Flow control device and installation method therefor

Abstract

The present invention provides: a flow control device that can maintain the structural strength of a fluid pipe to be installed over a long period of time; and an installation method therefor.　A flow control device 1 comprises: a protective pipe 20 which is installed in an uninterrupted flow state on an existing fluid pipe 2 constituting a pipeline and which is externally fitted around the outer circumferential surface of the fluid pipe 2 in a sealed state; an enclosure 3 externally fitted around at least a part of the protective pipe 20 in a sealed state; a rubber ring 26 serving as a sealing material interposed around the entire circumference at a specific section TP farther to the outside than cut end faces 35, 35 of the fluid pipe 2 between the circumferential surfaces of the fluid pipe 2 and the protective pipe 20; and a filler 24 filling a space S formed between the circumferential surfaces of the fluid pipe 2 and the protective pipe 20, excluding the specific section TP.

Description

Flow control device and its installation method

[0007] ,

[0001] The present invention relates to a flow control device installed in a fluid pipe constituting a pipeline in a non-stop flow state and an installation method thereof.

[0002] Conventionally, when installing a flow control device on a fluid pipe, in the case where the fluid pipe to be installed is a fragile pipe with poor structural strength, a protective pipe is externally fitted to this fluid pipe in a sealed manner, and a filler is filled between the peripheral surfaces of the fluid pipe and the protective pipe. Thus, after reinforcing the structure of this fluid pipe, there is a method of cutting the pipe wall within a housing surrounding the pipe (see, for example, Patent Document 1).

[0003] Japanese Patent Laid-Open No. 8-145266 (page 3, Figure 4)

[0004] However, in Patent Document 1, since the filler between the peripheral surfaces of the fluid pipe and the protective pipe is not always sufficient, a part of the in-pipe fluid filling the housing due to the cutting of the fluid pipe enters between the peripheral surfaces of the protective pipe and the fluid pipe in the pipe axis direction and stays for a long time. Thus, there is a problem that corrosion and aging deterioration of this fluid pipe may be accelerated.

[0005] The present invention has been made paying attention to such problems, and an object thereof is to provide a flow control device and an installation method thereof that can maintain the structural strength of a fluid pipe to be installed over a long period.

[0006] In order to solve the above problems, the flow control device of the present invention is a flow control device installed in a fluid pipe constituting a pipeline in a non-stop flow state, including a protective pipe externally fitted to the outer peripheral surface of the fluid pipe in a sealed manner, a housing externally fitted to at least a part of the protective pipe in a sealed manner, a sealing material interposed over the entire circumference at a specific location outside the cutting location of the fluid pipe between the peripheral surfaces of the fluid pipe and the protective pipe, and a filler filled between the peripheral surfaces of the fluid pipe and the protective pipe excluding the specific location. According to this feature, since the in-pipe fluid filling the housing due to the cutting of the fluid pipe is sealed by the sealing material between the peripheral surfaces of the fluid pipe and the protective pipe, it does not enter the peripheral surface between the pipes in the pipe axis direction beyond this sealing material, and the structural strength of the fluid pipe reinforced by the protective pipe can be maintained over a long period.

[0007] The protective tube is characterized by being composed of multiple segmented tubes whose ends can be connected to each other in a sealed manner in the axial direction of the tube. This feature makes it easy to interpose a sealing material between the circumferential surfaces of the protective tube and the fluid tube by designating the vicinity of the ends of the segmented tubes as specific locations for the sealing material.

[0008] The aforementioned specific location of the sealing material is characterized in that it is near the cut location. This feature allows the fluid inside the pipe to be sealed by the sealing material near the cut surface of the fluid pipe, thereby increasing the length of the fluid pipe reinforced by the protective pipe.

[0009] The aforementioned specific location of the sealing material is located inside the housing. This feature prevents fluid from entering the space between the fluid tube and the protective tube at the housing mounting location, thus ensuring long-term stability of the housing mounting structure.

[0010] To solve the aforementioned problems, the present invention provides a method for installing a flow control device in a fluid pipe constituting a pipeline in a continuous flow state, comprising: a protective pipe installation step of fitting a protective pipe in a sealed manner onto the outer surface of the fluid pipe and interposing a sealing material around the entire circumference at a specific location outside the planned cutting location of the fluid pipe between the circumferential surfaces of the fluid pipe and the protective pipe; a filling step of filling the space between the circumferential surfaces of the fluid pipe and the protective pipe, excluding the specific location, with a filler material; a housing installation step of fitting a housing in a sealed manner onto at least a part of the protective pipe; and a cutting step of cutting the fluid pipe together with the protective pipe inside the housing. According to this feature, the fluid inside the pipe that fills the housing after the fluid pipe is cut is sealed by the sealing material between the circumferential surfaces of the fluid pipe and the protective pipe, so that it does not penetrate beyond the sealing material in the axial direction between the circumferential surfaces, and the structural strength of the fluid pipe reinforced by the protective pipe can be maintained for a long period of time.

