Flow restrictor and flow path switching method using same

Abstract

To provide a flow control device capable of attaching and detaching a flow control device while maintaining an appropriate fluid pressure environment inside a housing. [Solution] The device is composed of a housing 3 that is hermetically fitted onto a fluid pipe 2 that forms a flow path, and a plug 4 that is removably installed inside the housing 3 and acts as a fluid control device that blocks the flow path, and the housing 3 at least comprises drain ports 13a, 13b as a pair of openings that open on either side of the plug 4, and a communicating pipe section 35 that forms a communicating passage 35a that connects the pair of drain ports 13a, 13b to each other in an openable and closable manner, and the pair of drain ports 13a, 13b open at approximately the same height position.

Description

[Technical Field]

[0001] The present invention relates to a flow control device comprising a housing hermetically fitted onto a fluid pipe constituting a flow path, and a flow control device detachably installed within the housing to block the flow path, and a flow path switching method using the same. [Background technology]

[0002] Conventionally, a fluid control device has been installed inside a housing fitted to the fluid pipe that constitutes the flow path, which temporarily blocks the flow path and changes the flow path, such as by constructing a new flow path, and then appropriate construction work is carried out, and after this construction work is completed, the pressure inside the housing is equalized and the flow path inside the housing is restored (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-298244 A (page 7, Figure 7) Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, the communication passage that connects the flow paths inside the housing blocked by the fluid regulator extends in the vertical direction, which causes a pressure difference due to head pressure to occur inside the communication passage, and this pressure difference cannot be resolved inside the housing blocked by the fluid regulator, which creates the problem that the fluid regulator cannot be properly attached or detached from the housing.

[0005] The present invention has been made in response to these problems, and aims to provide a flow control device that can attach and detach a flow control device while maintaining an appropriate fluid pressure environment within the housing, and a flow path switching method using the same. [Means for solving the problem]

[0006] In order to solve the above problems, the flow restrictor of the present invention comprises: A flow control device comprising a housing that is hermetically fitted onto a fluid pipe that forms a flow path, and a flow control device that is detachably installed within the housing and blocks the flow path, The housing is characterized in that it has at least a pair of openings that are opened so as to sandwich the fluid control valve, and a communicating pipe section that forms a communicating passage that connects the pair of openings to each other in an openable and closable manner, and that the pair of openings are open at approximately the same height position. According to this feature, by opening a pair of openings located at approximately the same height within a housing whose flow path is blocked by the fluid control, the fluid communicates through the communicating pipe section, so that no differential head pressure occurs within the housing that sandwiches the fluid control, and the fluid control can be attached and detached within the housing in an environment of appropriate fluid pressure.

[0007] The communication pipe portion is characterized by including at least a horizontal pipe portion extending in a substantially horizontal direction. According to this feature, the movement of the fluid passing through the communicating pipe portion can be stabilized.

[0008] The horizontal pipe section is characterized in that an on-off valve for opening and closing the communication passage is provided in the horizontal pipe section. According to this feature, the communication passage can be opened and closed appropriately without being affected by the hydraulic head pressure.

[0009] The communication pipe section further includes a pair of vertical pipe sections that are interposed between the pair of openings and the horizontal pipe section and extend in a substantially vertical direction. According to this feature, by interposing the vertical pipe section between the pair of openings and the horizontal pipe section, the height position of the horizontal pipe section can be set with a high degree of freedom.

[0010] The pair of openings are characterized by being open to the bottom of the housing. This feature makes it possible to prevent the housing from becoming bulky in plan view.

[0011] The valve is characterized by being provided with a branched communication passage that connects the communication passage to a storage section that can store the fluid control unit removed from the housing. According to this feature, the pressure inside the accommodation portion can be made substantially the same as that of the communication passage, so that the fluid control device can be removed in a more stable state.

[0012] The housing is characterized by being provided with an air vent. According to this feature, the pipe can be filled with fluid while air is removed from the housing.

[0013] The housing is fitted tightly around the fluid pipe, and the fluid pipe inside the housing is cut off to install the fluid regulator, thereby blocking the flow path. According to this feature, the flow path can be blocked while being placed in an environment of appropriate fluid pressure.

[0014] After the flow path is blocked, the flow control device is removed from the housing, thereby opening the flow path. According to this feature, the flow path can be opened while being placed in an environment of appropriate fluid pressure. [Brief explanation of the drawings]

[0015] [Figure 1] (a) is a schematic plan view showing the planned installation location of a flow meter equipment in an existing fluid pipe, (b) is a schematic plan view showing the state in which a bypass pipe has been newly installed in the existing fluid pipe via a flow control device and a branching housing as Example 1 to switch the flow path, and (c) is a schematic plan view showing the state in which the flow meter equipment has been installed at the planned installation location. [Figure 2] 1(d) is a schematic plan view showing a state in which the primary side and secondary side of the plug in the housing are at the same pressure, and FIG. 1(e) is a schematic plan view showing a state in which the plug has been removed from the housing. [Figure 3] 1A is a partially cutaway rear view showing the process of cutting a fluid pipe using a cutting device, and FIG. 1B is a partially cutaway rear view showing the vicinity of a drain port of a housing. [Figure 4]FIG. 10 is a partially cutaway rear view showing the process of inserting a plug using the insertion device. [Figure 5] FIG. 10 is a partially cutaway rear view showing a state in which fluid is being discharged from a drain port on the secondary side of the plug in the housing. [Figure 6] 1(a) is a partially cutaway rear view showing a state in which the primary side and secondary side of the plug in the housing are at approximately the same pressure, and FIG. 1(b) is an enlarged side view of the main part showing the lower part of the housing and the communicating tube part. [Figure 7] FIG. 4 is a partially cutaway plan view showing a fluid communication state between the housing and the communication pipe portion. [Figure 8] 1A is a rear view of the lower part of the housing showing the drain port, and FIG. 1B is an enlarged cross-sectional view showing the housing, the drain port, and the drain pipe. [Figure 9] FIG. 10 is a partially cutaway rear view showing the state in which the plug has been retrieved from the housing by the insertion device. [Figure 10] FIG. 10 is a partially cutaway rear view showing the process of inserting the inner lid using the insertion device. [Figure 11] 1A is a partially cutaway plan view showing the state in which the flange lid is attached to the drain valve, and FIG. 1B is a partially cutaway rear view showing the state in which the upper opening of the housing is closed with the inner lid and main body lid. [Figure 12] (a) is a schematic plan view showing a state in which an existing valve is installed in an existing fluid pipe, (b) is a schematic plan view showing a state in which a bypass pipe is newly installed in an existing fluid pipe via a flow control device as Example 2 to switch the flow path, and (c) is a schematic plan view showing a state in which the existing valve has been removed. [Figure 13] FIG. 1(d) is a schematic plan view showing a state in which the primary side and secondary side of the plug are at the same pressure through a communicating pipe portion provided in the housing, and FIG. 1(e) is a schematic plan view showing a state in which the plug has been removed from the housing. [Figure 14] 10 is a partially cutaway front view showing a process of cutting a fluid pipe by the cutting device. FIG. [Figure 15] 10 is a partially cutaway front view showing the process of inserting a plug using an insertion device. FIG. [Figure 16] FIG. 10 is a partially cutaway front view showing a state in which fluid is being discharged from a drain port on the secondary side of the housing. [Figure 17]1(a) is a partially cutaway front view showing a state in which the primary side and secondary side of the plug in the housing are at approximately the same pressure, and FIG. 1(b) is an enlarged side view of the main part showing the lower part of the housing and the communicating tube part. [Figure 18] FIG. 4 is a partially cutaway plan view showing a fluid communication state between the housing and the communication pipe portion. [Figure 19] FIG. 10 is a partially cutaway front view showing a state in which the plug has been retrieved from the housing by the insertion device. [Figure 20] 10 is a partially cutaway front view showing the process of inserting the inner lid by the insertion device. FIG. [Figure 21] 1A is a partially cutaway plan view showing the state in which a flange lid is attached to a drain valve, and FIG. 1B is a partially cutaway front view showing the state in which the upper opening of the housing is closed with an inner lid and a main body lid. Example 1

[0016] A flow control device according to a first embodiment of the present invention will be described with reference to Figures 1 to 11. In the following description, the lower side of Figure 1 will be referred to as the front of the flow control device, the upper side as the rear, the left side as the left side, and the right side as the right side. Furthermore, the white arrows in Figures 1 and 2 indicate the direction in which the fluid flows down inside the pipe, and the dotted areas indicate areas filled with the fluid.

