Pipe connection member removal device

Abstract

To provide a pipe connection member removal device capable of reliably and simply sealing a gap between a base member and a neck part of a branch pipe part.SOLUTION: A pipe connection member removal device hermetically encloses a pipe connection member U1 attached to a branch pipe part 2 with a work case 30 having: a base member 9 of a split structure fixed to a neck part 2A of the branch pipe part 2 that is branched off integrally from a main pipe part 1A of an existing flow path component member 1; and a case member 21 hermetically assembled to a base member 9, and removes the pipe connection member U1 in the work case 30 in an uninterrupted flow state. The pipe connection member removal device comprises fall prevention means 22 for preventing falling of a guide bolt 12 that guides attachment and detachment of the branch pipe part 2 and the pipe connection member U1.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a removal device and a method for removing a pipe connection member connected to a flow path component member in a non-stop flow state.

Background Art

[0002] Conventionally, when removing a pipe connection member (e.g., a valve body or a manhole cover) connected via a flange portion to a branch pipe portion branching from a flow path component member such as an existing water pipe, a work case is attached in a sealed manner so as to surround the pipe connection member, and the pipe connection member is generally removed in a non-stop flow state inside the work case.

[0003] A removal device used for such a removal operation of a pipe connection member is composed of a split base member having a diameter larger than that of the flange of the branch pipe portion of the existing pipe and a cylindrical case member assembled on the base member. After attaching the base member to the neck portion of the branch pipe portion, the case member can be assembled on the base member so that the work case can be assembled without interfering with the flange of the branch pipe portion (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in Patent Document 1, a packing is attached to the inner circumferential surface of the base member, and the two-part base member is placed on the neck of the branch pipe section. The packing is compressed between the base member and the neck of the branch pipe section by the fastening force that fastens the base members together, thereby sealing the base member to the neck of the branch pipe section. As a result, high manufacturing and installation precision of the base member and packing is required, and the condition of the packing is difficult to see, making the process of reliably sealing the space between the base member and the neck of the branch pipe section complicated.

[0006] This invention was made in view of these problems, and aims to provide a pipe connection member removal device and a pipe connection member removal method that can reliably and easily seal the space between the base member and the neck portion of the branch pipe. [Means for solving the problem]

[0007] To solve the above problems, the pipe connection member removal device of the present invention is A pipe connection member removal device comprising a work case comprising a split-structure base member fixed to the neck of a branch pipe section branching from the main pipe section of a flow path component, and a case member assembled to the base member, thereby sealing and enclosing a pipe connection member attached to the branch pipe section, and removing the pipe connection member within the work case in a continuous flow state, The base member is characterized in that a notched recess for a sealing member is formed in the base member so as to surround the neck portion of the branch pipe, opening to one axial side and the inner diameter side of the branch pipe portion. With this feature, the base member can be installed on the outer circumferential surface of the neck portion of the branch pipe, and the notched recess can be viewed from one axial side of the branch pipe while the gap between the base member and the neck portion of the branch pipe can be sealed using a predetermined sealing member within the notched recess. This ensures that the gap between the base member and the neck portion of the branch pipe can be sealed reliably and easily.

[0008] The notched recess is characterized in that it is formed on the working case side of the base member. This feature allows for easy access to the notched recess from the work case side, making the sealing process simpler.

[0009] The notched recess is characterized in that it is formed over more than half of the plate thickness of the base member. This feature allows for a larger sealed area to be secured between the base member and the neck of the branch pipe.

[0010] The base member is characterized in that a press ring, which presses a sealing ring (acting as a sealing member) into the notched recess, can be attached to it. This feature allows for sealing between the base member and the neck portion with a simple configuration using a seal ring and a thrust ring.

[0011] The aforementioned notched recess is characterized by having an inclined surface that extends from one end face on the axial side toward the inner diameter side, becoming deeper in that direction. This feature allows for improved sealing performance because, when the seal ring is compressed between the notched recess and the thrust ring, the inclined surface guides the seal ring to elastically deform toward the neck of the branch pipe, thereby enhancing sealing performance.

[0012] The neck portion is characterized by having a straight portion that extends along the axial direction of the neck portion and contacts the seal ring. This feature allows the seal ring to stably contact the straight section of the branch pipe, thereby improving sealing performance.

[0013] The invention is characterized in that a fall prevention means is provided between the guide bolt, which guides the attachment and detachment of the branch pipe section and the pipe connecting member, and the base member, to prevent the guide bolt from falling. This feature prevents the guide bolt from falling during operation.

