JP4977546B2 - Pressure seal device - Google Patents

Description

  The present invention relates to a pressure-resistant sealing device for stopping a fluid flowing in a pipe when a valve connected to a pipe in a plant facility is replaced or when the valve is overhauled.

  FIG. 7 is a drawing schematically showing a system of the nuclear power plant 1. The nuclear power plant 1 shown in FIG. 7 is a so-called boiling water reactor, and heats the cooling water in the reactor pressure vessel 2 by using heat generated by the fission reaction in the core 3 in the reactor pressure vessel 2. To produce steam. This steam is transferred to the steam turbine 5 through the main steam pipe 4 to rotate the steam turbine 5. The generator 6 connected to the steam turbine 5 generates electricity by this rotation. The steam is cooled by seawater through the condenser 7 and returned to the water. Thereafter, water is poured into the reactor pressure vessel 2 through the pipe 8 and the plurality of valves 9. In this way, the cooling water circulates in the nuclear power plant 1.

  Thus, since the nuclear power plant 1 uses the heat generated by the fission reaction in the core 3 to heat the cooling water and generate steam, the pressure and temperature around the core 3 are increased during the operation of the nuclear reactor. To rise. Further, a recirculation pump 10 for forcibly sending cooling water to the core 3 is provided, and fluid vibration is generated by the flow of the fluid that the recirculation pump 10 sends to the core 3. Since the pipe 8 and the plurality of valves 9 are used in such a severe environment where pressure and temperature rise around the core 3 and fluid vibration occur, a large load acts on the members 8 and 9. Become. Therefore, it is fully expected that the pipe 8 and the valve 9 will be damaged or broken. There is no prior art document in this regard.

  However, if cracks or breaks occur in the piping 8 and the valve 9 etc. for some reason, the nuclear power plant 1 is in a high radiation control area, so that it approaches the piping 8 and the valve 9 etc. during the reactor operation. It is extremely difficult to do. Moreover, it is impossible to repair it.

  Therefore, as a means for repairing the pipe 8 and the valve 9 that is predicted to be damaged, it is conceivable to replace the pipe 8 and the valve 9 in advance during the periodic inspection work of the nuclear power plant 1. The replacement work of the pipe 8 and the valve 9 is accompanied by a pressure leak test. After the replacement, it is necessary to check the safety of the pipe 8 and the valve 9 by performing a pressure leak test. This pressure leak test needs to be performed with the upstream and downstream valves 9 of the replaced valve 9 closed. However, all the valves 9 have the same valve opening / closing direction, that is, perform the same opening / closing operation with respect to flows in the same direction. Therefore, when a fluid flows through the pipe 8, one of the upstream side valve 9 and the downstream side valve 9 is always opened. Therefore, both the upstream and downstream valves 9 cannot be used for the pressure leak test, and it is necessary to use a separate device for water-stopping the pipe 8, which makes long-term construction. There is a problem of becoming. As described above, when the construction is performed for a long period of time, there is a problem that not only the periodical inspection period is prolonged and the operation rate of the nuclear power plant 1 is lowered, but also the radiation exposure amount of workers is increased.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a pressure-resistant sealing device that can stop a fluid flowing in a pipe safely and reliably in a short time.

The present invention is a pressure-resistant sealing device for stopping a fluid flowing in a pipe to which a valve is connected, and is configured to be detachable in the valve, and achieves a seal in the pipe by being mounted in the valve. A seal mechanism that is attached in a state where the seal mechanism is mounted; a jack that supports the seal mechanism against a force that the seal mechanism receives from a fluid flowing in the pipe; and a holding plate that holds the jack in the valve ; The valve includes a valve body that opens and closes a flow path connected to a pipe, a valve chamber that houses the valve body, and an upper portion of the valve chamber to be inserted and disposed in the valve chamber. The holding plate is disposed across the valve chamber and the valve body insertion hole, and a support plate that can be fitted into the valve body insertion hole is integrated with the holding portion plate. Provided, Lifting plate, the support plate that is supported on the bottom of the valve chamber in a state fitted to the valve body insertion hole, a pressure-resistant seal device that is held in the valve chamber.

