JPH0781669B2 - Anti-branch pipe working method and branch pipe blocking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to, for example, a water stop installed in the middle of a branch pipe for a terminal device such as a fire hydrant or an air valve that is branched and connected to a water main. The present invention relates to a method for working a branch pipe in which the sluice valve is exchanged while water is being supplied through a water main pipe while preventing water leakage from the branch pipe, and a branch pipe blocking device used in the method.

More specifically, regarding the method, <1> a step of shutting off the branch pipe by a sluice valve interposed in the middle of the branch pipe branch-connected to the main pipe for fluid transportation, <2> the branch pipe Removing the terminal device attached to the end, <3> attaching a lid to the end of the branch pipe to close the end opening of the branch pipe, <4> opening the sluice valve <5> In the sealed state, the operating shaft penetrating slidably in the axial direction is slidably operated to slide an obturator provided on the inner end side of the operating shaft to a portion upstream of the sluice valve. <6> A pair of pressing plates attached to the inner end side of the operation shaft are moved toward and away from each other in the axial direction to sandwich the elastic ring state interposed between the pressing plates from the axial direction. A process of closing the branch pipe by pressing and elastically deforming it into a diameter-expanded state in which it is in close contact with the inner peripheral wall of the branch pipe. <7> A step of removing the sluice valve, <8> A step of maintenance work or a step of attaching a new sluice valve, <9> The branching by the obturator by releasing the clamping pressure of the pressing plate against the elastic ring-shaped body. Releasing the blockage of the pipe, <10> moving the obturator until it is housed in the lid, <11> blocking the branch pipe with the sluice valve, and then removing the lid, 12> A step of opening the sluice valve after mounting the terminal device, and a method of working a branch pipe.

On the other hand, as for the device, the downstream side end of the sluice valve or the end of the branch pipe that is branched and connected to the main pipe for fluid transport and in which the sluice valve is interposed is closed. A lid body that can be attached to an end of a pipe portion to be connected, and a tubular first body that penetrates the lid body in a sealed state so as to be slidable in an axial direction.
An operating shaft and a second penetrating slidably through the first operating shaft
An operating shaft is provided, separate pressing plates are attached to the inner end sides of the first operating shaft and the second operating shaft, and a pressing force is applied between the pair of pressing plates in the axial direction by the pair of pressing plates. The branch pipe shield is provided with an elastic ring-shaped body that elastically deforms to a diameter-expanded state in which the branch pipe closely contacts the inner peripheral wall of the branch pipe and shields the inner peripheral wall from the outer peripheral portions of the pair of pressing plates. Regarding closure device.

[Conventional technology]

When performing branch pipe work such as replacement of a sluice valve installed on the above-mentioned branch pipe, conventionally, in the step <9> described above, after a new sluice valve is attached, the branch pipe is blocked by a closing tool. , It was released by warming the pinching force on the elastic ring-shaped body of the obturator from the axial direction and elastically restoring and deforming it to a reduced diameter state in which a gap is formed between it and the inner peripheral wall of the branch pipe (Reference) I can't name it).

[Problems to be Solved by the Invention] However, in the case of the above-mentioned conventional method, there are the following problems.

That is, in the state where maintenance or a new sluice valve is installed, the differential pressure between the fluid pressure on the upstream side and the atmospheric pressure on the downstream side causes the elastic ring-shaped body to move to the inner peripheral wall of the branch pipe and Since it acts as a force for pressing the downstream pressing plate, even if the pressing pressure on the elastic ring-shaped body by the pressing plate is released, the elastic ring-shaped body will still have the downstream pressure plate and the branch pipe due to the differential pressure. It is pressed against the inner peripheral wall of the pipe and held in close contact with it, and the branch pipe tends to be released smoothly without being released.Especially when the fluid is transported to the main pipe at high pressure, the work efficiency is significantly reduced. Was to come.

In view of the conventional circumstances, an object of the first invention is to provide a method for working an anti-branch pipe capable of smoothly releasing blockage of a branch pipe, and an object of the second invention is to provide such an anti-branch pipe. An object of the present invention is to provide a branch pipe blocking device useful for a pipe working method.

