JP2015143562A5 - - Google Patents

Description

Valve lid removal method and valve lid removal jig for gate valve

  The present invention is the gate valve connected to the fluid piping system, when the valve body having a short life compared to the valve box reaches the set durability years, or when the valve body malfunctions, The present invention relates to an improved technique of a valve lid removal method for a gate valve that removes a valve lid including a valve body and a valve stem from a valve box in an uninterrupted state.

  As a gate valve connected to the fluid piping system, generally, the flange formed continuously on the opening periphery of the valve body mounting opening of the valve box and the flange formed on the valve lid are made watertight with bolts and nuts. A gate valve that is fastened and fixed is used.

As a valve lid removal method using such a general gate valve,
The lower housing of the divided structure that surrounds substantially the entire gate valve in a state including a part of both the fluid pipes in both the upstream and downstream fluid pipes connected to the valve box of the gate valve in a watertight state. Installation process,
A step of maintaining the watertight state between both flanges by sandwiching and fixing the flange of the valve box and the flange of the valve lid from the outside by a flange holding device provided in the lower housing;
Removing the bolts and nuts that fasten and fix the flange of the valve box and the flange of the valve lid;
A step of connecting a lower end portion of a lower divided lifting shaft portion among a plurality of divided lifting shaft portions constituting a lifting shaft of a lifting and lowering conveying device equipped in an upper housing to an upper end portion of a valve stem of a gate valve;
Fixing the lower flange of the work on-off valve to the flange of the upper opening of the lower housing in a watertight state with bolts and nuts;
The upper part of the lifting / lowering shaft part of the lifting / lowering conveying device provided in the upper housing is connected to the lower part of the lifting / lowering shaft part connected to the valve rod of the gate valve and the upper flange of the work on / off valve. Fixing the lower flange of the upper housing in a watertight state with bolts and nuts,
After releasing the pinching between the flange of the valve box and the flange of the valve lid by the flange holding device, the lifting shaft of the lifting and lowering conveying device is lifted so that the valve lid with the valve body and the valve stem is placed in the storage space of the upper housing Taking out the inside and closing the work on-off valve,
Removing the valve lid taken out in the storage space of the upper housing;
A valve lid removal method having the above steps has been proposed (see, for example, Patent Document 1).

JP 2007-177945 A

  In the conventional valve lid removal method of the gate valve, by operating from the outside of the lower housing, a flange clamping device provided in the lower housing surrounding substantially the entire gate valve in a state including a part of both fluid pipes, The flange clamping member located in the lower housing part must be moved to a predetermined clamping position where the flange of the valve box and the flange of the valve lid can be clamped from the outside, and much labor is required for clamping both flanges. There is a case. That is, when the relative positional relationship between the two flanges, the lower housing, and the flange clamping device, the moving direction of the flange clamping member, etc. are deviated from the intended positional relationship or the intended moving direction, etc. Therefore, it becomes very difficult to move the flange clamping member located in the lower housing to a predetermined clamping position.

  In addition, the flange of the valve box and the flange of the valve lid are fastened and fixed with a large number of bolts and nuts, and it is necessary to perform the removal operation of the large numbers of bolts and nuts in a limited space in the lower housing. Therefore, there is an inconvenience that a great deal of labor is required to release the connection between the flange of the valve box and the flange of the valve lid.

The present invention has been made in view of such a situation, and the purpose thereof is a gate valve capable of efficiently and easily removing a valve lid provided with a valve body and a valve stem in an uninterrupted flow state. To provide a valve lid removal method and a valve lid removal jig .

In order to achieve the above object, the valve lid removal method of the gate valve according to the present invention is as follows:
Received in the valve box through the valve body which is connected between the Ryokan portion constituting a fluid piping system, and a valve cover that is fixedly coupled to the valve box, the valve stem formed through to the valve cover Of the gate valve provided with the valve body, the valve lid provided with the valve body and the valve rod is removed from the valve box in a state in which the flow of fluid in the both pipe portions is maintained. It is a lid removal method, and its characteristic composition is
The valve lid cover for covering a portion of the valve cover, the steps of instrumentation attachment fixed to the valve lid,
It sets up a frame member for fixing pressing the valve cap relative to the valve body through the valve cover and detachably holding and the valve lid cover surrounding freely attachment the outer periphery of the valve lid cover Process,
The pressing member of the frame-like member, a step of pressing with fixing the valve cover through the front Kibenfuta cover relative to said valve body,
A step of releasing the connection between the valve lid and the valve box in the pressing and fixing state by the frame member ;
A split ring having a split structure is supported and fixed in a state where it is pressed from the side of the both pipe portions against the flange of the valve box, and the attachment detached from the frame-shaped member is attached to the valve lid and the valve lid cover. a step of fixed sealingly to the split ring in a state surrounding the outer peripheral side of,
The presser means provided on the attachment, the step of pressing with fixing the valve cover through the valve lid cover to the valve body,
And removed by withdraw the frame member, a step of releasing the pressing with fixed the valve lid cover by the frame-like member,
Attaching a work on / off valve to the attachment, attaching a work housing provided with a lifting and lowering conveying means connected to the valve lid cover to the work on / off valve, and sealing a work target portion of the gate valve;
The pressing and fixing of the valve lid cover by the pressing means provided on the attachment is released, and the valve lid and the valve lid cover including the valve body and the valve rod are stored in the work housing by the lifting and lowering conveying means. After taking out the space, in that it and a step of removal with the previous SL work housing Kiben cover and the valve lid cover prior to closing operating the working-off valve.

According to the above configuration, when a valve body that has a shorter life than the valve box has reached the set endurance life among the gate valves connected to the fluid piping system, or when a malfunction of the valve body has occurred When there is a need to remove the valve lid with the valve body and valve stem from the valve box in an uninterrupted flow state, the valve lid cover is attached and fixed with a frame-like member covering part of the valve lid Then, the valve lid is pressed and fixed to the valve box in a sealed state.
The frame-shaped member is placed in a state of being detachably holding the surrounding free attachment to the outer peripheral side of the valve cover and valve lid cover. By the frame member, pressing with securing the valve cover relative to the valve box through the valve lid cover.
Therefore, the operation of fixing the pressing in close contact with the valve cover relative to the valve box, rather than indirectly performed from the outside of the housing such that surrounding substantially the entire gate valve, directly with the eye viewing through the frame member The operation can be performed easily, quickly, reliably and efficiently. At this time, the attachment that can freely surround the outer periphery of the valve lid and the valve lid cover is in a state of being held by the frame-like member , so that the attachment by the frame-like member is not disturbed by the attachment or other members. The valve lid can be pressed against the valve box via the valve lid cover.
In a state in which pressed against the valve body the valve cover through the valve lid covered by the frame member, even when canceling consolidated the valve casing and the valve cover, and visually through the opening portion of the frame member Therefore, the work can be performed directly, and the disconnection work can be performed easily, quickly, reliably and efficiently. Further, as described above, the attachment is because while being held by the frame member, without being disturbed to the attachment or other member, it is possible to perform the consolidation release operation. Even when the valve box and the valve lid are disconnected, the valve lid is pressed against the valve lid by the frame-like member, so that the valve lid does not pop out due to fluid pressure.

Next, the split ring having the split structure is supported and fixed in a state where it is pressed from the side of both pipe parts ( downward side ) with respect to the flange of the valve box, and the attachment is detached from the frame-shaped member , and the valve lid and the valve lid removably securing sealingly despite wheels division structure in a state surrounding the outer peripheral side of the cover. Then, the presser means provided on the attachment, press with securing the valve cover relative to the valve box through the top of the valve lid cover, and remove the frame-like member from Ryokan unit, the valve lid by the frame member to cancel the press with fixed cover.
For this reason, when releasing the connection between the valve box and the valve lid , the valve lid is pressed against the valve box by a frame-like member that can easily perform the connection release operation. in operation, for example, a structure to perform pressing from the outer side of the attachment of the valve cover to the valve box by presser means, attachment, for a split ring or the like of the divided structure, the working housing and provided with a lifting conveyor means described later work Even when a load such as an on-off valve is applied, a sturdy structure capable of withstanding the load can be obtained.

Furthermore, a work on / off valve is attached to the attachment, a work housing having a lifting and lowering conveying means connected to the valve lid cover is attached to the work on / off valve, the work target portion of the gate valve is sealed, and then provided to the attachment. Release the pressing and fixing of the presser means.
In this state, since the lifting / lowering conveying means of the work housing and the valve lid cover are connected, the valve lid does not pop out due to fluid pressure, and the lifting / lowering conveying means operates the valve lid including the valve body and the valve stem. It can be reliably taken out into the housing space of the housing, and the taken-out valve lid is removed together with the lifting and lowering conveying means and the work housing after the work on-off valve is closed.
In the valve lid removal method of this gate valve, it is not necessary to provide a housing that encloses substantially the entire valve box and part of both pipe portions in a watertight manner from the lower side and the upper side. There is no need to dig a pit.

  Therefore, it is possible to efficiently and easily remove the valve lid provided with the valve body and the valve stem in a non-continuous flow state, and to reduce the construction cost.

Other characteristic configuration, the frame-like member, said pressing member includes a moving mechanism for causing the near-spaced relative to the valve cap, by closer moves the pressing member by the moving mechanism, a pre Kibenfuta The point is to press and fix the valve box.

According to the above configuration, when fixing pressed against the valve body the valve cover through the valve lid covered by the frame-shaped member, by operating the moving mechanism in the direction of proximity movement, valve body and valve cover Can be pressed against. By restricting the movement by the moving mechanism, it is possible to maintain the fixed state pressed to the valve casing side of the valve cover.
This ensures that the operation of fixing pressing the valve lid to the valve casing, rather than indirectly performed from the outside of the housing such that surrounding substantially the entire gate valve, operated directly while viewing the respective components The operation can be performed more efficiently and reliably.

In addition, because they are more configured in the shape of a frame member, a portion other than the portion where the respective members constituting these frame member present can face the connecting portion for connecting the valve lid and a valve casing from the outside It can be an opening. As a result, the connection release operation between the valve lid and the valve box can be performed directly while visually observing through the opening, and the operation can be performed easily, quickly, and efficiently. At this time, the attachment that can freely surround the outer peripheral side of the valve lid and the valve lid cover is mounted so as to be positioned above the valve lid and the valve lid cover in a state of being suspended from the frame-like member , for example. Therefore, the operation of releasing the connection between the valve lid and the valve box can be performed easily, quickly, and efficiently without being obstructed by the attachment or other members.