According to the present invention, by mounting the seal mechanism in the valve, the seal mechanism can be attached in a state where the seal is achieved in the pipe. Further, by supporting the seal mechanism by the jack held by the holding plate, the seal mechanism is supported against the force received from the fluid flowing in the pipe, and the fluid in the pipe can be stopped without leakage. In this way, the fluid in the pipe can be stopped without leaking by a simple operation of attaching the seal mechanism to the valve and further supporting it with a jack. As a result, the fluid in the pipe can be stopped reliably in a short time. For example, the sealing device for the pressure leak test performed after the valve replacement work performed at the periodic inspection of the nuclear reactor can be reliably performed in a short time, and the radiation exposure amount of the worker can be greatly reduced. According to the invention, the holding plate is inserted from the valve body insertion hole and disposed in the valve chamber and the valve body insertion hole, so that the support plate is fitted into the valve body insertion hole, and the holding plate is fitted to the valve chamber. Supported at the bottom of the. As a result, the holding plate is held in the valve chamber. The holding plate can be mounted in the valve chamber by such a simple operation, and the holding plate can be securely held in the valve in a short time.

  In the above invention, the seal mechanism includes a plurality of seal members and a seal body, and the plurality of seal members are respectively formed in an annular shape and spaced from each other on the outer peripheral surface of the seal body in a compressed state. It is preferable that the seal main body has a configuration that can be disposed in the pipe in a state where the inner wall of the pipe and the outer peripheral surface of the seal main body are sealed by the plurality of seal members. .

  According to the present invention, the plurality of seal members are disposed on the outer peripheral surface of the seal body with a space therebetween, and the space between the seal body and the inner wall of the pipe is sealed by the plurality of seal members. As a result, even if a high-pressure fluid flows in the pipe, it can be stopped without leaking. In addition, by compressing each seal member in advance with a compression mechanism, deformation of the seal member is suppressed, and a gap is generated between the seal member and the inner wall of the pipe, and high pressure fluid in the pipe is prevented from leaking from this gap. be able to. According to such a configuration, for example, the water stoppage during the periodic inspection of the reactor as described above can be performed in a short time and surely, the amount of radiation exposure of the worker can be greatly reduced, and the work can be performed safely. be able to.

  In the above invention, it is preferable that the sealing mechanism further includes a plurality of pressing mechanisms that press and compress a corresponding sealing member among the plurality of sealing members. According to the present invention, the pressing force acting for each sealing member can be adjusted, and the sealing member can be compressed with an appropriate pressing force. Thereby, each seal member is disposed between the seal main body and the inner wall of the pipe in an appropriate state, and a good seal can be achieved.

  In the above invention, it is preferable that the sealing mechanism further includes a pressing mechanism that presses and compresses the plurality of sealing members. According to the present invention, since a plurality of seal members can be compressed at a time, the operation of compressing the seal members is easy, and the seal mechanism can be reliably installed in the pipe in a short time.

  In the above invention, the jack is configured to be extendable toward the seal mechanism, and one end portion in the extending / contracting direction is held by the holding plate, and the other end portion in the extending / contracting direction is formed in a partial spherical shape, It is preferable that the mechanism has a seat portion on which the other end portion of the jack extending and contracting is seated, and the seat portion is a spherical seat.

  According to the present invention, the jack can be securely seated on the seal mechanism by expanding and contracting the jack. In addition, the other end of the jack extending and contracting is formed in a partially spherical shape, and the seat on which the other end is seated is a spherical seat, so that the jack supports the seal mechanism without hitting it. Accordingly, the contact of the seal member in the pipe is suppressed, and the sealing performance can be maintained even if the jack is seated on the seat portion of the seal mechanism in any state. Thus, even if it is a simple operation of simply expanding and contracting the jack, the seal mechanism can be mounted in the pipe in a state of being securely sealed, and the seal mechanism can be mounted reliably in a short time.

  In the above invention, the holding plate has an engaging portion that can be engaged with the inner wall surface of the valve, and can be disposed in the valve by engaging the engaging portion with the inner wall surface of the valve. It is preferable.

  According to the present invention, the holding plate can be disposed in the valve by engaging the engaging portion of the holding plate with the inner wall of the valve. Since this is a simple operation that only involves engagement, the holding plate can be mounted reliably in a short time.

  In the above invention, it is preferable that a contact plate is interposed between the valve and the inner wall of the valve. According to the present invention, it is possible to suppress the engagement portion from biting into the inner wall of the valve by interposing the contact plate between the engagement portion and the inner wall of the valve. This prevents the inner wall of the valve from being damaged or broken.

  In the above-mentioned invention, it is further provided with a suspending means capable of suspending the seal mechanism, and the suspending means is detachable from the valve, and can be attached to the pipe in a suspended state. It is preferable that

  According to the present invention, the seal mechanism can be suspended by the suspension means, and the seal mechanism can be attached in the pipe. As a result, for example, even if the piping is arranged in a position where the lower hand cannot reach within the valve, the sealing mechanism can be attached by using the suspending means, and the installation work is easy. Therefore, the seal mechanism can be attached in a short time. Moreover, since this suspending means can be mounted in the valve, the labor of removing the suspending means from the seal mechanism can be saved.