[Means for solving problems]

The feature of the method for working a branch pipe according to the first aspect of the present invention is that the step of releasing the blockage of the branch pipe by the obturator after the maintenance or after installing a new sluice valve is performed on the downstream side of the obturator. A step of making the internal pressure of the branch pipe substantially equal to the internal pressure of the branch pipe on the upstream side of the obturator, and <b> releasing the clamping pressure of the pressing plate against the elastic ring-shaped body. It is in.

[Action]

That is, according to the method for working the branch pipe of the first aspect of the present invention, when the blockage of the branch pipe is released, the internal pressures of the upstream side and the downstream side of the obturator become substantially the same, so that the elastic ring by the pressing plate is used. When the pinching pressure on the cylindrical body is released, there is almost no force due to the differential pressure of the internal pressure of the branch pipe that presses the elastic ring-shaped body against the pressing plate on the downstream side and the inner peripheral wall of the branch pipe, The elastic ring-shaped body is easily elastically restored and deformed into a reduced diameter state in which a gap is formed between the elastic ring-shaped body and the inner peripheral wall of the branch pipe.

〔The invention's effect〕

As a result, even when the fluid is transported into the main pipe at high pressure, the branch pipe can be smoothly unblocked by releasing the pinching pressure on the elastic ring-shaped body, and maintenance and replacement of the sluice valve can be performed. It has become possible to improve the efficiency of work on the branch pipe.

[Means for solving problems]

The branch pipe blocking device according to the second aspect of the present invention is characterized by a pair of pressing plates for elastically deforming the elastic ring-shaped body into a diameter-expanded state in which the elastic ring body is brought into close contact with the inner peripheral wall of the branch pipe by a pinching force from the axial direction. Fluid is generated by the pinching pressure of the pair of pressing plates against the elastic ring-shaped body at a contact portion between the inner peripheral wall of the branch pipe or the inner peripheral wall of the branch pipe and the elastic ring-shaped body becomes a predetermined value or less. The flow path is formed so as to pass from the upstream side to the downstream side of the elastic ring-shaped body.

[Action]

That is, when the branch pipe blocking device of the second aspect of the present invention is used, when the pinching pressure of the pair of pressing plates against the elastic ring-shaped body becomes a predetermined value or less, the flow path is opened and the fluid flows on the upstream side of the elastic ring-shaped body. Since it passes from the downstream side to the downstream side, the internal pressure of the branch pipe on both sides of the elastic ring becomes almost the same, and there is a gap between the elastic ring and the inner peripheral wall of the branch pipe. Restore and transform.

Moreover, the pressure equalization between the upstream side and the downstream side of the elastic ring-shaped body for smoothly releasing the blockage of the branch pipe described above is a pair of pressing plates originally provided in this type of device. It is possible to do so by providing a flow path at the contact point between the inner peripheral wall of the branch pipe or the inner peripheral wall of the branch pipe and the elastic ring-shaped body, so some modification to those components is possible. It only needs to be added, and moreover, it can be done by only warming the clamping pressure on the elastic ring-shaped body.

〔The invention's effect〕

As a result, when performing maintenance or replacement of the sluice valve or the like installed in the branch pipe, by using the branch pipe shutoff device according to the second aspect of the present invention, maintenance work has been completed or a new sluice valve or the like has been installed. After closing the branch pipe, the blockage of the branch pipe can be released smoothly by making the internal pressures on both sides of the elastic ring-shaped body substantially the same, so that the working efficiency can be improved.

Moreover, since the structure for that purpose can be obtained by a slight modification of the parts originally possessed by this type of device, for example, a bypass flow path communicating both sides of the elastic ring-shaped body and a valve for opening and closing the bypass flow path. It is possible to eliminate the need to install a large-scale device, such as the provision of
It is possible to avoid an increase in working space. Furthermore, in order to release the blockage of the branch pipe, no special operation is required to make the internal pressures on both sides of the elastic ring-shaped body almost the same except the operation of warming the clamping pressure on the elastic ring-shaped body. It is possible to perform work with the same operation feeling and without fear of forgetting the operation.