The valve lid removal method for other gate valves to achieve the above objective is:
Received in the valve box through the valve body which is connected between the Ryokan portion constituting a fluid piping system, and a valve cover that is fixedly coupled to the valve box, the valve stem formed through to the valve cover Of the gate valve provided with the valve body, the valve lid provided with the valve body and the valve rod is removed from the valve box in a state in which the flow of fluid in the both pipe portions is maintained. It is a lid removal method, and its characteristic composition is
With a portion of the valve lid cover covering securing instrumentation attachment to the valve cap of the valve cover, to support and fix in a state of pressing from the side of the two pipe portions split ring of divided structure against the flange of the valve body Process,
The presser means provided across said split ring and said valve lid cover, the valve lid cover in close proximity moving relative to the split ring, secured to pressing with the valve cap relative to the valve body Process,
A step of releasing the connection between the valve lid and the valve box in a pressing and fixing state by a pressing means provided across the valve lid cover and the split ring ;
And attaching pre SL two pipe portions, the valve body, the housings of the split structure surrounding the valve closure and the valve lid cover in tight sealed state,
A step of pressing with fixing the valve cover through the valve lid cover to the valve body by presser means provided on the housings,
Releasing the pressing and fixing of the valve lid cover by a pressing means provided across the valve lid cover and the split ring ;
A step of said mounting work on-off valve housings, attached work housing with a lifting conveyor means is coupled to the valve lid cover to the working-off valve to seal the working target portion of the gate valve,
The pressing and fixing of the valve lid cover by the holding means provided in the housing is released, and the valve lid and the valve lid cover provided with the valve body and the valve rod are moved by the lifting and lowering conveying means of the work housing. After taking out the storage space, in that it and a step of removal with the previous SL work housing Kiben cover and the valve lid cover prior to closing operating the working-off valve.

According to the above configuration, when a valve body that has a shorter life than the valve box has reached the set endurance life among the gate valves connected to the fluid piping system, or when a malfunction of the valve body has occurred etc., if need be removed from the valve body the valve cover with the valve body and valve stem at constant flow condition occurs, the pressing means provided across the valve lid cover and Wariwa, the valve cover one The valve lid is pressed and fixed in a sealed state against the valve box via a valve lid cover that is mounted and fixed in a state of covering the portion .
In that case, first, a valve lid cover that covers a part of the valve lid is detachably attached to the valve lid, and the split ring of the split structure is placed on the side of both pipes ( lower side) with respect to the flange of the valve box ) supported and fixed in a state of pressing from the presser means, provided over the split ring of the valve lid cover a divided structure. Since the split ring with the split structure is pressed against the flange of the valve box from below, the split ring is cut so as not to interfere with the head of the connecting bolt or the connecting nut that connects the flange of the valve box and the flange of the valve lid. An interference avoiding portion such as a notch is formed.
Then, by close move valve lid cover against the split ring of split structure by pressing means provided across the valve lid cover and Wariwa, pressing with fixed relative to the valve box and the valve cover.
For this reason, the operation of pressing and fixing the valve lid in close contact with the valve box is not performed indirectly from the outside of the housing or the like surrounding substantially the whole of the gate valve, but is performed over the valve lid and the valve lid cover. through the opening of the adjacent movable presser means provided valve lid cover against the split ring of split structure Te can be performed directly while viewing, facilitate the work quickly, reliably be efficiently It can be carried out.
In a state where pressing the valve cover relative to the valve box through the valve lid cover by pressing means provided across the valve lid cover and Wariwa, even when canceling consolidated the valve casing and the valve cover , through the opening portion of the presser means you can work directly with visually the connection release operation, easy, fast, can be carried out reliably efficiently. Even by releasing connecting the valve box and the valve cover, the valve lid is so pressed against the valve lid by presser means, never valve lid pop hydraulically.

Next, the two pipe portions, valve box, after which attached preparative housings split structure surrounding the valve cover and valve lid cover, the presser means provided on housings of the valve cover through the valve lid cover valve press and with fixed against the box, to release the pressing with fixed valve lid cover by pressing means provided across the valve lid cover and Wariwa.
For this reason, when the connection between the valve box and the valve lid is released, the connection release operation can be performed directly and easily with respect to the valve box by the presser means provided across the valve cover and the split ring . performs pressing of the valve lid, on the one hand, the work other than the connection release operation, for example, a structure to perform pressing from the outer side of the housings of the valve cover to the valve box by presser means, the housings or the like, described later Even when a load such as a work housing or a work on / off valve provided with a lifting and lowering conveying means is applied, a sturdy structure capable of withstanding the load can be obtained.

Further, attaching a working off valve housings, the working housing with a lifting conveyor means is coupled to the valve lid cover is attached to the working-off valve, after sealing the working target portion of the gate valve, it is provided in the housing Release the pressing and fixing of the presser means.
In this state, since the lifting / lowering conveying means of the work housing and the valve lid cover are connected, the valve lid does not pop out due to fluid pressure, and the lifting / lowering conveying means operates the valve lid including the valve body and the valve stem. It can be reliably taken out into the housing space of the housing, and the taken-out valve lid is removed together with the lifting and lowering conveying means and the work housing after the work on-off valve is closed.

  Therefore, it is possible to efficiently and easily remove the valve lid provided with the valve body and the valve stem in a non-continuous flow state, and to reduce the construction cost.

The characteristic configuration of the valve lid removal jig is a split ring with a split structure that comes into contact with the flange of the valve box connected between both pipe parts constituting the fluid piping system from the side of both pipe parts, A leg portion mounted on an outer peripheral surface of the lateral valve box portion positioned between the pipe portions of the valve box, and a pressing member connected to the leg portion and pressing the split ring against the flange. And a housing having a reaction force receiving portion for supporting the split ring and a work on-off valve and attached to the split ring in a sealed state .

According to the said structure, even when the load of a housing etc. is applied to the split ring etc. of a division | segmentation structure, it can be set as the strong structure which can endure the said load.

Another characteristic configuration of the valve lid removal jig is that an annular seat packing is provided between the outer peripheral side of the flange and the split ring .

According to the said structure, it can prevent that a fluid leaks from between the flange of a valve box, and a split ring.

Another characteristic configuration of the valve lid removal jig includes a valve lid cover that covers a valve lid fixedly connected to the valve box, and the housing is fixed to the split ring in a sealed state, and the valve lid and the valve There is an attachment that can freely surround the outer peripheral side of the lid cover, and the attachment is provided with a push bolt that presses the valve lid toward the valve box via the valve lid cover so that it can be operated from the radial direction. There is in point.

According to the above Symbol configuration, operating since the pressing of the valve lid to the valve box by pushing the bolt from the outer side of the attachment is easy.

Perspective view of gate valve and valve lid cover connected between both water pipes of water pipe system Partially cutaway front view of gate valve, first presser means, valve lid cover and attachment Partially cutaway front view showing the connection release operation of the connecting bolt and the connecting nut in the pressing-fixed state by the first presser means Partially cutaway front view showing the attachment state of the attachment and split structure split ring Partially cutaway side view showing the pressing and fixing state by the second presser means Partially cutaway front view showing the pressing and fixing state by the second presser means Partially cutaway front view showing an assembled state of a work housing provided with a work on / off valve and a lifting and lowering conveying means Partially cutaway front view showing a state in which the valve lid is taken out into the storage space of the work housing and the work on / off valve is closed. Partially cutaway front view showing the assembly state of the work housing with the valve box water stop jig connected to the lifting and lowering conveying means to the work on / off valve Partially cutaway front view showing a state in which the flow path in the valve box is stopped by the valve box water stop jig and the water stop is maintained by the second presser means. Partially cutaway front view showing a state where the work housing is removed from the work on-off valve and the seal member is replaced. Partially cutaway front view showing the assembly state of the work housing with a new valve lid connected to the lifting and lowering conveying means to the work on / off valve Partially cutaway front view of gate valve, valve lid cover, split ring with split structure, and third presser means connected between water pipes of water pipe system Top view showing a state in which a split ring with a split structure is attached to a gate valve connected between both water pipes of a water pipe system Partially cutaway front view showing a state in which the lower housing and the upper housing are attached to both pipe portions and the valve lid cover is pressed by the fourth pressing means. Partially cutaway front view showing a state in which the pressing and fixing by the third pressing means is released and the action housing having the work on-off valve and the lifting and lowering conveying means is assembled to the upper housing. Partially cutaway side view showing a state in which the working housing provided with the working on-off valve and the lifting and lowering conveying means is assembled to the upper housing after the pressing and fixing by the third pressing means is released Partially cutaway front view showing a state in which the flow path in the valve box is stopped by a bag type flow path closing device as a valve box water stop jig Partially cutaway front view showing an example of a split ring split ring

[First Embodiment]
1 to 4 show a gate valve V1 that is flange-joined in the middle of a water pipe (an example of both pipe portions) 1 of a water pipe system (an example of a fluid piping system).
The gate valve V1 is formed in a cast iron valve box 2 that is connected to the upstream and downstream water pipes 1 and has a substantially inverted T shape when viewed from the side, and an opening is formed at the upper end of the valve box 2. A cast iron valve lid 4 mounted on the valve body mounting port 3 from above and a valve rod 5 penetrating the valve lid 4 are detachable from the valve body mounting port 3 of the valve box 2. And a valve body 6 with a rubber lining attached thereto (see FIG. 8).

  The valve box 2 includes a pair of connection flanges 2A that are fixedly connected to the connection flanges 1A of both water pipes 1A and 7B in a watertight state by connection bolts 7A and connection nuts 7B. The horizontal valve box portion 2B is composed of a vertical valve box portion 2C having a substantially rectangular shape (a rounded rectangular shape) as a cross-sectional shape integrally formed in a direction orthogonal to the central portion in the flow axis direction. Yes. An annular flange in which a plurality of bolt insertion holes (not shown) are formed at predetermined intervals in the circumferential direction on the opening peripheral edge of the valve body mounting port 3 side on the outer peripheral surface of the vertically oriented valve box portion 2C. 2D is integrally formed in a state of projecting outward in the radial direction.

  The valve lid 4 can be joined to the flange 2D of the valve box 2 from above and below, and a bolt insertion hole (not shown) is formed in a portion corresponding to the bolt insertion hole 2a of the flange 2D. 4A is integrally formed, and a shaft support portion 4B is provided at the center portion of the valve lid 4 to penetrate and support the valve rod 5 in a watertight state so as to be freely rotatable.

  In addition, a pair of substantially L-shaped hook portions 4C extending from between the flange 4A and the shaft support portion 4B toward the flow path axis direction of the valve box portion 2B are integrally formed on the outer surface of the valve lid 4. Is formed.

  The flange 2D of the valve box 2 and the flange 4A of the valve lid 4 are tightened by a connecting bolt 8A and a connecting nut 8B inserted through the bolt insertion hole of the flange 2D and the bolt insertion hole of the flange 4A that are opposed to each other in the vertical direction. It is fixedly connected by. A seal mounting groove (an example of an annular groove) 2b formed on the upper surface of the flange 2D of the valve box 2 is in a water-tight state between the joint surfaces of the flange 2D and the flange 4A by tightening the connecting bolt 8A and the connecting nut 8B. A gasket (an example of a sealing member) 9 is mounted (see FIG. 8). The flange 2D of the valve box 2 and the flange 4A of the valve lid 4 are formed to have substantially the same shape (same diameter) in a top view. The lower surface of the flange 2D of the valve box 2 includes a flat surface portion (not shown) that can press the upper surface of a split ring 35 having a divided structure, which will be described later, from below.

