Method for Removing Fluid Tubes

Abstract

To provide a cutoff method of a fluid pipe which can cut off the fluid pipe in a box body while tightly surrounding a conduit part and a branch part of the fluid pipe by the box body.SOLUTION: A cutoff method of a fluid pipe 1 for cutting off a part of the fluid pipe 1 in a non-interrupted state has: a step in which at least a box body 5 tightly surrounds a conduit part 2a of the fluid pipe 1 and a branch part 2b branched from the conduit part 2a, and a branch straight pipe 4 connected to the branch part 2b; and a step in which a center drill 72b drills a position avoiding a seal material which is interposed between the branch part 2b and the branch straight pipe 4 by using a cutter 72 having a hole saw 72a and the center drill 72b in the box body 5, and the hole saw 72a cuts off the conduit part 2a of the fluid pipe 1 and the branch straight pipe 4 so as to be separable.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a flow restrictor in which a fluid is continuously restricted within a housing that seals a fluid pipe, and to a method for installing the flow restrictor. [Background technology]

[0002] Conventionally, when a failure such as a leak occurs in one of the pipeline components that make up a flow path, a plug device (flow control) is installed in the piping around the failed component in a continuous flow state as necessary, the water is stopped downstream of the plug device, and the distribution branch pipe and the downstream branch pipe are repaired, or a switching valve (flow control) is installed in a continuous flow state and a temporary bypass route is constructed to detour around the flow path via the switching valve, and the water is stopped in the flow path near the failed component to a minimum extent, and the component is repaired or replaced (see, for example, Patent Documents 1 and 2).

[0003] In addition, the switching valve controls the flow of fluid toward the main pipeline and the bypass pipeline using a valve body installed inside, making it possible to carry out construction under uninterrupted flow conditions without blocking the entire flow path. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-7232 A (page 4, figure 3) [Patent Document 2] JP 2005-240892 A (page 3, figure 3) Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Documents 1 and 2, when a failure such as leakage occurs in the pipeline itself, valves, joints, irregular pipes, etc. that constitute the branch pipeline branching off from the main pipeline (pipe section), if the failed component is located near the branch point of the main pipeline, it is not possible to secure space to install a fluid control device near the failed component in the branch pipeline, so in order to block the flow of fluid around the failed component, a fluid control device must be installed on both the upstream and downstream sides of the branch point of the main pipeline, and a fluid control device must be installed downstream of the failed component in the branch pipeline to block the flow near the failed component, and further, temporary bypass paths must be installed separately to bypass the main pipeline side and the branch pipeline side. This causes problems in that the number of temporary bypass paths installed in the flow path increases, and the area of ​​water outage becomes wide, making the construction complicated. In this case, by using a switching valve as the fluid control device, it is possible to install a bypass path via these switching valves, but there is still a problem in that the number of temporary bypass paths installed in the flow path increases, making the construction complicated.

[0006] The present invention has been made in response to these problems, and aims to provide a flow control device and an installation method for a flow control device that can reduce the number of temporary bypass routes installed in a flow path and narrow the area of ​​water interruption. [Means for solving the problem]

[0007] In order to solve the above problems, the flow restrictor of the present invention comprises: a housing that hermetically fits a pipeline portion of a fluid pipe and a branch portion branching off from the pipeline portion, and a fluid regulator that is installed in a cut-away portion between the pipeline portion and the branch portion in the housing and controls a flow path in the fluid pipe, The housing has an opening into which a cutter capable of cutting between the pipeline portion and the branch portion is inserted. According to this feature, the pipeline section and branch section of the fluid pipe are cut off together with a cutter inserted from an opening inside a sealed housing, and a fluid control device is installed at the cut point inside the housing in an uninterrupted flow state. This makes it possible to simultaneously control the fluid flowing in the pipeline direction and the branch direction, thereby reducing the number of temporary bypass paths installed in the flow path and narrowing the area of ​​water interruption.

