JP2007332982A - Passage blocking tool, and updating method of supply pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a passage blocking tool having structure more simplified than a conventional one. <P>SOLUTION: The passage blocking tool is provided with: a multiunit tube 5 inserted into a first supply tube 1 through which gas flows from the direction reverse to the flowing direction of gas, having a closed one end; and a fluid feeding means under pressure attached to the other end of the multiunit tube 5. The multiunit 5 has a guide tube 51 having flexibility, an intermediate layer 52 to cover the surface, and a covering layer 53 covered on the intermediate layer 52. The covering layer 53 has a pair of notches 54a, 54b circumferentially stripped off at a predetermined interval in the axial direction. The notches 54a, 54b communicates with the inside of the guide tube 51. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a flow path closing tool used for renewing a supply pipe through which a fluid such as a gas flows, and a supply pipe renewal method using the same.

  In the gas piping, fuel gas such as city gas and natural gas is supplied to customers through a main branch pipe buried in the ground in parallel with the road and a supply pipe branched therefrom. As this branch pipe, cast iron pipe has been used, which has the advantage of being strong against gas pressure and external pressure (earth pressure, etc.) and having high durability, and that can be easily taken out by drilling work. Switching to resin pipes (for example, PE pipes), which have excellent properties and earthquake resistance, is increasing. Switching from a cast iron pipe to a resin pipe is, for example, after shutting off the gas supply to the downstream side of a supply pipe connected to an existing main pipe (cast iron pipe, etc.) and then cutting, disassembling and removing the supply pipe The construction is performed in such a manner that a new supply pipe is connected to the newly established main pipe (PE pipe or the like). However, when this supply pipe replacement work is performed, there is an inconvenience that gas cannot be used by the consumer during the work. In addition, even after completion of the reassignment work, it is necessary to enter the customer's facility and perform a safety check including an ignition test. Therefore, the reassignment work may not be performed as scheduled due to the convenience of the customer.

  Therefore, in order to carry out the replacement work without shutting off the gas supply from the supply pipe to the customer, after connecting a certain section of the supply pipe with a bypass pipe via a joint, After cutting the supply pipe, a method of connecting the supply pipe to the newly established main pipe has been studied (see FIG. 7). That is, according to this construction method, as shown in FIG. 7, the joint 40 having two branch ports 401 and 402 is attached to the supply pipe 30 branched from the existing main pipe 10 and connected to the customer 20. One of the two branch ports is connected to each other by a bypass pipe 50 to ensure the supply of gas from the existing main branch pipe 10 to the customer 20. Next, in each joint 40, a gas blocking bag (not shown) is inserted into the supply pipe 30 from the branch port 402 to block the section AB. At this time, gas is supplied from the existing main branch pipe 10 to the customer 20 through the bypass pipe 50. Next, the supply pipe (broken line in the figure) in the section A-B is cut and removed, and the new supply pipe 30 ′ branched from the new main pipe 10 ′ is connected to the joint 40 on the consumer side. Thereafter, after the gas shut-off bag is removed, the bypass pipe 50 is removed, and the gas supply to the customer 20 is switched from the newly installed main branch pipe 10 '. According to this live-tube branching and blocking method, there is an advantage that reconnection work can be performed without stopping supply of gas to the customer and without entering the customer's facility. A plurality of joints having a special structure with a branch port are required, and a plurality (two places) of the supply pipe 30 need to be perforated with respect to one joint, which increases the construction cost.

  Another method has also been proposed in which the replacement work is performed without shutting off the gas supply from the supply pipe to the customer. For example, in Patent Document 1, in order to repair a part of an existing pipeline in a state in which gas supply is ensured, a communication hole that connects the inside and the outside of the existing pipeline is formed at both end portions to be blocked. By inserting a double-type bag connected with a gas shut-off device from these communication holes, connecting the gas shut-off device with a bypass pipe, and introducing inflation air into the bag, It is described that distribution can be blocked.

  Further, in Patent Document 2, in order to repair a part of an existing pipeline with gas supply secured, a communication hole that communicates the inside and the outside of the existing pipeline is formed at both end portions to be blocked. The gas shut-off device is connected through these communication holes and a double bag connected through an air passage having a multi-pipe structure is inserted, and the gas shut-off device is connected by a bypass pipe, and then expanded to the bag. The introduction of air is described. The air passage having a multi-pipe structure has one end facing the first air passage facing the inside of the first air bag, the second air passage facing the inside of the second air bag, and the space located between the two bags. It has 3 air passages. In Patent Document 2, according to this repair method, even if the gas pressure is high and the back cannot be sealed completely, the gas that has entered the space located between the bags is used as the third pressure. It is supposed that it can be discharged to the outside through the air passage.