[0014] The pipe connection member removal method of the present invention is A method for removing a pipe connection member, comprising a work case comprising a split-structure base member fixed to the neck of a branch pipe section branching from the main pipe section of a flow path component, and a case member assembled to the base member, wherein the pipe connection member attached to the branch pipe section is enclosed in a sealed manner, and the pipe connection member is removed within the work case in a state of continuous flow, The divided base members are installed so as to surround the neck of the branch pipe section, and a sealing process is performed from the working case side to seal the space between the inner surface of the base members and the outer surface of the neck of the branch pipe section. This feature allows the base member to be installed on the outer surface of the neck of the branch pipe, and the space between the base member and the neck of the branch pipe can be visually inspected from the work case side while sealing the space between the base member and the neck of the branch pipe using a predetermined sealing member. This ensures that the space between the base member and the neck of the branch pipe is sealed reliably and easily. [Brief explanation of the drawing]

[0015] [Figure 1] This figure shows an existing fluid pipe to which a pipe connecting member is connected in Embodiment 1 of the present invention. [Figure 2] This figure shows the state after changing the orientation of the bolt and nut from the state shown in Figure 1. [Figure 3] (a) is a diagram showing the base member attached to an existing fluid pipe, and (b) is a cross-sectional view AA of (a). [Figure 4] This diagram shows the state in which the neck portion of the branch pipe and the base member are sealed. [Figure 5] (a) is a diagram showing modified example 1 of the notched recess and the thrust ring, and (b) is a diagram showing modified example 2 of the notched recess and the thrust ring. [Figure 6] (a) is a diagram showing the state after the bolt and nut have been replaced with a guide bolt from the state in Figure 3, and (b) is a diagram showing the structure of the anti-rotation washer and lock nut. [Figure 7] This diagram shows the state after the guide bolts have been replaced. [Figure 8](a) shows a state where a pressing cylinder is attached to a base member, and (b) is a view of the existing fluid pipe with the pressing cylinder attached as seen from above. [Figure 9] It is a figure which shows the state which supported the guide bolt by the fall prevention means in Example 1. [Figure 10] It is a figure which shows the state which removes a pipe connection member in a work case. [Figure 11] (a) is a view of a pressing cylinder provided with a fall prevention means in Example 2 of the present invention as seen from above, and (b) is a cross-sectional view taken along the line B - B of (a), showing a state where the pressing cylinder is attached to a base member. [Figure 12] It is a figure which shows the state in the middle of replacing a bolt and nut with a guide bolt in Example 3 of the present invention. [Figure 13] (a) to (c) are figures showing the attachment procedure of a special nut in Example 3 of the present invention. [Figure 14] It is a figure which shows the state which supported the guide bolt by the fall prevention means in Example 3. [Figure 15] (a) is a figure showing the fall prevention means in Example 4 of the present invention, and (b) is a figure showing a state where the guide bolt is supported by the fall prevention means.

Modes for Carrying Out the Invention

[0016] Modes for carrying out the pipe connection member removal device and the pipe connection member removal method according to the present invention will be described below based on examples.

Examples

[0017] The pipe connection member removal device and the pipe connection member removal method according to Example 1 will be described with reference to FIGS. 1 to 10.

[0018] As shown in Figure 1, the existing fluid pipe 1 (hereinafter simply referred to as fluid pipe 1) as a flow path component is a so-called T-shaped pipe comprising a main pipe section 1A extending horizontally and a branch pipe section 2 communicating with the main pipe section 1A and branching vertically upward. The branch pipe section 2 has a neck section 2A extending vertically upward from the main pipe section 1A and a branch pipe flange section 3 (flange section) provided at the upper end of the neck section 2A. Here, the main pipe section 1A or the neck section 2A may be arranged at an angle.

[0019] Furthermore, in this embodiment, the design is often for high-pressure pipelines, and the branch pipe section 2 is formed to be shorter vertically than its pipe diameter, so that it can be used, for example, in spaces with little soil cover. The neck section 2A is provided with a straight section 2a that extends vertically upward in a straight line from the main pipe section 1A, and a tapered section 2b that slopes to widen in diameter from the straight section 2a toward the branch pipe flange section 3, and a space for bolt replacement work, which will be described later, is secured below the tapered section 2b side of the branch pipe flange section 3. In this embodiment 1, the straight section 2a and the tapered section 2b (the so-called neck flange) are shown as connected at the weld bead section 2c, but they may be formed by casting or other methods.

[0020] An existing pipe connection unit U1 (pipe connection member) is sealed and connected to the branch pipe flange portion 3 by interposing an annular packing 7. This pipe connection unit U1 consists of a manhole cover 4 having a flange portion 4a at its lower end that is fastened to the branch pipe flange portion 3 with existing bolts and nuts 10, and a repair valve 6 attached to the upper part of the manhole cover 4. Normally, an existing air valve or other pipe connection member is connected above the repair valve 6, but in Figure 1, these pipe connection members have already been removed by closing the repair valve 6. In this case, for example, a flanged short pipe may be used as the pipe connection member. Furthermore, although the fluid in the fluid pipe in this embodiment 1 is tap water, it is not limited to tap water in this embodiment 1, but may also be industrial water, agricultural water, sewage, gas, or a gas-liquid mixture of gas and liquid.

[0021] In this embodiment, the fluid tube 1 is made of steel. However, the fluid tube according to the present invention may be made of ductile cast iron, formed in a substantially circular shape in cross-section, and its inner surface may be covered with an epoxy resin layer. It may also be made of other metals such as cast iron or stainless steel, or concrete, polyvinyl chloride, polyethylene, or polyolefin. Furthermore, the inner surface of the fluid tube is not limited to an epoxy resin layer; for example, it may be covered with mortar or the like, or an appropriate material may be applied to the inner surface of the fluid tube by powder coating.