[0008] The housing has the opening through which the pipe portion can be cut into a substantially C-shape by the cutter. According to this feature, the cutter is inserted through the opening to cut the pipeline section together with the branching section of the fluid pipe into an approximately C-shape, thereby reducing the area of ​​the fluid pipe that needs to be cut, thereby making it possible to miniaturize various devices for attaching the flow control device.

[0009] The fluid pipe includes a branch pipe connected to the branch portion, and the housing is characterized in that it hermetically fits around a connection portion between the branch portion and the branch pipe. According to this feature, the pipeline portion of the fluid pipe and the connection portion between the branch portion and the branch pipe can be cut off together within a sealed housing using a cutter inserted through an opening.

[0010] The housing is made up of a plurality of divided bodies joined to each other, and each of the divided bodies extends in the pipeline direction of the pipeline portion and in the branching direction of the branching portion. According to this feature, by joining each divided body extending in the pipeline direction of the pipeline section of the fluid pipe and in the branching direction of the branching section by welding, bolt and nut joints, etc. to form a casing, even if the pipeline section and the branching section are removed within the casing, the rigidity of the fluid pipe can be maintained by the casing which is fitted tightly around it.

[0011] The housing is characterized by having a seat in which the flow restrictor is sealingly mounted. According to this feature, by installing the fluid regulator in a seat inside the housing, leakage of fluid between the fluid regulator and the housing can be prevented, and initial flow path control can be performed by the fluid regulator installed inside the housing.

[0012] A method for attaching the flow control device to the fluid pipe in an uninterrupted flow state, comprising the steps of: sealingly surrounding the pipeline portion and the branch portion of the fluid pipe with the housing; a step of inserting the cutter through the opening and cutting the fluid pipe from the pipe line portion to the branch portion; inserting the fluid control valve through the opening to hermetically close the inside of the housing; The present invention is characterized by the following: According to this feature, the pipeline section and branch section of the fluid pipe are cut off together with a cutter inserted from an opening inside a sealed housing, and a fluid control device is installed at the cut point inside the housing in an uninterrupted flow state, thereby making it possible to simultaneously control the fluid flowing in the pipeline direction and the branch direction, thereby reducing the number of temporary bypass paths installed in the flow path, simplifying construction and narrowing the area of ​​water interruption. [Brief description of the drawings]

[0013] [Figure 1] 1 is a front cross-sectional view showing a housing of a flow restrictor attached to a fluid pipe in an embodiment. FIG. [Diagram 2] FIG. 13 is a top view showing the housing attached to the fluid conduit. [Diagram 3] 1 is a side view showing a cutting machine installed in an opening of a housing via a working valve. FIG. [Figure 4] FIG. 4 is a partially enlarged cross-sectional side view showing a cutter for cutting a fluid pipe. [Diagram 5] 13 is a top view showing the inside of the housing cut by a cutter. FIG. [Figure 6] 13 is a side view showing an installation machine installed in an opening of a housing via a working valve. FIG. [Figure 7] 11 is a side view showing a flow control device installed in a housing by an installation machine. FIG. [Figure 8]FIG. 4 is a partial front cross-sectional view showing a flow control device installed in a housing. [Figure 9] This is a top view showing an example of construction when installing a flow control device to repair or replace a faulty valve installed in a branch straight pipe. [Figure 10] 10 is a partially enlarged cross-sectional side view showing a diameter adjusting member and an inserting member in Modification 1. FIG. [Figure 11] 13 is a top view showing a housing attached to a fluid pipe in Modification 2. FIG. [Figure 12] 13 is a top view showing a housing attached to a fluid pipe in Modification 3. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A flow restrictor and a method for attaching a flow restrictor according to the present invention will be described below with reference to the following examples. EXAMPLES

[0015] In the embodiment, as a flow control device and its installation method, a series of steps from cutting out a predetermined portion of an existing fluid pipe 1 constituting a pipeline component within a housing 5 to installing a flow control device 10 at the cut-out portion in an uninterrupted flow state will be described with reference to Figures 1 to 8. Note that the fluid in the fluid pipe 1 is clean water in this embodiment, but it may be, for example, industrial water, sewage, gas, or a gas-liquid mixture of gas and liquid.