[0017] In this Example 1, a flow control device as Example 1 of the present invention is described, which is used in a process of installing a flowmeter equipment in a state where the flow is not interrupted at a planned installation location of an existing flow path. Specifically, based on Figures 1(a) to 2(e), a new installation process of the flowmeter equipment is described, from installing a bypass pipe to temporarily blocking the existing flow path, installing the flowmeter equipment, to opening the existing flow path and removing the bypass pipe. Details of each process are also described with reference to Figures 3 to 11.

[0018] In this embodiment, the fluid in the fluid pipe 2 is tap water. However, it may be, for example, industrial water, agricultural water, sewage, or other liquids other than water, or it may be gas or a gas-liquid mixture. The fluid pipe 2 is a ductile cast iron pipe formed into a straight pipe with a generally circular cross section. In this embodiment, the fluid pipe 2 is disposed generally horizontally. The fluid pipe according to the present invention may also be made of other metals, such as cast iron or steel, or concrete, polyvinyl chloride, polyethylene, or polyolefin. Furthermore, the inner surface of the fluid pipe may be coated with an epoxy resin layer, mortar, plating, or the like, or may be powder coated with an appropriate material.

[0019] [New flow meter equipment installation process] First, as shown in FIG. 1(a), a planned installation location P1 of a flowmeter equipment 100 (see FIG. 1(c)) is set at a predetermined location in an existing fluid pipe 2. Next, as shown in FIG. 1(b), branch pipe casings 30A and 30B are hermetically fitted onto the primary side (upstream side) and secondary side (downstream side) of the planned installation location P1 in the fluid pipe 2, and these branch pipe casings 30A and 30B are connected to each other by a bypass pipe 9 via on-off valves 37A and 37B. Next, the fluid pipe 2 inside the branch pipe casings 30A and 30B is cut in an uninterrupted flow state by a cutting device 70 (see FIG. 3(a)), allowing the fluid to flow from the fluid pipe 2 to the bypass pipe 9. The process of cutting the fluid pipe 2 is substantially the same as the process of cutting the fluid pipe 2 performed when installing flow control devices 1A and 1B, which will be described later, and therefore will not be described in detail here.

[0020] Next, the casings 3, 3 of the flow control devices 1A, 1B according to the first embodiment of the present invention are hermetically fitted onto the primary and secondary sides of the planned installation location P1 between the branch pipe casings 30A, 30B in the fluid pipe 2. Since the flow control devices 1A, 1B have the same configuration, the following description will focus on the upstream flow control device 1A, and a description of the flow control device 1B will be omitted.

[0021] As shown in FIG. 3( a), the housing 3 is mainly composed of a main body 5 made of steel and formed into a cylindrical shape with an open top, side body portions 6, 6 formed into a cylindrical shape that protrude from the left and right sides of the peripheral wall of the main body 5 in a left-right direction that is approximately perpendicular to the central axis of the main body 5 that faces in the up-down direction and is capable of covering the fluid pipe 2, and a bottom portion 7 that closes the lower opening of the main body 5.

[0022] The housing 3 has a split structure that is split into two, upper and lower, as a split T-pipe consisting of an upper housing 3a and a lower housing 3b along the central axis of the side bodies 6, 6. More specifically, the lower housing 3b is formed by integrating the lower parts of the main body 5 and the side bodies 6, 6 into a roughly T-shape in front view, and is capable of covering the lower part of the fluid pipe 2. The upper housing 3a is formed by integrating the upper parts of the main body 5 and the side bodies 6, 6 into a roughly inverted T-shape in front view, and is capable of covering the upper part of the fluid pipe 2. Then, by integrating the lower housing 3b and the upper housing 3a by welding, they are attached in a sealed manner so as to cover predetermined parts of the fluid pipe 2 from above and below.

[0023] The ends of the side barrels 6, 6 in the tube axis direction are fitted tightly, and the housing 3 is fixed to the fluid pipe 2 by press rings 10, 10. An air vent plug 15 is provided at the top of the side barrels 6, 6, and an air vent plug 16 is provided at the top of the main barrel 5. In addition, a centering bolt 17 for the fluid pipe 2 is provided at an appropriate position, such as the bottom of the side barrels 6, 6.

[0024] As shown in Figure 3(a), a steel seat 8 is provided on the inner surface of the housing 3 to project therefrom. The seat 8 receives a plug 4 as a fluid regulator that is inserted from the top opening of the housing 3. The seat 8 is composed of a horizontal seat 8a (see Figure 3(b)) that projects from the upper surface of the bottom 7 of the housing 3, which is circular in plan view, a vertical seat 8b (see Figure 3(b)) that connects with the front and rear ends of the horizontal seat 8a, projects from the inner surface of the main body 5, and extends upward, and an upper seat 8c that connects with the upper end of the vertical seat 8b and extends circumferentially.

[0025] 3(b), drain ports 13a and 13b are formed penetrating the primary and secondary sides of the horizontal seat 8a in the pipe axial direction at the lower part of the peripheral wall of the main body 5. A drain pipe 31a having a drain valve 32a (see FIG. 7(a)) is connected to the primary-side drain port 13a, and a drain pipe 31b having a drain valve 32b (see FIG. 7(a)) is connected to the secondary-side drain port 13b, so that chips and the like inside the main body 5 can be discharged together with the fluid inside the pipe by opening the drain valves 32a and 32b. The drain ports 13a and 13b will be described in detail later.

[0026] As shown in FIG. 3( a), the top surface of the main body 5 is open, and a flange 3e is formed around the periphery of the opening, projecting radially outward. A plurality of cylindrical portions 27 projecting radially outward are formed circumferentially above the upper seat portion 8c on the lower outer peripheral surface of the main body 5. A threaded hole is formed inside each cylindrical portion 27, and a fixing pin 28 is screwed into the threaded hole in a sealed manner. The fixing pin 28 can be rotated around its axis from the outside of the cylindrical portion 27 with a tool or the like, retracting the tip of the fixing pin 28 into the cylindrical portion 27 to allow insertion of the plug 4, or projecting the tip of the fixing pin 28 into the main body 5 and abutting against the upper surface of the lid portion 42 to fix the plug 4 (see FIG. 5). The tip of the fixing pin 28 is tapered toward the inner diameter.