JP 2001-271983 (pages 3 to 5, FIG. 1, FIG. 2, FIG. 3) JP 2001-50471 A (pages 3 to 4, FIG. 1 and FIG. 2)

  Since the above-described gas shut-off device requires two pairs of air bags, the structure becomes complicated and the cost is increased. Further, according to the repair method described above, since the double-type air bag is configured to be installed on both sides of the repair blocking section, holes for inserting the airbag are drilled on both sides (two places) of the repair section. In addition, since this drilling operation is performed in the pit, the construction man-hour is increased.

  An object of the present invention is to solve the above-described problems and provide a flow path closing tool having a simplified structure as compared with the conventional art.

  Another object of the present invention is to provide a supply pipe renewal method that solves the above-described problems and can reduce the number of construction steps as compared with the prior art.

  In order to achieve the above object, the flow path closing tool of the present invention includes a composite pipe that is inserted into the first supply pipe through which gas flows from the opposite direction to the gas flow direction and sealed at one end. A fluid pumping means mounted on the other end of the composite tube, the composite tube comprising a flexible guide tube, an intermediate layer covering the surface thereof, and a coating layer deposited on the intermediate layer. And the covering layer has a pair of notches separated in the circumferential direction at a predetermined interval along the axial direction, and the inner peripheral side of the notches communicates with the inside of the guide tube. It is characterized by that.

  In the present invention, it is preferable that the guide tube is made of a polyolefin resin, the intermediate layer is made of an elastomer, and the coating layer is made of a heat-shrinkable tube.

  Further, the flow path closing tool of the present invention includes a composite pipe that is inserted from the direction opposite to the gas flow direction into the inside of the first supply pipe through which the gas flows, and has one end sealed, and the other end of the composite pipe. An injection means for injecting a raw material for forming a sealing member for blocking gas flow, and the composite pipe is supported by the guide pipe and supported by the guide pipe and of the first supply pipe. It has a pair of regulating members that define a section that is in close contact with the inner surface and blocks the flow of gas, and the inside and outside of the guide tube pass through part of the section.

  In the flow path closing tool of the present invention, the sealing member is formed of a two-component foamable resin, the guide member is a parasol-like member, and the neck portion is attached to the surface of the guide tube. It can be sandwiched between the coated layers.

  In order to achieve the other object, the supply pipe renewal method according to the present invention is such that a confluence joint is attached to a first supply pipe, a second supply pipe is connected thereto, and at least the inside of the confluence joint is provided. After blocking from the outside air, the first supply pipe is perforated, the composite pipe is fed into the first supply pipe through the opening, and the pressurized fluid is supplied into the composite pipe from the fluid pumping means. Then, a portion of the intermediate layer is expanded from the notch, the expanded portion is brought into close contact with the inner surface of the first supply pipe, and then sandwiched between the expanded portions of the first supply pipe It is characterized by separating.

  The renewal method of the supply pipe according to the present invention includes a junction joint attached to the first supply pipe, a second supply pipe is connected to the junction joint, and at least the inside of the junction joint is shut off from the outside air. The first supply pipe is pierced, the composite pipe is fed into the first supply pipe through the hole, and the foaming resin composition is filled into the composite pipe from the injection means, thereby allowing the gas to flow. A configuration may be employed in which the section in which the sealing member of the first supply pipe is formed is separated after the sealing member that blocks the flow is formed.

  Since the flow path closing tool of the present invention is composed of a composite pipe having a multilayer structure and means for supplying pressurized fluid into the composite pipe or means for injecting a raw material for forming a sealing member, Can also be a greatly simplified tool. Therefore, according to the present invention, cost reduction of the tool can be achieved.

  The supply pipe renewal method of the present invention is such that a confluence joint is attached to the first supply pipe, then a second supply pipe is connected to the joint and then drilled, and a composite pipe is inserted through the hole by a predetermined length. Then, after supplying the pressurized fluid or the raw material for forming the injection member to the inside of the composite pipe, the gas flow to the downstream side of the first supply pipe can be surely cut off by the operation of cutting only a predetermined section. . Therefore, according to the present invention, the replacement work can be performed with fewer man-hours than in the past.

  In particular, in the present invention, since the supply pipe is perforated only once, the number of replacement man-hours can be greatly reduced as compared with the conventional art.