  The valve body 6 screwed into the threaded shaft portion of the valve stem 5 has a flow path open position (valve open position) by a rotational operation of a square shaft-shaped rotational operation portion 5 a formed at the upper end portion of the valve stem 5. It is configured to slide up and down between the flow path blocking position (valve closing position).

  Next, among the gate valves V1 connected to the water pipe 1 on the upstream side and the downstream side of the water pipe system, when the valve body 6 having a shorter life than the valve box 2 has reached the set durable life, or When a malfunction of the valve body 6 occurs, the valve lid 4 provided with the valve body 6 and the valve rod 5 is in an uninterrupted water state (non-discontinuous flow state) in which the flow of fluid in both water pipes 1 is maintained. The valve lid removal method of the gate valve V1 to be removed from will be described.

[1] FIG. 1 shows a step of attaching and fixing a valve cover 10 covering the upper part of the valve cover 4 to the valve cover 4 of the gate valve V1 in a detachable manner.
The valve lid cover 10 has a circular shape when viewed from above and a substantially hat shape when viewed from the cross section. The valve lid cover 10 is externally attached to the shaft support portion 4B from above while contacting the upper surface of the shaft support portion 4B of the valve lid 4. 10 C of presser cover parts, the cyclic | annular collar part 10B provided continuously from the outer periphery lower end of 10 A of presser cover parts, the screw cylinder shape which has an internal diameter which accept | permits the protrusion of the rotation operation part 5a of the valve rod 5, and a valve body 6 and a connected portion 10C that is detachably threadedly connected to the female screw of the connecting portion 51 on the lifting and lowering conveying means E side that moves up and down the valve lid 4 provided with the valve rod 5 and the like.

  A plurality of insertion holes 10b (FIG. 1) through which a pair of bolt shaft portions 11a of the U-shaped bolts 11 can be respectively inserted into a plurality of circumferential positions (four in FIG. 1) of the bottom wall portion 10a in the presser cover portion 10A. Then, 4) are formed through. Each U-bolt 11 has a pair of bolt shaft portions 11a inserted through the insertion holes 10b of the presser cover portion 10A with the U-shaped portion engaged with the hook portion 4C of the valve lid 4 from below. The fastening nut 12 can be screwed into the protruding portion of each bolt shaft portion 11a from each insertion hole 10b. That is, the valve lid cover 10 and the valve lid 4 can be integrally mounted and fixed when the fastening nut 12 is screwed to the bolt shaft portions 11a to the tightening side.

  Therefore, when the valve lid cover 10 is attached and fixed to the valve lid, the U-shaped portion of each U-bolt 11 is engaged with each hook portion 4C of the valve lid 4 from the lower side with a pair of bolts. The shaft portion 11a is inserted into each insertion hole 10b of the presser cover portion 10A, and the fastening nut 12 is screwed into the protruding portion of each bolt shaft portion 11a from each insertion hole 10b. Then, the fastening nut 12 is further screwed into the fastening side, and the valve lid 4 and the valve lid cover 10 are integrated with the bottom wall portion 10a of the presser cover portion 10A in contact with the upper surface of the shaft support portion 4B. To be fixed. In the state where the valve lid cover 10 is mounted and fixed to the valve lid 4, the flange portion 10 </ b> B is disposed so as to be located on the radially outer side from the flange 2 </ b> D of the valve box 2 and the flange 4 </ b> A of the valve lid 4. Yes.

[2] FIG. 2 shows that the first presser means C1 made of a frame-like member that presses and fixes the valve lid 4 against the valve box 2 via the valve lid cover 10 is the valve box of the outer peripheral surfaces of the both water pipes 1. And a step of attaching and detaching over both parts across 2 and a downward projecting member (an example of the first pressing member) 23 of the first pressing means C1 from the upper opening 30B of the attachment 30 to the valve lid. A process of pressing and fixing the valve lid 4 to the valve box 2 in a sealed state through the upper part of the cover 10 is shown.

  The first presser means C1 includes a pair of split joint bodies 20 that are detachably fitted and fixed over both parts of the outer peripheral surfaces of both water pipes 1 with the valve box 2 interposed therebetween, and both water pipes A main body portion 21 disposed at a position corresponding to the upper side of the pair of split ring bodies 20 and the valve box 2 in a state along the tube axis direction of the one pipe, A moving mechanism 22 that is movable in the approaching / separating direction and a lower protruding member 23 that protrudes downward from a portion of the main body 21 corresponding to the upper side of the valve cover 10 are provided.

Each divided joint body 20 is configured by a semicircular divided body 20A that is divided into two parts, upper and lower, and each divided body 20A has a connecting flange portion 20B formed at both ends of each divided body 20A with bolts 20C. By being connected and fixed by the nut 20 </ b> D, it is configured to be connectable in an annular shape while being externally fitted to the outer peripheral portion of the water pipe 1.
Further, in the divided body 20A of the divided body 20A that is externally fitted to the upper side of the water pipe 1, a long bolt shaft 22A is inserted into a female screw hole (not shown) formed at the top portion, and a retaining nut 22B. Is screwed and attached in a retaining state. The bolt shaft 22 </ b> A is mounted so as to extend upward so as to be perpendicular to the tube axis of the water pipe 1.

The main body 21 is constituted by a longitudinal member that can be disposed at a position corresponding to the upper side of the pair of split joints 20 and the valve box 2 in a state along the pipe axis direction of both the water pipes 1. A through hole (not shown) through which the bolt shaft 22A can be inserted is formed in both ends of the tube axis direction in the main body 21, and the bolt shaft 22A is inserted into the bolt shaft 22A in a state where the bolt shaft 22A is inserted into the through hole. The pushing nut 22C screwed from the upper side of the main body 21 is configured to restrict the main body 21 from moving upward with respect to the bolt shaft 22A.
In addition, a pair of annular hanging hooks 21 </ b> A projecting upward is provided at a position sandwiching the central portion in the tube axis direction at the upper portion of the main body portion 21, and the main body portion 21 and thus the main body portion 21. The bolt shaft 22 </ b> A and the divided joint body 20, etc., assembled in the above-described structure can be suspended and moved by a crane or the like.
Furthermore, a holding portion 21B that holds an attachment 30 (described later) in a detachable manner is provided at the lower end portion of the main body portion 21 at the end portion side of each hanging hook 21A in the tube axis direction. The holding portion 21B is configured by a member that can suspend and support the attachment 30 on the main body portion 21. In FIG. 2, the holding portion 21B is configured by an annular belt (not shown). The attachment 30 is configured to be held in a state where it is suspended from the main body 21 by being spanned over a screw cylinder 30C provided on the cylindrical case body 30A of the attachment 30.

  Further, the lower protruding member 23 is formed in a cylindrical shape, and integrally protrudes downward from a portion corresponding to the upper side of the valve cover 10 at the center of the main body 21. The inner diameter of the lower protruding member 23 is slightly larger than the outer diameter of the connected portion 10 </ b> C of the valve lid cover 10.

Accordingly, one end side of the bolt shaft 22A is screwed into the female screw portion of the divided body 20A that is externally fitted to the upper side of the water pipe 1, and is set in a retaining state by the retaining nut 22B, and the other end side of the bolt shaft 22A is secured. Is inserted into the main body 21 and the upward movement of the main body 21 is restricted by the push nut 22C, and the attachment 30 is suspended and held by the main body 21 by the holding part 21B. A wire (not shown) is bridged between the pair of suspension hooks 21A and is suspended by a crane.
Then, the main body 21, the bolt shaft 22A, the divided body 20A (upper side only), the lower protruding member 23 and the attachment 30 are integrally suspended and moved so that the lower protruding member 23 is concentric with the connected portion 10C. Then, the lowering operation is performed so that each divided body 20 </ b> A is located at a predetermined mounting portion sandwiching the valve box 2 on the outer peripheral surfaces of the both water pipes 1. In this state, the attachment 30 is configured to be positioned on the outer peripheral side and the upper side of the valve lid 4 and the valve lid cover 10.
And both the connection flange part 20B of each division 20A of the state externally fitted by the upper part of the water pipe 1 and both connection flanges 20B of each division 20A externally fitted to the downward side of the water pipe 1 are bolt 20C. And fixedly connected by the nut 20D.

  Thereafter, each push nut 22 </ b> C is screwed to the tightening side, and the main body 21 is moved close to the pair of split split ring bodies 20, so that the lower protrusion integrally formed with the main body 21 is formed. With the lower end portion of the member 23, the outer diameter side portion of the connected portion 10C in the presser cover 10A is pressed and fixed. At this time, since the lower end portion of the downward projecting member 23 is formed in an annular shape, the presser cover 10A can be evenly pressed in the circumferential direction.

That is, the moving mechanism 22 is configured to include the bolt shaft 22A, the retaining nut 22B, and the pushing nut 22C, and the moving mechanism 23 moves the main body portion 21 close to the pair of split ring bodies 20, The upper part of the valve lid cover 10 can be pressed downward by the downward projecting member 23, and the valve lid 4 can be pressed and fixed to the valve box 2.
For this reason, the operation of pressing and fixing the valve lid 4 in close contact with the valve box 2 is not performed indirectly from the outside such as a housing surrounding substantially the whole of the gate valve V1, but is constituted by a frame-like member. The first pressing means C1 can be directly viewed through the opening portion of the first pressing means C1, and the operation can be performed easily, quickly, and efficiently. At this time, the attachment 30 that can freely surround the outer peripheral sides of the valve lid 4 and the valve lid cover 10 is in a state of being attached to the first presser means C1, and therefore is obstructed by the attachment 30 and other members. In addition, the valve lid 4 can be pressed against the valve box 2 through the valve lid cover 10 by the downward projecting member 23.

[3] FIG. 3 shows a step of releasing the connection of the connection bolt 8A and the connection nut 8B for connecting the flange 4A of the valve lid 4 and the flange 2D of the valve box 2 in the pressing and fixing state by the downward projecting member 23. .

In the state of FIG. 3, since the valve lid 4 is pressed and fixed to the valve box 2 via the valve lid cover 10 by the downward projecting member 23 of the first pressing means C1, in this state, the connecting bolt 8A Even if the pressing force by the connecting nut 8B is released, the gasket 9 interposed between the flange 4A of the valve lid 4 and the flange 2D of the valve box 2 can be reliably maintained in a compressed watertight state. it can.
Therefore, after the pressing and fixing by the first pressing means C1, the connecting bolt 8A and the connecting nut 8B are removed, and the fixed connection between the valve box 2 flange 2D and the flange 4A of the valve lid 4 is released.

  Thus, even when releasing the connection between the plurality of connection bolts 8A and the connection nut 8B, the operation can be performed directly while visually observing through the opening portion of the first pressing member C1, and the connection release operation can be performed. Easy, quick, reliable and efficient. Further, as described above, since the attachment 30 is attached to the first pressing means C1, the connection bolt 8A and the connection nut 8B are disconnected without being obstructed by the attachment 30 and other members. be able to.