  In the above invention, it is preferable that a positioning guide for positioning the sealing mechanism in the valve is further provided, and the positioning guide is configured to be detachable from the sealing mechanism.

  According to the present invention, the position of the seal mechanism within the valve is determined by the positioning guide. As a result, the operator can reliably perform the positioning of the seal mechanism within the valve, and the installation can be facilitated, and the time spent for the positioning can be reduced. Therefore, the seal mechanism can be securely mounted in a short time.

  In the above invention, the pressure-resistant sealing device is connected to the pipe on the upstream side and the downstream side of the one valve, respectively, in a pressure-resistant leak test performed after replacing one of the plurality of valves connected to the plant pipe. It is preferable that it is disposed in at least one of the valves to be used and used to stop the fluid flowing through the pipe.

  According to the present invention, when the pressure-resistant leak test is performed, the fluid in the pipe can be stopped in a short time and reliably by the pressure-resistant sealing device. In particular, the installation of the sealing device for the pressure leak test performed after the valve replacement work performed at the periodic inspection of the reactor can be performed in a short time and with certainty, and the radiation exposure amount of the worker can be greatly reduced.

  As apparent from the above description, according to the present invention, the fluid flowing through the pipe can be stopped in a short time, safely and reliably.

  In-valve pressure-resistant sealing device (hereinafter simply referred to as “pressure-sealing device”) 50 according to an embodiment of the present invention is provided in a valve interposed in piping of a plant such as a nuclear power plant, and flows in the piping. For example, it is a device for stopping cooling water. The pressure seal device 50 is used in a nuclear power plant to perform a pressure leak test mainly after exchanging valves. However, the pressure-resistant sealing apparatus 50 is not limited to what is used for a nuclear power plant, You may use it by piping, such as another plant. Below, an example of the structure of the nuclear power plant using the pressure-resistant sealing apparatus 50 is demonstrated first, and the pressure-resistant sealing apparatus 50 is demonstrated next.

  FIG. 1 is a diagram schematically showing a system of a nuclear power plant 21. The nuclear power plant 21 includes a reactor pressure vessel 22. Inside the reactor pressure vessel 22, a core 23 composed of a large number of fuel assemblies (not shown) is accommodated. The lower part of the core 23 is supported by a core support plate 24, and the upper part is supported by an upper lattice plate 25. Further, a core upper plenum 26 is formed above the core 23 in the reactor pressure vessel 22.

  Cooling water is supplied into the reactor pressure vessel 22, and this cooling water is heated by the core 23 to become a two-layer fluid and flows into the core upper plenum 26. The inflowing two-layer fluid is uniformly mixed in the upper core plenum 26 and further gas-liquid separated. The steam thus separated is dried by a steam dryer 27 provided on the upper side of the reactor pressure vessel 22.

  The dried steam thus dried is transferred to the steam turbine 29 via the main steam pipe 28 connected to the reactor pressure vessel 22. The transferred dry steam rotates the steam turbine 29, and thereby the generator 30 to which the steam turbine 29 is connected generates power. Thus, the dry steam provided for the power generation of the generator 30 is cooled by seawater through the condenser 31 and returned to the water. Thereafter, water is injected into the reactor pressure vessel 22 through the piping 32 connected to the reactor pressure vessel 22 and the plurality of valves 33 interposed in the piping 32. In this way, the cooling water circulates in the nuclear power plant 21. Further, the reactor pressure vessel 22 is provided with a recirculation pump 34 for feeding cooling water into the core 23. The recirculation pump 34 feeds the cooling water in the reactor pressure vessel 22 to the core 23 and heats the cooling water in the core 23.

  FIG. 2 is a cross-sectional view showing the valve 33 interposed in the pipe 32. The valve 33 is a so-called check valve, and includes a valve chamber 41, a valve body insertion hole 42, a valve body 43, and a lid body 44. The valve chamber 41 is interposed in the pipe 32 and has an inner wall surface 45 formed in a partial spherical shape. The valve chamber 41 is formed with an in-valve piping 41 a that protrudes inward of the valve chamber 41 from the end of the upstream portion 32 a (the left portion in FIG. 2) of the piping 32. A seat portion 46 is disposed on the inner wall surface of the in-valve piping 41a over the entire circumference.

  Further, a cylindrical valve body insertion hole 42 for inserting the valve body 43 into the valve chamber 41 is connected to the upper portion of the valve chamber 41. The valve body 43 is inserted into the valve chamber 41 through the valve body insertion hole 42 and is disposed in the valve chamber 41 so as to be seated on the seat portion 46. Further, the valve body 43 is connected to a swing member 48, and the swing member 48 is pivotally supported by the valve body insertion hole 42 by a swing pin member 47.