[0022] Hereafter, we will describe how to remove the pipe connection unit U1 from the branch pipe flange 3 in a continuous flow state using the pipe connection member removal device (hereinafter sometimes simply referred to as "removal device") in this embodiment 1.

[0023] As shown in Figure 2, first, the bolts and nuts 10, whose bolt heads are positioned below the branch pipe flange 3 and flange 4a (on the branch pipe flange 3 side), are replaced one or a predetermined number of times with new bolts and nuts 10' whose bolt heads are positioned above the branch pipe flange 3 and flange 4a (on the flange 4a side). At this time, it is preferable to clamp the branch pipe flange 3 and flange 4a with a jig (not shown), such as a vise. This allows the bolts and nuts 10' to be removed from above even after the annular base member 9, which will be described later, is attached to the fluid pipe 1, thus avoiding the risk of the bolts and nuts 10 becoming impossible to remove even in a fluid pipe 1 where the space between the branch pipe flange 3 and the main pipe 1A is narrow. In this embodiment 1, the example shows replacing existing bolts and nuts 10 with new bolts and nuts 10', but the orientation of the existing bolts and nuts 10 may also be changed.

[0024] Next, as shown in Figure 3(a), the annular base member 9 (base member) is attached to the fluid pipe 1. As shown in Figures 3(a) and 3(b), the annular base member 9 has a two-part split structure consisting of split members 9A and 9B, and includes an annular plate portion 91 (annular in top view) which is formed to surround the straight portion 2a of the neck portion 2A of the branch pipe portion 2 when the split members 9A and 9B are assembled, and a base portion 94 which extends below the annular plate portion 91 and is formed to rest on the main pipe portion 1A of the fluid pipe 1.

[0025] Joint portions 93a and 93b are formed at the circumferential ends of the divided members 9A and 9B, which face each other. The divided members 9A and 9B are positioned to sandwich the neck portion 2A from the radial direction, and the annular base member 9 is installed on the fluid pipe 1 by fastening the joint portions 93a and 93b together with bolts and nuts N1. After fastening the joint portions 93a and 93b together with bolts and nuts N1, the joint portions 93a and 93b are welded together to seal the space between the divided members 9A and 9B. Alternatively, the annular base member 9 may be welded and fixed to the fluid pipe 1 or the branch portion 2.

[0026] The base portion 94 includes leg portions 94a, 94a (see Figure 10) that extend axially in a plan view and are curved along the outer surface of the main pipe portion 1A in an axial view, and a plurality of rib portions 94b that connect the leg portions 94a, 94a to the annular plate portion 91. The annular base member 9 only needs to have at least the annular plate portion 91, and instead of the base portion 94, for example, a concrete foundation to support the annular plate portion 91 may be provided, or the annular plate portion 91 may be made of concrete, and depending on the ground conditions around the existing fluid pipe and the size of the work case to be installed on the existing fluid pipe, steel plates or timber may be laid on the excavated ground, or ground excavated to a suitable depth may be used, or the pipe body of the fluid pipe 1 may be used. Furthermore, the annular base member 9 is not limited to being two-part, but may be composed of three or more divided members.

[0027] On the inner diameter side of the annular plate portion 91, an annular notched recess 92 is formed, opening to the inner diameter side and the upper side (one axial side of the branching portion 2 in this embodiment), surrounding the straight portion 2a of the neck portion 2A. This notched recess 92 includes a vertical surface 92a extending substantially vertically downward from the upper surface of the annular plate portion 91, a flat surface 92c extending substantially horizontally toward the inner diameter side from the lower end of the vertical surface 92a, and an inclined surface 92d that slopes from the inner diameter side end of the flat surface 92c toward the inner diameter side, becoming deeper toward the inner diameter side. In addition, multiple screw holes 92e for attaching the retaining ring 20, which will be described later, are formed along the circumferential direction on the flat surface 92c. Furthermore, a screw hole 92f for attaching the retaining cylinder 21, which will be described later, is formed on the outer diameter side of the annular plate portion 91.

[0028] The depth of the notched recess 92 is approximately equal to the thickness of the annular plate portion 91. The depth of the notched recess 92 can be changed as appropriate, and preferably, the notched recess should extend over more than half the thickness of the annular plate portion 91. Furthermore, the processing method of the notched recess 92 is not limited as long as it is open on the inner diameter side and on one axial side of the branch pipe portion 2. For example, the annular plate portion 91 may be formed by notching, by casting, or by providing an annular wall portion rising from the upper surface of the annular plate portion 91 and forming the notched recess 92 between the wall portion and the upper surface of the annular plate portion 91 on the inner diameter side of the wall portion.