[0011] The protective tube installation process is characterized by the steps of fitting a first divided pipe constituting the protective tube onto the fluid pipe in a sealed manner, interposing the sealing material near the end of the first divided pipe (designated as the specified location), and then sealingly connecting a second divided pipe constituting the protective tube to the end of the first divided pipe. This feature makes it easier to interpose the sealing material between the circumferential surfaces of the protective tube and the fluid pipe by designating the area near the end of the divided pipe as the specified location for the sealing material.

[0012] (a) is a front view showing the state in which the connection part of an existing fluid pipe is supported by a suspension support in an embodiment of the present invention, and (b) is a front view showing the state in which the suspension support that supports the downstream connection part has been changed to a pipe support jack. (a) is a partially broken front view showing the state in which the downstream connection part of the fluid pipe is surrounded by a divided pipe, and (b) is a partially broken front view showing the state in which the upstream connection part is surrounded by a divided pipe. This is a partially broken enlarged front view showing the state in which the downstream connection part of the fluid pipe is surrounded by a divided pipe. (a) is a partially broken front view showing the state in which the divided pipes on the upstream and downstream sides of the fluid pipe are supported from below by pipe support jacks, and (b) is a partially broken front view showing the state in which the space between the upstream and downstream connection parts is surrounded by a divided pipe. This is a partially broken enlarged front view showing the state in which the space between the upstream and downstream connection parts of the fluid pipe is surrounded by a divided pipe. This is a partially cutaway front view showing the housing attached to the divided pipe. This is a partially cutaway front view showing the fluid pipe being cut by connecting the work valve device and the drilling device to the top of the housing. This is an enlarged cross-sectional view of the main part showing the fluid pipe after it has been cut. This is a partially cutaway front view showing the plug being installed by connecting the insertion device to the top of the housing. (a) is a plan view showing the plug installed inside the housing, and (b) is a partially cutaway front view.

[0013] The embodiments for implementing the flow control device and installation method according to the present invention will be described below based on examples.

[0014] A flow control device and its installation method according to an embodiment of the present invention will be described with reference to Figures 1 to 10. In the following description, the front side of Figure 1 is the front of the fluid pipe, the back side is the rear, the left side is the left direction, and the right side is the right direction, with the left side being the upstream side of the flow path and the right side being the downstream side of the flow path.

[0015] As shown in Figure 1, the existing fluid pipe 2 in this embodiment is constructed by connecting multiple pipe bodies made of PC pipes (core-type prestressed concrete pipes) in the axial direction to form a flow path (pipeline). A receiving portion 2a is formed at one end of each pipe body, and an insertion portion 2b is formed at the other end. An annular sealing material (not shown) is provided between the inner circumferential surface of the receiving portion 2a of one of the pipe bodies being connected and the outer circumferential surface of the insertion portion 2b of the other pipe body which is inserted into the receiving portion 2a, thereby sealing the receiving portion 2a and the insertion portion 2b and forming the connection portions CN1 and CN2.

[0016] When installing a flow control device 1 (see Figure 10) or the like, which is a pipeline component forming a pipeline, at a predetermined location in such a fluid pipe 2, it is necessary to cut the pipe wall of the fluid pipe 2 as will be described later. However, if each PC pipe (core-type prestressed concrete pipe) has weakened due to deterioration over time or other reasons, there is a risk that the fluid pipe 2 may be damaged and leak when the existing fluid pipe 2 is cut in a continuous flow state. Therefore, in this embodiment, as shown in Figures 6 and 7, a protective pipe 20, which will be described later, is fitted onto the existing fluid pipe 2 in a sealed manner, and a filler material 24 is filled between the circumferential surfaces of the fluid pipe 2 and the protective pipe 20 to reinforce the structure of the fluid pipe 2. Then, a predetermined location of the protective pipe 20 is surrounded by a housing 3, and the pipe wall is cut inside the housing 3. The flow control device 1 and its installation method will be described below.

[0017] In this embodiment, the fluid in the fluid pipe 2 is tap water, but it may also be industrial water, agricultural water, sewage, or other liquids, or even gas or a gas-liquid mixture. Furthermore, the fluid pipe 2 is a PC pipe (core-type prestressed concrete pipe) and is formed as a straight pipe with a roughly circular cross-section, but the fluid pipe according to the present invention may also be a centrifugal reinforced concrete pipe (so-called Hume pipe), or made of metal such as cast iron, ductile cast iron, or steel, or made of polyvinyl chloride, polyethylene, or polyolefin. In addition, the inner circumferential surface of the fluid pipe may be covered with an epoxy resin layer, mortar, plating, or a suitable material may be applied to the inner circumferential surface of the fluid pipe by powder coating.