[4] FIG. 4 shows that the split ring 35 having a split structure is supported and fixed in a state where it is pressed from the lower side against the flange 2D of the valve box 2, and the attachment 30 is detached from the first presser means C1, and the valve lid 4 and the process of fixing detachably in a sealed state on the upper surface of the split ring 35 in a state of surrounding the outer peripheral side of the valve cover 10.

  The split ring 35 having a split structure is configured by a half split disk-shaped split split ring 35A that is detachably applied to the flange 2D of the valve box 2 in a pressed state from below. The ring 35A includes a split plate portion 35a having a substantially semi-disc shape in plan view that is divided into two at the central position in the short side direction of the valve box 2, and a connecting plate projecting downward from both ends of each split plate portion 35a. The unit 35b is integrally provided.

An annular leg portion 30E that protrudes downward from an outer peripheral end portion of the lower surface of the connection flange 30C of the attachment 30 is fitted on the upper surface of each divided plate portion 35a, so that the connection flange of the split ring 35 and the attachment 30 is connected. An annular fitting groove 35c that prevents relative movement in the horizontal direction with respect to 30C is formed. In each of the divided plate portions 35a, a plurality of bolt insertion holes 35d are formed at equal intervals in the circumferential direction at positions slightly on the inner circumferential side of the annular fitting groove portion 35c (not shown, but, for example, in the circumferential direction) 8 places).
Further, on the upper surface of each divided plate portion 35a, the space between the upper surface of each divided plate portion 35a and the lower surface of the flange 2D of the valve box 2 is in a watertight state at a position corresponding to the outer peripheral portion of the flange 2D of the valve box 2. An annular sheet packing 36 is mounted.

Each divided plate portion 35a includes a reaction force receiving portion 37 that presses and fixes each divided plate portion 35a to the flange 2D of the valve box 2 from below.
The reaction force receiving portion 37 is provided on the outer peripheral surface of the lateral valve case portion 2B between the vertical valve case portion 2C and the connecting flange 2A from above in a state parallel to the transverse section of the lateral valve case portion 2B. A pair of plate-like leg portions 37a to be mounted, through holes (not shown) formed at both ends of each plate-like leg portion 37a, both screw bolts 37b that can be inserted through the through-holes at one end side, and through holes A pressing nut 37c that can be screwed into both screw bolts 37b inserted through the holes, and a pressing member 37d having a mounting female screw hole (not shown) that can screw the other end side of both screw bolts 37b from below. I have.

In the step of attaching the split ring 35 with the split structure, each plate-like leg portion 37a is mounted on the outer peripheral surface of the lateral valve box portion 2B between the vertical valve box portion 2C and the connecting flange 2A. Then, the flange 2D of the valve box 2 with the other end side of both screw bolts 37b screwed into each mounting female screw hole formed on the lower surface of each pressing member 37d and the pressing nut 37c screwed to one end side. On the other hand, both the split plate portions 35b are mounted from the short side direction of the valve box 2 (the direction of the pipe axis of the water pipe 1), and the upper surface of each split plate portion 35b is connected to the flange 2D via the seat packing 36. Make contact with the bottom surface. At this time, one end side of the both screw bolts 37c screwed into the mounting female screw holes (lower side than the place where the pressing nut 37d is screwed) is inserted into the through holes of the plate-like leg portions 37a.
Note that the mounting order of each plate-like leg portion 37a, both screw bolts 37b, the pressing nut 37c, the pressing member 37d, and the divided plate portion 35a is not limited to the mounting order and can be changed as appropriate as long as each member can be mounted securely. Can do.

  In this state, the coupling plate portions 35b facing each other are bolt insertion holes formed in the coupling plate portion 35b with a sheet packing (not shown) interposed between the joint surfaces of the both coupling plate portions 35b. After tightening and fixing with bolts 35e and nuts 35f inserted (not shown), the pressing nut 37c screwed into both screw bolts 37b is moved to the pressing side (the pressing nut 37c and the connecting plate portions 35b are relatively And the lower surface of the pressing nut 37d contacts the upper surface of each plate-like leg portion 37a, the upper surface of the pressing member 37d contacts the lower surface of each divided plate portion 35a, and The upper surface of each divided plate portion 35a is tightened and fixed until it is securely pressed and fixed to the lower surface of the flange 2D of the valve box 2 via the seat packing 36 in a watertight state.

  Next, the attachment 30 is detachably fixedly connected to the split ring 35 in a state of surrounding the outer periphery of the valve lid 4 and the valve lid cover 10, and the attachment 30 is detachably attached to the valve lid 4. Second presser means C2 is provided for pressing and fixing the valve lid 4 against the valve box 2 in a watertight state via the valve lid cover 10.

The attachment 30 includes a cylindrical case body 30A formed of an annular substantially cylindrical member, and an annular leg portion 30E is formed on the lower side of the lower surface of the connecting flange 30C formed at the lower end portion of the cylindrical case body 30A. A plurality of bolt insertion holes 30a are formed in portions corresponding to the plurality of bolt insertion holes 35d formed in the split plate portion 35a of the split ring 35 at a position slightly inside the annular leg portion 30E. Is formed.
Further, an annular seal mounting groove 30b is formed on the lower surface of the connecting flange 30C on the inner diameter side of the bolt insertion hole 30a, and the seal mounting groove 30b is inserted into the bolt insertion hole 35d and the bolt insertion hole 30a. An O-ring (an example of a sealing material) 32 is mounted to make the space between the upper surface of the split ring 35 and the lower surface of the connecting flange 30C by a tightening and fixing operation using the bolt 31A and the nut 31B.

  In the attachment process of the attachment 30, the annular belt which is the holding portion 21 </ b> B holding the attachment 30 on the main body portion 21 is removed, the attachment 30 is detached from the main body portion 21, and the connection flange 30 </ b> C of the attachment 30 is inserted through the bolt. In a state where the hole 30a and the bolt insertion hole 35d of the split ring 35 are aligned, the attachment 30 is placed on the upper surface of the split ring 35, and the bolt 31A and the nut 31B are extended over both the bolt insertion holes 30a and 35d. After inserting, tighten and fix in a watertight state.

[5] FIGS. 5 and 6 are a process of pressing and fixing the valve lid 4 against the valve box 2 in a sealed state via the upper part of the valve lid cover 10 by the second pressing means C2 provided on the attachment 30; The process of removing the first pressing means C1 from both the water pipes 1 and releasing the pressing and fixing of the upper portion of the valve cover 10 by the first pressing means C1 is shown.

The attachment 30 is provided with second presser means C <b> 2 for pressing and fixing the valve lid 4 against the valve box 2 in a sealed state via the upper portion of the valve lid cover 10.
The second pressing means C2 includes screw cylinders 30C communicating with the internal space of the cylindrical case body 30A at a plurality of circumferential positions (four positions in the present embodiment) of the cylindrical case body 30A, and the screw shaft core thereof is a valve lid. An annular tapered surface 10c formed on the outer peripheral edge of the upper surface of the flange 10B is fixed to the screw cylinder 30C in a state of being positioned on a horizontal axis passing through the upper surface of the flange 10B of the cover 10 or the vicinity thereof. Further, it is configured by screwing a push-in bolt 33 provided with a taper-shaped presser surface 33a that abuts in the horizontal direction.

  Therefore, when the attachment 30 is placed on the upper surface of the split ring 35 and is fastened and fixed in a watertight manner by the bolt 31A and the nut 31B, the screw shaft core of the screw cylinder 30C in the second pressing means C2 is the valve lid cover. 10 is located on the horizontal axis passing through the upper surface of the flange portion 10B or the vicinity thereof, and the presser bolt 33 screwed to the screw cylinder 30C is screwed to the presser side, and the tapered presser surface of the presser bolt 33 is The valve lid 4 is pressed and fixed to the valve box 2 side through the flange portion 10B by contacting the annular tapered surface 10c on the upper surface of the flange portion 10B by 33a.

Subsequently, in a state where a wire is bridged between the pair of hanging hooks 21A of the main body portion 21, the connection between the bolts 20C and the nuts 20D for connecting and fixing the connection flange portions 20B of the divided bodies 20A is released, and the main body portion 21 is released. The bolt shaft 22A, the divided body 20A (upper side only), the lower projecting member 23, and the attachment 30 are integrally suspended and moved to remove these members.
As a result, the pressing and fixing of the valve lid 4 to the valve box 2 via the valve lid cover 10 by the downward projecting member 23 is released.

  Thus, even if the pressing force by the downward projecting member 23 of the first pressing jig C1 is released, the valve lid 4 is pressed and fixed to the valve box 2 side by the tightening operation of the plurality of pressing bolts 33. Therefore, the gasket 8 interposed between the flange 4A of the valve lid 4 and the flange 2D of the valve box 2 is maintained in a compressed watertight state.

[6] FIG. 7 shows that the work on / off valve V2 is attached to the attachment 30 and the work housing H provided with the lifting and lowering conveying means E connected to the valve lid 4 is attached to the work on / off valve V2. The process of sealing an object part is shown.

  Of the valve case 40 of the work opening / closing valve V2, the inner surface of the fitting mounting cylinder portion 40A that is mounted on the cylindrical case body 30A of the attachment 30 from the upper side is attached to the upper end surface of the cylindrical case body 30A from above. The annular protrusion 40a for fitting position restriction to be in contact is integrally formed, and is formed to protrude from the upper end portion of the outer peripheral surface of the cylindrical case body 30A at a plurality of locations in the circumferential direction of the fitting mounting cylinder portion 40A of the valve case 40. A pulling bolt 41 having a tapered pressing surface (not shown) that comes into contact with the lower tapered surface (not shown) of the annular protrusion 30c from the horizontal direction is screwed.

  Further, an inner corner formed by the inner surface of the fitting mounting cylinder portion 40A and the fitting position regulating annular projection 40a in the valve case 40, and an upper tapered surface (not shown) of the annular projection 30c of the cylindrical case body 30A. An O-ring (not shown) is mounted between the opposing surfaces of the valve case 40, and the fitting position restricting annular protrusion 40a of the valve case 40 is attached to the valve case 40 while compressing the O-ring in a watertight state by tightening the pulling bolt 41. It is comprised so that it may draw and fix to the upper end surface of 30 cylindrical case bodies 30A.

The work housing H includes a work housing main body 43 including a lower connection flange 43A that is fixedly connected to the upper connection flange 40B of the valve case 40 by a bolt 42A and a nut 42B, and an upper flange 43B of the work housing main body 43. And a canopy 45 fixedly connected in a watertight state by bolts 44A and nuts 44B.
A storage space S in which the valve lid 4 including the valve body 6 and the valve stem 5 can be stored is formed in the work housing main body 43.

  In order to constitute the lifting / lowering conveying means E, a lifting / lowering shaft 52 is slidably supported by a cylindrical shaft support 50 provided at the center of the canopy 45 of the work housing H so as to be slidable in the vertical direction. A connecting portion 51 that is screwed and connected to the connected portion 10C of the valve lid cover 10 is provided at the lower end portion of the valve lid cover 10, and the valve body 6 and the valve are provided at the upper end portion of the lifting shaft 52. The valve lid 4 provided with the rod 5 is moved up by a crane or the like in the storage space S of the work housing main body 43, or the work housing main body 43 in which the valve lid 4 is stored is suspended at a predetermined position by a crane or the like. A suspension ring (not shown) for carrying is provided.