[0029] Next, as shown in Figure 4, a seal ring 11 (sealing member) made of an elastic material and having a substantially circular cross-section in its natural state is placed between the inclined surface 92d of the notched recess 92 and the outer circumferential surface of the straight portion 2a of the neck portion 2A, and an annular pressure ring 20 is attached to the flat surface 92c of the notched recess 92 with a bolt N2. This pressure ring 20 has a segmented structure consisting of multiple arc-shaped plate members, and when the bolt N2 is fastened to the screw hole 92e, the seal ring 11 is crushed vertically between the pressure ring 20 and the inclined surface 92d, thereby sealing the space between the annular base member 9 and the neck portion 2A. More specifically, since the seal ring 11 is in contact with the straight portion 2a of the neck portion 2A, it is more stable and the sealing performance is improved compared to when it is in contact with the tapered portion 2b. Here, the head of the bolt N2 may be made so as not to protrude upward as in the modified example 1 described later.

[0030] Furthermore, when the seal ring 11 is compressed vertically between the thrust ring 20 and the inclined surface 92d, the seal ring 11 is guided by the inclined surface 92d to elastically deform toward the neck portion 2A, thereby improving sealing performance. In addition, since the seal ring 11 has a roughly circular cross-sectional shape in its natural state, it can be elastically deformed uniformly when compressed vertically between the thrust ring 20 and the inclined surface 92d.

[0031] Furthermore, since the thickness of the thrust ring 20 is approximately the same as the vertical surface 92a, when the thrust ring 20 is attached to the annular plate portion 91, the thrust ring 20 does not protrude above the upper surface of the annular plate portion 91 and fits within the notched recess 92. The seal ring 11 has a roughly circular cross-sectional shape, but is not limited to this, and the cross-sectional shape can be changed as appropriate. For example, it may have an elliptical cross-sectional shape or a so-called K-shape or A-shape. Also, the seal ring 11 is not limited to being continuous in the circumferential direction and endlessly, for example, the seal ring may be formed with ends, and by bonding the ends together, it may be processed to be continuous in the circumferential direction when the thrust ring 20 is attached to the annular plate portion 91.

[0032] Here, we will describe some modifications of the notched recess and the thrust ring. As modification 1 of the notched recess and thrust ring, as shown in Figure 5(a), the notched recess 920 has a vertical surface 920d extending substantially vertically downward from the inner diameter side end of the flat surface 92c, and a horizontal surface 920e extending substantially horizontally toward the inner diameter side from the lower end of the vertical surface 920d.

[0033] The thrust ring 200 in this modified example 1 comprises a flat plate portion 200a and a projection portion 200b that protrudes downward from the inner diameter side end of the flat plate portion 200a, and has a substantially L-shape in cross-section. When the thrust ring 200 is attached to the annular plate portion 91 with a bolt N2, the seal ring 11 is compressed between the vertical surface 920d, the horizontal surface 920e, and the projection portion 200b, sealing the space between the annular base member 9 and the straight portion 2a of the neck portion 2A. Thus, the notched recess does not necessarily have to have an inclined surface. Furthermore, since the flat plate portion 200a of the thrust ring 200 has a receiving recess 200c for accommodating the head of the bolt N2, the head of the bolt N2 can be prevented from protruding above the upper surface of the thrust ring 200 and the annular plate portion 91. Alternatively, the bolt N2 may be made into a countersunk screw so as not to protrude above the upper surface of the thrust ring 200 and the annular plate portion 91.

[0034] Furthermore, as a second modification of the notched recess and the thrust ring, as shown in Figure 5(b), the notched recess 92' of this modification 2 has the same shape as the notched recess 92 of Embodiment 1, except that it does not have a screw hole 92e. Also, on the upper surface of the annular plate portion 91 on the outer diameter side of the notched recess 92', an annular rising piece 95 is formed that rises upward, and multiple screw holes 95a that penetrate radially are formed in the rising piece 95 along the circumferential direction (only one is shown here). A bolt N3 is screwed into the screw hole 95a, and the inner diameter side end of the bolt N3 is tapered. Furthermore, the thrust ring 201 of this modification 2 comprises an annular flat plate portion 201a and a rising piece 201b that rises upward from the flat plate portion 201a, and a tapered surface 201c is formed on the rising piece 201b that can contact the inner diameter side end of the bolt N3.

[0035] With the bolt N3 retracted to the outer diameter side, the thrust ring 201 is positioned on the flat surface 92c of the notched recess 92', and the bolt N3 is advanced to the inner diameter side. As a result, the inner diameter end of the bolt N3 contacts the tapered surface 201c of the rising piece 201b, causing the thrust ring 201 to move in a direction that compresses the seal ring 11 toward the inclined surface 92d. In this way, by operating the bolt N3 from the outer diameter side, the seal ring 11 can be clamped between the thrust ring 201 and the inclined surface 92d. Therefore, even if the branch pipe section 2 is formed to be short in the axial direction of the branch pipe, it is easy to operate the thrust ring 201 without interfering with the tapered section 2b or the branch pipe flange section 3.

[0036] Returning to Example 1, the bolts and nuts 10' are then replaced with guide bolts 12, as shown in Figure 6(a). Specifically, the bolts and nuts 10' are removed one or a predetermined number at a time, and the guide bolts 12 are inserted. This may be done while the branch pipe flange 3 and flange 4a are held in place by a jig (not shown), such as a vise. After that, with the guide bolts 12 supported, the anti-rotation washer 13 is inserted from below and the lock nut 14 is screwed on.