[0016] The fluid pipe 1 of this embodiment is a ductile cast iron pipe, and as shown in Figs. 1 and 2, it is composed of a T-shaped pipe 2, which is an irregular pipe having a pipe line portion 2a and a small-diameter branch portion 2b branching from the pipe line portion 2a, a pair of straight pipes 3, 3 connected to both ends of the pipe line portion 2a of the T-shaped pipe 2 and extending in the pipe line direction, and a branch straight pipe 4 (branch pipe, see Fig. 3) connected to the branch portion 2b of the T-shaped pipe 2 and extending in the branch direction, and is formed in a substantially circular shape in cross section. In this embodiment, the pipe line direction and branch direction of the fluid pipe 1 extend in a substantially horizontal direction, and therefore the T-shaped pipe 2 is arranged to form a T shape in a plan view. The fluid pipe according to the present invention may be made of other metals such as cast iron and steel, or made of concrete, vinyl chloride, polyethylene, polyolefin, etc. Furthermore, the inner peripheral surface of the fluid pipe may be covered with an epoxy resin layer, mortar, plating, etc., or the inner peripheral surface of the fluid pipe may be covered with an appropriate material by powder coating.

[0017] The fluid pipe of the present invention may be composed of a plurality of pipes connected together, including at least a special-shaped pipe, as in this embodiment, or may be a single special-shaped pipe, such as a welded steel product. The special-shaped pipe is a general term for pipes having at least a portion of various special-shaped parts, such as a curved pipe section, a branch section (branch pipe), a cross section (cross pipe), a section with a different diameter, a joint ring section, a short pipe section, a drain section, etc.

[0018] First, as shown in FIG. 1, a housing 5 constituting a flow control device is fitted around the fluid pipe 1 in a sealed manner. The housing 5 has a multi-part structure, and in this embodiment, it is mainly composed of a housing body 50 composed of a first divided body 51 (divided body) constituting the upper side and a second divided body 52 (divided body) constituting the lower side, and a pair of joint covers 53, 53 divided into two in the vertical direction. The divided structure of the housing 5 is not limited to this embodiment, and may be divided, for example, in the horizontal direction, and may be divided into a predetermined number of parts, such as three or more. In this embodiment, the divided housings are joined together by welding, but the joining is not limited to this and may be joined by fastening members such as bolts and nuts via packing, for example.

[0019] As shown in FIG. 2, the housing body 50 is formed in an approximately T-shape when viewed from above and is made up of a conduit housing portion 50a extending in the conduit direction along the conduit portion 2a of the T-shaped pipe 2, a branch housing portion 50b extending in the branching direction along the branch straight pipe 4 connected to the branch portion 2b of the T-shaped pipe 2, and a bottomed, approximately cylindrical flow-control housing portion 50d (see FIG. 3) that extends in the vertical direction between the conduit housing portion 50a and the branch housing portion 50b and has an opening portion 50c that opens upward.

[0020] A pair of joint covers 53, 53 surrounding the connection parts 30, 30 between both ends of the pipe section 2a of the T-shaped pipe 2 and the pair of straight pipes 3, 3 are integrally joined to the mounting flanges 50e, 50e in the pipe casing 50a. A pair of first pressure rings 54, 54 divided into upper and lower parts to prevent separation are attached in a sealed manner to the opening of the joint covers 53, 53 extending to the connection ends of the straight pipes 3, 3. Here, the sealing position may be above the T-shaped pipe 2. Furthermore, before installation of the casing 5, the connection parts 30, 30 may be reinforced with separation prevention fittings described later in Modification 2.

[0021] The branch housing part 50b extends to the connection end of the branch straight pipe 4 that is connected to the branch part 2b of the T-shaped pipe 2, and a second pressing ring 55 that is divided into upper and lower parts and prevents separation is attached in a sealed manner to the opening of the branch housing part 50b. The dividing direction and number of the first pressing ring 54 and the second pressing ring 55 are not limited to those in this embodiment.