[0018] [Method for installing the flow control device] As shown in Figure 1(a), the installation location of the flow control device 1 is identified in the substantially straight flow path consisting of the existing fluid pipe 2 buried underground, and an excavation hole 9 is formed by excavating an opening so that the identified installation location is exposed. The depth dimension of the excavation hole 9 from the ground GL to the bottom 9a is set to such an extent that a space is formed between the existing fluid pipe 2 and the bottom 9a. In this embodiment, the installation location of the flow control device 1 is the position approximately in the center of the pipe axis direction of the straight pipe section between the connection parts CN1 and CN2 of the existing fluid pipe 2 exposed by the opening excavation, so this installation location is designated as the cutting location P.

[0019] Furthermore, during the excavation of the opening, a support column 10 is placed across the opening of the excavation hole 9 in the left-right direction, and a suspension support 11 suspended from the support column 10 supports the vicinity of both sides in the axial direction of the pipes of each connection part CN1 and CN2. This protects the connection parts CN1 and CN2 from bending due to the weight of the pipe body exposed by excavation, preventing the insertion part 2b from detaching from the receiving part 2a. In addition, the outer surface of the fluid pipe 2 is cleaned to check for damage such as peeling, and repairs are made as necessary.

[0020] Next, as shown in Figure 1(b), both sides of one connection portion CN2 in the direction of the pipe axis are supported from below by pipe support jacks 12, 12 installed at the bottom 9a, and the fluid pipe 2 is supported by changing from the suspension support 11 to the pipe support jacks 12, or by using both the suspension support 11 and the pipe support jacks 12 in combination as needed.

[0021] Next, as shown in Figure 2(a), a divided pipe 20B, which constitutes part of the protective pipe 20, is fitted onto the outer surface of the connection portion CN2 of the fluid pipe 2 in a sealed manner. At the same time, a round rubber 26 (see Figure 3) is interposed around the entire circumference of a specific location TP (see Figure 5) near the planned cutting location P of the fluid pipe 2, that is, downstream of the planned cutting location P, between the circumferential surfaces of the fluid pipe 2 and the divided pipe 20B (protective pipe installation step).

[0022] The protective tube 20 is made of steel and, as shown in Figure 4(b), is constructed by integrating a divided tube 20A that surrounds the upstream connection point CN1 on the outer surface of the fluid tube 2, a divided tube 20B that surrounds the downstream connection point CN2, and a divided tube 20C that surrounds the space between connection points CN1 and CN2. Since the divided tubes 20A and 20B are arranged symmetrically and have the same configuration, the following description will focus on the divided tube 20B, and the description of the divided tube 20A will be omitted.

[0023] As shown in Figure 3, the divided pipe 20B is mainly composed of a first cylindrical portion 21 consisting of a large-diameter portion 21a surrounding the outer circumferential surface of the connection portion CN2 of the fluid pipe 2 and a small-diameter portion 21b surrounding the vicinity of the upstream side of the connection portion CN2, and a second cylindrical portion 22 surrounding the vicinity of the downstream side of the connection portion CN2.

[0024] The first cylindrical portion 21 is composed of a two-part split structure and has semi-cylindrical split members 21c and 21d in side view. The inner diameters of the large-diameter portion 21a and the small-diameter portion 21b are larger than the outer diameter of the fluid pipe 2, so that when attached to the fluid pipe 2, a space S is formed between the outer surface of the fluid pipe 2 and the inner surface of the first cylindrical portion 21. In addition, cylindrical inlets 23, 23 are formed at two locations in the direction of the pipe axis on the top of one of the split members 21c. There may be three or more inlets 23, or there may be one, but it is preferable to have multiple inlets 23 and use one of them for air venting. Furthermore, an arc-shaped guide portion 25 made of steel with a circular cross-section is fixed to the upstream side of the inner surface of each split member 21c and 21d in the circumferential direction.

[0025] The second cylindrical portion 22 is composed of a two-part split structure and has semi-cylindrical split members 22a and 22b (split member 22b is not shown) in side view. The inner diameter of the second cylindrical portion 22 is larger than the outer diameter of the fluid pipe 2, so that when attached to the fluid pipe 2, a space S is formed between the outer surface of the fluid pipe 2 and the inner surface of the second cylindrical portion 22. Flanges 22c and 22d that protrude in the outer diameter direction are provided at both ends of the second cylindrical portion 22 in the direction of the pipe axis. In addition, arc-shaped guide portions 29 that protrude in the inner diameter direction are extended in the circumferential direction from the downstream side of the inner surface of each split member 22a and 22b.