[0037] As shown in Figure 6(b), the anti-rotation washer 13 comprises a rectangular plate portion 13a in a bottom view that can abut against the lower surface of the branch pipe flange portion 3, a first piece portion 13b rising upward from one side of the plate portion 13a, and second pieces 13c, 13c extending downward from both sides adjacent to one side of the plate portion 13a. The lock nut 14 is tightened from below the guide bolt 12, and the distance between the lower end of the guide bolt 12 and the upper surface of the annular plate portion 91 is adjusted so that when the plate portion 13a of the anti-rotation washer 13 abuts against the lower surface of the branch pipe flange portion 3, the distance between the lower end of the guide bolt 12 and the upper surface of the annular plate portion 91 becomes a predetermined distance.

[0038] Then, as shown in Figure 7, the nut 15 is tightened from above the guide bolt 12, and the nut 15 and the lock nut 14 clamp the branch pipe flange portion 3, the flange portion 4a, and the anti-rotation washer 13 in the vertical direction. At this time, the first piece 13b of the anti-rotation washer 13 abuts against the outer circumferential surface of the branch pipe flange portion 3, and the lock nut 14 is positioned between the second pieces 13c, 13c in a state where rotation is restricted. This prevents the anti-rotation washer 13 and the lock nut 14 from unintentionally rotating and loosening.

[0039] Next, as shown in Figure 8(a), the retaining cylinder 21 is fixed to the upper surface of the annular plate portion 91 using bolts N4. This retaining cylinder 21 is a cylindrical body that surrounds the periphery of the branch pipe portion 2, and multiple retaining blocks 22 (fall prevention means) that can be moved radially back and forth by operating from the outside are provided at its lower end, spaced apart in the circumferential direction to correspond to the guide bolts 12 mentioned above. In addition, multiple fixing pins 23 that can be moved radially back and forth by operating from the outside are provided at the upper end of the retaining cylinder 21, spaced apart in the circumferential direction. Furthermore, an annular O-ring 24 is provided on the lower end surface of the retaining cylinder 21, and the annular plate portion 91 and the retaining cylinder 21 are sealed together when the O-ring 24 is compressed between the annular plate portion 91 and the retaining cylinder 21. Note that in Figure 8(b), the branch pipe flange portion 3 and the pipe connection unit U1 are omitted from the illustration for the sake of explanation.

[0040] Subsequently, as shown in Figure 9, the multiple retaining blocks 22 are sequentially moved toward the inner diameter, and the tip members 22a of the retaining blocks 22 are pressed between the lower end of the guide bolt 12 and the upper surface of the annular plate portion 91. The upper surface of the tip member 22a has an inclined surface 22b that slopes downward toward the inner diameter, making it easy to press the tip member 22a between the lower end of the guide bolt 12 and the upper surface of the annular plate portion 91.

[0041] Furthermore, the fixing pin 23 is moved toward the inner diameter side, and the tip of the fixing pin 23 is locked to the upper edge of the outer circumference of the flange portion 4a. The fixing pin 23 is a bolt with a tapered shape, where the tip on the inner diameter side tapers to a point, and is screwed into a threaded hole 21a formed in the upper end of the retaining cylinder 21. By rotating the fixing pin 23, it can be moved forward and backward in the radial direction.

[0042] Next, as shown in Figure 10, the lower working case 25, working valve device 26, upper working case 27, and inserter mounting lid 28 are assembled in a sealed manner on top of the retaining cylinder 21 to form the working case 30, and the inserter 29 is sealed and attached to the inserter mounting lid 28. In other words, the working case 30 is composed of an annular base member 9 and the retaining cylinder 21, lower working case 25, working valve device 26, upper working case 27, and inserter mounting lid 28 assembled on the annular base member 9, with the retaining cylinder 21, lower working case 25, working valve device 26, and upper working case 27 functioning as case members. Note that the working case 30 is not limited to the form of this embodiment 1, and the configuration of the divided structure can be set as appropriate, as long as it is configured to at least be able to seally surround the pipe connection member.

[0043] Next, the hanging bracket 16 connected to the repair valve 6 is connected to the insertion machine 29 using a window provided in the case member that can be opened and closed. Then, the nut 15 is removed from the guide bolt 12 and sealed, and water is poured into the work case 30 to make the pressure inside the fluid pipe 1 approximately equal. As described above, since the tip member 22a of the retaining block 22 is press-fitted between the lower end of the guide bolt 12 and the upper surface of the annular plate portion 91, the guide bolt 12 can be prevented from falling even if the nut 15 is removed from the guide bolt 12 from the state shown in Figure 9.