[0022] The opening 50c of the flow-restricting casing section 50d has a radial center located on the branching section 2b of the T-shaped pipe 2, and is formed above the branching point between the pipe line section 2a and the branching section 2b of the T-shaped pipe 2. The opening 50c in this embodiment is formed to include the connection section 40 between the branching section 2b of the T-shaped pipe 2 and the branch straight pipe 4. Before the installation of the casing 5, the connection section 40 may be reinforced with a detachment prevention fitting, which will be described later in Modification 2.

[0023] Next, as shown in FIG. 3, an operation valve 6 capable of closing the opening 50c is attached to the mounting flange 50f of the flow-restricting casing portion 50d of the casing 5, and a cutting machine 7 is installed above the operation valve 6.

[0024] The cutting machine 7 is mainly composed of a mounting flange tube 71, a cutter 72 for cutting the fluid pipe 1, and a drive mechanism 73 for rotating the cutter 72 in the mounting flange tube 71 and moving the cutter 72 up and down. The cutter 72 is composed of a hole saw 72a with a cutting blade along the circumferential direction at the tip, and a center drill 72b arranged coaxially with the rotation axis of the hole saw 72a and protruding beyond the cutting blade. As shown by the chain line A in FIG. 2, the hole saw 72a of the cutter 72 is configured concentrically with the opening 50c of the flow restricting housing part 50d of the housing 5, and can be inserted into the flow restricting housing part 50d of the housing 5 from the opening 50c and advanced to a position near the bottom of the flow restricting housing part 50d.

[0025] In the specific process of cutting the fluid pipe 1 by the cutting machine 7, first, the valve body (not shown) inside the working valve 6 is withdrawn to open the opening 50c of the housing 5, and then, as shown in Fig. 4, the cutter 72 of the cutting machine 7 is rotated and advanced downward to cut the fluid pipe 1 in a state of uninterrupted flow. In this embodiment, a part of the branched portion 2b side of the pipe line portion 2a of the T-shaped pipe 2 constituting the fluid pipe 1 (see Fig. 2), the entire branched portion 2b, and a part of the branched portion 2b side of the branched straight pipe 4 connected to the branched portion 2b of the T-shaped pipe 2 are cut at once by the advancement of the hole saw 72a constituting the cutter 72. At this time, it is preferable that the center drill 72b is positioned at a position that avoids the portion of the connection portion 40 of the branched portion 2b where the sealing material is inserted, or on the branched straight pipe 4.

[0026] Also, as shown in Figure 5, on the inside of the opening 50c of the housing 5 in a plan view, there can be seen a cut opening that is approximately C-shaped in a plan view on the pipe section 2a side of the T-shaped pipe 2 when viewed from above, and a cut opening of the branch straight pipe 4.

[0027] In addition, a drain 56 (see Figs. 2 and 3) capable of discharging the fluid to the outside is attached to the bottom of the flow control housing 50d together with an openable and closable valve, so that cutting chips generated when the fluid pipe 1 is cut by the cutter 72 can be discharged to the outside together with the fluid. This drain 56 can also be used as a bypass for filling with water during the flow control operation.

[0028] Although not shown, when the fluid pipe 1 is cut by the cutter 72, the cut piece separated from the fluid pipe 1 is held in the hole saw 72a. Then, the cutter 72 is raised together with the cut piece into the mounting flange tube 71, and the opening 50c of the housing 5 is closed by a valve body (not shown) inside the working valve 6, completing the cutting operation of the fluid pipe 1. After the fluid pipe 1 is cut by the cutter 72, the pipe line portion 2a of the T-shaped pipe 2 and the branch straight pipe 4 that remain in the housing 5 are separated from each other, but are held together by the pipe line housing portion 50a and the branch housing portion 50b of the housing 5. Although not shown, the cutting machine 7 is removed with the opening 50c of the housing 5 closed by a valve body (not shown) inside the working valve 6.

[0029] Next, as shown in FIG. 6, an operation valve 6 capable of closing the opening 50c is attached to the mounting flange 50f of the flow-restricting housing portion 50d of the housing 5, so that an installation machine 8 can be installed above the operation valve 6.