Therefore, as a whole, it was possible to provide a branch pipe blocking device which is used when performing the work of the counter branch pipe while continuing the fluid transportation, in terms of both operation and cost.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

First, prior to the description of the working method for the branch pipe according to the first aspect of the present invention, the branch pipe blocking device according to the second aspect of the present invention used therefor will be described.

As shown in FIG. 3, this branch pipe blocking device is branched and connected to a water main (A) buried in the ground, and an air valve (1) is connected to its end and an In the case of replacing the water shutoff valve (2) of the branch pipe (B) having the water shutoff valve (2), which is an example of a gate valve, in the branch pipe (B), the water shutoff valve (2) of the water shutoff valve (2) is replaced. A device for stopping water in an upstream pipe portion (3) in a state in which replacement of the water stop valve (2) is allowed, the device comprising a water stop (5) and a fixing means (6). Has been done.

The branch pipe (B) is a human-hole lid (B ₁ ) which is flange-connected to the flanged T-shaped pipe of the water main (A) at a large diameter portion on one end side, and the human-hole lid (B ₁ ) Valve box (B ₂ ) of the water shutoff valve (2) flanged on one end side to the small diameter end of the
And a short pipe (B ₃ ) for attaching an air valve that is flange-connected to the other end of the valve box (B ₂ ), and the upstream pipe portion (3) to be stopped is It is a small diameter pipe part of the human hole cover (B ₁ ).

The lid (4) closes the other end opening of the water shutoff valve (2) from which the short pipe (B ₃ ) is removed, as shown in FIGS. 1 (b) and 2. In addition, it is a container that can be flange-connected to the other end of the water shutoff valve (2) and that can incorporate the water shutoff device (5) therein.

The water stop (5) is, as shown in FIG. 1 (e) and FIG. 2, an operation shaft that penetrates the shaft core portion of the lid body (4) in a watertight state so as to be slidable in the shaft core direction. (5A) and this operating axis (5
It consists of an obturator (5B) attached to the inner end of (A).

The operation shaft (5A) is composed of a cylindrical first operation shaft (5a) and a second operation shaft (5b) penetrating the inside of the first operation shaft (5a) in a watertight state.

The obturator (5B) includes a first pressing plate (5c) attached to an inner end of a first operating shaft (5a) of the operating shaft (5A),
Of the operation shaft (5A), the second operation shaft (5b) is mounted on the inner end side of the second pressing plate (5d) slidably fitted on the inner end part of the second operation shaft (5b), and the second operation is performed. A pressing operation tool for moving the second pressing plate (5d) closer to the first pressing plate (5a) by sliding the shaft (5b) in the axial direction on the outer end side with respect to the first operating shaft (5a). 5e) and the second pressing plate (5d) move closer to each other, the pressing plates (5c) and (5d) are pressed from the axial direction, and the closing plates (5c) and (5d) are pressed. The elastic ring-shaped body (5f) elastically expands and deforms so as to close the gap between the outer peripheral portion and the inner peripheral wall of the upstream pipe portion (3).

The pressing plates (5c) and (5d) are formed to have a diameter smaller than the minimum inner diameter of the branch pipe (B) so that they can move in the axial direction in the branch pipe (B), and the elasticity of the elastic plates is reduced. Ring-shaped body (5
Similarly, f) is also formed to have a diameter smaller than the minimum inner diameter of the branch pipe (B) in the natural state where the pinching pressure is released. Further, the second pressing plate (5d) is formed with a drop-out preventing projection (5g) which engages with and holds the elastic ring-shaped body (5f).