  Further, the mounting plate portion 56 formed on the upper end portion of the shaft support portion 50 so as to face both ends of the lifting operation rod 55 fastened and fixed to the upper portion of the lifting shaft 52 with a nut 54 in the vertical direction. A screw-type forced feeding mechanism 57 that lowers a member located at a predetermined storage position in the storage space S of the work housing main body 43 against the water pressure is provided between the both ends of the main housing 43.

  The screw-type forced feed mechanism 57 includes a long bolt 57A inserted through both ends of the mounting plate portion 56 of the shaft support portion 50 and both ends of the lifting operation rod 55, and lower surfaces of both ends of the mounting plate portion 56. A first nut 57B that is screwed to each long bolt 57A in a state of being in contact with each other, and a second nut 57C that is screwed to each of the long bolts 57A in a state of being in contact with the upper surfaces of both ends of the lifting operation rod 55. It is composed of

  In this housing mounting step, the valve lid 4 is pressed and fixed to the valve box 2 side by the tightening operation of the plurality of pressing bolts 33 of the second pressing means C2. The valve lid 4 can be pressed and fixed to the valve box 2 side in a watertight state by tightening the second nut 57C of the screw-type forced feed mechanism 57.

[7] FIG. 8 shows that the pressing and fixing of the upper portion of the valve lid cover 10 by the second pressing means C2 is released, and the valve lid 4 and the valve lid cover 10 provided with the valve body 6 and the valve stem 5 by the lifting and lowering conveying means E. And removing the valve lid 4 and the valve lid cover 10 taken out together with the lifting / lowering conveying means E and the work housing H after closing the work on-off valve H and taking them out into the storage space S of the work housing H. Indicates.

Specifically, the plurality of pressing bolts 33 of the second pressing means C2 are loosened to form a tapered pressing surface 33a of each pressing bolt 33 on the outer peripheral edge of the upper surface of the flange portion 10B of the valve lid cover 10. It is made to detach | leave from the taper surface 10c made to the radial direction outer side.
When releasing the pressing and fixing of the valve lid 4 by the second pressing means C2, the valve lid 4 is pressed against the valve box 2 in a watertight state by tightening the second nut 57C of the screw-type forced feeding mechanism 57. It is fixed.

  Thereafter, the valve lid 4 pressed against the valve box 2 is moved up to a predetermined storage position in the storage space S of the work housing main body 43 by a crane or the like connected to the lifting shaft 52 of the lifting and lowering conveying means E, The valve element 39 of the work on / off valve V2 is closed.

  In the step of removing the valve lid 4 taken out in the storage space S of the work housing H, a bolt 42A for fixedly connecting the upper connection flange 40B of the valve case 40 and the lower connection flange 43A of the work housing body 43, and The nut 42B is removed, and the work housing main body 43 including the removed valve lid 4 and the lifting and lowering conveying means E is suspended and conveyed to a predetermined removal position by a crane or the like and removed.

[8] FIG. 9 shows the valve box in a state where the flow of the fluid in the both water pipes 1 is maintained in the lifting / lowering conveying means E of the work housing body 43 of the work housing H in a work place different from the position where the valve box 2 exists. A step of attaching a valve box water stop jig Q that can freely stop the flow path that communicates with the valve body mounting opening 3 and attaching the work housing H provided with the lift conveying means E to the work on-off valve V2. Indicates.

  The valve box water stoppage jig Q is formed on the inner peripheral surface 2c of the flow path communicating with the valve body mounting port portion 3 of the valve box 2 and goes from the valve body mounting port portion 3 side to the both water pipes 1 side. The water stop part 60 which consists of a ring-shaped elastic member which contacts the diameter-reduced annular inner peripheral surface 2d, and the penetration which is formed in the front end side from the water stop part 60 and penetrates in the pipe axis direction of both water pipes 1 A hole portion 61 and an annular plate member 62 that is formed on the proximal end side with respect to the water stop portion 60 and orthogonal to the moving direction of the lifting and lowering conveying means E are provided. The cross-sectional shape of the reduced diameter annular inner peripheral surface 2d is formed in a substantially rectangular shape with rounded four corners. The reduced diameter annular inner peripheral surface 2d is a flow formed in the valve box 2. Depending on the shape of the road, if it is roughly circular, various shapes such as a circular shape, an elliptical shape, an oval shape, a quadrangular shape with rounded four corners, or a shape in which the inner peripheral surface has irregularities, etc. can do.

The valve box water stoppage jig Q includes a main body shaft portion 63, a plate member 62 is disposed on the base end side (upper end side) of the main body shaft portion 63, and the water stop portion 60 and the penetrating hole on the distal end side (lower end side). A hole 61 is formed.
Specifically, an annular member 64 having an annular shape when viewed from the pipe axis direction of the water pipe 1 is provided at the distal end portion of the main body shaft part 63, and the central part of the annular member 64 is arranged in the pipe axis direction. It is formed as a through-hole portion 61 that penetrates.
The water stop portion 60 is formed at the upper end portion of the annular member 64, and the outer diameter of the water stop portion 60 around the axis of the main body shaft portion 64 is larger than the outer diameter of the front end portion of the main body shaft portion 64. It is formed of an annular elastic member having a tapered outer peripheral surface 60a that has a large diameter and further decreases in diameter toward the distal end side.

The annular plate member 62 is formed of a circular disk-like member in a top view, and a connected portion 62a that is detachably connected to the connecting portion 51 on the lifting and lowering conveying means D side is located on the upper side at the center. The outer peripheral edge of the upper surface of the plate member 62 is in contact with the tapered pressing surface 33a of the pressing bolt 33 of the second pressing means (an example of the water stop state maintaining means) C2 from the horizontal direction, A tapered surface 62b is formed for pressing and fixing the water stop portion 60 of the valve box water stop jig Q against the reduced-diameter annular inner peripheral surface 2d in a watertight state.
Further, the plate member 62 is formed with at least one operation opening 62c penetratingly formed at a portion other than the center as viewed in the moving direction of the lifting and lowering conveying means E (four positions equally in the circumferential direction in FIG. 9). The operation opening 62c may be of a size that can pass through a cleaning member of a known cleaning device, but is preferably formed to a size that allows the operator's hand or arm to be inserted.

  The operation of attaching the valve box water stopping jig Q having such a configuration to the lifting / lowering conveying means E is performed by connecting the connected portion 62a formed on the plate member 62 to the connecting portion 51 of the lifting / lowering conveying means D. The work housing H provided with the lifting / lowering conveying means E in a state where the valve box water stop jig Q is connected is attached to the lower connection flange 43A of the work housing main body 43 and the upper connection flange 40B of the work on-off valve V2. This is performed by fixing and connecting in a watertight state with bolts 42A and nuts 42B.

[9] FIG. 10 shows that the working on-off valve V2 is opened, and the water stop portion 60 provided in the valve box water stop jig Q by the lifting and lowering conveying means E is connected to the valve body mounting port 3 of the valve box 2. A process of stopping the flow path by contacting the reduced diameter annular inner peripheral surface 2d of the flow path communicating with the flow path and maintaining the water stop portion 60 in the water stop state of the flow path by the second pressing means C2. Indicates.

  Specifically, the valve body 39 of the work opening / closing valve V2 is opened, and the lifting shaft 52 of the lifting / lowering conveying means E provided with the valve box water stopping jig Q is connected to the valve box water stopping jig Q. The taper-shaped outer peripheral surface 60a of the water-stopping portion 60 is moved downward to such an extent that the water-stopper 60 can abut against the reduced-diameter annular inner peripheral surface 2d. In this operation, the tapered outer peripheral surface 60a and the reduced-diameter annular inner peripheral surface 2d of the water stop portion 60 are brought into contact with each other by simply pressing and moving the elevating shaft 52 downward to the extent that it becomes difficult to press. Water can be stopped.

In this state, the tip of the annular member 64 provided at the tip of the main body shaft 63 is in contact with or close to the inner peripheral surface of the water pipe 1, and the upper surface of the plate member 62 Is located at a position where it can come into contact with the tapered pressing surface 33a of the pressing bolt 33 from the horizontal direction.
Therefore, the pressing bolt 33 screwed and attached to the screw cylinder 30C is screwed to the pressing side, and the tapered pressing surface 33a of the pressing bolt 33 contacts the annular tapered surface 62b on the upper surface of the plate member 62, The water stop 60 is pressed and fixed to the lower side through the plate member 62.
For this reason, a flow path communicating with the valve body mounting port 3 of the valve box 2 on which the valve lid 4 removed together with the valve body 6 is mounted by the water stop section 60 of the valve box water stop jig Q is provided. The water is stopped, and on the upstream side (both water pipes 1 side) of the water stop part 60, while maintaining the flow of the fluid, on the downstream side (flange 2D side of the valve box 2) of the water stop part 60, The flow of fluid can be interrupted.

[10] FIG. 11 shows the upper side of the work on / off valve V2 formed by removing the work housing H from the work on / off valve V2 in a state where the water stop state of the flow path is maintained by the second presser means C2. A process of replacing the gasket 9 mounted in the seal mounting groove 2b formed on the upper surface of the flange 2D of the valve box 2 with a new gasket 9 through the opening 46 will be described.

Specifically, the bolt 42A and the nut 42B that fixedly connect the upper connection flange 40B of the valve case 40 and the lower connection flange 43A of the work housing main body 43 are removed, and the removed valve lid 4 and lifting / lowering conveying means are removed. The work housing main body 43 provided with E is suspended by a crane or the like until the upper connection flange 40B and the lower connection flange 43A have a predetermined distance between adjacent ones.
Then, in a state where a sufficient work space is formed, the operator can manually operate the upper opening 46 of the work on-off valve V2 and the operation opening 62c of the plate member 62 of the valve box water stoppage jig Q. The arm 9 is inserted, the gasket 9 is removed from the seal mounting groove 2b formed on the upper surface of the flange 2D of the valve box 2, and a new gasket 9 is mounted in the seal mounting groove 2b.

For this reason, on the upper surface of the flange 2D of the valve box 2 in a state where the fluid flow is blocked, the gasket 9 mounted in the seal mounting groove 2b formed on the upper surface can be easily ejected without ejecting fluid. It can be replaced with a new seal member 9. At this time, since the water stop state at the water stop portion 60 is maintained by the second presser means C2, the gasket 9 can be removed with a sufficient time, and the gasket 9 can be removed reliably. Can be realized.
Further, the upper opening 46 of the working on-off valve V2 that can be a relatively large opening can be used to access the seal mounting groove 2b formed on the upper surface of the flange 2D of the valve box 2, The replacement work of the gasket 9 can be performed more easily and efficiently.
The gasket 9 is mounted in a relatively narrow seal mounting groove 2b formed on the upper surface of the flange 2D of the valve box 2, and the gasket 9 can be removed integrally by simply removing the valve lid 4. In addition, the removal work of the gasket 9 is likely to be a very troublesome work due to aging, sticking, etc. Further, the work of attaching the gasket 9 to the seal attachment groove 2b is unexpectedly troublesome work. Therefore, it is very important that the replacement work of the gasket 9 can be performed easily and efficiently.