[0030] The installation machine 8 is mainly composed of a mounting flange tube 81, a valve hanging fitting 82 for suspending the fluid control valve 10, and a drive mechanism 83 for vertically advancing and retreating the valve hanging fitting 82 within the mounting flange tube 81. The fluid control valve 10 of this embodiment is a so-called plug mainly composed of a partition wall 11 and an upper cover portion 12, and a first seal member S1 is attached to the partition wall 11 from the lower end to both sides, and an annular second seal member S2 is attached to the outer periphery of the upper cover portion 12. The first seal member S1 and the second seal member S2 are composed of elastic materials such as rubber, elastomer, resin, etc., including NBR, SBR, and CR.

[0031] The specific installation process of the fluid control device 10 using the installation machine 8 is as follows: first, the valve body (not shown) inside the working valve 6 is retracted to open the opening 50c of the housing 5, and then, as shown in FIG. 7, the fluid control device 10 suspended by the valve hanging bracket 82 of the installation machine 8 is advanced downward and the fluid control device 10 is inserted into a predetermined position within the flow-control housing section 50d of the housing 5.

[0032] 8, side wall steps 50g, 50g (seats) that are generally U-shaped when viewed from above and protrude further inward than other portions of the housing 5 are formed to face each other on the side inner wall surface of flow-controlling housing section 50d of housing 5. Therefore, when flow control section 10 is inserted into flow-controlling housing section 50d of housing 5, both side portions of partition wall 11 of flow control section 10 are guided by side wall steps 50g, 50g, preventing the insertion position of flow control section 10 from shifting.

[0033] Also, a bottom wall step 50h (seat) continuous with the side wall steps 50g, 50g is formed on the bottom inner wall surface of the flow-restricting housing part 50d of the housing 5 (see FIG. 5). Therefore, by inserting the flow-restricting housing part 50d of the housing 5 to a predetermined depth, the first seal member S1 attached from the lower end of the partition wall 11 of the flow-restricting housing part 50d to both side portions is pressed into the bottom wall step 50h and the side wall steps 50g, 50g formed in the flow-restricting housing part 50d in a sealed manner, and the annular second seal member S2 attached around the outer periphery of the upper lid part 12 of the flow-restricting housing part 50d of the housing 5 is pressed against the side inner wall surface on the opening 50c side of the flow-restricting housing part 50d of the housing 5.

[0034] In this way, the flow control device 10 is installed within the flow control housing section 50d of the housing 5 so as to separate the pipe section 2a and the branch section 2b of the T-shaped pipe 2, thereby preventing leakage of fluid between the flow control device 10 and the housing 5.

[0035] Next, the pressure screws N, which are provided in a circumferential direction of the opening 50c of the housing 5 and can be advanced and retreated in the radial direction, are advanced in the inner radial direction of the opening 50c (see Figs. 2 and 8). As a result, the pressure screws N engage the upper cover part 12 of the fluid control device 10 so as to press it from above, preventing the fluid control device 10 from slipping out of the opening 50c of the housing 5.

[0036] In this way, the set screw N presses the upper cover portion 12 of the flow control device 10 from above, making it possible to remove the installation device 8 and the operation valve 6 from the housing 5.

[0037] Next, lid member 57, which is annular when viewed from above, is fixed to mounting flange 50f of flow-controlling casing portion 50d of casing 5. At this time, lid member 57 presses the upper surface of upper lid portion 12 of fluid control 10 from above, and prevents fluid control 10, together with pressure screw N, from slipping out of opening 50c of casing 5. This completes the installation of fluid control 10 in casing 5. Needless to say, when cutting or installing valves while the flow is uninterrupted, lids are hermetically attached to all windows, through-holes, working holes, etc.

[0038] As described above, the flow control device of this embodiment is configured to cut out both the pipe line section 2a and the branch section 2b branching off from the pipe line section 2a of the T-shaped pipe 2 that constitutes the fluid pipe 1 within the casing 5 that is hermetically fitted around the pipe line section 2a and the branch section 2b branching off from the pipe line section 2a, using the hole saw 72a of the cutter 72 of the cutting machine 7 inserted through the opening 50c, and to install a flow control device 10 at the cut-out point within the casing 5. This makes it possible to simultaneously control the flow of fluid flowing in the pipe line direction of the pipe line section 2a of the T-shaped pipe 2 and in the branching direction of the branch section 2b, thereby reducing the number of temporary bypass paths installed in the flow path and narrowing the area of ​​water outage.