As shown in FIGS. 4 and 5, the elastic ring-shaped body (5f) is provided with a plurality of notches (5x) along the circumferential direction on the first pressing plate (5c) side thereof. ing. The notch (5x) is closed by elastic deformation of the elastic ring-shaped body (5f) in the sandwiched state, and is opened when the sandwiched pressure is below a predetermined level to communicate both sides of this elastic ring-shaped body (5f). A flow path (F) is formed, and as will be described later, a branch pipe formed by the obturator (5B) after a new water stop valve (2) is attached when replacing the water stop valve (2). In releasing the blockage of (B), the pair of pressing plates (5c), (5
When the clamping pressure by d) becomes less than a predetermined value, the fluid is released to allow the fluid to pass from the upstream side to the downstream side of the elastic ring-shaped body (5f), which causes the internal pressure of both sides of the elastic ring-shaped body (5f). Are substantially equal to each other so that the elastic ring-shaped body (5f) can be smoothly elastically restored and deformed in a natural state so that the branch pipe (B) can be released without obstruction.

As shown in FIG. 1 (e) and FIG. 2, the fixing means (6) is provided on the inner end side of the water stop (5) with respect to the large diameter portion of the human hole lid (B ₁ ). A detachable retainer (6A) is attached, and an operating portion (6B) for the retainer (6a) having an outer end portion of the second operating shaft (5b) as an operating portion (6a) is attached to the water stop (5). ) Built in.

In the fixing device (6A), the second operation shaft (5b) makes the first operation between the other end of the second operation shaft (5b) and the second pressing plate (5d) of the obturator (5B). When in a sliding position where the pressing operation tool (5e) is brought into contact with the second pressing plate (5d) with respect to the shaft (5a),
Protrusions (6b) that are bent in a V shape and are formed in the middle of the refraction.
Projecting outward so as to engage with the large diameter portion of the human hole lid (B ₁ ) from the axial direction, and the second operating shaft (5b) presses the first operating shaft (5a). When the (5e) is in a sliding position where it is located at a set distance from the second pressing plate (5d), the protrusion (6b) is positioned substantially linearly and is smaller than the minimum inner diameter of the branch pipe (B). Inner link (6c)
A plurality of these are interposed at intervals in the circumferential direction.

In other words, the fixator (6A) is by engagement of the large-diameter portion of the link manhole lid of projections formed in (6c) (6b) (B 1),
The water stop (5) is prevented by the water pressure that prevents the water stop (5) from moving toward the water stop edge (2) and that acts on the water stop (5).
Of the water stop (5) so that the obturator (5B) is located in the small-diameter pipe part (3) of the human hole lid (B ₁ ) by blocking the movement of the water stop to the water main (A) side. It is fixed to.

The operation tool (6B) for the fixing device (6A) is also used as the second operation shaft (5b).

Further, the branch pipe blocking device is the second one of the operation shafts (5A).
A nut (7) for pinching operation, which is screwed onto the outer end side of the operation shaft (5b) and presses the outer end of the first operation shaft (5a) toward the inner end side,
A first retainer fitting (8) removably fitted near the outer end of the first operation shaft (5a) and a second retainer fitting detachably capped on the outer end of the second operation shaft (5b). (9) and.

The first retainer fitting (8) has a first hook (8a) attached thereto engaged with a protrusion (4a) formed on the lid body (4) when mounted on the first operating shaft (5a). This prevents the first operation shaft (5a) from moving outward with respect to the lid body (4), and the means for fixing the first pressing metal fitting (8) to the first operation shaft (5a) is , A means for engaging the set bolt (11) with the circumferential groove (10) formed in the first operation shaft (5a).

The second holding metal fitting (9) is operated by a second hook (8b) attached to the first holding metal fitting (8) in a state of being attached to the second operation shaft (5b), whereby a second operation is performed. Axis (5
It is intended to prevent the sliding of b) to the first operation shaft (5a) to the outside.

In addition, the outer end portion of the second operation shaft (5b) of the operation shaft (5A) is formed as a different diameter portion (12) for preventing the second operation shaft (5b) from rotating. , The pinching operation nut (7) is provided in the outer shape of the first operating shaft (5a) so as to allow the water stop (5) to be pulled out from the lid (4) to the inner end side. It is formed to fit. Further, the lid body (4) is formed with a water stop confirmation port (14) which is opened and closed by the stopper (13) and releases water in the lid body (4) in the opened state.

Next, the anti-branch pipe working method according to the first aspect of the present invention will be described step by step, taking as an example the replacement work of the water shutoff valve (2) using the above branch pipe blocking device.