[0026] To install the divided pipe 20B at the connection portion CN2 on the outer surface of the fluid pipe 2, the divided members 21c and 21d of the first cylindrical portion 21 are positioned at the front and rear of the fluid pipe 2 such that their respective divided surfaces are inclined approximately 45 degrees circumferentially from the upper and lower positions of the fluid pipe 2. The divided members 21c and 21d are fastened together with bolts and nuts N1, and their respective divided surfaces are sealed and integrated by welding. Similarly, the divided members 22a and 22b of the second cylindrical portion 22 are positioned at the front and rear of the fluid pipe 2 such that their respective divided surfaces are located above and below the fluid pipe 2. The divided members 22a and 22b are fastened together with bolts and nuts N2, and their respective divided surfaces are sealed and integrated by welding. Then, as shown in Figure 3, the flange 22c of the second cylindrical portion 22 is brought into contact with the downstream end face of the first cylindrical portion 21 and joined in the axial direction of the pipe by welding W, thereby integrating the first cylindrical portion 21 and the second cylindrical portion 22.

[0027] Next, a round rubber 26, serving as a sealing material, is arranged in a ring shape on the outer circumferential surface of the fluid tube 2 upstream of the first cylindrical portion 21, and inserted into the annular space S formed between the outer circumferential surface of the fluid tube 2 and the inner circumferential surface of the first cylindrical portion 21. Then, the round rubber 26 is pushed towards the upstream end of the first cylindrical portion 21 and pressed in a sealed manner until it contacts the guide portion 25 in the annular space S formed between the outer circumferential surface of the fluid tube 2 and the inner circumferential surface of the first cylindrical portion 21. Furthermore, to prevent the round rubber 26 from being pushed out by the filler 24 when the filler 24 is injected (described later), putty 27 is applied to the upstream side of the round rubber 26 to seal the opening at the upstream end of the first cylindrical portion 21.

[0028] Furthermore, a round rubber 28 is arranged in a ring on the outer circumferential surface of the fluid pipe 2 downstream of the second cylindrical portion 22, and positioned towards the downstream end of the second cylindrical portion 22. Next, a split compression ring 30 is arranged in a ring downstream of the round rubber 28, and then the flange 22d of the second cylindrical portion 22 and the compression ring 30 are connected with a bolt and nut N3. By tightening the bolt and nut N3, the round rubber 28 is pressed towards the guide portion 29 in the annular space S formed between the outer circumferential surface of the fluid pipe 2 and the inner circumferential surface of the second cylindrical portion 22, thereby sealing the opening at the downstream end of the second cylindrical portion 22.

[0029] In this manner, the first cylindrical portion 21 and the second cylindrical portion 22 are integrated into a divided pipe 20B, and round rubbers 26 and 28 are inserted into both ends in the pipe axis direction of the divided pipe 20B. As a result, the divided pipe 20B is positioned concentrically with the fluid pipe 2, and the outer surface of the connection portion CN2 and its vicinity are sealed and surrounded by the divided pipe 20B, forming a space S between the outer surface of the fluid pipe 2 and the inner surface of the divided pipe 20B.

[0030] Next, a filler 24 made of epoxy resin is injected from one of the inlet ports 23, 23 of the first cylindrical portion 21 into the space S between the circumferential surfaces of the divided pipe 20B and the fluid pipe 2 (filling step). As described above, by using the remaining inlet port 23 for air venting, the space S can be filled with the filler 24 with almost no voids remaining. Once the space S is filled, the inlet ports 23, 23 are plugged. After curing, as the filler 24 hardens, the divided pipe 20B is integrally attached to the outer surface of the fluid pipe 2 via the filler 24, reinforcing the fragile existing fluid pipe 2. The plugging of the inlet ports 23, 23 may be done after hardening.

[0031] Furthermore, as shown in Figure 2(b), the upstream connection portion CN1 of the fluid pipe 2 is also reinforced in the same way as the downstream connection portion CN2, by installing a divided pipe 20A on the outer surface of the connection portion CN1 and injecting a filler material 24 into the space S and allowing it to harden.

[0032] After the injected filler 24 has hardened, as shown in Figure 4(a), the support jack 12 is placed below the divided pipes 20A and 20B to support each divided pipe 20A and 20B from below, thereby allowing the support column 10 and suspension support 11 to be removed. Next, as shown in Figure 4(b), the divided pipe 20C is installed in the straight section between the divided pipes 20A and 20B, including the planned cutting location P on the outer surface of the fluid pipe 2. By installing the divided pipes 20A and 20B at the connection points CN1 and CN2, the round rubber 26, 26, which serve as sealing material, are placed at specific locations TP, TP (see Figure 5) near both sides of the planned cutting location P in the pipe axis direction.

[0033] As shown in Figure 5, the divided pipe 20C is mainly composed of a cylindrical tubular portion 41 and connecting tubular portions 42, 42 fixed to both sides of the tubular portion 41 in the direction of the pipe axis and extending in the direction of the pipe axis. The divided pipe 20C is made of a cylindrical member composed of a two-part divided structure and has semi-cylindrical divided members 43a, 43b when viewed from the side. The inner diameter of the divided pipe 20C is larger than the outer diameter of the fluid pipe 2, so that when it is attached to the fluid pipe 2, a space S is formed between the outer surface of the fluid pipe 2 and the inner surface of the divided pipe 20C. In addition, circular inlets 45, 45 are formed at two locations in the direction of the pipe axis on the top of one of the divided members 43a downstream from the center position in the direction of the pipe axis. There may be three or more inlets 45, or there may be one, but it is preferable to have multiple inlets 45 and use some of them for air venting.