[0039] Specifically, as shown in FIG. 9, for example, even if a failed valve V1 is located near a branch point of a fluid pipe 1 and there is no space to install an inserting valve V2 upstream of the failed valve V1 in a straight branch pipe 4, a housing 5 can be hermetically fitted around the pipe line section 2a and branch section 2b (see FIG. 2) of a T-shaped pipe 2 that constitutes the branch area of ​​the fluid pipe 1, and within the housing 5, the pipe line section 2a and branch section 2b can be cut off together with a hole saw 72a of a cutter 72 of a cutting machine 7, and a fluid control device 10 can be installed at the cut-out point within the housing 5, thereby blocking the flow of fluid from the pipe line section 2a of the T-shaped pipe 2 to the branch section 2b while maintaining an uninterrupted flow of fluid in the pipe direction. Therefore, in order to maintain the uninterrupted flow of the fluid in the pipe line direction in the pipe line section 2a of the T-shaped pipe 2, it is not necessary to provide valves (fluid control valves) on both the upstream and downstream sides of the branching point of the fluid pipe 1 and to temporarily provide a bypass path that detours from the branching point to the pipe line direction, as in the conventional method. By providing one fluid control valve 10, the fluid flowing in the pipe line direction of the pipe line section 2a of the T-shaped pipe 2 and the fluid flowing in the branching direction of the branching section 2b can be controlled simultaneously, making construction easier. In addition, by newly providing an inserting valve V2 downstream of the broken valve V1 in the branch straight pipe 4, a temporary bypass path (not shown) can be provided to maintain the uninterrupted flow of the fluid in the branching direction, and the water interruption range in the fluid pipe 1 can be configured as narrow as possible. The inserting valve V2 is not limited to a new valve, and an existing valve may be used.

[0040] In addition, by using the cutter 72 inserted from the opening 50c of the housing 5 to cut the pipe section 2a together with the branch section 2b of the T-pipe 2 into an approximately C-shape, the cutting range of the fluid pipe 1 can be reduced, and various devices such as the working valve 6, cutting machine 7 and installation machine 8 for attaching the flow control device can be made smaller.

[0041] In addition, when viewed from above, the inside of the opening 50c of the housing 5 can see the C-shaped cut opening on the pipe section 2a side of the T-shaped pipe 2 and the cut opening of the branch straight pipe 4 on the branch section 2b side of the T-shaped pipe 2. Therefore, by inserting the cutter 72 from the opening 50c into the housing 5, the pipe section 2a of the T-shaped pipe 2 and the branch straight pipe 4 can be easily approached.

[0042] Furthermore, since the cutter 72 has a hole saw 72a, the pipe line portion 2a and the branch portion 2b of the T-shaped pipe 2 can be cut off together by rotating the hole saw 72a, making the cutting easy.

[0043] The housing 5 is provided with a housing body 50 divided into two parts, an upper part and a lower part, which are joined to each other, and each housing body 50 is mainly composed of a pipeline housing section 50a extending in the pipeline direction along the pipeline section 2a of the T-shaped pipe 2, and a branch housing section 50b extending in the branching direction along the branch straight pipe 4 connected to the branching section 2b of the T-shaped pipe 2. By forming the housing 5 by joining each housing body 50 extending in the pipeline direction of the pipeline section 2a of the T-shaped pipe 2 and in the branching direction of the branching section 2b of the T-shaped pipe 2 by welding or the like, the rigidity of the fluid pipe 1 can be maintained by the housing 5 which is fitted tightly around the housing 5 even if the pipeline section 2a and the branching section 2b of the T-shaped pipe 2 are removed within the housing 5.