[11] FIG. 12 shows that after the gasket 9 is replaced with a new gasket 9, the work housing H is attached to the work on-off valve V2, and the maintenance of the water stop state of the flow path by the second pressing means C2 is released. The valve box water stopping jig Q is taken out into the storage space S of the work housing H by the lifting and lowering conveying means E, and the valve box water stopping jig Q taken out by closing the work on-off valve V2 is moved up and down. After the step of removing together with E and the work housing H, another valve cover 4 equipped with a new valve element 6 is attached to the lift conveying means E, and the lift conveying means E is attached to the work closing valve V2. Indicates.

Specifically, the removal of the valve box water stop jig Q is the same as the removal of the valve lid 4 using the above-described lifting and lowering conveying means E, but the work housing H is attached to the work on-off valve V2. The plurality of push bolts 33 are loosened, and the taper-shaped pressing surfaces 33a of the push bolts 33 are separated from the tapered surface 62b on the upper surface of the plate member 62 radially outward. Thereafter, the valve box water stopping jig Q pressed against the reduced diameter annular inner peripheral surface 2d in the valve box 2 is moved upward to a predetermined storage position in the storage space S of the work housing main body 43 by a crane or the like. The valve element 39 of the work on / off valve V2 is closed. In the step of removing the valve box water stop jig Q taken out in the storage space S of the work housing H, the upper connection flange 40B of the valve case 40 and the lower connection flange 43A of the work housing body 43 are fixedly connected. The bolt 42A and the nut 42B are removed, and the removed work box main body 43 having the valve box water stopping jig Q and the lifting and lowering conveying means E is hung to a predetermined removal position by a crane or the like and removed.
As a result, the valve lid 4 is removed from the valve box 2 while maintaining the fluid flow in the both water pipes 1, and the gasket 9 in the seal mounting groove 2 b on the upper surface of the flange 2 </ b> D of the valve box 2 is replaced with the new gasket 9. To prepare for the work to install a new valve lid 4 to the flange 2D of the valve box 2, a short pipe equipped with an inner plug, a repair valve, etc. in a sealed state, as necessary. Can do.

For example, as shown in FIG. 12, after the valve lid 4 is removed and the gasket 9 in the seal mounting groove 2d on the upper surface of the flange 2D of the valve box 2 is replaced with a new gasket 9, at least a new valve body 6 is provided. When attaching another valve lid 4 that has been made, the procedure is substantially the reverse of the above-described valve lid removal operation process.
That is, after the removal process of the valve lid 4,
A step of connecting a connected portion 21d of another valve lid 4 equipped with at least a new valve body 6 to a connecting portion 51 of the lifting shaft 52 of the lifting and lowering conveying means E provided in the work housing H;
Fixing and connecting the lower connection flange 43A of the work housing main body 43 of the work housing H and the upper connection flange 40B of the valve case 40 of the work on / off valve V2 in a watertight state with bolts 42A and nuts 42B;
After opening the valve body 39 of the work on-off valve V2, the feed nut 57C of the screw-type forced feed mechanism 57 is tightened to operate another valve lid 4 in the storage space S of the work housing H. And lowering the valve shaft 2 integrally with the lifting shaft 52 to connect the flange 4A of another valve lid 4 and the flange 2D of the valve box 2;
A step of pressing and fixing another valve lid 4 to the valve box 2 side with a pressing bolt 33 of the second pressing means C2,
After rotating the lifting shaft 52 to the screw release side to release the connection between the connecting portion 51 of the lifting shaft 52 and the connected portion 21d of the other valve lid 4, the cylindrical case body 30A of the attachment 30 and the work Removing the work housing H provided with the work open / close valve V2 and the lifting and lowering conveying means E from the cylindrical case body 30A by releasing the fixing bolt 41 which is fixedly connected to the valve case 40 of the open / close valve V2;
A step of fixing and connecting the flange 4A of another valve lid 4 and the flange 2D of the valve box 2 with a connecting bolt 8A and a connecting nut 8B;
A bolt 31A and a nut 31B that release the pressing of another valve lid 4 by the pressing bolt 33 of the second pressing means C2 and fixedly connect the connecting flange 30C of the cylindrical case body 30A and the split plate portion 35a of the split ring 35 are fixed. A step of removing the attachment 30 and removing the attachment 30 from the split ring 35;
While loosening the pressing nut 37c of the reaction force receiving portion 37, the bolt 35e and the nut 35f that connect the connecting plate portions 35b of the split split ring 35A of the split ring 35 are unlocked, and the reaction force receiving portion 37 and Removing the split ring 35 with a split structure;
The fastening nut 12 that fixes and connects the valve lid cover 10 and the U-bolt 11 in a state of engaging with the hook 4C of the other valve lid 4 is unlocked, and the valve lid cover 10 and the valve lid cover 10 Removing the U-bolt 11;
Execute.

[Second Embodiment]
A valve lid removal method for the gate valve V1 according to the second embodiment will be described.
In addition, since the gate valve V1 of the structure similar to 1st Embodiment is used as a gate valve provided with the valve cover 4 used as removal object, about the structure similar to 1st Embodiment, the same code | symbol is attached | subjected. Therefore, the description is omitted.

[1] In FIG. 13, a valve lid cover 70 covering the upper portion of the valve lid 4 is detachably attached to the valve lid 4 and the split ring 80 having a divided structure is attached to the flange 2D of the valve box 2 from below. The step of supporting and fixing in the pressed state and the third presser means C3 provided between the valve lid cover 70 and the split ring 80 with the split structure allow the valve cover 70 to be separated from the split ring 80 with the split structure. The process of making it move close and pressing and fixing the valve lid 4 to the valve box 2 in a sealed state is shown.

  The valve lid cover 70 is formed in a disc shape having a circular shape when viewed from above, and a disc portion 70 </ b> A placed from above in a state of contacting the upper surface of the shaft support portion 4 </ b> B of the valve lid 4 of the valve lid 4. And a connection on the lifting and lowering conveying means E side which lifts and lowers the valve lid 4 and the like provided with a valve body 6 and the valve stem 5 and having a bore that allows the rotation operation portion 5a of the valve stem 5 to protrude. And a connected portion 70B that is detachably connected to the female screw of the portion 51.

  A plurality of insertion holes (not shown, 4 in FIG. 1) through which a pair of bolt shaft portions 11a of each U-shaped bolt 11 can be inserted in a plurality of circumferential positions (four in FIG. 14) of the disk portion 70A. Are formed through. Each U-bolt 11 has a pair of bolt shaft portions 11a inserted through the insertion holes of the disc portion 70A in a state where the U-shaped portion is engaged with the hook portion 4C of the valve lid 4 from below. A fastening nut 12 can be screwed into a protruding portion of each bolt shaft portion 11a from each insertion hole. That is, the valve lid cover 70 and the valve lid 4 can be integrally mounted and fixed when the fastening nut 12 is screwed to the bolt shaft portions 11a to the tightening side.

  The split ring 80 having a split structure is configured by a semi-ring-shaped split split ring 80A having a two-split structure that is detachably applied and fixed to the flange 2D of the valve box 2 from below. The split ring 80A protrudes downward from both ends of each divided plate portion 80a and a substantially semi-annular divided plate portion 80a in a plan view divided into two at the short side direction central position of the valve box 2. The connecting plate portion 80b is integrally provided.

When the upper surface of each divided plate portion 80a is pressed from the lower side of the flange 2D of the valve box 2 and the connecting plate portions 80b are tightened and connected to each divided plate portion 80a by bolts 80c and nuts 80d, An interference avoidance hole 80e for avoiding interference with the head of the connection bolt 8A or the connection nut 8B that connects the flange 2D of the box 2 and the flange 4A of the valve lid 4 is formed.
The interference avoidance hole 80e can surround the outer peripheral surface of the valve box 2, and among the heads of the plurality of connection bolts 8A or the connection nuts 8B, the mating surface of each connection plate portion 80b (the center position in the short side direction of the valve box 2). ) Is formed in a shape that can avoid interference with the head of the connecting bolt 8A or the connecting nut 8B biased to the connecting flange 2A side of the lateral valve box 2B.

A pair of protruding screw cylinders 81 formed with female threads are fixed to the upper surface of each divided plate portion 80a on both sides of the central portion in the long side direction of the interference avoidance hole 80e. Bolts 82 to be inserted into bolt insertion holes (not shown) formed at two locations in the circumferential direction of the valve cover 70 are screwed and fixed with locking nuts 83, A push nut 84 that presses and fixes the valve lid 4 to the valve box 2 side is screwed together with a tightening operation in a state of being in contact with the upper surface of the lid cover 70.
Each divided plate portion 80a includes a reaction force receiving portion 37 that presses and fixes each divided plate portion 80a to the flange 2D of the valve box 2 from below.

  In the step of attaching the split ring 80 having the divided structure, as shown in FIG. 14, first, of the plurality of connecting bolts 8A and connecting nuts, the mating surface of each connecting plate portion 80b (the center position in the short side direction of the valve box 2). The pair of connecting bolts 8A and the connecting nut 8B located at) are released and removed. And each plate-like leg part 37a is mounted | worn with the outer peripheral surface of the horizontal valve box part 2B between 2C of vertical valve box parts, and 2A of connection flanges. The other end side of both screw bolts 37b is screwed into each mounting female screw hole formed on the lower surface of each pressing member 37d, and the pressing nut 37c is screwed to one end side with respect to the flange 2D of the valve box 2. Then, both the divided plate portions 80b are mounted from the short side direction of the valve box 2 (the direction of the pipe axis of the water pipe 1), and the upper surface of each divided plate portion 80b is brought into contact with the lower surface of the flange 2D of the valve box 2. . At this time, the head of the connecting bolt 8A in the connected state enters the interference avoiding hole 80e formed in each divided plate portion 80a. Further, one end side of both screw bolts 37c screwed into the mounting female screw holes (lower side than the place where the pressing nut 37d is screwed) is inserted into the through holes of the plate-like leg portions 37a. Note that the mounting order of each plate-like leg portion 37a, both screw bolts 37b, the pressing nut 37c, the pressing member 37d, and the divided plate portion 80a is not limited to the mounting order and can be changed as appropriate as long as each member can be mounted securely. Can do.

  In this state, the connecting plate portions 80b facing each other are fastened and fixed with bolts 80c and nuts 80d inserted into bolt insertion holes (not shown) formed in the connecting plate portion 80b, and then both screw bolts. The pressing nut 37c screwed to 37b is screwed to the pressing side (to the side where the pressing nut 37c and both connecting plate portions 80b are relatively separated), and the lower surface of the pressing nut 37d is connected to each plate-like leg portion. The upper surface of the pressing member 37d is in contact with the lower surface of each divided plate portion 80a, and the upper surface of each divided plate portion 80a is securely pressed and fixed to the lower surface of the flange 2D of the valve box 2. Tighten until fixed. Thereafter, the locking nut 83 is tightened, and the lower surface of the locking nut 83 is contacted and fixed to the upper surface of the protruding screw cylinder 81.