  The valve body 43 thus disposed swings around the swing pin member 47 as a fulcrum between a position where the valve body 43 is seated on the seat portion 46 and a position away from the seat portion 46. Open and close. On the inner wall surface 45 of the valve chamber 41, the swinging valve body 43 is seated in a state of being separated from the seat portion 46, thereby forming a seating portion 45a that restricts the swinging of the valve body 43. . Further, a lid 44 is detachably attached to the opening of the valve body insertion hole 42 and is fastened and fixed by a plurality of fastening bolts 49 (only one fastening bolt 49 is shown in FIG. 2). . Thereby, the opening is closed.

  When the cooling water flows in the direction of the arrow A in FIG. 2, which is the direction from the upstream side to the downstream side in the pipe 32, the valve body 43 opens the in-valve pipe 41a. When the cooling water flows in the direction of the arrow B in FIG. 2, the valve body 43 closes the in-valve piping 41a. Thereby, the valve 33 prevents the cooling water from flowing backward in the direction of the arrow B through the pipe 32.

  In the nuclear power plant 21 having such a configuration, high-temperature and high-pressure cooling water heated in the core 23 flows in the pipe 32 and fluid vibration is generated by the recirculation pump 34. The pipe 32 and the valve 33 that are exposed to such a harsh environment are easily damaged and broken. Therefore, before the damage and breakage, the pipe 32 and the valve 33 are replaced at the time of periodic inspection of the nuclear power plant 21. After the pipe 32 and the valve 33 are replaced, a pressure-resistant leak test is performed to check the pressure-resistant performance and leak of the pipe 32 and the valve 33. This pressure leak test needs to be performed while blocking the upstream side and the downstream side of the replaced valve 33. In this embodiment, the pressure resistance leak test is performed in the valve 33 disposed on the downstream side of the valve 33 to be replaced. The sealing device 50 is attached to block the cooling water, and then the valve 33 is replaced and a pressure leak test is performed.

  FIG. 3 is a front sectional view showing the pressure-resistant sealing device 50 according to the first embodiment of the present invention. FIG. 4 is a plan sectional view showing the pressure seal device 50. FIG. 5 is a front view showing the seal mechanism 51. The pressure seal device 50 includes a seal mechanism 51, a holding plate 52, and a pressing jack 53. Further, the seal mechanism 51 includes a seal body 55, a first seal member 56, an intermediate ring 57, a pressing plate 58, and a second seal member 59. The seal body 55 is made of stainless steel and is generally formed in a cylindrical shape. The outer peripheral surface of the seal body 55 is formed with a three-stage notch in a stepped shape over the entire circumference. Hereinafter, the first outer peripheral surface 55a, the second outer peripheral surface 55b, the third outer peripheral surface 55c, and the fourth outer peripheral surface 55d are referred to in order from the outer peripheral surface of one end portion in the axial direction with the largest diameter. A first seal member 56 that is an O-ring is fitted to the second outer peripheral surface 55b.

  The third outer peripheral surface 55c is fitted with a bottomed cylindrical intermediate ring 57 made of stainless steel, and the intermediate ring 57 is configured such that the third outer peripheral surface 55c can be slidably displaced in the axial direction of the seal body 55. Has been. An O-ring 60 is interposed between the intermediate ring 57 that is a pressing mechanism and the third outer peripheral surface 55 c, and sealing is achieved by the O-ring 60. The other end portion in the axial direction of the seal body 55 is inserted into the bottom portion 57a of the intermediate ring 57, and two fastening screws 61 are screwed along the axial direction. The tightening screw 61 passes through the bottom portion 57 a and is screwed into two female screw portions 61 a formed in the seal body 55. The tightening screw 61 is configured to be tightened with a dedicated wrench. A stepped portion 57 b is formed on the opening end side of the intermediate ring 57. As a result, a small-diameter small-diameter outer peripheral surface 57d and a large-diameter large-diameter outer peripheral surface 57e are formed on the outer peripheral surface, and the opening end portion 57c of the intermediate ring 57 is configured to be slidably displaced on the second outer peripheral surface 55b. At the same time, the first seal member 56 can be pressed by sliding displacement.