[0027] Next, the process of cutting the fluid pipe 2 will be described. First, as shown in Figure 3(a), the side body sections 6, 6 are hermetically attached along the axis of the fluid pipe 2, and predetermined portions of the fluid pipe 2 are hermetically covered with the housing 3. Then, the gate valve device 50 is hermetically connected to the upper opening of the main body section 5. The gate valve device 50 has a cylindrical valve box 50a that penetrates vertically, a valve cover (not shown) that protrudes rearward from the valve box 50a and is connected to the valve box 50a via a communication port (not shown) formed on the inner peripheral surface, a valve disc 50c that is arranged to be movable substantially horizontally between the valve box 50a and the valve cover (not shown), and a seat (not shown) that serves as a valve seat for receiving the valve disc 50c. A seal member (not shown) for the valve disc 50c can be tightly fitted to the seat (not shown).

[0028] The valve box 50a is hermetically connected via a seal member (not shown) to the open end (opening) on ​​the upper side of the main body 5. Furthermore, the end of a valve stem (not shown) that is threadedly engaged with a valve element 50c inside the valve lid protrudes from the tip of the valve cover, and the inside of the housing 3 can be opened and closed by rotating an operating handle (not shown) attached to the end of this valve stem to move the valve element 50c between the valve box 50a and the valve cover.

[0029] Next, a cutting device 70 is hermetically connected to the upper open end of the valve box 50a. The cutting device 70 is mainly composed of a mounting flange tube 71, a cutter 72 for cutting the fluid pipe 2, a drive motor 74 for rotating the cutter 72 within the mounting flange tube 71, and an advance / retract mechanism 73 for moving the cutter 72 up and down. The cutter 72 is formed in a cylindrical shape with an outer diameter larger than the outer diameter of the fluid pipe 2, and is composed of a hole saw 72a with a cutting blade along the circumferential direction at its lower end, and a center drill 72b arranged coaxially with the rotation axis of the hole saw 72a and protruding beyond the cutting blade.

[0030] The cutter 72 is arranged so that the central axis of the center drill 72b is concentric with the central axis of the main body 5 of the housing 3, and is inserted into the main body 5 from the upper open end and can advance to a position where it penetrates at least the pipe wall of the fluid pipe 2.

[0031] Next, the valve element 50c of the gate valve device 50 is moved toward the valve cover (not shown) side to open the inside of the housing 3, the cutter 72 is rotated about its rotation axis by the drive motor 74 of the cutting device 70, and the cutter 72 is advanced downward by the advance / retract mechanism 73 to cut the fluid pipe 2 without interrupting the flow. When the fluid pipe 2 is cut by the cutter 72, a cut piece (not shown) separated from between the ends 2H, 2T (see FIG. 4) of the fluid pipe 2 is held in the hole saw 72a, and the advance / retract mechanism 73 retracts the cutter 72 together with the cut piece (not shown) into the inside of the mounting flange tube 71, and the valve element 50c of the gate valve device 50 is moved toward the valve box 50a side to close the inside of the housing 3.

[0032] Most of the foreign matter such as chips generated by cutting is discharged by water pressure from the drain ports 13a, 13b at the bottom of the housing 3 together with the fluid in the pipe, but over time some of it gradually sinks due to gravity and falls to the bottom 7 of the housing 3, where it accumulates. In this case, the foreign matter that has accumulated at the bottom 7 of the housing 3 is discharged to the outside by attaching a discharge device (not shown) to the valve box 50a after removing the mounting flange cylinder 71 from the valve box 50a and removing the cutting device 70.

[0033] Next, a plug installation process is performed in which a plug 4 serving as a fluid regulator is installed in the housing 3. As shown in Figure 4, first, with the gate valve device 50 closed, a cylindrical member 90a is hermetically connected to the upper side of the valve box 50a. Next, an air vent plug 16 formed above the upper seat portion 8c in the main body 5 of the housing 3 is connected to a drain plug (not shown) formed at the bottom of the cylindrical member 90a via a connecting pipe (not shown), thereby communicating between the inside of the housing 3 and the inside of the cylindrical member 90a. The cylindrical member 90a is filled with fluid while air is vented from an air vent valve (not shown) provided at the top of the cylindrical member 90a, and water pressure approximately equal to that in the fluid pipe 2 is applied to the cylindrical member 90a to check for leakage. After confirming that the air has been vented from the cylindrical member 90a, the air vent valve (not shown) is closed. Next, with the pressure inside the housing 3 and the pressure inside the cylindrical member 90a being approximately equal, the valve body 50c is opened, and the drive mechanism 90b of the insertion device 90 is operated to move the plug 4 down.

[0034] The plug 4 mainly comprises a plate-shaped partition wall 41 arranged to partition the inside of the main body 5 in the tube axis direction, a disk-shaped lid 42 fixed approximately horizontally to the upper part of the partition wall 41 and closing the top opening of the main body 5, and a packing 43 extending over the lower end surface and side end surfaces of the partition wall 41 and the peripheral end surface of the lid 42.

[0035] When the plug 4 enters the housing 3 and the packing 43 is pressed against the seat 8 and set in a predetermined position, the top opening of the housing 3 is hermetically closed by the lid 42, and the partition wall 41 separates the ends 2H and 2T of the fluid pipe 2 inside the housing 3 to stop water leakage, thereby separating the fluid into the primary side and secondary side of the plug 4 (see FIG. 5). After the plug 4 is set in a predetermined installation position, the multiple fixing pins 28 arranged circumferentially on the main body 5 are advanced toward the inner diameter side of the main body 5 and abut against the outer peripheral surface of the lid 42 (see FIG. 5). As a result, the lid 42 is locked by the fixing pins 28, restricting its upward movement and holding it in a predetermined installation position, thereby preventing the plug 4 from coming off the housing 3.

[0036] Thereafter, the drain plug (not shown) provided at the bottom of the cylindrical member 90a is opened, and after confirming that the gasket 43 of the plug 4 has sealed off the water, the insertion device 90 and the gate valve device 50 are removed from the housing 3. Next, as shown in Fig. 5, the main body lid 30 is placed on top of the housing 3 from above the lid portion 42, and the flange 3e of the main body 5 and the main body lid 30 are fastened together with a plurality of fastening members 95 consisting of bolts and nuts to form a sealed connection, thereby completing the installation of the plug 4.

[0037] As shown in Figure 1(b), when the installation of plugs 4 is completed in the left and right flow control devices 1A and 1B with the flow path of the bypass pipe 9 open, the water supply is cut off between the flow control devices 1A and 1B in the fluid pipe 2, and the flow path is switched to the bypass pipe 9 via the branch pipe housings 30A and 30B.

[0038] After switching the flow path to the bypass pipe 9, the drain valve 32b of the drain pipe 31b connected to the secondary side drain port 13b from the plug 4 inside the housing 3 of the flow control device 1A is opened, and the fluid inside the housing 3 is discharged to the outside via the drain port 13b, the drain pipe 31b, and the drain valve 32b, as shown in Figure 5.

[0039] As shown in Figure 1(b), the planned installation location P1 side of the flow control devices 1A and 1B is the secondary side, so for the flow control device 1A, the drain valve 32b on the secondary side (left side in the figure) of the plug 4 is opened to discharge the fluid to the outside from the drain port 13b, while for the flow control device 1B, the drain valve 32a on the secondary side (right side in the figure) of the plug 4 is opened to discharge the fluid to the outside from the drain port 13a.

[0040] After the fluid in the fluid pipe 2 between the flow control devices 1A and 1B has been completely discharged, the flowmeter equipment 100 is installed at the planned installation location P1, as shown in FIG. 1(c).

[0041] [Bypass pipe removal process] 2, after the installation of the flowmeter equipment 100 is completed, the plugs 4, 4 of each of the flow control devices 1A, 1B are removed to release the blocked state of the pipeline and restore the flow path at the existing position consisting of the fluid pipe 2. In order to do this, first, before removing the plugs 4, 4, a process is carried out to equalize the fluid pressure on the primary side and the secondary side of the flow control devices 1A, 1B. Note that because the secondary sides of the flow control devices 1A, 1B are in the same connected space, the following describes the process of equalizing the fluid pressure on the primary side and the secondary side of the flow control device 1A, and omits the description of the process of equalizing the fluid pressure on the primary side and the secondary side of the flow control device 1B.