[0044] Furthermore, by installing the fluid regulator 10 in a sealed manner against the side wall steps 50g, 50g and the bottom wall step 50h within the flow-controlling housing section 50d of the housing 5, leakage of fluid between the fluid regulator 10 and the housing 5 (flow-controlling housing section 50d) can be prevented, and initial flow path control can be performed by the fluid regulator 10 installed in the flow-controlling housing section 50d of the housing 5.

[0045] In the above embodiment, the cutter 72 of the cutting machine 7 is rotated and advanced downward to directly cut off the fluid pipe 1. However, as shown in FIG. 10 as a first modified example of the present invention, a diameter adjustment member 100 (adjustment portion) may be provided within the housing 5 above the branch straight pipe 4 to adjust the pipe line portion 2a of the T-shaped pipe 2 and the branch straight pipe 4 (branch portion 2b of the T-shaped pipe 2) to have approximately the same diameter. In this case, by rotating the cutter 72 of the cutting machine 7 and moving it downward, the hole saw 72a of the cutter 72 comes into contact with the outer peripheral surface of the pipe line section 2a of the T-shaped pipe 2 having a larger diameter and the upper surface of the diameter adjustment member 100 (adjustment portion) provided at the upper end of the outer peripheral surface of the branch straight pipe 4 having a smaller diameter at approximately the same time. In other words, the hole saw 72a of the cutter 72 will not come into contact with only one side of the outer peripheral surface of the pipe line section 2a of the T-shaped pipe 2, and the resistance to the hole saw 72a during cutting acts approximately uniformly, thereby suppressing the inclination of the cutter 72, making it easier to cut off the pipe line section 2a and branch section 2b (branch straight pipe 4) of the T-shaped pipe 2 together with the cutter 72. Furthermore, it is preferable to select a material for the diameter adjustment member 100 (adjustment portion) that has the same rigidity as the pipe line section 2a and the branch straight pipe 4 of the T-shaped pipe 2 to be cut, such as cast iron or steel. By doing so, the cutting resistance applied by the cutting machine 7 to the pipe line section 2a, the branch straight pipe 4, and the diameter adjustment member 100 (adjustment portion) can be made uniform, making cutting even easier.

[0046] In addition, a cylindrical insert member 101 (insertion portion) into which the center drill 72b of the cutter 72 is inserted is provided on the outer circumferential surface of the branching portion 2b of the T-shaped pipe 2. By inserting the center drill 72b into the insert member 101, the rotation axis of the hole saw 72a arranged coaxially with the center drill 72b can be positioned, so that the pipe line portion 2a and the branching portion 2b (branching straight pipe 4) of the T-shaped pipe 2 can be cut together without misalignment. The diameter adjustment member 100 and the insert member 101 may be fixed to the fluid pipe 1 (T-shaped pipe 2 and branching straight pipe 4) by welding or a band. Furthermore, the installation position, dimensions, and shapes of the diameter adjustment member 100 and the insert member 101 may be freely configured according to the fluid pipe 1 in which the fluid control 10 is installed. Also, only the diameter adjustment member 100 or the insert member 101 may be installed.

[0047] In the above embodiment, the flow-controlling housing part 50d of the housing 5 is formed so that its radial center is located on the branching portion 2b of the T-shaped tube 2, and the opening 50c is formed to straddle the pipe line portion 2a and the branching portion 2b of the T-shaped tube 2, and a form is exemplified in which a part of the pipe line portion 2a and the entire branching portion 2b of the T-shaped tube 2 constituting the fluid pipe 1, and a part of the branched straight pipe 4 connected to the branching portion 2b of the T-shaped tube 2 are cut by the cutter 72. However, as shown in FIG. 11 as a modified example 2 of the present invention, the flow-controlling housing part 150d of the housing 105 may be configured so that its radial center is located on the pipe line portion 2a of the T-shaped tube 2, and the opening 150c is formed to straddle the pipe line portion 2a and the branching portion 2b of the T-shaped tube 2, and a part of the pipe line portion 2a and the branching portion 2b of the T-shaped tube 2 are cut off together by the cutter 72, as shown by the dashed line B. In particular, in this case, it is preferable to install the above-mentioned anti-detachment fittings at the connection parts 30, 30 and the connection part 40 before the installation of the housing 5, in order to prevent the movement of the pipe section 2a during cutting and to fix the remaining parts of the T-shaped pipe 2 after cutting. In more detail, the connection parts 30, 30 and the connection part 40 are provided with a seal that seals these connection parts using a press ring. Here, the anti-detachment press ring shown by the dotted line in FIG. 11 has a main body divided in the circumferential direction and has a locking member (not shown) built into the main body that bites into and locks the straight pipe 3, the branch straight pipe 4, or the outer circumferential surface of the pipe section 2a. The bolts and nuts connecting the press ring and the socket are replaced one by one, and the anti-detachment fittings are installed by connecting them via the anti-detachment press ring and biting into the locking member. The anti-detachment fittings may also be fittings that have a locking member in a main body divided in the circumferential direction and are fitted into the socket across the press ring.