  A large-diameter outer peripheral surface 57e of the intermediate ring 57 is fitted with a bottomed cylindrical pressing plate 58 made of stainless steel. The pressing plate 58 slides the large-diameter outer peripheral surface 57e in the axial direction of the seal body 55. It is configured to be capable of dynamic displacement. A through hole 58b is formed in the pressing plate 58, which is a pressing mechanism, and its bottom 58a, and the other axial end of the seal body 55 is inserted into the through hole 58b. Further, a counterbore 62 is formed in the bottom 58a at a position corresponding to the head of each tightening screw 61, and the head of each tightening screw 61 is inserted. Two fastening screws 63 are screwed onto the bottom 58a. These fastening screws 63 pass through the bottom portion 57 a and are also screwed into the bottom portion 57 a of the intermediate ring 57, and further pass through the bottom portion 57 a of the intermediate ring 57 to form two female screw portions formed in the seal body 55. Each is screwed to 63a. The tightening screw 63 is configured to be tightened with a dedicated wrench.

  The second seal member 59, which is an O-ring, is disposed between the opening end 58 c of the pressing plate 58 and the stepped portion 57 b of the intermediate ring 57 arranged in this manner. The outer peripheral surface 57e is fitted. As a result, the second seal member 59 is attached to the seal body 55 via the intermediate ring 57.

  The intermediate ring 57 and the pressing plate 58 configured as described above can be slid toward the one axial end portion of the seal body 55 by tightening the fastening screws 61 and 63. By sliding the intermediate ring 57, the first seal member 56 is sandwiched between the first contact surface 55e connected to the second outer peripheral surface 55b and the first outer peripheral surface 55a and the opening end portion 57c of the intermediate ring 57, and further slides. The first seal member 56 is compressed by being pressed. Further, by sliding the pressing plate 58, the second seal member 59 is formed by the second contact surface 57f that is continuous with the small-diameter outer peripheral surface 57d and the small-diameter outer peripheral surface 57d, the opening end 58c of the pressing plate 58, and the second contact surface 55e. The second seal member 59 is compressed by being sandwiched and further slid and pressed.

  In this way, the first contact surface 55e and the second contact surface 57f that sandwich the first seal member 56 and the second seal member 59, respectively, increase in diameter from the other end in the axial direction of the seal body 55 toward one end. It is formed in the taper shape which inclines in this way. Accordingly, the first seal member 56 and the second seal member 59 are prevented from being excessively compressed to be damaged and broken, and the first seal member 56 and the second seal member 59 are aided to be compressed with an appropriate pressing force. is doing.

  As described above, the seal members 56 and 59 can be compressed by an easy operation of simply tightening the fastening screws 61 and 63, and can be attached to the seal body 55 in an appropriate state. Further, by changing the tightening amount for each of the tightening screws 61 and 63, the pressing force of each of the seal members 56 and 59 can be adjusted to an appropriate value, whereby the respective seal members 56 and 59 can be compressed to an appropriate state. .

  The seal mechanism 51 configured in this way is attached to the in-valve piping 41a. As a result, the first seal member 56 and the second seal member 59 seal the space between the seal mechanism 51 and the in-valve piping 41a. By compressing the first seal member 56 and the second seal member 59 and attaching them within the valve pipe 41a, deformation of the seal members 56 and 59 can be suppressed, and a satisfactory seal can be achieved. Further, by adjusting the pressing force of the seal members 56 and 59, the seal members 56 and 59 are crushed to an appropriate state, and thereby, a seal can be achieved in a good state.

  The sealing mechanism 51 is provided with a hanging ear 64 and a positioning guide 65. The hanging ear 64, which is a hanging means, is made of stainless steel, so that the sealing mechanism 51 can be held in a substantially horizontal state with the sealing mechanism 51 suspended, that is, the sealing mechanism 51 is suspended. Are provided in the seal mechanism 51 so that their axes are substantially parallel to the horizontal direction. In the present embodiment, the hanging ear 64 is provided at the upper part in the vertical direction of the bottom part 58a of the pressing plate 58 (corresponding to the upper part of the drawing in FIG. 3). However, it is not limited to being provided in such a position. Thus, since the seal mechanism 51 can be suspended and inserted into the valve element insertion hole 42, it is possible to easily work even at a position where it is difficult to reach, as in the present embodiment. Further, since the seal mechanism 51 is held in a substantially horizontal shape, it is easy to perform the operation of inserting it into the valve piping 41a of the seal mechanism 51.

  Further, the hanging ear 64 is configured to be supported by the pin member 66 at a position where the swinging member 48 is pivotally supported by the swinging pin member 47 in a state where the seal mechanism 51 is attached to the in-valve piping 41a. Thus, the seal mechanism 51 can be supported by the hanging ear 64, and the operation can be interrupted once in this state. As a result, even if the work time of each worker is only allowed for a short time, as in the high radiation control area of the nuclear power plant 21, it is possible to carry out the work on its own. Further, it is possible to omit the work of removing the hanging ear 64 after the sealing mechanism 51 is attached to the in-valve piping 41a, and the attaching operation of the hanging ear 64 when removing the sealing mechanism 51 from the valve piping 41a. The work time can be shortened.