The details of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a cross-sectional view of a supply pipe provided with a flow path closing tool according to the first embodiment of the present invention, FIG. 2 is a cross-sectional view showing a use state of the flow path closing tool, and FIG. FIG. 4 is a sectional view of a supply pipe provided with a flow path closing tool according to the second embodiment of the present invention, and FIG. 5 is a flow path closing tool shown in FIG. FIG. 6 is an enlarged cross-sectional view of a portion C in FIG. 5. In FIGS. 4 to 6, the same functional parts as those in FIG. 1 are denoted by the same reference numerals.

  As shown in FIG. 1, a first supply pipe 1 (hereinafter referred to as an existing pipe) that is an existing pipe buried in the ground is branched from this branch pipe (not shown), and gas G flows in the direction of the arrow. ing. A second supply pipe (not shown, hereinafter referred to as a new pipe) newly provided in parallel with the existing pipe 1 has an end portion of the connecting pipe 2 connected through, for example, an EF joint (not shown) at the junction joint 3. The gas G flowing from the direction of the arrow can be caused to flow into the existing pipe 1. In the EF joint, a heating wire is embedded in a joint body made of a thermoplastic resin such as polyethylene, and when the heating wire is energized, an inner diameter portion of the joint body and a resin pipe (new pipe and connecting pipe 2) are connected. The resin pipe is connected by fusing.

  The joint 3 has an upper clamp 31 and a lower clamp 32 that are fixed to the existing pipe 1, and a cheese portion 33 that is fixed by being screwed into the upper clamp 31. The upper clamp 31 and the lower clamp 32 are formed by covering the outer surfaces of the main bodies 311 and 321 made of a steel material such as malleable cast iron with linings 312 and 322 made of a resin having corrosion resistance such as vinyl chloride, and the cheese portion. Similarly to these, the outer surface of the main body 331 made of a steel material 33 is coated with a lining 332 made of a resin having corrosion resistance. The cheese portion 33 has a branch portion 34 into which an end portion of the new pipe 2 is inserted, and is expanded by a method such as bulging after a stiffener 35 is attached to the inner surface of the end portion of the connecting pipe 2. The connecting pipe 2 and the branch part 34 are connected, and sealing is performed by a packing 36 interposed between the connecting pipe 2 and the branch part 34.

  The flow path closing tool 4 inserted into the existing pipe through the joint joint 3 includes the composite pipe 5 inserted from the cheese portion 33 of the joint joint 3 toward the inside of the existing pipe 1 and one end thereof ( A pressure means (not shown) such as a hand-pushing air pump connected to the upper end), a pressure gauge (not shown) for monitoring the pressure of the fluid pumped by the pressure means, and the other of the composite pipe 5 The sealing member 6 which seals an edge part is provided.

  The composite tube 5 includes a guide tube 51, an intermediate layer 52 attached to the surface thereof, and a covering layer 53 covering the surface.

  The guide pipe 51 is formed of a polyolefin-based resin such as polyethylene or polybutene so as to be bent by a predetermined angle (for example, a right angle) after being inserted into the junction joint 3 so that the guide pipe 51 can be inserted into the existing pipe 1. Sex has been granted.

  The intermediate layer 52 has a length that extends a predetermined length from the upper end of the joint 3 when the entire guide pipe 51 is inserted into the existing pipe 1 and expands when subjected to internal pressure. In order to be able to extend (elongate), it is formed of an elastomer (rubber elastic body) such as natural rubber, butyl rubber, olefin rubber such as ethylene-propylene rubber.

  The covering layer 53 is formed over substantially the entire length of the intermediate layer 52. In the middle of the covering layer 53, in order to expose the intermediate layer 52 at two locations, a notch 54a continuous along the circumferential direction, 54b is provided. That is, the covering layer 53 sandwiches the first covering layer 531 extending from the pressurizing means side (upper part in FIG. 1), the second covering layer 532 partially inserted into the inner surface of the end, and the notch 54a. It is divided into a third coating layer 533 adjacent to the second coating layer 532 and a fourth coating layer 534 adjacent to the third coating layer 533 across the notch 54b. The covering layer 53 can be formed by adhering a heat-shrinkable tube made of, for example, vinyl chloride, polyester, polyethylene terephthalate, or fluororesin (PFA, FEP, etc.) to the intermediate layer 52. Further, at least one communication hole 511 is provided in the middle of the guide tube 51 and in the vicinity of the notch portion 54a and the notch portion 54b, respectively, along the tube axis direction (see FIG. 3).

