly and assembly device, It is characterized in that The invention comprises a connecting sleeve (8), an arc-shaped washer (9), a thrust bearing (10), a threaded cover (12), a screw rod (14), a bridge and a power device; the bridge is installed on the flange of the main steam safety valve; the bottom of the screw rod (14) passes through the center of the bridge and extends into the interior of the connecting sleeve (8); the threaded cover (12) is sleeved on the screw rod (14) and matches with the spherical surface of the upper end of the ball head (11); the screw rod (14) is connected to the power device, and the power device drives the screw rod (14) to rise and fall and transmits the movement to the sealing plug (3) through the threaded cover (12) and the connecting sleeve (8), thereby completing the disassembly and assembly of the sealing plug of the main steam safety valve; the bottom of the screw rod (14) passes through the center of the bridge and forms a close contact with the arc-shaped washer (9); the arc-shaped washer The iron (9) is provided with an arc, and the bottom of the screw rod (14) is provided with a ball head (11) matching the arc; the ball head (11) is in close contact with the arc; the bottom of the arc-shaped pad iron (9) is installed with a thrust bearing (10); the bridge comprises a mounting bridge plate (13) and a pull-out bridge plate (16); the center of the mounting bridge plate (13) is provided with a threaded hole matching the screw rod (14), and the bottom of the screw rod (14) passes through the threaded hole in the center of the mounting bridge plate (13) to form a close contact with the arc-shaped pad iron (9); the center of the pull-out bridge plate (16) is provided with a through hole with a diameter larger than the outer diameter of the screw rod (14), and the bottom of the screw rod (14) passes through the through hole in the center of the pull-out bridge plate (16) to form a close contact with the threaded cover (12).

2. The main steam safety valve sealing plug disassembly and assembly device according to claim 1, It is characterized in that The ball head (11) is matched with the arc of the threaded cover (12).

3. The main steam safety valve sealing plug disassembly and assembly device according to claim 1, It is characterized in that The main steam safety valve sealing plug disassembly and assembly device further comprises a nut matching the middle flange bolt (6); bolt holes matching the middle flange bolt (6) are provided at both ends of the bridge; the end of the middle flange bolt (6) of the main steam safety valve away from the valve body (5) passes through the bolt holes at both ends of the bridge and is threadedly connected to the nut.

4. The main steam safety valve sealing plug disassembly and assembly device according to claim 1, It is characterized in that The power device comprises an installation power device and a removal power device; the installation power device is connected to the screw rod (14), drives the screw rod (14) to rotate to generate downward pressure, the pressure is transmitted to the sealing plug (3), and the sealing plug (3) is pushed into the nozzle (1); the removal power device is respectively connected to the screw rod (14) and the sealing plug (3), drives the screw rod (14) to generate an upward pulling force, the pulling force is transmitted to the sealing plug (3), and the sealing plug (3) is pulled out of the nozzle (1).

5. The main steam safety valve sealing plug disassembly and assembly device according to claim 4, It is characterized in that The installation power device is a ratchet wrench (15); the ratchet wrench (15) matches the screw rod (14); the top of the screw rod (14) is connected to the ratchet wrench (15), and the ratchet wrench (15) is held to drive the screw rod (14) to rotate, thereby generating downward pressure, which is transmitted to the sealing plug (3), so that the sealing plug (3) is pushed into the nozzle (1).

6. The main steam safety valve sealing plug disassembly and assembly device according to claim 4, It is characterized in that The removal power device comprises a connecting pin (7), a hollow jack (17), a washer (18), a nut (19) and a hydraulic pump (20); a pin hole matching the pin hole of the sealing plug (3) is provided at the bottom of the connecting sleeve (8); the connecting pin (7) is connected to the pin holes of the connecting sleeve (8) and the sealing plug (3) respectively, so that the connecting sleeve (8) and the sealing plug (3) are connected as a whole; the hollow jack (17) is installed on the pull-out bridge plate (16); The left side of the hollow jack (17) is connected to a hydraulic pump (20); the top of the screw rod (14) passes through the hollow jack (17) and is threadedly connected to the nut (19), and a washer (18) is arranged between the hollow jack (17) and the nut (19); the hydraulic pump (20) applies a lifting force to the hollow jack (17), driving the screw rod (14) to move upward, and the force is transmitted to the threaded cover (12) and the connecting sleeve (8), so as to pull the sealing plug (3) out of the nozzle (1).

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