<1> Close the water shutoff valve (2) to shut off the branch pipe (B).

<2> As shown in FIG. 1 (b), removing the air valve, which is an example of a terminal device (1) for each short pipe (B _3), from Tomesuiben (2).

<3> As shown in FIG. 1 (b), the lid (4) holding the water stop (5) is attached to the water stop valve (2), and the branch pipe (B) is attached.
Close the end opening of the. In this case, the water stop (5) has the first operation shaft (5a) of the second operation shaft (5b) previously attached to the first and second retainer fittings (8) and (9) and the second hook (8b).
The slide (6) is in a reduced diameter state in which the outward sliding is blocked.

<4> Open the water shutoff valve (2).

<5-a> As shown in Fig. 1 (c), by pressing the first operating shaft (5a) of the operating shafts (5A), the obturator (5B) and the fixing device (6A) Is moved to the inside of the human hole lid (B ₁ ) upstream of the water shutoff valve (2) and held at that position by the first hook (8a).

<5-b> As shown in FIG. 1 (d), the second hook (8
While removing b) from the second holding metal fitting (9),
By removing the holding metal fitting (9) from the second operation shaft (5b) and pulling the water pressure and the second operation shaft (5b), the link (6c) of the fixator (6A) is bent.

<5-C> As shown in FIG. 1 (E), the first hook (8
a) is removed and the first operation shaft (5a) is pulled up, and the water stop (5) is moved to the outside, so that the obturator (5B) of the water stop (5B) is moved to the small diameter pipe part of the human hole lid (B ₁ ). (3) At the same time, the protrusion (6b) of the bent link (6c) is engaged with the inlet hole lid (B ₁ ) to fix the water stop (5).

<6> As shown in FIG. 1 (f), the nut (7) for pinching operation is screwed with the second operating shaft (5b) stopped to rotate, and the first pressing plate (5c) ) Is pressed against the side of the second pressing plate (5d) to squeeze it to elastically deform the elastic ring-shaped body (5f) into a diameter-expanded state, press it into close contact with the inner peripheral wall of the branch port, and stop water. After that, the stopper (13) is opened, water is discharged from the water stop confirmation port (14), the water stop is confirmed to stop the water stop, and the first holding metal fitting (8) is removed.

<7> As shown in FIG. 1 (g), the connection of the water shutoff valve (2) to the human hole lid (B ₁ ) is released, and the lid body (4) and the water shutoff device (5) move outward. Pull out to the side.

The above is the removal work of the water shutoff valve (2) in the first half of the anti-branch work, and the water shutoff valve (2) in the second half of the anti-branch work.
The installation work after replacing the above is the reverse of the above operation. That is, <8> attach a new water shutoff valve (2) to the lid (4), attach it to the water shutoff device (5), and connect the water shutoff valve (2) to the inlet lid (B ₁ ), Attach the first retainer fitting (8) to the operation shaft (5A) of the water stop (5). The state where this process is completed is
This is the same as the state shown in the first (f).

<9-a> The internal pressure of the branch pipe (B) downstream of the obturator (5B) is made substantially equal to the internal pressure of the branch pipe (B) upstream of the obturator (5B). Specifically, in this process, the nut (7) for pinching operation is slightly loosened and the pair of pressing plates (5)
c), (5d) the clamping force against the elastic ring-shaped body (5f) to a predetermined value or less, the elastic ring-shaped body (5f) through the notch (5x) formed in the elastic ring-shaped body (5f) A fluid is passed from the upstream side to the downstream side of the elastic ring-shaped body (5)
It is carried out by filling the inside of the branch pipe (B) on the downstream side with the fluid. By performing this step, there is almost no difference in internal pressure between the branch pipes (B) on both sides of the obturator (5B), and the first pressing plate (5c) against the elastic ring-shaped body (5f) due to the pressure difference. ) And the pushing force to the inner peripheral wall side of the branch pipe (B) is almost eliminated, so that the branch pipe (B) can be simply operated by loosening the clamping pressure on the elastic ring-shaped body (5f) in the next step <9-B>. ) Will be able to release the blockage smoothly.