[0042] Specifically, as shown in Figures 6(a), (b) and 7, a pair of drain ports 13a, 13b that open to sandwich the plug 4 installed inside the housing 3, and a communicating pipe section 35 that can communicate the pair of drain ports 13a, 13b with each other form a communicating passage 35a that can open and close the flow path blocked by the plug 4.

[0043] As shown in FIG. 8( a), the drain ports 13a and 13b are formed to open at approximately the same height on both circumferential sides (left and right sides) of the vertical seat portion 8b in the lower peripheral wall of the main body portion 5 of the casing 3. More specifically, the drain ports 13a and 13b are formed below the side body portions 6 and on one side (rearward in this example) in the axial direction of the fluid pipe 2 in the peripheral wall of the main body portion 5. Furthermore, the drain ports 13a and 13b are formed at positions where the vertical dimension L1 from the upper surface 7a of the bottom portion 7 of the main body portion 5 of the casing 3 to their respective center positions C and C is the same, so that the respective center positions C and C are located on the same horizontal plane. Furthermore, the drain ports 13a and 13b are formed as approximately circular holes, and as shown in FIG. 8( b), the lower ends of the drain ports 13a and 13b are formed to be slightly lower than the upper surface 7a of the bottom portion 7. This allows for the efficient discharge of chips and the like that accumulate on the upper surface 7a of the bottom portion 7 during the cutting process.

[0044] As shown in Figure 7, the drain pipes 31a, 31b are straight pipes with a generally circular cross section that extend rearward from the periphery of the drain ports 13a, 13b on the outer circumferential surface of the main body 5, i.e., in a generally horizontal direction perpendicular to the pipe axis of the side body sections 6. The drain valves 32a, 32b are hermetically flange-connected to the drain pipes 31a, 31b, and can be opened and closed using an operating tool (not shown). The connecting pipes 33a, 33b are curved pipes with a generally circular cross section that extend generally horizontally and are hermetically flange-connected to the drain valves 32a, 32b. A connecting valve 18 is provided at the top of the connecting pipe 33a.

[0045] Connecting pipe 33a is hermetically flange-connected to drain valve 32a, and connecting pipe 33b is hermetically flange-connected to drain valve 32b, so that connecting pipes 33a and 33b are hermetically flange-connected to each other. As a result, drain pipes 31a and 31b, drain valves 32a and 32b, and connecting pipes 33a and 33b form a communicating pipe section 35 that is generally U-shaped in plan view, and communicates between the primary side and secondary side of plug 4 inside housing 3. As shown in FIGS. 6(a), 6(b), and 7, communicating pipe section 35 has a horizontal pipe section 35b that is made up of drain pipes 31a and 31b, drain valves 32a and 32b, and connecting pipes 33a and 33b, which extend in a substantially horizontal direction.

[0046] Next, after forming a communication passage 35a using the drain ports 13a and 13b and the communication pipe portion 35, the drain valves 32a and 32b are opened, so that the fluid on the primary side of the plug 4 inside the housing 3 flows from the drain port 13a into the drain pipe 31a, the drain valve 32a and the connecting pipe 33a, and then flows from the connecting pipe 33b, the drain valve 32b and the drain pipe 31b through the drain port 13b into the secondary side of the plug 4 inside the housing 3 and the inside of the fluid pipe 2 (see FIG. 2(d)). Then, while air is being bled from the air bleed plug 15 of the housing 3, the inside of the housing 3 and the fluid pipe 2 on the secondary side of the plug 4 are filled with fluid, and water pressure approximately the same as that on the primary side is applied to the secondary side of the plug 4 to check for leakage, and then the air bleed plug 15 is closed after it is confirmed that the air has been bled from the fluid pipe 2.

[0047] Next, as shown in Figures 6(a) and 7, one end of a connecting pipe 19 is connected to an air vent plug 16 provided at the top of the main body 5 of the housing 3, and the other end of the connecting pipe 19 is connected to a connecting valve 18 provided at the top of the connecting pipe 33a to form a branched communication passage 19a, thereby connecting the inside of the housing 3 with the inside of the check valve device 50 as a storage section and the inside of the cylindrical member 90a.

[0048] Then, the operating part 18a (see FIG. 7(b)) of the connection valve 18 is opened to supply the fluid inside the communication passage 35a and the housing 3 to the cylindrical member 90a, and the pressure inside the gate valve device 50 and the cylindrical member 90a is equalized to the pressure inside the housing 3. Next, as shown in FIG. 9, with the pressure inside the housing 3 and the pressure inside the cylindrical member 90a approximately equalized, the valve element 50c is opened and the drive mechanism 90b of the insertion device 90 is operated to lift the plug 4. Once the plug 4 is accommodated inside the cylindrical member 90a, the valve element 50c is moved into the valve box 50a to close the inside of the housing 3. This restores the flow path at the existing position, consisting of the fluid pipe 2 (see FIG. 2(e)).

[0049] In this way, by opening a pair of drain ports 13a, 13b that open at approximately the same height within the housing 3, whose flow path is blocked by the plug 4, the fluid communicates via the communicating pipe section 35, so that no differential head pressure occurs within the housing 3 that sandwiches the plug 4, and the plug 4 can be removed while maintaining an appropriate fluid pressure environment within the housing 3.

[0050] In addition, the communicating pipe section 35 connected to the drain ports 13a, 13b is entirely composed of a horizontal pipe section 35b that is approximately parallel to the pipe axis of the fluid pipe 2, making it less likely that a differential pressure in the head pressure will occur within the housing 3 that sandwiches the plug 4.

[0051] Furthermore, since the communicating pipe section 35 protrudes radially outward (rearward in this example) from the peripheral wall of the main body section 5 of the housing 3, the connecting pipes 33a, 33b can be installed and removed, and the drain valves 32a, 32b and the connecting valve 18 can be opened and closed in a space that does not interfere with the fluid pipe 2, thereby improving workability.

[0052] After the plug 4 is housed inside the cylindrical member 90a and the inside of the valve box 50a is closed with the valve body 50c, the fluid inside the cylindrical member 90a is drained through a drain plug (not shown) provided at the bottom, the insertion device 90 is detached from the gate valve device 50, and the plug 4 is removed. Next, the cylindrical member 90a, which houses the inner lid 45 attached to the valve hanger, is hermetically connected to the top of the valve box 50a, and the air vent plug 16 on the main body 5 of the casing 3 is connected to the drain plug (not shown) at the bottom of the cylindrical member 90a with a connecting pipe (not shown) to communicate between the inside of the casing 3 and the inside of the cylindrical member 90a, the cylindrical member 90a is filled with fluid while air is vented through an air vent valve (not shown) provided at the top of the cylindrical member 90a, and water pressure approximately the same as that inside the fluid pipe 2 is applied inside the cylindrical member 90a to check for leaks, and then the air vent valve (not shown) is closed after it is confirmed that the air has been vented from the cylindrical member 90a.

[0053] 10, with the pressure inside the housing 3 and the pressure inside the cylindrical member 90a at approximately the same level, the valve body 50c inside the valve box 50a is opened, and the drive mechanism 90b of the insertion device 90 is operated to lower the inner lid 45, which is placed on top of the housing 3 and fixed with the fixing pin 28. After the inner lid 45 is fixed, the fluid inside the cylindrical member 90a is drained from a drain plug (not shown) provided at the bottom, and the insertion device 90 and the gate valve device 50 are removed from the housing 3.