[0044] Subsequently, the fixing pin 23 is retracted in the outward direction to release the locking of the manhole cover 4 by the fixing pin 23, and the insertion machine 29 is operated to pull up the repair valve 6 and manhole cover 4 (pipe connection unit U1), closing the valve body (not shown) of the work valve device 26. This completes the process of removing the pipe connection unit U1 from the branch pipe section 2 in a continuous flow state. Although not shown here, when connecting a new pipe connection unit to the branch pipe section 2 following the above removal work, the new pipe connection unit is connected to the branch pipe section 2 in the reverse order of the above work. Furthermore, since the guide bolt 12 guides the direction in which the pipe connection unit U1 is pulled up and the direction in which the new pipe connection unit is connected, the removal and replacement of pipe connection members to the branch pipe section 2 can be performed accurately.

[0045] Furthermore, after removing the pipe connection unit U1 from the branch pipe section 2 in a continuous flow state and connecting the new pipe connection unit to the branch pipe section 2 in a continuous flow state, the work case 30 is removed from the fluid pipe 1. Alternatively, the retaining cylinder 21, lower work case 25, work valve device 26, upper work case 27, and insertion machine mounting cover 28 may be removed, leaving the annular base member 9 in place on the fluid pipe 1.

[0046] As described above, in this embodiment 1, the pipe connection member removal device has a notched recess 92 for a seal ring 11 that opens to the upper side (one axial side) and the inner diameter side of the branch pipe section 2, formed in the annular plate portion 91 of the annular base member 9, so as to surround the neck portion 2A of the branch pipe section 2. With this, when the annular plate portion 91 is installed in a ring on the outer circumferential surface of the neck portion 2A of the branch pipe section 2, the space between the annular plate portion 91 and the neck portion 2A of the branch pipe section 2 can be sealed using the seal ring 11 within the notched recess 92 while the notched recess 92 is visible from the upper side of the branch pipe section 2. Therefore, regardless of the manufacturing accuracy or mounting accuracy of the annular plate portion 91, the space between the annular plate portion 91 and the neck portion 2A of the branch pipe section 2 can be reliably and easily sealed.

[0047] Furthermore, since the notched recess 92 is formed on the working case 30 side of the annular plate portion 91, it is easier to access the notched recess 92 from the working case 30 side compared to performing the sealing process on the main pipe portion 1A side of the fluid pipe 1, thus simplifying the sealing process. This is particularly useful when removing the pipe connection unit U1 connected to a branch pipe section 2 that is shorter than a typical branch pipe section, as in this embodiment 1, while maintaining a continuous flow. Moreover, when removing the pipe connection unit U1, the pressure of the fluid inside the working case 30 acts in a direction that crushes the seal ring 11, thus improving the sealing performance.

[0048] Furthermore, the notched recess 92 is formed over more than half the thickness of the annular plate portion 91. Specifically, the depth of the notched recess 92 is approximately the same as the thickness of the annular plate portion 91, so that when the seal ring 11 is compressed vertically between the annular plate portion 91 and the retaining ring 20, a large area (sealing area) can be secured in which the seal ring 11 contacts the neck portion 2A of the branch pipe portion 2.

[0049] Furthermore, a pressing ring 20 can be attached to the annular plate portion 91 to press the seal ring 11 into the notched recess 92 as a sealing member, and a sealing process between the annular plate portion 91 and the neck portion 2A can be performed with a simple configuration in which the seal ring 11 is compressed between the notched recess 92 and the pressing ring 20.

[0050] Furthermore, since the notched recess 92 has an inclined surface 92d that extends from the upper surface of the annular plate portion 91 toward the inner diameter, when the seal ring 11 is compressed between the notched recess 92 and the thrust ring 20, the seal ring 11 is guided by the inclined surface 92d to elastically deform toward the neck portion 2A of the branch pipe portion 2, thereby improving the sealing performance. Note that the inclined surface 92d only needs to be formed in at least a part of the notched recess 92.

[0051] Furthermore, since the seal ring 11 is in contact with the straight portion 2a that extends along the axial direction of the neck portion 2A, the seal ring 11 can stably contact the straight portion 2a of the branch pipe portion 2 while avoiding the tapered portion 2b and the weld bead portion 2c between the straight portion 2a and the tapered portion 2b, thereby improving the sealing performance.

[0052] Furthermore, a retaining block 22 is positioned between the guide bolt 12, which guides the attachment and detachment of the branch pipe section 2 and the pipe connection, and the annular plate section 91 to prevent the guide bolt 12 from falling. Therefore, even if the nut 15 is removed from the guide bolt 12, the guide bolt 12 will not fall.

[0053] Furthermore, in the pipe connection member removal method of this embodiment 1, with the divided annular plate portion 91 installed in a ring shape surrounding the neck portion 2A of the branch pipe portion 2, a sealing process is performed from the work case 30 side to seal the space between the inner circumferential surface of the annular plate portion 91 and the outer circumferential surface of the neck portion 2A of the branch pipe portion 2. With this, with the annular plate portion 91 installed on the outer circumferential surface of the neck portion 2A of the branch pipe portion 2, the space between the annular plate portion 91 and the neck portion 2A of the branch pipe portion 2 can be visually inspected from the work case 30 side and the sealing process can be performed using the seal ring 11, thus ensuring a reliable and simple sealing of the space between the annular plate portion 91 and the neck portion 2A of the branch pipe portion 2.