  The positioning guide 65 is configured to guide the seal mechanism 51 to the in-valve piping 41a and to position the sealing mechanism 51 in the in-valve piping 41a. In the present embodiment, the positioning guide 65 is provided below the bottom portion 58a of the pressing plate 58 (corresponding to the upper portion of the paper surface of FIG. 3). However, it is not limited to being provided in such a position. The positioning guide 65 is configured so as to be able to contact the inner wall surface 45 of the lower portion of the valve chamber 41, and can be guided to the valve piping 41 a of the sealing mechanism 51 by the contact, and further the seal in the valve piping 41 a. The mechanism 51 can be positioned. By providing such a positioning guide 65, the seal mechanism 51 can be easily mounted in the valve piping 41a and mounted at an accurate position even in an unstable state where the positioning guide 65 is suspended by the hanging ear 64. Therefore, the mounting operation can be performed in a short time and with certainty.

  A holding plate 52 is disposed on the downstream side in the valve chamber 41 with a space from the seal mechanism 51. The holding plate 52 is made of stainless steel and is generally formed in a disc shape. The holding plate 52 is configured to be engageable with the inner wall surface 45 of the valve chamber 41. More specifically, a notch 67 is formed on the outer peripheral portion of the holding plate 52 so as to avoid a seating portion 45 a formed on the inner wall surface 45 of the valve chamber 41. This notch 67 can be used as a positioning means. Further, an engaging portion 68 made of an elastic member, for example, synthetic rubber, is provided on the outer peripheral portion of the holding plate 52 over the entire circumference in the circumferential direction excluding the notch 67.

  The holding plate 52 is pushed into the valve chamber 41 to the downstream side, so that the engaging portion 68 is fitted and held on the inner wall surface 45 of the valve chamber 41. At this time, since the engaging portion 68 is elastically deformed in accordance with the shape of the inner wall surface 45, the engaging operation is easy, and the holding plate 52 can be easily attached in a short time. Further, since it is elastically deformed in this way, the inner wall surface 45 is not damaged.

  A pressing jack 53 is interposed between the holding plate 52 and the sealing mechanism 51. The pressing jack 53 that is a jack is made of stainless steel and has a base 71 and a metric trapezoidal screw portion 72. The base 71 is fixed to the surface of the holding plate 52 that faces the seal mechanism 51. The metric trapezoidal screw part 72 is detachably screwed to the base 71. The screwed metric trapezoidal screw portion 72 is configured to project or retract toward the seal mechanism 51 by rotating. Therefore, the pressing jack 53 is configured to be expandable and contractable toward the seal mechanism 51 by rotating the metric trapezoidal screw portion 72.

  The press jack 53 configured as described above is configured such that the head 73 of the metric trapezoidal screw portion 72 can come into contact with the spherical plate 75 of the seal body 55 of the seal mechanism 51. The spherical dish 75 is formed on the surface facing the holding plate 52, specifically, on the other axial end of the seal body 55. By bringing the head 73 into contact with the spherical plate 75, the pressing jack 53 causes the sealing mechanism 51 to receive a force from the fluid flowing in the pipe 32 in the direction of arrow A in FIG. 3 (the same direction as the arrow A in FIG. 2). Can be supported.

  The head 73 and the spherical plate 75 will be described in more detail. The head 73 of the metric trapezoidal screw portion 72 is formed into a surface that is seated on the spherical plate 75, that is, a partial spherical shape having a convex end surface. It is formed in a concave partial spherical shape, that is, formed as a spherical seat. As a result, even if the seal mechanism 51 and the press jack 53 come into contact with each other with their axis lines shifted, the press jack 53 can be prevented from hitting the seal mechanism 51 and a good seal can be achieved. Therefore, when the pressing jack 53 is brought into contact with the seal mechanism 51, the restriction on the relative positions of the pressing jacks 53 can be reduced, and the attachment work is facilitated accordingly.

  Further, even if they are in contact with each other in a shifted state, the force acting on the pressing jack 53 from the seal mechanism 51 acts in a direction substantially parallel to the axis of the pressing jack 53, that is, a force in the axial direction with high rigidity. Can act. Accordingly, even in the pressure-resistant leak test in which high-pressure fluid is supplied into the pipe, damage or breakage of the press jack 53 can be suppressed, and the press jack 53 can be downsized.