[0034] Furthermore, the wall thickness of the cylindrical portion 41 is smaller than that of the divided pipes 20A and 20B, making it easier to cut in the cutting process described later. Also, the wall thickness of the connecting cylindrical portion 42 is slightly larger than that of the divided pipes 20A and 20B. The length of the divided pipe 20C in the axial direction is longer than the length from the downstream end of the divided pipe 20A to the upstream end of the divided pipe 20B.

[0035] To install such divided pipes 20C on the outer surface of the fluid pipe 2, the dividing members 43a and 43b are positioned in front of and behind the fluid pipe 2 such that their respective dividing surfaces are inclined at approximately 25 degrees circumferentially from the vertical position of the fluid pipe 2. Next, the connecting cylindrical portions 42, 42 at both ends are overlapped so as to cover the outer surface of the end portions of the first cylindrical portions 21, 21 of the divided pipes 20A and 20B, respectively, and the dividing members 43a and 43b are fastened together with bolts and nuts N5, and the respective dividing surfaces are sealed and integrated by welding. Then, the inner surfaces of the connecting cylindrical portions 42, 42 are brought into contact with the outer surface of the end portions of the first cylindrical portions 21, 21 of the divided pipes 20A and 20B, respectively, and joined by welding W. In this way, a cylindrical protective pipe 20 is formed by the divided pipes 20A, 20B, and 20C that are connected and integrated in the direction of the pipe axis.

[0036] Next, a filler 24 made of epoxy resin or the like is injected into the space S between the circumferential surface of the divided pipe 20C and the fluid pipe 2 through one of the injection ports 45, 45 formed in the divided member 43a. Once the space S is filled, the injection port 45, 45 is plugged (filling step). Plugging may be done after hardening. Furthermore, round rubber 26, 26 are sealed at specific locations TP, TP on both sides in the axial direction of the planned cutting location P near the center in the axial direction of the divided pipe 20C, so that the space S can be filled with the filler 24 without leakage and with almost no voids remaining. In addition, as described above, the remaining injection port 45 can be used for air venting. Once the filler 24 that has filled the space S hardens, the divided pipe 20C is integrally attached to the outer surface of the fluid pipe 2 via the filler 24, reinforcing the fragile existing fluid pipe 2.

[0037] Next, the housing 3 constituting the flow control device 1 (see Figure 10) is installed centered on the cutting point P, which is approximately the center of the divided pipe 20C in the direction of the pipe axis, as shown in Figure 6 (housing installation process). The housing 3 is made of steel and mainly consists of a main body 5 formed in a cylindrical shape with an open top, side body parts 6, 6 that are formed in a cylindrical shape and protrude from the left and right sides of the peripheral wall of the main body 5 in the direction of the pipe axis and capable of covering the fluid pipe 2, a bottom 7 that closes the lower opening of the main body 5, and side rings 8, 8 joined to both ends of the side body parts 6, 6.

[0038] Furthermore, the housing 3 has a split T-tube structure consisting of an upper housing 3a and a lower housing 3b along the central axis of the side body sections 6, 6, and is attached in a sealed manner so as to cover the planned cutting point P of the split pipe 20C from above and below. When attached to the outer surface of the split pipe 20C, the side rings 8, 8 are positioned on the outer circumference of the connecting cylinder sections 42, 42, and the side rings 8, 8 and the connecting cylinder sections 42, 42 are joined circumferentially by welding W. After the housing 3 is installed and the hydrostatic pressure test is completed, support concrete 60 is poured into the bottom 9a to fix the lower halves of the fluid pipe 2 and the split pipes 20A, 20B, and 20C.

[0039] Next, as shown in Figure 7, a work valve device 50 is sealed and connected to the upper part of the housing 3, and a drilling device 70 is sealed and connected to the upper part of the work valve device 50. The work valve device 50 mainly consists of a valve body 50a, a valve cover (not shown), and a valve element 50c that is movable between the valve body 50a and the valve cover (not shown). The drilling device 70 mainly consists of a mounting flange cylinder 71, a cutter 72 for cutting the fluid pipe 2, and a drive unit 73 having a drive source for rotating the cutter 72 and a retraction mechanism for moving the cutter 72 up and down.

[0040] Then, the cutter 72 is rotated around its axis by the drive source of the drilling device 70, and the cutter 72 is advanced downward by the reciprocating mechanism, cutting the fluid pipe 2 and the divided pipe 20C in a continuous flow state. By cutting the fluid pipe 2 at the planned cutting location P with the cutter 72, the region of the divided pipe 20C including the inlet ports 45, 45 is cut together with the fluid pipe 2 (cutting process).