[0054] In this embodiment 1, the notched recess 92 was formed to open to the upper side of the annular plate portion 91 (towards the work case 30), but it is not limited to this, and may be formed to open to the lower side of the annular plate portion 91 (opposite side from the work case 30).

[0055] Furthermore, in this embodiment 1, an example was given in which the annular base member 9 is installed so as to surround the neck portion 2A of the branch pipe portion 2 by fastening the divided members 9A and 9B with bolts and nuts N1. However, for example, the annular base member 9 may be installed by providing set bolts on the annular base member 9 and biting the set bolts into the fluid pipe 1. Also, if the annular base member 9 is installed in a sealed manner on the fluid pipe 1, it is not necessary to fix the annular base member 9 to the fluid pipe 1. Moreover, after fastening the joint portions 93a and 93b of the divided members 9A and 9B with bolts and nuts N1, the joint portions 93a and 93b are not limited to being welded and sealed, but the joint portions 93a and 93b may also be sealed with a curable resin or a packing.

[0056] Furthermore, although this embodiment 1 illustrates a configuration in which a seal ring 11 is used as a sealing member, the space between the notched recess 92 and the neck portion 2A of the branch pipe 2 may be sealed by welding or with a curable resin. Moreover, the notched recess 92 is not necessarily limited to being formed; the annular base member may be formed into a flat plate shape, and the space between the annular base member and the neck portion 2A of the branch pipe 2 may be sealed by welding or with a curable resin from one or both sides in the axial direction of the neck portion 2A.

[0057] Furthermore, in this embodiment 1, the pipe connection unit U1, which serves as a pipe connection member, is shown as being composed of a manhole cover 4 and a repair valve 6. However, the pipe connection member may be a valve cover or a repair valve, and can be changed as appropriate. [Examples]

[0058] Next, the pipe connection member removal device and pipe connection member removal method according to Example 2 will be described with reference to Figure 11. Note that descriptions of components that are identical to those in Example 1 and therefore redundant will be omitted.

[0059] As shown in Figure 11, the retaining cylinder 210 of Embodiment 2 has a two-part structure consisting of circumferentially divided arc-shaped members 210a and 210b. This retaining cylinder 210 is assembled by fastening it with bolts and nuts N5 with packings 17, 17 interposed between the joints 210c and 210d formed at both circumferential ends of the arc-shaped members 210a and 210b.

[0060] Furthermore, an annular projection 210e is formed on the lower side of the retaining cylinder 210, projecting inward in the diameter direction. This projection 210e supports the lower ends of multiple guide bolts 12 together. This prevents the guide bolts 12 from falling even when the nuts 15 are removed from them. In other words, the projection 210e functions as a fall prevention means in Embodiment 2. Also, because the projection 210e is annular, there is no need to align it with the multiple guide bolts 12 in the circumferential direction, and it can be supported simply. The retaining cylinder 210 may also have a segmented structure of three or more parts. In addition, the arc-shaped members may be sealed together by welding or with a hardening resin. [Examples]

[0061] Next, the pipe connection member removal device and pipe connection member removal method according to Embodiment 3 will be described with reference to Figures 12 to 14. Note that descriptions of components identical to those in Embodiment 1 and therefore redundant will be omitted.

[0062] As shown in Figure 12, the bolt and nut 10' connecting the branch pipe flange 3 and flange 4a are replaced with a guide bolt 12, and the anti-rotation washer 13 is inserted from below the guide bolt 12 and the lock nut 14 is screwed on.

[0063] Next, as shown in Figure 13(a), a special nut 18 is placed between the lower end of the guide bolt 12 and the upper surface of the annular plate portion 91. At this time, the guide bolt 12 is not screwed into the female thread portion 18a formed on the inner circumferential surface of the special nut 18. Then, as shown in Figure 13(b), the lower end of the guide bolt 12 is screwed into the female thread portion 18a of the special nut 18, and the lock nut 14 is screwed upward onto the guide bolt 12 until the anti-rotation washer 13 engages with the branch pipe flange portion 3. In this way, the special nut 18 is pressed against the upper surface of the annular plate portion 91, thereby supporting the guide bolt 12. Then, as shown in Figure 13(c), a nut 15 is tightened from above the guide bolt 12, and this nut 15 and the lock nut 14 clamp the branch pipe flange portion 3, the flange portion 4a, and the anti-rotation washer 13 in the vertical direction.

[0064] In this way, as shown in Figure 14, the replacement of the bolt and nut 10' with the guide bolt 12 is completed. Since the special nut 18 is placed on the upper surface of the annular plate portion 91 and supports the guide bolt 12, it is possible to prevent the guide bolt 12 from falling even if the nut 15 is removed from the guide bolt 12. In other words, the special nut 18 functions as a fall prevention means in Embodiment 3. Alternatively, a bolt other than the guide bolt 12 may be screwed into the female thread portion 18a of the special nut 18 to prevent it from falling. [Examples]

[0065] Next, the pipe connection member removal device and pipe connection member removal method according to Example 4 will be described with reference to Figure 15. Note that descriptions of components that are identical to those in Example 1 and therefore redundant will be omitted.