  In order to seal the other end of the composite tube 5, the sealing member 6 includes a cylindrical cap 61 mounted on the inner surface of the guide tube 51, a stopper 62, and a pin 63 whose tip is formed in a wedge shape. 51, and a ring 64 that is externally fitted to the fourth coating layer 534 and fastens the end of the composite pipe 5 (see FIG. 3).

  Next, referring to FIG. 2 and FIG. 3 as well, the supply comprising the steps 1) to 6) below, including the operation of blocking the flow of gas inside the existing pipe 1 using the above-mentioned channel closing tool 4. Explain the work of pipe replacement. FIGS. 1 and 2 show a state in which pits (not shown) having a size necessary for connecting the supply pipes are formed.

1) The junction joint 3 is assembled at a predetermined position of the existing pipe 1 and branched from the end of the connecting pipe 2 attached to the branch section 34 and the newly installed branch pipe to both ends of the electric fusion joint (socket). The end of the new pipe is inserted, and the connecting pipe 2 and the new pipe are fusion bonded by electric fusion.

2) After covering the junction joint 3 with a no-blow bag (not shown) and blocking from the atmosphere, a cutter (not shown) is set in the cheese portion 33, and the cheese portion is punched at a predetermined position. Remove the cutter from 33.

3) Insert the composite pipe 5 from the upper end of the cheese portion 33 (in the direction of arrow X in FIG. 1) and push the composite pipe 5 until the guide pipe 51 is located inside the existing pipe 1 over its entire length.

4) A pressurizing means (for example, a hand-pushing air pump) and a pressure gauge are connected to the end of the composite pipe 5 and the pressurizing means is operated to compress the pressurized fluid (for example, 150 to 180 kPa) inside the composite pipe 2. Air). Before supplying the pressurized fluid, the intermediate layer 52 is in close contact with the outer surface of the guide tube 51 due to its elasticity and the tightening force of the fourth coating layer 534 (second coating layer 532). When supplied from 511 to the outer periphery of the guide tube, a gap is formed between the outer surface of the guide tube 51 and the inner surface of the intermediate layer 52 that is expanded by the pressure of the pressurized fluid. 2 and 3, the pressurized fluid A flows through the gap between the guide tube 51 and the intermediate layer 52 from the communication hole 511 of the guide tube 51, and blows out to the notch portion 54a and the notch portion 54b. The layer 52 is bulged outward. That is, the notches 54 a and 54 b are formed with inflated portions 521 and 522 that are in close contact with the inner surface of the existing pipe 1. Thereafter, when the supply of the pressurized fluid is stopped, the outer surface of the guide tube 51 and the inner surface of the intermediate layer 52 are brought into close contact with each other due to the elasticity of the intermediate layer 52 and the tightening force of the fourth coating layer (second coating layer). Since it is blocked, the state where the inflating portions 521 and 522 are formed is maintained.

5) As described above, even after the supply of the pressurized fluid is stopped, the state of being in close contact with the inner surface of the existing pipe 1 is maintained, and the gas flow is blocked between the expansion portions 521 and 522, so that the expansion portion 521 And the existing pipe 1 in the section between 522 and the composite pipe 5 are cut and removed.

6) By sealing the upper end portion of the cheese portion 33, it becomes possible to supply gas to the customer side downstream of the existing pipe 1 through the junction joint 3.

The flow path closing tool 4 of the present invention is not limited to the above, and can be configured as follows, for example.
A flow path closing tool 4 shown in FIG. 4 includes a composite pipe 5 having flexibility, and means (not shown) for injecting a raw material for sealing member connected to one end (upper end) thereof. A sealing member 6 for sealing the other end of the composite pipe 5 is provided. In addition, since the sealing member 6 is comprised similarly to FIG. 1, the description is abbreviate | omitted.

The composite pipe 5 has a guide pipe 55 having a length that extends a predetermined length from the upper end portion of the junction joint 3 when one end side of the composite pipe 5 is inserted into the existing pipe 1 by a predetermined length. only part of the length of the length L ₁ has a coating layer 56 is deposited. Parasol-like regulating members 57a and 57b made of an elastic material such as general rubber (for example, IR or SBR) and closely attached to the inner surface of the existing pipe 1 are mounted on both end sides of the covering layer 56, and both end surfaces of the neck portion are provided. Is sandwiched between the covering layers 56. Parasol shape regulating member 57a, between the 57 b, together with the predetermined length L ₂ by the coating layer 56 is pulled peeled off is the guide pipe 55 is configured so as to be exposed, the exposed portion, the circumferential and axial A plurality of apertures 551 are provided along. A sealing member 58 is formed inside the existing pipe 1 using these openings 551.