[0041] By cutting the fluid pipe 2 and the divided pipe 20C, cut end faces 35, 35 are formed on the cut upstream and downstream pipe bodies, as shown in Figure 8 (the upstream cut end face 35 is not shown in Figure 8). Here, the space S formed between the outer surface of the fluid pipe 2 and the inner surface of the divided pipe 20C is filled with a filler material 24. However, if there are parts in the space S where the filler material 24 has not spread sufficiently, fluid may seep in the axial direction of the pipe between the outer surface of the fluid pipe 2 and the inner surface of the divided pipe 20C at the cut end faces 35, 35.

[0042] However, according to the present invention, in addition to the round rubbers 28, 28 provided on both ends of the protective tube 20 in the axial direction, round rubbers 26, 26 are provided in an annular manner around the circumference between the outer surface of the fluid tube 2 and the inner surface of the divided tube 20C at specific locations TP, TP downstream of the cut end face 35, that is, near the outside of the cut point. This prevents the fluid from penetrating deeply to the outside (upstream or downstream) in the axial direction of the tube, thus effectively suppressing corrosion and deterioration of the fluid tube 2 over time.

[0043] On the other hand, since the openings at the ends of each of the second cylindrical portions 22 are sealed by the round rubbers 28 disposed in the split pipes 20A and 20B respectively, the protection pipe 20 extending in the pipe axis direction, even if fluid enters the space S, leakage does not occur from the openings at the ends. Here, different from the present invention, even if the round rubbers 26, 26 disposed on the downstream side of the cut end face 35 are not provided, the openings at the ends of each of the second cylindrical portions 22 are sealed by the round rubbers 28 provided on both ends in the pipe axis direction of the protection pipe 20, and leakage does not occur from the openings. However, if fluid enters and stays for a long time over the entire length of the protection pipe, there is a risk of accelerating the corrosion and aging of the fluid pipe 2.

[0044] When the cutting by the drilling device 70 is completed, the cutter 72 is retracted into the mounting flange cylinder 71, the working valve device 50 is closed, and the drilling device 70 is removed.

[0045] Next, as shown in FIG. 9, a partition valve installation step of installing a plug 4 as a control fluid in the housing 3 is performed. First, with the working valve device 50 closed, a cylindrical member 90a is connected to the upper side of the valve box 50a in a sealed manner. Next, the insertion device 90 connected to the plug 4 is suspended and connected to the upper side of the cylindrical member 90a in a sealed manner. Then, the cylindrical member 90a is filled with fluid, and after confirming that air has escaped, an air vent valve (not shown) is closed, and a water pressure substantially the same as that in the fluid pipe 2 is applied to check for water leakage. Then, with the inside of the housing 3 and the inside of the cylindrical member 90a at substantially the same pressure, the valve body 50c is opened, the drive unit 90b of the insertion device 90 is operated to lower the plug 4, and it is installed in the housing 3.

[0046] After the plug 4 is installed at a predetermined installation position, a plurality of fixing pins 18 arranged in the circumferential direction of the main body portion 5 are advanced to the inner diameter side of the main body portion 5 to restrict upward movement of the plug 4. Next, the insertion device 90 and the working valve device 50 are removed from the housing 3. Then, as shown in FIG. 10, the main body lid 19 is placed on the upper part of the housing 3, and the main body portion 5 and the main body lid 19 are fastened and connected in a sealed manner with a plurality of bolts and nuts N6 composed of bolts and nuts, thereby completing the installation of the plug 4.

[0047] The flow control device 1 configured as described above includes a protective pipe 20, a housing 3, round rubbers 26, 26 interposed at specific locations TP, TP, and a filling material 24 filled between the circumferential surfaces of the fluid pipe 2 and the protective pipe 20 excluding the specific locations TP, TP.

[0048] [Operation and Effect] As described above, the flow control device 1 as an embodiment of the present invention is installed in an existing fluid pipe 2 that constitutes a pipeline in a non-stop flow state, and a protective pipe 20 that externally fits the outer circumferential surface of the fluid pipe 2 in a sealed manner, a housing 3 that externally fits at least a part of the protective pipe 20 in a sealed manner, round rubbers 26 as sealing materials interposed over the entire circumference at specific locations TP outside the cut end surfaces 35, 35 of the fluid pipe 2 between the circumferential surfaces of the fluid pipe 2 and the protective pipe 20, and a filling material 24 filled in a space S formed between the circumferential surfaces of the fluid pipe 2 and the protective pipe 20 excluding the specific locations TP.

[0049] According to this, since the in-pipe fluid filling the inside of the housing 3 due to the cutting of the fluid pipe 2 is sealed by the round rubbers 26, 26 between the circumferential surfaces of the fluid pipe 2 and the protective pipe 20, it does not penetrate axially between the circumferential surfaces beyond these round rubbers 26, 26, and the structural strength of the fluid pipe 2 reinforced by the protective pipe 20 can be maintained over a long period.