[0054] 11(b), the lid 30 is placed on top of the housing 3 from above the inner lid 45, and the flange 3e of the main body 5 and the lid 30 are fastened together with a plurality of fastening members 95 consisting of bolts and nuts to form a hermetic connection, thereby completing the process of removing the plug 4. As shown in FIG. 2(e), when the removal of the plugs 4, 4 from the left and right flow control devices 1A, 1B is completed, a flow state is established between the flow control devices 1A, 1B in the fluid pipe 2, and the flow path is switched from the bypass pipe 9 to the fluid pipe 2.

[0055] Finally, as shown in FIG. 11(a), the drain valves 32a and 32b are closed, the connecting pipes 33a and 33b are removed from the drain valves 32a and 32b, and the flange covers 36a and 36b are attached to the end openings of the drain valves 32a and 32b, completing the installation.

[0056] In the above, in the first embodiment, the process of newly installing the flowmeter equipment 100 in an existing flow path has been described, but the repair process of repairing an existing flowmeter equipment installed in an existing flow path can also be performed in the same manner as the above-mentioned process of newly installing the flowmeter equipment 100. Furthermore, the present invention is not limited to the installation or repair of the flowmeter equipment 100, but may also be applied to other devices or equipment such as valves, or to the installation or repair of a fluid pipe. Example 2

[0057] Next, a flow control device according to a second embodiment of the present invention will be described with reference to Figures 12 to 21. In the following, differences from the first embodiment will be mainly described, and detailed descriptions of configurations and parts similar to those of the first embodiment will be omitted by assigning similar reference numerals or reference numerals obtained by adding "200" to the similar reference numerals.

[0058] In this Example 2, a flow control device according to Example 2 of the present invention is described, which is used in a process of moving a predetermined section of piping in an existing flow path to another space without interrupting the flow due to occupation or the like. Specifically, based on Figures 12(a) to 13(e), a pipeline renewal process is described, from installing a new bypass pipe to blocking the existing flow path, to removing the predetermined section of piping and making the bypass pipe the permanent pipe. Details of each process are also described with reference to Figures 14 to 21.

[0059] [Pipe renewal process to move permanent piping] As shown in Figure 12(a), in order to relocate a valve 201 installed in an existing fluid pipe 2 to another space, a predetermined section including the valve 201 is set as a removal section. Next, as shown in Figure 12(b), housings 203, 203 constituting flow control devices 201A, 201B are hermetically fitted onto the primary side (upstream side) and secondary side (downstream side) of the valve 201 in the fluid pipe 2, and these housings 203, 203 are connected to each other by a bypass pipe 209. Note that since the flow control devices 201A, 201B have the same configuration, the following description will focus on the upstream side of the flow control device 201A, and a description of the downstream side of the flow control device 201B will be omitted.

[0060] As shown in FIG. 14 , the casing 203 is mainly composed of a main body 205 made of steel and formed into a cylindrical shape with an open top, side body sections 206, 206 formed into a cylindrical shape that protrude from the left and right sides of the peripheral wall of the main body 205 in a left-right direction that is approximately perpendicular to the central axis of the main body 205 that faces in the up-down direction and that can cover the fluid pipe 2, a front body section 214 that protrudes from the front side of the peripheral wall of the main body 205 in a forward direction that is approximately perpendicular to the central axis of the main body 205 that faces in the up-down direction, and a bottom section 207 that closes the lower opening of the main body 205.

[0061] The casing 203 has a split structure that is split into two, upper and lower, as a split T-pipe consisting of an upper casing 203a and a lower casing 203b along the central axis of the side barrel sections 206, 206 and the forward barrel section 214. More specifically, the lower casing 203b is formed by integrating the lower parts of the main barrel section 205, the side barrel sections 206, 206, and the forward barrel section 214 into a generally T-shape in front view, and is capable of covering the lower part of the fluid pipe 2. The upper casing 203a is formed by integrating the upper parts of the main barrel section 205, the side barrel sections 206, 206, and the forward barrel section 214 into a generally inverted T-shape in front view, and is capable of covering the upper part of the fluid pipe 2. The lower casing 203b and the upper casing 203a are then integrated by welding, whereby they are attached in a sealed manner so as to cover predetermined parts of the fluid pipe 2 from above and below.

[0062] The ends of the side barrel sections 206, 206 in the pipe axis direction are fitted over the exterior in a sealed manner, and the housing 203 is fixed to the fluid pipe 2 by press rings 10, 10. An air vent plug 15 is provided at the top of the downstream side barrel section 206, and an air vent plug 16 is provided at the top of the main barrel section 205. In addition, a centering bolt 17 for the fluid pipe 2 is provided at an appropriate position, such as the bottom of the downstream side barrel section 206. In addition, the end of the pipe axis direction of the forward barrel section 214 is fitted over the exterior in a sealed manner, and the housing 203 is fixed to the bypass pipe 209 by a press ring (not shown).

[0063] As shown in Fig. 14, a steel seat 208 is provided to protrude from the inner surface of the housing 203. The seat 208 receives a plug 204 as a fluid regulator and is inserted from an upper opening of the housing 203. The seat 208 is composed of a horizontal seat 208a protruding from the upper surface of a bottom 207 of the housing 203 that is circular in plan view, vertical seat 208b (see Fig. 18) that is connected to the front and rear ends of the horizontal seat 208a, protruding from the inner surface of the main body 205 and extending upward, and an upper seat 208c that is connected to the upper end of the vertical seat 208b and extends circumferentially.

[0064] 18 , the horizontal seat portion 208a of the seat 208 extends radially from the diagonally forward right side to the diagonally rearward left side in plan view so as to divide the interior of the main body section 205 into a primary side and a secondary side of the flow path, and is formed in a generally curved shape in plan view. The front end portion of the horizontal seat portion 208a and the vertical seat portion 208b extending upward from the front end portion are disposed between the secondary-side hole 206a in the peripheral wall of the main body section 205 and the hole 214a in the forward body section 214 side, and the rear end portion of the horizontal seat portion 208a and the vertical seat portion 208b extending upward from the rear end portion are disposed near the primary-side hole 206a in the region between the primary-side hole 206a and the secondary-side hole 206a in the peripheral wall.

[0065] Drain ports 213a and 213b are formed in the bottom 207 of the main body 205 so as to straddle the primary and secondary sides with respect to the horizontal seat portion 208a. Drain pipes 234a and 231a having drain valves 232a are connected to the primary-side drain port 213a, and drain pipes 234b and 231b having drain valves 232b are connected to the secondary-side drain port 213b, so that wastewater, chips, and the like can be discharged from inside the main body 205 by opening the drain valves 232a and 232b. The drain ports 213a and 213b will be described in detail below.

[0066] The plug 204 differs from the plug of Example 1 in that the flow path switching surface 241c of the partition wall portion 241 is curved. That is, when the flow path switching surface 241c is installed inside the housing 203, the flow path switching surface 241c is formed as a concave surface having a recess that curves in the downstream direction of the fluid in the pipe from upstream to downstream. This makes it difficult for turbulence to occur in the flow of the fluid flowing downstream in the pipe, and fluid resistance is therefore unlikely to occur. Therefore, the load on the plug 204 due to turbulence of the fluid can be reduced, the sealing performance of the plug 204 can be maintained for a long period of time, and pressure loss of the fluid can be suppressed.