  Below, the attachment method of the pressure-resistant sealing apparatus 50 comprised in this way is demonstrated. First, the swing pin member 47 is removed, and the swing member 48 and the valve body 43 are taken out from the valve body insertion hole 42. Next, the tightening screws 61 and 63 are tightened in advance, and the seal mechanism 51 in which the first seal member 56 and the second seal member 59 are compressed is suspended by the suspension ear 64 and inserted from the valve element insertion hole 42, and the positioning guide 65. Is lowered until it comes into contact with the lower inner wall surface 45 in the valve chamber 41. Here, the first seal member 56 and the second seal member 59 are not necessarily compressed in advance, and may be after the seal mechanism 51 is attached. Further, the sealing mechanism 51 is moved toward the in-valve piping 41a while the positioning guide 65 is in contact. As a result, the seal mechanism 51 is guided by the inner wall surface 45, and the seal mechanism 51 is mounted in the valve piping 41a in a state where the seal mechanism 51 is positioned. Then, the hanging ear 64 is fastened with a pin member 66 and disposed at a position in the valve element insertion hole 42 that does not interfere with the work described later.

  Next, the holding plate 52 to which the pressing jack 53 is fixed is inserted from the valve element insertion hole 42. At this time, the pressing jack 53 is contracted. The inserted holding plate 52 is pushed into and engaged with the inner wall surface 45 on the downstream side of the valve chamber 41 to be held thereby. In this state, the metric trapezoidal screw portion 72 is rotated and extended toward the seal mechanism 51, thereby bringing the head 73 of the metric trapezoidal screw portion 72 into contact (sitting) with the spherical plate 75. By bringing the head 73 into contact with the spherical plate 75, the pressure-resistant sealing device 50 is completely installed in the valve 33, whereby the valve 33 can be replaced and a pressure-resistant leak test can be performed. Moreover, when removing, the pressure-resistant sealing apparatus 50 can be removed and the valve body 42 can be mounted | worn by the reverse procedure of the attachment procedure mentioned above.

  As described above, since the attaching operation of the sealing mechanism 51, the holding plate 52, and the pressing jack 53 is simple, the pressure-resistant sealing device 50 can be attached in the valve 33 in a short time and accurately. In particular, when work such as replacement of the valve 33 and pressure-resistant leak test in the nuclear power plant 21 as in the present embodiment takes a long time, the radiation exposure amount of the worker increases. Therefore, a reliable operation that requires a short time and no leakage is required. Since the pressure-resistant sealing device 50 can stop the cooling water in the pipe by a simple operation as described above, the holding plate 52, the pressing jack 53, and the positioning guide 65 can reliably stop the water. In the nuclear power plant 21, it is a more suitable water stop device. By using this pressure-resistant sealing device 50, it is possible to reduce the work man-hours of the worker at the time of water stoppage. As a result, water can be reliably stopped in a short time, the amount of radiation exposure of workers can be greatly reduced, and a pressure-resistant leak test can be performed safely. In addition, since the work can be completed in such a short time, the operation stop period can be shortened by shortening the period of the periodic inspection of the nuclear power plant 21, and the operating rate of the nuclear power plant 21 can be improved.

  FIG. 6 is a front sectional view showing a pressure-resistant sealing device 50A according to the second embodiment of the present invention. The pressure sealing device 50A of the second embodiment is similar in configuration to the pressure sealing device 50 of the first embodiment. Accordingly, only the configuration different from the pressure sealing device 50 of the first embodiment will be described with respect to the configuration of the pressure sealing device 50A, and the same components are denoted by the same reference numerals and description thereof is omitted.

  The pressure seal device 50 </ b> A basically includes a seal mechanism 51, a holding plate 52 </ b> A, and a pressing jack 53. The holding plate 52 </ b> A is generally formed in a disc shape, and is supported by a downstream bottom portion of the inner wall surface 45 of the valve chamber 41 with a contact plate 81 interposed therebetween. The contact plate 81 is a steel plate, and by interposing it, the holding plate 52A can be prevented from biting, and damage and breakage of the inner wall surface 45 due to the biting can be prevented.

  Further, the upper end of the holding plate 52A extends to the valve element insertion hole 42, and a support plate 82 is integrally fixed to the upper end. The support plate 82 is configured to be fitted into the valve body insertion hole 42. Therefore, by inserting the holding plate 52A into the valve element insertion hole 42, the support plate 82 is fitted and the lower portion of the holding plate 52A is supported by the inner wall surface 45, so that the holding plate 52A is held. Further, a pressing jack 53 is fixed to the holding plate 52 </ b> A similarly to the holding plate 52.

  The holding plate 52A having such a configuration can be easily held by holding the holding plate 52A only by pressing the upper end portion of the holding plate 52A with the support plate 82 after being fitted into the inner wall surface 45. Therefore, the same effect as the pressure-resistant sealing device 50 of the first embodiment can be obtained.