[0050] Further, since the protective pipe 20 is composed of a plurality of split pipes 20A, 20B, 20C that can connect their ends to each other in a sealed manner in the pipe axis direction, by arranging the round rubbers 26, 26 near the ends of the split pipes 20A, 20B on both sides in the pipe axis direction as the specific locations TP, TP, it becomes easier to interpose the round rubbers 26, 26 between the circumferential surfaces of the protective pipe 20 and the fluid pipe 2.

[0051] Further, since the split pipe 20C installed at the planned cutting location P and the split pipes 20A, 20B where the round rubbers 26, 26 are arranged are separately configured, the load applied to the split pipe 20C during the cutting of the fluid pipe 2 hardly affects the round rubbers 26, 26, so a decrease in sealing performance can be prevented.

[0052] Furthermore, since the specific points TP, TP of the round rubber 26, 26 are near the cutting points (cut end faces 35, 35), the fluid inside the pipe can be sealed by the round rubber 26, 26 near the cut end faces 35, 35 of the fluid pipe 2, thus allowing the extension of the fluid pipe 2 reinforced by the protective pipe 20 to be increased. It is preferable that the specific points TP, TP of the round rubber 26, 26 be close to the cutting points (cut end faces 35, 35), preferably the distance between the specific points TP, TP is 1.5 times the outer diameter of the cutter 72 or less, and even more preferably the distance between the specific points TP, TP is 1.2 times the outer diameter of the cutter 72 or less.

[0053] Furthermore, since the specific location TP of the round rubber 26 is inside the housing 3, fluid does not enter the space between the fluid pipe 2 and the protective pipe 20 at the mounting location of the housing 3, thus ensuring long-term stability of the housing 3's mounting structure.

[0054] Furthermore, the method for installing the flow control device 1 is an installation method for installing the flow control device 1 in an existing fluid pipe 2 that constitutes a pipeline in a continuous flow state, and includes a protective pipe installation step (see Figures 2 to 5) in which a protective pipe 20 is fitted in a sealed manner onto the outer surface of the fluid pipe 2, and a round rubber 26 is interposed around the entire circumference at a specific location TP outside the planned cutting location P of the fluid pipe 2 between the fluid pipe 2 and the protective pipe 20, and a filling step (see Figure 6) in which a filler material 24 is filled between the circumferential surfaces of the fluid pipe 2 and the protective pipe 20, excluding the specific location TP, and protection The process includes a housing attachment step (see Figure 6) in which the housing 3 is fitted onto at least a portion of the pipe 20 in a sealed manner, and a cutting step (see Figure 7) in which the fluid pipe 2 is cut together with the protective pipe 20 inside the housing 3. As a result of cutting the fluid pipe 2, the fluid inside the pipe that fills the housing 3 is sealed by the round rubber 26 between the circumferential surfaces of the fluid pipe 2 and the protective pipe 20. Therefore, the fluid does not penetrate beyond the round rubber 26 in the axial direction between the circumferential surfaces, and the structural strength of the fluid pipe 2, which is reinforced by the protective pipe 20, can be maintained over a long period of time.

[0055] Furthermore, the protective tube installation process involves sealing the first divided tube 20B, which constitutes the protective tube 20, onto the fluid tube 2, interposing a round rubber 26 near the end of the divided tube 20B at a designated point TP, and then sealingly connecting the second divided tube 20C, which constitutes the protective tube 20, to the end of the divided tube 20B. By designating the area near the end of the divided tube 20B as the designated point for the round rubber 26, it is easy to interpose the round rubber 26 between the circumferential surfaces of the protective tube 20 and the fluid tube 2. In addition, by keeping the fluid tube 2 straight, stable construction can be performed when installing or cutting the housing 3, and the load on the fluid tube 2 can be reduced.

[0056] Although embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and any changes or additions that do not depart from the spirit of the present invention are also included.

[0057] For example, in the above embodiment, a configuration was shown in which specific locations TP, TP for placing the round rubber 26, 26 as sealing material are set in a location near the outside (upstream or downstream) of the cut end surface 35. However, the present invention is not limited to this, and the specific locations TP, TP can be set at any location inside (towards the planned cutting location P) of the round rubber 28, 28 provided on both ends of the protective tube 20 in the axial direction, and do not necessarily have to be set inside the housing 3. In addition, multiple sealing materials may be placed at multiple locations between the planned cutting location P and the round rubber 28.

[0058] Furthermore, in the above embodiment, a configuration in which round rubber 26, 26 is provided as a sealing material at the end of the divided pipes 20A, 20B on the side of the planned cutting location P was illustrated, but the present invention is not limited thereto, and may be provided at both ends of the divided pipe 20C in the direction of the pipe axis. In this case, after setting up the divided pipe 20C and providing the round rubber 26, 26 at both ends in the direction of the pipe axis, the ends of the divided pipes 20A, 20B on the side of the planned cutting location P may be overlapped and provided to cover both ends of the outer surface of the divided pipe 20C in the direction of the pipe axis.