[0067] Next, after connecting the housings 203, 203 with the bypass pipe 209, as shown in Fig. 14, the fluid pipe 2 inside the housing 203 is cut by the cutting device 70 in a state where the flow is not interrupted, allowing the fluid to flow from the fluid pipe 2 into the bypass pipe 209. Note that the process of cutting the fluid pipe 2 is substantially the same as the process of cutting the fluid pipe 2 performed when installing the flow control devices 1A and 1B of the first embodiment (see Fig. 3), and therefore a detailed description thereof will be omitted here.

[0068] 15 and 16, a plug installation step is performed in which a plug 204 serving as a flow control device is installed in the housing 203. Note that the plug installation step is also substantially the same as the plug installation step (see FIGS. 4 and 5) performed when installing the flow control devices 1A and 1B of Example 1, and therefore a detailed description thereof will be omitted here.

[0069] As shown in Figure 12(b), when the installation of the plugs 204, 204 is completed in the left and right flow control devices 201A, 201B, the water supply is cut off between the flow control devices 201A, 201B in the fluid pipe 2, and the flow path is switched to the bypass pipe 209 via the flow control devices 201A, 201B.

[0070] After switching the flow path to the bypass pipe 209, the drain valve 232b of the drain pipe 231b connected to the secondary side drain port 213b from the plug 204 inside the housing 203 of the flow control device 201A is opened, and the fluid inside the housing 203 is discharged to the outside via the drain port 213b, the drain pipes 234b, 231b, and the drain valve 232b, as shown in Figure 16.

[0071] As shown in Figure 12(b), the valve 201 side of the flow control devices 201A and 201B is the secondary side, so for the flow control device 201A, the fluid flows out to the outside from the drain port 213b on the secondary side (right side in the figure) of the plug 204, while for the flow control device 201B, the fluid is discharged to the outside from the drain port 213a on the secondary side (left side in the figure) of the plug 204.

[0072] After the fluid in the fluid pipe 2 between the flow control devices 201A and 201B has been completely discharged, a predetermined section of piping 2h including the valve 201 is cut and removed, as shown in Figure 12(c). Furthermore, by cutting and removing piping 2h, pipe caps 2b are hermetically fixed to the end openings of short pipes 2a, 2a, which are part of the fluid pipe 2 left in the secondary-side side bodies 206, 206 of the casings 203, 203 of the flow control devices 201A and 201B, to seal off the water.

[0073] [Plug removal process] After piping 2h is cut and removed, plugs 204, 204 of flow control devices 201A, 201B are taken out and removed from housing 203. Therefore, before removing plugs 204, 204, a process of equalizing the fluid pressure on the primary side and secondary side of flow control devices 201A, 201B is first carried out. Note that since the secondary sides of flow control devices 201A, 201B are in the same connected space, the following describes the process of equalizing the fluid pressure on the primary side and secondary side of flow control device 201A, and omits the description of the process of equalizing the fluid pressure on the primary side and secondary side of flow control device 201B.

[0074] Specifically, as shown in Figures 17(a), (b) and 18, a pair of drain ports 213a, 213b that open to sandwich a plug 204 installed inside the housing 203, and a communicating pipe section 235 that can communicate the pair of drain ports 213a, 213b with each other form a communicating passage 235a that can open and close the flow path blocked by the plug 204.

[0075] 16, the drain ports 213a, 213b are formed on both sides (left and right sides) of the horizontal seat portion 208a in the bottom portion 207 of the main body portion 205 of the casing 203, opening at approximately the same height below the pipe axis of the fluid pipe 2. More specifically, the drain ports 213a, 213b are formed to open on the flat upper surface 207a of the bottom portion 207 of the main body portion 205 of the casing 203, and therefore the drain ports 213a, 213b are located on the same horizontal plane. Furthermore, the drain ports 213a, 213b are formed as approximately circular holes, and because they are formed in the bottom portion 207, chips and the like that accumulate on the upper surface 207a of the bottom portion 207 during the cutting process can be uniformly collected from the outer periphery of the drain ports 213a, 213b, which are circular holes, and suitably discharged. Furthermore, since each drain port 213a, 213b is formed along the pipe axis of the fluid pipe 2 in a plan view, chips and the like that move along with the fluid in the pipe flowing along the pipe axis can be efficiently discharged.

[0076] As shown in Figures 17(a) and 17(b), the drain pipes 234a and 234b are straight pipes with a generally circular cross section that extend downward in a generally vertical direction from the periphery of each drain port 213a and 213b formed through the bottom 207. As shown in Figures 17(a), 17(b), and 18, the drain pipes 231a and 231b are curved pipes with a generally circular cross section that are hermetically flanged to the lower ends of the drain pipes 234a and 234b, bend toward the rear, and extend in a generally horizontal direction. As shown in Figure 18, the drain valves 232a and 232b are hermetically flanged to the drain pipes 231a and 231b, and the pipes can be opened and closed using an operating tool (not shown). The connecting pipes 233a and 233b are curved pipes that are hermetically flanged to the drain valves 232a and 232b, and extend in a generally horizontal direction. Furthermore, a connection valve 18 is provided at the top of the connecting pipe 233a.

[0077] Then, connecting pipe 233a is hermetically flange-connected to drain valve 232a, and connecting pipe 233b is hermetically flange-connected to drain valve 232b, so that connecting pipes 233a and 233b are hermetically flange-connected to each other. As a result, drain pipes 234a and 234b, drain pipes 231a and 231b, drain valves 232a and 232b, and connecting pipes 233a and 233b form communicating pipe section 235 that is generally U-shaped in plan view, and communicates between the primary side and secondary side of plug 204 inside housing 203.

[0078] 17(a), 17(b), and 18, the communicating pipe section 235 includes a horizontal pipe section 235b including drain pipes 231a, 231b, drain valves 232a, 232b, and connecting pipes 233a, 233b extending in a substantially horizontal direction, and a pair of vertical pipe sections 235c interposed between the pair of drain ports 213a, 213b and the horizontal pipe section 235b and extending in a substantially vertical direction. The vertical pipe section 235c is composed of drain pipes 234a, 234b and vertical sections formed in front of the drain pipes 231a, 231b.

[0079] Next, after forming a communication passage 235a using drain ports 213a, 213b and communication pipe portion 235, drain valves 232a, 232b are opened, so that, as shown in FIG. 18, the fluid on the primary side of plug 204 inside housing 203 flows from drain port 213a into drain pipes 234a, 231a, drain valve 232a, and connecting pipe 233a, and then flows from connecting pipe 233b, drain valve 232b, and drain pipes 231b, 234b via drain port 213b into the secondary side of plug 204 inside housing 203 and the inside of short pipe 2a (see FIG. 13(d)). Then, while air is being released from the air vent plug 15 of the housing 203, the housing 203 and the inside of the short pipe 2a on the secondary side of the plug 204 are filled with fluid, and water pressure approximately the same as that on the primary side is applied to the secondary side of the plug 204 to check for leakage, and then the air vent plug 15 is closed after it is confirmed that the air has been released from the short pipe 2a.

[0080] Next, as shown in Figures 17(a) and 18, one end of a connecting pipe 19 is connected to an air vent plug 16 provided at the top of the main body 205 of the housing 203, and the other end of the connecting pipe 19 is connected to a connecting valve 18 provided at the top of the connecting pipe 233a to form a branched communicating passage 19a, thereby connecting the inside of the housing 203 with the inside of the check valve device 50 as a storage section and the inside of the cylindrical member 90a.