  In the present embodiment, two seal members, the first seal member 56 and the second seal member 59, are provided, but three or more seal members may be provided.

  As described above, the pressure-resistant sealing device according to the present invention has an excellent effect of being able to stop the flow of piping in a short time, safely and reliably, and is beneficial when used for piping of a nuclear power plant, for example.

1 is a diagram schematically showing a system of a nuclear power plant 21. 4 is a cross-sectional view showing a valve 33 interposed in a pipe 32. FIG. It is front sectional drawing which shows the pressure | voltage resistant sealing apparatus 50 of the 1st Embodiment of this invention. 3 is a plan sectional view showing a pressure-resistant sealing device 50. FIG. FIG. 6 is a front view showing a sealing mechanism 51. It is front sectional drawing which shows the pressure-resistant sealing apparatus 50A of the 2nd Embodiment of this invention. 1 is a diagram schematically showing a system of a nuclear power plant 1.

Explanation of symbols

41 Valve chamber 42 Valve body insertion hole 43 Valve body 45 Inner wall surface 50, 50A Pressure-resistant sealing device 51 Seal mechanism 52, 52A Holding plate 53 Press jack 55 Seal body 56 First seal member 57 Intermediate ring 58 Press plate 59 Second seal member 64 Hanging Ear 65 Positioning Guide 68 Engaging Portion 73 Head 75 Spherical Plate 81 Batch Plate 82 Support Plate

Claims (10)

A pressure-resistant sealing device for stopping a fluid flowing in a pipe to which a valve is connected,
A seal mechanism configured to be detachable in the valve and attached in a state where a seal is achieved in the pipe by being mounted in the valve;
A jack that supports the seal mechanism against a force that the seal mechanism receives from a fluid flowing in the pipe;
A holding plate for holding the jack in the valve ;
The valve includes a valve body that opens and closes a flow path connected to a pipe, a valve chamber that houses the valve body, and an upper portion of the valve chamber to be inserted and disposed in the valve chamber. A continuous valve body insertion hole,
The holding plate is disposed across the valve chamber and the valve element insertion hole,
The holding plate is integrally provided with a support plate that can be fitted into the valve body insertion hole,
The holding plate, the support plate that is supported on the bottom of the valve chamber in a state fitted to the valve body insertion hole, pressure-resistant seal device characterized that you have been retained in the valve chamber. The seal mechanism has a plurality of seal members and a seal body,
The plurality of seal members are each formed in an annular shape, and are attached to the outer peripheral surface of the seal body at intervals with each other in a compressed state.
The said seal body is a structure which can be arrange | positioned in the said piping in the state with which the space between the inner wall of piping and the outer peripheral surface of a seal body was sealed by these several sealing members. The pressure-resistant sealing device described.   The pressure-resistant sealing device according to claim 2, wherein the sealing mechanism further includes a plurality of pressing mechanisms that press and compress a corresponding sealing member among the plurality of sealing members.   The pressure-resistant sealing device according to claim 2, wherein the sealing mechanism further includes a pressing mechanism that presses and compresses the plurality of sealing members. The jack is configured to extend and contract toward the seal mechanism, and one end in the extending and contracting direction is held by the holding plate and the other end in the extending and contracting direction is formed in a partial spherical shape,
The seal mechanism has a seat portion on which the other end portion of the jack extends and contracts,
The pressure-resistant sealing device according to claim 1, wherein the seat is a spherical seat. The holding plate has an engaging portion that can be engaged with an inner wall surface of the valve;
The pressure-resistant sealing device according to any one of claims 1 to 5, wherein the engagement portion is configured to be disposed in the valve by engaging the inner wall surface of the valve. The pressure-resistant sealing device according to claim 6, wherein the engagement portion is engaged with an inner wall of the valve with a backing plate interposed. A suspension unit capable of suspending the seal mechanism;
The hoisting means is detachable in the valve, in any one of claims 1 to 7, characterized in that the sealing mechanism in a state of suspended being attachable configured in the pipe The pressure-resistant sealing device described. A positioning guide for positioning the seal mechanism in the valve;
The pressure-resistant sealing device according to any one of claims 1 to 8 , wherein the positioning guide is configured to be detachable from the seal mechanism. The pressure-resistant sealing device according to any one of claims 1 to 9 , wherein the pressure-resistant leak test is performed upstream of the one valve in a pressure-resistant leak test performed after replacing one of a plurality of valves connected to plant piping. A pressure-resistant sealing device, which is disposed in at least one of the valves connected to the pipe on the side and the downstream side, and is used to stop the fluid flowing through the pipe.

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