[0059] Furthermore, although the above embodiment illustrates a configuration in which the protective tube 20 is made up of multiple divided tubes 20A, 20B, and 20C, the present invention is not limited thereto, and may be made up of four or more divided tubes, or a single tube (for example, only divided tube 20C). Also, the protective tube does not have to be a circular tube, and its cross-sectional shape is arbitrary. In addition, the length dimension in the axial direction of the tube is arbitrary and can be changed in various ways to correspond to the area to be reinforced.

[0060] Furthermore, although the above embodiment illustrates a configuration in which round rubber 26 is used as a sealing material, the present invention is not limited thereto, and may be composed of packing, putty, synthetic resin gaskets, etc., with different cross-sectional shapes.

[0061] Furthermore, although the above embodiment illustrates an example in which epoxy resin is used as a filler, the present invention is not limited thereto, and any filler that can reinforce the fluid pipe, such as other synthetic resins or mortar, can be used.

[0062] Furthermore, although the above embodiment illustrates a configuration in which the first divided pipes 20A and 20B are installed at the connecting parts CN1 and CN2, the present invention is not limited to this, and they may be installed at any location other than the connecting parts CN1 and CN2. Also, although the above embodiment illustrates connecting parts CN1 and CN2 with a receiving part 2a and a spigot part 2b, the connecting parts may also be of the joint ring type.

[0063] Furthermore, although the above embodiment illustrates a configuration in which the divided pipes 20A, 20B, 20C and the housing 3 have a two-part divided structure, the present invention is not limited thereto, and may have a three-part or more divided structure.

[0064] Furthermore, in the above embodiment, a plug 4 (stopcock) was used as an example of a control fluid capable of controlling the flow of fluid, but the present invention is not limited thereto, and the control fluid may be a valve body such as a gate valve, switching valve, or butterfly valve that can open and close the flow path. In addition, the gate valve may have a partition wall, or it may have a valve body that can switch the flow path provided on the partition wall.

[0065] 1 Flow control device 2 Fluid pipe 3 Housing 5 Main body 6 Side body 9 Excavation hole 11 Lifting support 12 Pipe support jack 20 Protective pipe 20A, 20B Divided pipe (first divided pipe) 20C Divided pipe (second divided pipe) 21 First cylindrical part 21c, 21d Divided member 22 Second cylindrical part 22a, 22b Divided member 23 Inlet 24 Filling material 26 Round rubber (sealing material) 27 Putty 28 Round rubber 30 Press ring 35 Cut end face (cutting location) 41 Cylindrical part 42 Connecting cylindrical part 43a, 43b Divided member 45 Inlet 50 Work valve device 70 Drilling device 90 Insertion device CN1, CN2 Connection part P Planned cutting location S Space TP Specific locations

Claims

1. A flow control device installed in a fluid pipe constituting a pipeline in a continuous flow state, comprising: a protective pipe fitted to the outer surface of the fluid pipe in a sealed manner; a housing fitted to at least a part of the protective pipe in a sealed manner; a sealing material interposed around the entire circumference at a specific location outside the cut point of the fluid pipe between the circumferential surfaces of the fluid pipe and the protective pipe; and a filling material filled between the circumferential surfaces of the fluid pipe and the protective pipe, excluding the specific location.

2. The flow control device according to claim 1, characterized in that the protective tube is composed of a plurality of divided tubes whose ends can be sealed and connected to each other in the axial direction of the tube.

3. The flow control device according to claim 1, characterized in that the specific location of the sealing material is near the cutting location.

4. The flow control device according to any one of claims 1 to 3, characterized in that the specific location of the sealing material is inside the housing.

5. A method for installing a flow control device in a fluid pipe constituting a pipeline in a continuous flow state, comprising: a protective pipe installation step of fitting a protective pipe in a sealed manner onto the outer surface of the fluid pipe and interposing a sealing material around the entire circumference at a specific location outside the planned cutting location of the fluid pipe between the circumferential surfaces of the fluid pipe and the protective pipe; a filling step of filling the space between the circumferential surfaces of the fluid pipe and the protective pipe, excluding the specific location, with a filler material; a housing installation step of fitting a housing in a sealed manner onto at least a part of the protective pipe; and a cutting step of cutting the fluid pipe together with the protective pipe inside the housing.

6. The method for installing a flow control device according to claim 5, characterized in that the protective tube installation step is a step of fitting a first divided tube constituting the protective tube onto the fluid tube in a sealed manner, interposing the sealing material near the end of the first divided tube as the specified location, and connecting a second divided tube constituting the protective tube to the end of the first divided tube in a sealed manner.

Images