[0066] Figure 15(a) shows a ring member 19 as a fall prevention means in this embodiment 4. The ring member 19 is composed of two metal arc-shaped members 19a and 19b that are divided in the circumferential direction, and in this embodiment it has a two-part structure. Recesses 19d having a constricted portion 19c at the end are formed at both ends of the arc-shaped member 19a in the circumferential direction, and engaging portions 19e that can engage with the recesses 19d are formed at both ends of the arc-shaped member 19b in the circumferential direction. The engaging portion 19e protrudes in the circumferential direction from both ends of the arc-shaped member 19b and comprises a first portion 19f that is loosely fitted into the constricted portion 19c, and a second portion 19g that bulges radially from the tip of the first portion 19f and engages with the end face on the recess 19d side of the wall portion constituting the constricted portion 19c. The ring member may also have a structure divided into three or more parts.

[0067] As shown in Figure 15(b), with the arc-shaped members 19a and 19b positioned to surround the neck portion 2A of the branch pipe portion 2, the ring member 19 is formed by engaging the engaging portion 19e of the arc-shaped member 19b with the recess 19d of the arc-shaped member 19a. Note that the arc-shaped members 19a and 19b are not limited to being connected by engagement using the recess 19d and the engaging portion 19e, but may also be connected by adhesive, welding, screws, etc., or may not be connected at all.

[0068] The ring member 19 is supported on the bolt N2. The ring member 19 may also be placed on the upper surface of the annular plate portion 91, or it may be fixed around the neck portion 2A by welding or the like.

[0069] The ring member 19 is designed to support the lower end of the guide bolt 12. This prevents the guide bolt 12 from falling even if the nut 15 is removed from it. The ring member 19 may also have a segmented structure consisting of three or more parts. Furthermore, the ring member 19 is not limited to metal, but may be made of ductile cast iron, other cast iron, concrete, polyvinyl chloride, polyethylene, polyolefin, or other resins.

[0070] Although embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and any changes or additions that do not depart from the spirit of the present invention are also included.

[0071] For example, in embodiments 1 to 4, the branch pipe section 2 is shown as being shorter in the axial direction of the branch pipe section relative to its diameter, but the extension of the branch pipe section can be freely changed. Also, in embodiments 1 to 4, the neck section 2A of the branch pipe section 2 is provided with a straight section 2a and a tapered section 2b, but it is not limited to this, and may be provided with only a straight section, for example. Furthermore, the annular base member 9 is formed in an annular shape when viewed from above in this embodiment, but it is not limited to this, and may be rectangular, elliptical, or other shapes. [Explanation of symbols]

[0072] 1. Existing fluid pipes (flow channel components) 1A Main pipe section 2 Branch pipe section 2A Neck 2a Straight section 2b Tapered section 3. Branch pipe flange section 4. Manhole cover (pipe connection member) 4a Flange section 6. Repair valve (pipe connecting component) 9. Annular base member (base member) 11. Seal ring (sealing component) 12 Guide bolts 18. Special nuts (means to prevent falling) 19. Ring component (means to prevent falling) 20 Pressing ring 21. Retaining tube (case component) 22. Retaining piece (means to prevent falling) 23 Fixing pins 25 Lower work case (case component) 27 Upper work case (case component) 30 work cases 91 Annular plate section (base member) 92 Notched recess 92d slope 94 Foundation part 200,201 Pressing ring 210 Retaining tube (case component) 920 Notched recess

Claims

1. A pipe connection member removal device comprising a work case comprising a split-structure base member that is sealedly fixed to the neck of a branch pipe section that branches integrally from the main pipe section of an existing flow path component, and a case member that is sealedly assembled to the base member, thereby sealingly enclosing a pipe connection member attached to the branch pipe section, and removing the pipe connection member in a continuous flow state within the work case, A pipe connection member removal device is provided with a fall prevention means for preventing the fall of a guide bolt that guides the attachment and detachment of the branch pipe section and the pipe connection member, wherein the fall prevention means has a support portion that supports the lower end of the guide bolt above the base member, and the support portion has a bottom surface that is attached to the case member and abuts against the upper surface of the base member, and is configured to move back and forth along the upper surface of the base member from the outside of the base member.

2. The pipe connection member removal device according to claim 1, characterized in that the fall prevention means has an operating part that allows the support part to move forward and backward from the outside of the base member.

3. The pipe connection member removal device according to claim 1, characterized in that the support portion has a support surface that is inclined with respect to the bottom surface and abuts against the lower end of the guide bolt.

4. The pipe connection member removal device according to claim 3, wherein the lower end of the guide bolt has an inclined surface that contacts the support surface of the support portion.

5. The pipe connection member removal device according to claim 1, characterized in that the lower end of the guide bolt is a male threaded portion.

6. The pipe connection member removal device according to any one of claims 1 to 5, characterized in that a rotation-preventing washer is provided to prevent rotation between the guide bolt and the nut screwed onto the guide bolt.

7. The pipe connection member removal device according to claim 1, wherein the support portion of the fall prevention means is movably provided with respect to the guide bolt.

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