<9-B> This is carried out simultaneously with the step <9-A>, but the nut (7) for pinching operation is further loosened and its thickness direction relative to the elastic ring-shaped body (5f). Release the clamping pressure on. The state in which this step is completed is the same as the state shown in FIG.

<10-a> Push down the first operating shaft (5a) to stop the water stop (5).
By moving inwardly, the bent link (6
The protrusion (6b) of c) is disengaged from the human-hole lid (B ₁ ) and the obturator (5B) is pulled out from the small-diameter pipe portion (3) of the human-hole lid (B ₁ ). Hook (8a) and lid (4)
It is engaged with the projection (4a) formed on the. The state in which this step is completed is the same as the state shown in FIG.

<10-B> By depressing the second operation shaft (5b), the link (6c) of the fixator (6A) is extended, and the second holding metal fitting (9) is attached to the second operation shaft (5b). The second hook (8b) is engaged with the second retainer fitting (9). The state in which this step is completed is the same as the state shown in FIG.

<10-C> Remove the first hook (8a), and then the first operating shaft (5a)
Is pulled up and the obturator (5B) and the fixture (6A) are moved until they are housed in the lid (4) downstream of the water shutoff valve (2).

<11> After shutting off the branch pipe (B) by the water shutoff valve (2) (this state is the same as the state shown in FIG. 1B), the water shutoff valve (2) of the lid (4) ), And remove the lid (4) together with the water stop (5). The state in which this step is completed is the same as the state shown in FIG.

<12> air valve is a terminal device (1) short pipe fitted with a (B ₃₎ is connected to a water stop valve (2), opens the Tomesuiben (2). The state in which this step is completed is the same as the state shown in FIG. At this time, the air valve (1) may be the same as it is, or may be a maintenance-completed one or a new one.

This completes the replacement work of the water shutoff valve (2), which is an example of the work of the branch pipe.

[Another embodiment]

In the following, another embodiment of the present invention will be listed separately for the branch pipe blocking device and the branch pipe working method.

In <A> branch Saegi閉device <A-1> above embodiment, as a fixed unit (6A), showed that the position is fixed by engagement of the manhole cover of the link (6c) (B ₁₎ , Its engagement structure can be changed as appropriate,
Further, the fixing device (6A) may be a device for fixing the position of the branch pipe (B) by tension or friction on the inner peripheral surface thereof.

<A-2> In the above embodiment, the operation tool (6
Although the second operation shaft (5b) of the operation shaft (5A) is also used as B), the operation tool (6B) may be one that penetrates through the second operation shaft (5b).

<A-3> In the above embodiment, the position of the obturator (5B) is fixed by the fixing device (6A), but the fixing device (6A) may be omitted.

<A-4> In the above embodiment, the flow path (F) is formed by the notch (5x) of the elastic ring-shaped body (5f) when the clamping pressure on the elastic ring-shaped body (5f) is not more than a predetermined value. Although the specific configuration for forming the flow path (F) can be changed as appropriate, several examples will be listed below.

<A-4-1> As shown in FIG. 6, the notch (5x) of the elastic ring-shaped body (5f) is connected to the notch (5x) of the elastic ring-shaped body (5f) by the branch pipe (B). It is formed in a portion that abuts the inner peripheral wall of the.

<A-4-2> As shown in FIG. 7, the notch (5x) of the elastic ring-shaped body (5f) is inserted into the branch pipe (B) from the portion in contact with the first pressing plate (5c). It is formed over the portion that abuts the peripheral wall.

<A-4-3> As shown in FIG. 8, the notch (5x) of the elastic ring-shaped body (5f) is formed over the entire circumference in cross section.

<A-4-4> As shown in FIG. 9, a small hole (5xx) communicating with the upper and lower sides of the elastic ring-shaped body (5f) is formed.

<A-4-5> As shown in FIG. 10, the first pressing plate (5
The groove (5y) is formed in c), and when the clamping pressure on the elastic ring-shaped body (5f) is less than or equal to a predetermined value, the elastic ring-shaped body (5f) comes out of the groove (5y), and thus the groove (5y). ), The flow path (F) is formed.