  Thereafter, with the U-shaped portion of each U-shaped bolt 11 engaged with each hook portion 4C of the valve lid 4 from below, the pair of bolt shaft portions 11a are inserted into the respective insertion holes of the valve lid cover 70. The fastening nut 12 is screwed into the protruding portion of each bolt shaft portion 11a from each insertion hole 10b, and the bolt 82 is inserted into a bolt insertion hole (not shown) of the valve lid cover 70. Then, the fastening nut 12 is screwed to the fastening side, and the valve lid 4 and the valve lid cover 70 are integrally mounted and fixed in a state where the valve lid cover 70 is in contact with the upper surface of the shaft support portion 4B. Thereafter, the push nut 84 is screwed to the tightening side, the valve cover 70 is moved close to the split ring 80, and the valve cover 4 is pressed and fixed to the valve box 2 in a sealed state. . That is, the third pressing means C3 includes the U-shaped bolt 11, the fastening nut 12, the reaction force receiving portion 37, the valve cover 70, the split ring 80, the protruding screw cylinder 81, the locking nut 83, and the pushing nut 84. It is prepared for.

From these, the operation of pressing and fixing the valve lid 4 in close contact with the valve box 2 is not performed indirectly from the outside of the upper housing 91 and the lower housing 90 that surround substantially the entire gate valve V1, An opening portion of the third presser means C3 provided across the valve lid 4 and the valve lid cover 70 and capable of moving the valve lid cover 70 close to the split ring 80 having a divided structure (the upper opening portion 91B of the upper housing 91). It is possible to carry out the operation easily, quickly and surely and efficiently while visually observing through the screen.
Further, the flange 2D of the valve box 2 and the flange 4A of the valve cover 4 are fixedly connected in a state where the valve cover 4 is pressed against the valve box 2 via the valve cover 70 by the third pressing means C3. Even when the plurality of connection bolts 8A and the connection nut 8B are disconnected, the operation can be performed directly while visually observing through the opening portion of the third presser means C3. It can be done reliably and efficiently. Even if the connection bolt 8A and the connection nut 8B are released from the connection, the valve cover 4 is pressed against the valve cover 4 by the third pressing means C3, so that the valve cover 4 does not pop out due to fluid pressure.

[2] FIG. 15 shows a step of releasing the connection of the connection bolt 8A and the connection nut 8B for connecting the flange 4A of the valve lid 4 and the flange 2D of the valve box 2 in a state of being fixed by the third pressing means C3. A lower housing 90 having a divided structure surrounding the lower part of both water pipes 1 over both parts of the outer peripheral surface of the water pipe 1 sandwiching the valve box 2, and the upper part of both water pipes 1, the valve box 2, the valve lid 4 and the upper housing 91 of the divided structure surrounding the valve lid cover 70 in a sealed state by bolts 92 and nuts 93, and the upper part of the valve lid cover 70 by the fourth pressing means C4 provided in the upper housing 91. The step of pressing and fixing the valve lid 4 to the valve box 2 in a sealed state and the step of releasing the pressing and fixing of the upper portion of the valve lid cover by the third pressing means C3 are shown.

In a state where the valve lid 4 is pressed and fixed to the valve box 2 via the valve lid cover 70 by the third presser means C3, the flange of the valve lid 4 can be removed even if the pressing force by the connecting bolt 8A and the connecting nut 8B is released. The gasket 9 interposed between 4A and the flange 2D of the valve box 2 can be reliably maintained in a compressed watertight state.
Therefore, after the pressing and fixing by the third pressing means C3, the connecting bolt 8A and the connecting nut 8B are removed, and the fixed connection between the valve box 2 flange 2D and the flange 4A of the valve lid 4 is released.
Thus, even when releasing the connection of the plurality of connection bolts 8A and the connection nut 8B, the upper housing 91 and the lower housing 90 that surround the substantially entire valve box 2 are in a state before being attached and fixed to both the water pipes 1, The work can be performed directly while visually observing through the opening portion of the third presser member C3, and the connection release work can be performed easily, quickly, and efficiently.

  The lower housing 90 is a box-like shape that can freely surround the lower portion of the valve box 2 and both water pipes 1 in a state including a part of both water pipes 1 with the valve box 2 sandwiched between the outer peripheral surfaces of both water pipes 1. It is comprised by the member and it is comprised so that the seal member 90a may be mounted | worn by the site | part fitted by the outer peripheral surface of both the water pipes 1, and a watertight state may be maintained.

In addition, the upper housing 91 includes a part of both the water pipes 1 with the valve box 2 sandwiched between the outer peripheral surfaces of the both water pipes 1, the valve box 2 and the upper parts of the both water pipes 1, and a valve lid 4 and the valve lid cover 70 are constituted by a box-like member that can freely surround, and a seal member 91a is attached to a portion fitted on the outer peripheral surface of both the water pipes 1 so as to maintain a watertight state. Has been.
On the upper portion of the upper housing 91, an annular wall portion 91A protruding upward is formed so as to freely surround the outer peripheral side of the valve box 2, the valve lid 4, each split split ring 80a and the valve lid cover 70.
Note that the joint between the lower housing 90 and the upper housing 91 is also maintained in a watertight state by the seal member 90a and the seal member 91a.

A fourth presser C4 that presses and fixes the valve lid 4 against the valve box 2 in a watertight state via a valve lid cover 70 that is detachably attached to the valve lid 4 to the annular wall portion 91A of the upper housing 91. Is provided.
The fourth presser means C4 includes screw cylinders 91a communicating with the internal space of the annular wall portion 91A at a plurality of circumferential positions (four locations in the present embodiment) of the annular wall portion 91A, and the screw shaft core thereof is provided. Each screw cylinder 91a is fixed to an annular tapered surface 70c formed on the outer peripheral edge of the upper surface of the valve lid cover 70. It is configured by screwing a push-in bolt 94 provided with a taper-like pressing surface 94a that comes in contact with the horizontal direction.

  Therefore, when the lower housing 90 and the upper housing 91 are externally fitted to the water pipe 1 so as to surround the valve box 2 and are tightened and connected in a watertight state by the bolt 92 and the nut 93, the fourth presser means C4 Since the screw shaft core of the screw cylinder 91a is located on the horizontal shaft core passing through the upper surface of the valve cover 70 or in the vicinity thereof, a push bolt 94 screwed to the screw cylinder 91a is screwed to the push side, The tapered pressing surface 94 a of the push-in bolt 94 abuts on the annular tapered surface 70 c on the upper surface of the valve lid cover 70, and the valve lid 4 is pressed and fixed to the valve box 2 side via the valve lid cover 70.

  Subsequently, the pushing nut 84 of the third pressing means C3 screwed to each bolt 82 is loosened and removed, and the pressing and fixing of the valve lid cover 70 to the divided plate portion 80a by the pushing nut 84 is released.

  Thus, even if the pressing force by the pressing nut 84 of the third pressing jig C3 is released, the valve lid 4 is pressed and fixed to the valve box 2 side by the tightening operation of the plurality of pressing bolts 94. The gasket 8 interposed between the flange 4A of the valve lid 4 and the flange 2D of the valve box 2 is maintained in a compressed watertight state.

  From these, when the connection of the connection bolt 8A and the connection nut 8B is released, it is not necessary to perform the connection release operation in a narrow space in the upper housing 91 and the lower housing 90 surrounding the entire valve box 2, The valve lid 4 is pressed against the valve box 2 by the third pressing means C3 that can be directly and easily performed. On the other hand, in operations other than the decoupling operation, for example, from the outer side of the upper housing 91, As a configuration for pressing the valve lid 4 against the valve box 2 by the four presser means C4, the load of the work housing H, the work on-off valve V2, etc. provided with the lifting and lowering conveying means E described later on the upper housing 91, the lower housing 90, etc. Even when applied, a sturdy structure capable of withstanding the load can be obtained.

[3] FIGS. 16 and 17 show that the working housing H provided with the lifting and lowering conveying means E attached to the flange 91b of the upper opening 91B of the upper housing 91 and connected to the valve lid 4 is used for working. The process of attaching to the on-off valve V2 and sealing the work object part of the gate valve V1 is shown.
Thereafter, the pressing and fixing of the upper portion of the valve lid cover 70 by the fourth pressing means C4 is released, and the valve lid 4 provided with the valve body 6 and the valve stem 5 and the valve lid cover 70 are moved by the lifting and lowering conveying means E to the work housing H. Then, the valve lid 4 and the valve lid cover 70 are removed together with the lifting and lowering conveying means E and the work housing H.
It should be noted that the step of sealing the working part of the gate valve V1, the step of removing the valve lid cover 70, and the seal member mounted in a seal mounting groove (not shown) on the upper surface of the flange 2D of the valve box 2 executed thereafter. Since the process etc. which replace | exchange for a new sealing member are the same as that of 1st Embodiment, description is abbreviate | omitted.

[Third Embodiment]
In the first and second embodiments described above, the gasket (an example of the seal member) 9 attached to the seal attachment groove (an example of the annular groove) 2b formed on the upper surface of the flange 2D of the valve box 2 is replaced with the new gasket 9. When the flow path in the valve box 2 is water-stopped (blocked), the water-blocking part 60, the through-hole part 61, and the plate member 62 are provided as the valve-box water-stopping jig Q. However, as the valve box water stopping jig Q, if it is a structure that can reliably stop the flow path in the valve box 2 while maintaining the flow of fluid in both water pipes 1, It can be changed as appropriate.
For example, as shown in FIG. 18, a bag-type channel closing device can be employed as the valve box water stopping jig Q. Briefly, the bag-type flow path closing device includes a sealed case 100 that is detachably connected to the working on-off valve V2, a flow path in the vertical valve box 2C of the valve box 2, and the closed case 100. A cylindrical shaft 101, which is slidably inserted in the sealing case 100 in a vertically slidable state and includes a flow path (not shown) therein, and is fixed to a tip 101A of the cylindrical shaft 101. A closing bag 102 that is elastically expandable and deformable on the diameter-expanding side by a diameter-expanding fluid supplied through the passage, and a pushing operation means that pushes and moves the cylindrical shaft 101 against the fluid pressure in the water pipe 1 (Not shown).
As a result, the sealed case 100 is connected to the work on-off valve V1 in a watertight state, the cylinder shaft 101 penetrating the sealed case 100 is pushed in, and the closure bag 102 provided at the tip of the cylinder shaft 101 is removed. In the state where it is positioned on the inner diameter side of the inner peripheral surface 2c of the flow path communicating with the valve body mounting opening 3 of the valve box 2, it expands into the closed bag 102 via the flow path in the cylindrical shaft 101. By supplying the diameter fluid, the closed bag 102 can be expanded to the diameter expansion side, and the inner peripheral surface 2c can be stopped. The diameter expansion fluid may be air or other gas, or may be a liquid such as water.
Moreover, as such a valve box water stop jig | tool Q, the structure which obstruct | occludes the internal peripheral surface 2c of the flow path connected with the valve body installation port part 3 of the valve box 2 is provided in the front-end | tip part of the cylinder shaft 101. In addition, an elastic member such as rubber that can be expanded in diameter can be provided.
In addition, in the case of these configurations, when closing the inner peripheral surface 2c of the flow path communicating with the valve body mounting port portion 3 of the valve box 2, there is a configuration that exhibits a lifting function in these configurations themselves, The lifting / lowering conveying means E can be omitted.