[0048] In the above embodiment, a form in which a part of the T-shaped pipe 2 forming a branch region mainly by the pipe line portion 2a and the branch portion 2b is cut off has been exemplified, but as shown in Fig. 12 as a modified example 3 of the present invention, the flow-controlling casing portion 250d of the casing 205 is located on the straight pipe 3 connected to the collar 202, and the opening 250c is formed to straddle the connection portion 230 between the collar 202 and the straight pipe 3, and as shown by the chain line C, the cutter 72 may cut off the branch region formed by a drain, bypass, etc. (not shown) provided on the bottom side of the collar 202 or the straight pipe 3 together with the connection portion 230. Note that the fluid pipe cut off by the cutter 72 may not have a drain, bypass, etc.

[0049] 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.

[0050] For example, in the above embodiment, a plug is used as the flow control valve 10, but the present invention is not limited to this as long as it controls the fluid in the fluid pipe 1. For example, the flow control valve may be a gate valve, a butterfly valve, a switching valve, or the like.

[0051] In addition, in the above embodiment, a configuration was illustrated in which the branching section 2b is configured to have a smaller diameter than the pipe line section 2a of the T-shaped pipe 2 that constitutes the fluid pipe 1, but the pipe line section and the branching section of the T-shaped pipe may have approximately the same diameter.

[0052] Furthermore, the fluid pipe 1 cut by the cutter 72 is not limited to a T-shaped pipe, but may be a bent pipe, a reducer, a cross pipe, or other irregular shaped pipe. [Explanation of symbols]

[0053] 1 Fluid tube 2 T-tube 2a Pipe section 2b Branch 3 Straight pipe 4 Branch straight pipe (branch pipe) 5. Cabinet 6 Working valve 7 cutting machine 8 Installation machine 10 Fluid control 11 Partition Wall 12 Top cover 50 Main unit 50a Pipe housing part 50b Branch housing part 50c opening 50d Flow-restricted housing 50f Mounting flange 50g Side wall step (seat) 50h Bottom wall step (seat) 51 1st divided body (divided body) 52 Second divided body (divided body) 57 Lid member 71 Mounting flange tube 72 Cutter 72a hole saw 72b center drill 73 Drive Mechanism 81 Mounting flange tube 82 Valve Hanger 83 Drive Mechanism 100 Diameter adjustment member 101 Insertion member 105 Case 150c opening 150d Flow-restricting housing 202 Connector 205 Case 230 Connection 250c opening 250d flow restriction housing

Claims

1. A method for removing a part of a fluid pipe in an uninterrupted flow state, comprising: a step of hermetically surrounding at least a pipe line portion of a fluid pipe, a branch portion branching from the pipe line portion, and a branch straight pipe connected to the branch portion with a housing; using a cutter equipped with a hole saw and a center drill inside the housing, the center drill drilling a hole at a position that avoids a sealing material interposed between the branch portion and the branch straight pipe, and the hole saw cutting through the remainder of the pipeline portion and the branch straight pipe at a position where the sealing material is located on the inner diameter side of the hole saw, while leaving a part of the pipeline portion of the fluid pipe in the pipeline direction.

2. 2. The method for cutting out a fluid pipe according to claim 1, wherein the center drill drills a hole in the pipe apex of the pipe line portion or the branch portion.

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