[0081] Then, the operating part 18a (see FIG. 17(b)) of the connection valve 18 is opened to supply the fluid inside the communication passage 235a and the housing 203 to the cylindrical member 90a, and the pressure inside the gate valve device 50 and the cylindrical member 90a is equalized to the pressure inside the housing 203. Next, as shown in FIG. 19, with the pressure inside the housing 203 and the pressure inside the cylindrical member 90a being approximately equal, the valve element 50c is opened and the drive mechanism 90b of the insertion device 90 is operated to lift the plug 204. Once the plug 204 is accommodated in the cylindrical member 90a, the valve element 50c is moved into the valve box 50a to close the inside of the housing 203. This creates a new flow path consisting of the bypass pipe 209 (see FIG. 13(e)).

[0082] In this way, by opening a pair of drain ports 213a, 213b that open at approximately the same height within the housing 203, whose flow path is blocked by the plug 204, the fluid communicates through the communicating pipe section 235, so that no differential head pressure occurs within the housing 203 that sandwiches the plug 204, and the plug 204 can be removed while the housing 203 is in an environment of appropriate fluid pressure.

[0083] In addition, the communicating pipe section 235 connected to the drain ports 213a, 213b is partially composed of a horizontal pipe section 235b that is approximately parallel to the pipe axis of the fluid pipe 2, making it less likely that a differential pressure in the head pressure will occur within the housing 203 that sandwiches the plug 204.

[0084] Furthermore, the drain pipes 231a, 231b of the communicating pipe section 235 extend to the rear of the housing 203, and a portion of the horizontal pipe section 235b protrudes from the bottom of the housing 203 in the outer diameter direction (rearward in this example), so that the connecting pipes 233a, 233b can be installed and removed and the drain valves 232a, 232b and the connecting valve 18 can be opened and closed in a space that does not interfere with the fluid pipe 2, thereby improving workability.

[0085] After the plug 204 is placed inside the cylindrical member 90a and the valve box 50a is closed with the valve body 50c, the fluid inside the cylindrical member 90a is discharged through a drain plug (not shown) provided at the bottom, the insertion device 90 is removed from the check valve device 50, and the plug 204 is removed. Next, a cylindrical member 90a containing an inner lid 45 attached to a valve hanging fitting is connected in a sealed manner to the upper side of the valve box 50a, and the air vent plug 16 on the main body 205 of the housing 203 is connected to a drain plug (not shown) at the bottom of the cylindrical member 90a with a connecting pipe (not shown) to communicate between the inside of the housing 203 and the inside of the cylindrical member 90a, and the cylindrical member 90a is filled with fluid while air is vented from an air vent valve (not shown) provided at the top of the cylindrical member 90a, and water pressure approximately the same as that inside the fluid pipe 2 is applied inside the cylindrical member 90a to check for leaks, and then the air vent valve (not shown) is closed after confirming that the air inside the cylindrical member 90a has been vented.

[0086] 20, with the pressure inside the housing 203 and the pressure inside the cylindrical member 90a at approximately the same level, the valve body 50c inside the valve box 50a is opened, and the drive mechanism 90b of the insertion device 90 is operated to lower the inner lid 45, which is placed on top of the housing 203 and fixed with the fixing pin 28. After the inner lid 45 is fixed, the fluid inside the cylindrical member 90a is drained from a drain plug (not shown) provided at the bottom, and the insertion device 90 and the gate valve device 50 are removed from the housing 203.

[0087] 21(b), the lid 30 is placed on top of the housing 203 from above the inner lid 45, and the flange 3e of the main body 205 and the lid 30 are fastened together with a plurality of fastening members 95 consisting of bolts and nuts to form a hermetic connection, thereby completing the removal process of the plug 204. As shown in FIG. 13(e), when the removal of the plugs 204, 204 is completed by the left and right flow restrictors 201A, 201B, the flow path switches to the bypass pipe 209.

[0088] Finally, as shown in Figure 21(a), the drain valves 232a, 232b are closed, the connecting pipes 233a, 233b are removed from the drain valves 232a, 232b, and the flange covers 236a, 236b are attached to the end openings of the drain valves 232a, 232b, completing the installation (see Figure 13(e)).

[0089] [Actions and Effects] As described above, the flow control devices 1A, 1B as embodiment 1 of the present invention are composed of a housing 3 that is hermetically fitted around a fluid pipe 2 that forms a flow path, and a plug 4 that is removably installed inside the housing 3 and acts as a fluid control device that blocks the flow path, and the housing 3 at least has drain ports 13a, 13b as a pair of openings that open on either side of the plug 4, and a communicating pipe section 35 that forms a communicating passage 35a that connects the pair of drain ports 13a, 13b to each other in an openable and closable manner, and the pair of drain ports 13a, 13b open at approximately the same height position (see Figures 6 to 8).

[0090] According to this, by opening a pair of drain ports 13a, 13b that open at approximately the same height within the housing 3, whose flow path is blocked by the plug 4, the fluid communicates via the communicating pipe section 35, so that no differential head pressure occurs within the housing 3 that sandwiches the plug 4, and the plug 4 can be attached and detached within the housing 3 in an environment of appropriate fluid pressure.

[0091] Furthermore, flow control devices 201A and 201B as embodiment 2 of the present invention are comprised of a housing 203 that is hermetically fitted onto a fluid pipe 2 that forms a flow path, and a plug 204 that is detachably installed within housing 203 and acts as a fluid control device that blocks the flow path, and housing 203 at least has drain ports 213a and 213b as a pair of openings that open on either side of plug 204, and a communicating pipe section 235 that forms a communicating passage 235a that connects the pair of drain ports 213a and 213b to each other in an openable and closable manner, and the pair of drain ports 213a and 213b open at approximately the same height position (see Figures 17 and 18).

[0092] According to this, by opening a pair of drain ports 213a, 213b that open at approximately the same height within the housing 203, whose flow path is blocked by the plug 204, the fluid communicates via the communicating pipe section 235, so that no differential pressure in the head pressure occurs within the housing 203 that sandwiches the plug 204, and the plug 204 can be attached and detached within the housing 203 in an environment of appropriate fluid pressure.

[0093] Furthermore, by including at least horizontal pipe portions 35b, 235b extending in a substantially horizontal direction, the movement of the fluid passing through the communicating pipe portions 35, 235 can be stabilized.

[0094] Furthermore, drain valves 32a, 32b, 232a, 232b are provided in the horizontal pipe sections 35b, 235b as opening and closing valves for opening and closing the communicating passages 35a, 235a, so that the communicating passages 35a, 235a can be opened and closed appropriately without being affected by head pressure.

[0095] Furthermore, a connecting pipe 19 is provided which constitutes a branched communicating passage 19a which connects the cylindrical member 90a, which serves as a storage section capable of accommodating the plugs 4, 204 removed from the housings 3, 203, to the communicating passages 35a, 235a. This makes it possible to make the pressure inside the cylindrical member 90a approximately the same as that of 35a, 235a, so that the plugs 4, 204 can be removed in an even more stable state.

[0096] Furthermore, since one end of the connecting pipe 19 is connected to the connecting pipes 33b, 233a that are removed after the plug is installed, the connecting hole of the connecting pipe 19 does not remain in the housing 3, 203 or the drain pipe, etc., thereby preventing the occurrence of water leakage, etc.

[0097] Furthermore, the housing 3, 203 is provided with an air vent plug 15 as an air vent portion, so that the fluid in the pipe can be filled while air is being vented from inside the housing 3, 203.

[0098] Furthermore, the communicating pipe section 235 of Example 2 further includes a pair of vertical pipe sections 235c that are interposed between the pair of drain ports 213a, 213b and the horizontal pipe section 235b and extend in an approximately vertical direction, thereby allowing the height position of the horizontal pipe section 235b to be set with a high degree of freedom.