<A-4-6> Notch for forming the flow path (F) (5
The number of x), small holes (5xx) or grooves (5y) is arbitrary, and the shape thereof can be appropriately changed.

<A-5> In the above embodiment, the water shutoff valve (2) provided in the branch pipe (B) for water supply is applied to the water shutoff for replacement.
The branch pipe shielding device according to the second aspect of the present invention is a branch pipe (B) for various fluids.
It can be applied not only to shut off the valve (2) inserted in the valve but also to form the branch pipe (B) inside.

<B> Working method for branch pipe <B-1> In the above-described embodiment, when the clamping pressure of the obturator (5B) against the elastic ring-shaped body (5f) becomes a predetermined value or less, the fluid is released and the fluid flows into the elastic ring. Although it has been shown that the internal pressure of the branch pipe (B) between the upstream side and the downstream side of the obturator (5B) can be made substantially equal by passing it from the upstream side to the downstream side of the body (5f). In order to realize the process of 9-a>, instead, the obturator (5B) having various configurations of <A-4> described above is used, or as shown in FIG. A small hole (5
z) is formed and the clamping force against the elastic ring-shaped body (5f) becomes a predetermined value or less, so that an obturator (5B) configured to allow fluid to pass through this small hole (5z) is used. Good.

<B-2> Further, in place of the method described in the above embodiment or the above <B-1>, although not shown, a bypass flow passage that passes through the upstream side and the downstream side of the obturator (5B) is provided. A cock that is provided separately from the branch pipe (B) and that opens and closes the bypass flow path is provided, and when the obstruction of the branch pipe (B) by the obturator (5B) is released, the cock is opened to open the obturator (5B). By passing the fluid from the upstream side to the downstream side, the internal pressures of these two portions may be made substantially equal.

<B-3> Furthermore, the same fluid as the fluid transported in the main pipe (A) inside the branch pipe (B) on the downstream side of the obturator (5B), or air that does not cause any trouble even if mixed with it Provided with a fluid press-fitting device for press-fitting another fluid, and the obturator (5B)
When the blockage of the branch pipe (B) is released by the operation of the fluid pressure device, the internal pressure of the branch pipe (B) on the downstream side of the obturator (5B) is increased on the upstream side of the obturator (5B). The internal pressure of the branch pipe (B) may be made substantially equal. In addition, the operation of the fluid press-fitting device may be configured to be performed manually, or may be configured to be automatically performed in association with a decrease in the clamping pressure on the elastic ring-shaped body (5f). Good.

<B-4> A step of making the internal pressure of the branch pipe (B) upstream of the obturator (5B) substantially equal to the internal pressure of the branch pipe (B) upstream of the obturator (5B), and elasticity. The step of releasing the pressing force in the thickness direction of the ring-shaped body (5f) may be performed simultaneously as described in the previous embodiment, or either one of them may be sequentially performed first. You may go to

<B-5> The specific configuration of the branch pipe blocking device used in this method can be appropriately changed, and the above-mentioned <A-1> to <A-3> can be changed. Only one of the pair of pressing plates (5c) and (5d) may be movable.

<B-6> In addition to the air valve (1) described in the previous embodiment, the terminal device may be a fire hydrant or the like and can be appropriately changed.

<B-7> As the branch pipe work performed by this method, in addition to the replacement work of the sluice valve (2) described in the previous embodiment, the maintenance work of the sluice valve (2) and the sluice valve (2).
In addition to the above, there is a work of inserting another device in the branch pipe (B).