[Fourth Embodiment]
In the above-described embodiment, when the split ring 35 or split ring 80 having a split structure is supported and fixed in a state of being pressed from the lower side against the flange 2D of the valve box 2, in the first embodiment, the upper surface of the split ring 35 and The seat packing 35 is interposed between the lower surface of the flange 2D of the valve box 2 so that a fluid is not ejected to the outside, and the load applied to the split ring 35 is fluidized via the reaction force receiving portion 37. In the second embodiment, the split ring 80 is surrounded by the lower housing 90 and the upper housing 91 to provide a sealed state in which no fluid is ejected to the outside. The load is received by the outer peripheral surface of the fluid pipe 1 through the reaction force receiving portion 37. However, the structure of the split ring with the split structure can be appropriately changed as long as it can prevent the fluid from being ejected to the outside and receives a load applied to the split ring so as not to be damaged.
For example, as shown in FIG. 19, the split ring 120 includes a connecting portion between the connecting flange 2A on one end side of the lateral valve box portion 2B and the connecting flange 1A of the water pipe 1, and other than the horizontal valve box portion 2B. Each split split ring is composed of a semi-disc shaped split split ring 120A having a two-part structure placed from the upper side across the connecting portion of the end side connecting flange 2A and the connecting flange 1A of the water pipe 1. 120A is a divided plate portion 120a having a substantially semi-disc shape in plan view divided into two at the short side direction center position of the valve box 2, and a connecting plate portion protruding downward from both ends of each divided plate portion 120a. 120b is integrally provided.
On the upper surface of each divided plate portion 120a, an annular protrusion 121 that restricts the distance between the upper surface of each divided plate portion 120a and the lower surface of the flange 2D of the valve box 2 to be equal to or smaller than a predetermined distance is provided on the valve box 2. The flange 2D is formed so as to protrude slightly from the outer peripheral portion of the flange 2D. A female screw hole (not shown) is provided at a position corresponding to a bolt insertion hole (not shown) formed in the connection flange 30C of the cylindrical case body 30A of the attachment 30 at the outer diameter side end of each divided plate portion 120a. The bolt 122 is screwed into the female screw hole from above the connecting flange 30C through the bolt insertion hole, and the attachment 30 and the divided plate portion 120a are connected and fixed. The lower surface of the connecting flange 30C and the upper surface of the divided plate portion 120a are in a water-tight state by a seal member (not shown) attached to a position on the inner diameter side slightly from the screwed portion of the bolt 122.
A bag device (not shown) including an annular (doughnut-shaped) bag 123 is attached to the inner diameter side of the annular protrusion 121 on the upper surface of each divided plate portion 120a, and fluid is supplied into the bag 123. Accordingly, the cross section of the bag 123 is configured to expand. Therefore, when the annular bag 123 is disposed in the space between the lower surface of the flange 2D of the valve box 2 and the upper surface of the divided plate portion 120a on the inner diameter side of the annular protrusion 121, the bag 123 is expanded in diameter. The space can be sealed. The load applied to the divided plate portion 120a can be reliably received by both the connecting flanges 1A and 2A. Therefore, the structure of the split ring 120 can be configured such that fluid can be prevented from being ejected to the outside and the load applied to the split ring 120 can be received and not damaged.
The split split ring 120a is pressed downward by expanding the diameter of the bag 123, but the pressing bolts 33 formed at a plurality of locations in the circumferential direction of the cylindrical case body 30A and the upper surface of the valve lid cover 10 come into contact with each other. As the cylindrical case body 30 </ b> A moves upward, the divided plate portion 120 a is relatively pressed against the lower surface of the flange 2 </ b> D of the valve box 2.

[Other Embodiments]
(1) In the above embodiment, when the gasket 9 is replaced, the work is performed through the upper open portion of the work on / off valve H formed by removing the work housing H from the work on / off valve V2. The gasket 9 may be replaced through a work window formed in the housing H that can be freely opened and closed.
Further, for example, when the annular plate member 62 of the valve box water stop jig has a gap that is significantly smaller than the inner diameter of the work housing H or the attachment 30, the gasket 9 is replaced through the gap. Work may be performed.

(2) In the above-described embodiment, the flange joint type gate valve V1 provided with the connecting flange 2A for the upstream and downstream water pipes 1 has been described as an example, but at least one end side is a receiving port or an insertion port. A gate valve configured as described above may be used.

  As described above, it is possible to provide a valve lid removal method for a gate valve that can efficiently and easily remove a valve lid including a valve body and a valve stem in an uninterrupted state.

C1 First presser means (frame member)
C2 Second presser means ( presser means provided on the attachment)
C3 Third presser means ( presser means provided across the valve cover and the split ring)
C4 Fourth presser means ( presser means provided on the housing)
E Lifting means H Work housing (housing)
S Storage space Q Valve box water stop jig V1 Gate valve V2 Work on / off valve (housing)
1 water pipe (both pipe parts)
2 Valve box
2B Sideways valve box part 2D Flange (valve box)
2b Seal mounting groove (annular groove)
2c Inner peripheral surface 2d Reduced-diameter annular inner peripheral surface 3 Valve body mounting port 4 Valve lid 4A Flange (valve lid)
5 Valve rod 6 Valve body 8A Connection bolt 8B Connection nut 9 Gasket (seal member)
DESCRIPTION OF SYMBOLS 10 Valve cover 20 Divided joint body 21 Main part 22 Movement mechanism 23 Lower side protrusion member 30 Attachment (housing)
33 Push-in bolt 35 Split ring
36 Sheet packing
37a Plate-shaped leg (leg)
37d Pressing member 60 Water stop portion 61 Through hole portion 63 Main body shaft portion 70 Valve cover cover 80 Split ring
90 Lower housing (housing)
91 Upper housing (housing)
120 split ring

Claims (6)

Received in the valve box through the valve body which is connected between the Ryokan portion constituting a fluid piping system, and a valve cover that is fixedly coupled to the valve box, the valve stem formed through to the valve cover Of the gate valve provided with the valve body, the valve lid provided with the valve body and the valve rod is removed from the valve box in a state in which the flow of fluid in the both pipe portions is maintained. The lid removal method,
The valve lid cover for covering a portion of the valve cover, the steps of instrumentation attachment fixed to the valve lid,
It sets up a frame member for fixing pressing the valve cap relative to the valve body through the valve cover and detachably holding and the valve lid cover surrounding freely attachment the outer periphery of the valve lid cover Process,
The pressing member of the frame-like member, a step of pressing with fixing the valve cover through the front Kibenfuta cover relative to said valve body,
A step of releasing the connection between the valve lid and the valve box in the pressing and fixing state by the frame member ;
A split ring having a split structure is supported and fixed in a state where it is pressed from the side of the both pipe portions against the flange of the valve box, and the attachment detached from the frame-shaped member is attached to the valve lid and the valve lid cover. a step of fixed sealingly to the split ring in a state surrounding the outer peripheral side of,
The presser means provided on the attachment, the step of pressing with fixing the valve cover through the valve lid cover to the valve body,
And removed by withdraw the frame member, a step of releasing the pressing with fixed the valve lid cover by the frame-like member,
Attaching a work on / off valve to the attachment, attaching a work housing provided with a lifting and lowering conveying means connected to the valve lid cover to the work on / off valve, and sealing a work target portion of the gate valve;
The pressing and fixing of the valve lid cover by the pressing means provided on the attachment is released, and the valve lid and the valve lid cover including the valve body and the valve rod are stored in the work housing by the lifting and lowering conveying means. After taken out in the space, the valve lid removal method of the partition valve and includes a step, the to remove the Kiben lid and the valve lid cover with the previous SL work front housing and closed operating the working-off valve. Said frame member is provided with a moving mechanism for causing the near-spaced said pressing member relative to the valve cap, by closer moves the pressing member by the moving mechanism, a pre Kibenfuta to the valve body The valve lid removal construction method of the gate valve according to claim 1 to be fixed by pressing. Received in the valve box through the valve body which is connected between the Ryokan portion constituting a fluid piping system, and a valve cover that is fixedly coupled to the valve box, the valve stem formed through to the valve cover Of the gate valve provided with the valve body, the valve lid provided with the valve body and the valve rod is removed from the valve box in a state in which the flow of fluid in the both pipe portions is maintained. The lid removal method,
With a portion of the valve lid cover covering securing instrumentation attachment to the valve cap of the valve cover, to support and fix in a state of pressing from the side of the two pipe portions split ring of divided structure against the flange of the valve body Process,
The presser means provided across said split ring and said valve lid cover, the valve lid cover in close proximity moving relative to the split ring, secured to pressing with the valve cap relative to the valve body Process,
A step of releasing the connection between the valve lid and the valve box in a pressing and fixing state by a pressing means provided across the valve lid cover and the split ring ;
And attaching pre SL two pipe portions, the valve body, the housings of the split structure surrounding the valve closure and the valve lid cover in tight sealed state,
A step of pressing with fixing the valve cover through the valve lid cover to the valve body by presser means provided on the housings,
Releasing the pressing and fixing of the valve lid cover by a pressing means provided across the valve lid cover and the split ring ;
A step of said mounting work on-off valve housings, attached work housing with a lifting conveyor means is coupled to the valve lid cover to the working-off valve to seal the working target portion of the gate valve,
The pressing and fixing of the valve lid cover by the holding means provided in the housing is released, and the valve lid and the valve lid cover provided with the valve body and the valve rod are moved by the lifting and lowering conveying means of the work housing. After taking out the storage space, the valve lid removal method of the partition valve and includes a step, the to remove the Kiben lid and the valve lid cover with the previous SL work front housing and closed operating the working-off valve . A split ring with a split structure that comes into contact with the flange of the valve box connected between both pipe parts constituting the fluid piping system, from the both pipe parts side;
A leg portion mounted on an outer peripheral surface of the lateral valve box portion positioned between the pipe portions of the valve box, and a pressing member connected to the leg portion and pressing the split ring against the flange. And a reaction force receiving portion that supports the split ring,
A valve lid removal jig comprising: a housing having a work on-off valve and attached to the split ring in a sealed state. The valve lid removal jig according to claim 4, wherein an annular seat packing is provided between an outer peripheral side of the flange and the split ring. A valve cover that covers the valve cover fixedly connected to the valve box;
The housing is fixed to the split ring in a sealed state, and has an attachment that can freely surround an outer peripheral side of the valve lid and the valve lid cover,
The valve lid removal treatment according to claim 4 or 5, wherein a push bolt for pressing the valve lid toward the valve box via the valve lid cover is provided on the attachment so as to be operable from a radial direction. Ingredients.