[0099] Furthermore, the pair of drain ports 213a, 213b in the second embodiment are open to the bottom 207 of the housing 203, so that the shape of the housing 203 in plan view can be prevented from becoming enlarged.

[0100] Furthermore, the fluid flow path is blocked by sealingly fitting a housing 3, 203 around the fluid pipe 2, cutting the fluid pipe 2 inside the housing 3, 203, and installing a plug 4, 204, so that the flow path can be blocked while being placed in an environment of appropriate fluid pressure.

[0101] Furthermore, after the flow path is blocked by installing the plugs 4, 204, the flow path is opened by removing the plugs 4, 204 from the housings 3, 203, so the flow path can be opened while being placed in an environment of appropriate fluid pressure.

[0102] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

[0103] For example, in the above-mentioned Examples 1 and 2, examples of openings are shown in which drain ports 13a and 13b formed in the lower part of the peripheral wall of the housing 3 and drain ports 213a and 213b formed in the bottom 207 of the housing 203 are used, but the present invention is not limited to this, and openings other than drain ports formed in locations other than the lower part or bottom of the housing (for example, air vent holes or newly created holes for connecting passages, etc.) may also be used.

[0104] In addition, in the first and second embodiments, the communicating pipes 35, 235 are formed outside the housings 3, 203, but the present invention is not limited to this, and they may be provided inside the housings.

[0105] In the first and second embodiments, the communicating pipe portion 35, 235 has at least the horizontal pipe portion 35b, 235b, but the present invention is not limited to this, and the horizontal pipe portion may not necessarily be included. In the second embodiment, the communicating pipe portion 235 has the vertical pipe portion 235c, but the present invention is not limited to this, and the vertical pipe portion may not necessarily be included.

[0106] In addition, in the above-mentioned Examples 1 and 2, the drain valves 32a, 32b, 232a, 232b are illustrated as being provided in the horizontal pipe sections 35b, 235b, but the present invention is not limited to this, and they may be provided in the communicating pipe sections 35, 235 other than the horizontal pipe sections 35b, 235b.

[0107] Furthermore, in the above-described first and second embodiments, the communicating pipe portion 35, 235 is exemplified as being provided at a rear position of the housing 3, 203, but the present invention is not limited to this, and the communicating pipe portion 35, 235 may be provided at a position vertically below the housing 3, 203 so as not to protrude in the outer diameter direction of the housing 3, 203.

[0108] Furthermore, in the first and second embodiments, the communicating pipe portion that constitutes the communicating passage that connects the pair of openings in an openable and closable manner is exemplified as having drain pipes 31a, 31b, 231a, 231b, drain valves 32a, 32b, 232a, 232b, and connecting pipes 33a, 33b, 233a, 233b, but the present invention is not limited to this and may include pipe bodies other than drain pipes and connecting pipes, valves other than drain valves, etc.

[0109] Furthermore, in the above-described Example 1, the connecting pipes 33a and 33b, which are part of the communicating pipe section 35, are removed after the plug 4 is removed, and in the above-described Example 2, the connecting pipes 233a and 233b, which are part of the communicating pipe section 235, are removed after the plug 204 is removed. However, the present invention is not limited to this, and it is not necessarily necessary to remove part of the communicating pipe section after the fluid control device is removed, and the entire communicating pipe section may remain.

[0110] Furthermore, in the first and second embodiments, the drain ports 13a, 13b, 213a, 213b are connected by the communicating pipe portions 35, 235 to allow air to be released from the air vent plug 15 of the casings 3, 203 while filling the interior of the casings 3, 203 and the fluid pipe 2 and short pipe 2a on the secondary side of the plugs 4, 204 with fluid, but the present invention is not limited to this. An air valve (not shown) may be provided in an appropriate position in the casings 3, 203, or an air valve (not shown) may be provided in a location other than the casings 3, 203, such as the fluid pipe 2 and short pipe 2a on the secondary side of the plugs 4, 204, and the fluid may be filled in the pipe body on the secondary side of the fluid control while air is released using the air valve.

[0111] Furthermore, in the above-mentioned Examples 1 and 2, a form in which a plug 4, 204 (stop valve) is applied is exemplified as an example of a fluid control device capable of blocking a flow path, but the present invention is not limited to this, and the fluid control device may be anything that can control the flow of a fluid as long as it has at least the function of being able to block the flow path, and may be a valve body such as a gate valve, a switching valve, or a butterfly valve that can open and close a flow path.

[0112] In addition, in the first and second embodiments, the housings 3, 203 are illustrated as having a divided structure divided into upper and lower halves, but the present invention is not limited to this. For example, the housings 3, 203 may have a divided structure divided into three or more circumferential sections. Furthermore, while the housings 3, 203 are made of steel, they may also be made of cast iron. Furthermore, while the upper housings 3a, 203a and the lower housings 3b, 203b are integrated by welding, they may also be integrated by fasteners such as bolts.

[0113] Furthermore, in the second embodiment, the forward section 214 to which the bypass pipe 209 is connected is formed on the peripheral wall of the main section 205 in the casing 203, but the present invention is not limited to this, and the forward section 214 may be formed on the bottom 207. [Explanation of symbols]

[0114] 1A, 1B, 201A, 201B flow control device 2, 204 fluid pipe 3, 203 housing 4, 204 Plug (fluid control) 5, 205 main fuselage 6, 206 Side body 7, 207 bottom 7a, 207a top surface 9, 209 Bypass pipe 13a, 13b, 213a, 213b Drain port (opening) 15, 16 Air bleed plug (air bleeder) 18 Connection valve 19 Connecting pipe 19a Branching passage 30A, 30B Branch pipe housing 31a, 31b, 231a, 231b Drain pipes 32a, 32b, 232a, 232b Drain valve (on-off valve) 33a,33b, 233a,233b connecting pipe 35, 235 Communication pipe section 35a, 235a communication path 35b, 235b horizontal pipe section 235c Vertical pipe section 50 Gate valve device 70 Cutting device 90 Insertion device (receptacle) 90a Cylindrical member 100 Flow meter equipment 201 Valve

Claims

1. A flow restrictor device comprising a housing that is hermetically fitted onto a fluid pipe that forms a flow path, and a fluid restrictor that is detachably installed within the housing and blocks the flow path, The housing has at least a pair of openings that are opened to sandwich the fluid control device, and a communicating pipe section that forms a communicating passage that connects the pair of openings in an openable and closable manner, the pair of openings opening at approximately the same height, and a branch communicating passage that connects the communicating passage to a storage section that can store the fluid control device removed from the housing is provided.

2. 2. The flow control device according to claim 1, wherein the communication pipe portion includes at least a horizontal pipe portion extending in a substantially horizontal direction.

3. 3. The flow restrictor according to claim 2, wherein an on-off valve for opening and closing the communication passage is provided in the horizontal pipe portion.

4. 4. The flow control device according to claim 2, wherein the communicating pipe section further comprises a pair of vertical pipe sections interposed between the pair of openings and the horizontal pipe section and extending in a substantially vertical direction.

5. 2. The flow restrictor device according to claim 1, wherein the pair of openings are open to the bottom of the housing.

6. 2. The flow restrictor device according to claim 1, wherein the housing is provided with an air vent.

7. A flow path switching method using a flow control device as described in claim 1, characterized in that the flow path is blocked by sealingly fitting the housing onto the fluid pipe, cutting the fluid pipe inside the housing, and installing the flow control device.

8. 8. The flow path switching method using a flow restrictor according to claim 7, wherein the flow path is opened by removing the flow restrictor from the housing after blocking the flow path.

Images