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

1 to 5 show an embodiment of an anti-branch pipe working method and a branch pipe blocking device according to the present invention, and FIGS. 1 (a) to (g) are sectional views showing working steps, and FIG. Is a vertical cross-sectional view of the branch pipe blocking device, FIG. 3 is a cross-sectional view of the target pipe, FIG. 4 is an enlarged cross-sectional view of an essential part, and FIG. 5 is a plan view of an elastic ring-shaped body. 6 to 10 are cross-sectional views of main parts showing another embodiment of the branch pipe blocking device, and FIG. 11 is a cross-section of main parts of the branch pipe blocking device showing another embodiment of the working method for branch pipes. It is a figure. (A) …… Main pipe, (B) …… Branch pipe, (1) …… Terminal device, (2) …… Silver valve, (4) …… Lid body, (5A) …… Operating shaft, (5B ) Obturator, (5a) ... 1st operation axis, (5b) ...
… Second operation axis, (5c), (5d) …… Pressing plate, (5f) ……
Elastic ring-shaped body, (F) ... Flow path.

Claims (2)

[Claims] <1> The branch pipe (B) is shut off by a sluice valve (2) interposed in the middle of a branch pipe (B) branched and connected to a main pipe (A) for fluid transportation. <2> removing the terminal device (1) attached to the end of the branch pipe (B), <3> attaching a lid (4) to the end of the branch pipe (B), and Step of closing an end opening of the branch pipe (B), <4> Step of opening the sluice valve (2), <5> Penetration of the lid body (4) in an axially slidable manner in a sealed state. Sliding operation of the operating axis (5A)
The occluder (5B) provided on the inner end side of (A) is connected to the sluice valve (2).
The step of moving to the upstream side portion, <6> the pair of pressing plates (5c), (5d) of the obturator (5B) attached to the inner end side of the operation shaft (5A) in the axial direction Pressing plates (5c), (5d) by moving close to each other
The branch pipe (B) is closed by pinching the elastic ring-shaped body (5f) interposed between the branch pipes (5f) from the axial direction and elastically deforming it into a diameter-expanded state in which it is in close contact with the inner peripheral wall of the branch pipe (B). <7> Removing the sluice valve (2), <8> Performing maintenance work or attaching a new sluice valve (2), <9> Elastic ring by the pressing plates (5c), (5d) Releasing the pinching pressure on the body (5f) to release the obstruction of the branch pipe (B) by the obturator (5B), <10> accommodating the obturator (5B) in the lid (4) Moving to a predetermined temperature, <11> shutting off the branch pipe (B) by the sluice valve (2), and then removing the lid body (4), <12> mounting the terminal device (1) And a step of opening the sluice valve (2), wherein the step of <9> comprises: 9 b> said obturator downstream branch pipe than (5B) (B)
To make the internal pressure of the pressure equal to the internal pressure of the branch pipe (B) upstream of the obturator (B), and <9-b> the elastic ring formed by the pressing plates (5c) and (5d). The method of working a pair of branch pipes, which comprises the step of releasing the pinching pressure on the sheet (5f). 2. A branch connection to a main pipe (A) for fluid transportation,
A branch pipe (B) having a sluice valve (2) interposed in the middle thereof
A lid body (4) which can be attached to the downstream end portion of the sluice valve (2) or the end portion of a pipe portion connected to the sluice valve (2) so as to close the end opening of the gate valve, and the lid body (4) in a sealed state. A cylindrical first operating shaft (5a) penetrating slidably in the axial direction, and the first
Second operation shaft (5b) that slidably penetrates through the operation shaft (5a)
And a separate pressing plate (5c), (5d) is attached to the inner end sides of the first operating shaft (5a) and the second operating shaft (5b), and the pair of pressing plates (5c), Between (5d), the pair of pressing plates (5c) and (5d) pinch pressure from the axial direction elastically deforms the inner diameter of the branch pipe (B) into a diameter-expanded state in which it is in close contact with the inner peripheral wall of the branch pipe (B). The peripheral wall and the pair of pressing plates (5
c), a branch pipe blocking device having an elastic ring-shaped body (5f) for blocking between the outer periphery of (5d), the pair of pressing plates (5c), (5d) On the downstream side of the branch pipe or on the contact portion between the inner peripheral wall of the branch pipe (B) and the elastic ring body (5f), the pair of pressing plates (5c), (5d)
When the clamping pressure on the elastic ring-shaped body (5f) due to
(F) that opens to allow passage from the upstream side to the downstream side of the
A branch pipe blocking device that is formed.