  The sealing member is formed of, for example, a rigid polyurethane foam. As a stock solution thereof, a first solution (isocyanate liquid) mainly composed of an organic polyisocyanate (TDI, MDI, etc.) and a low boiling point compound (dimethyl ether, etc.) And polyols (polyhydric alcohols such as glycerin and propylene glycol) and low-boiling compounds (dimethyl ether, etc.) as main components, and catalysts (trimethylamine, etc.) and foam stabilizers (organic silicon surfactants, etc.) as required A two-component resin composition comprising the second solution added in the step can be used.

  As the means for injecting the stock solution, containers filled with two kinds of solutions are used, and these containers are simultaneously opened and poured from conduits (not shown) connected to the containers and connected in a composite pipe. Then, foaming is performed by mixing in the composite tube, and a sealing member (rigid polyurethane foam) can be formed.

  According to the flow path closing tool 4 described above, the supply pipes can be replaced by the following procedure. First, by performing the same steps as 1) and 2) above, after drilling at a predetermined position of the existing pipe 1, the composite pipe 5 is inserted from the upper end of the cheese portion 33, and all the openings 551 are formed in the existing pipe. The composite tube 5 is pushed in until it is located inside 1.

  Next, a means for injecting the stock solution of the sealing member is connected to the end of the composite pipe 5, and the stock solution is supplied into the composite pipe 5 by operating this injection means. The stock solution mixed inside the composite pipe 5 is foamed and flows out from the respective openings 551, and, as shown in FIGS. 5 and 6, the foamed resin is introduced into the existing pipe 1 between the regulating members 57 a and 57 b. A sealing member 58 is formed to block the upstream side and the downstream side of the existing pipe 1.

  Then, by performing the same steps as in 5) and 6) above, the supply pipes can be replaced.

  The present invention can be applied to supply pipes having various diameters. However, in consideration of the insertion work of the composite pipe, it is particularly effective for the connection of supply pipes having a small diameter (for example, 20A to 30A) that can be easily bent.

  The present invention is not limited to the above, and various modifications can be made. For example, the junction joint can have a configuration in which a cheese portion and an upper clamp are integrated.

1 is a cross-sectional view of a supply pipe provided with a flow path closing tool according to a first embodiment of the present invention. It is sectional drawing which shows the use condition of the flow-path obstruction | occlusion tool of FIG. It is sectional drawing which expands and shows the B section of FIG. It is sectional drawing of the supply pipe | tube provided with the tool for flow path obstruction | occlusion concerning the 2nd Embodiment of this invention. It is sectional drawing which shows the use condition of the tool for flow-path obstruction | occlusion of FIG. It is sectional drawing which expands and shows the C section of FIG. It is a piping diagram which shows the construction method of a prior art typically.

Explanation of symbols

1: Existing pipe,
2: Connecting pipe 3: Merge joint, 31: Upper clamp, 311: Main body, 312: Cover layer, 32: Lower clamp, 321: Main body, 322: Cover layer, 33: Cheese part, 331: Main body, 332: Cover layer , 34: branching portion, 35: stiffener, 36: packing 4: tool for closing the flow path,
5: Composite pipe, 51: Guide pipe, 511: Communication hole, 52: Intermediate layer, 521, 522: Expansion part, 53: Cover layer, 531: First cover layer, 532: Second cover layer, 533: Third Coating layer, 534: fourth coating layer, 54a, 54b: notch,
55: guide tube, 551: aperture, 56: coating layer, 57a, 57b: regulating member, 58: sealing member 6: sealing member, 61: cap, 62: stopper, 63: pin, 64: ring

Claims (6)

A composite pipe inserted from the opposite direction to the gas flow direction into the inside of the first supply pipe through which the gas flows and sealed at one end, and a fluid pumping means attached to the other end of the composite pipe, The composite tube has a flexible guide tube, an intermediate layer covering the surface, and a coating layer deposited on the intermediate layer, and the coating layer is a circle with a predetermined interval along the axial direction. A tool for closing a flow path, which has a pair of notches separated in the circumferential direction, and the inner periphery of the notches communicates with the inside of the guide tube. 2. The flow path closing tool according to claim 1, wherein the guide tube is made of a polyolefin-based resin, the intermediate layer is made of an elastomer, and the coating layer is made of a heat-shrinkable tube. A composite pipe inserted from the opposite direction to the gas flow direction into the first supply pipe through which the gas flows and sealed at one end, and a sealing member for blocking the gas flow at the other end of the composite pipe An injection means for injecting the raw material to be formed, wherein the composite pipe is supported by the guide pipe and is in close contact with the inner surface of the first supply pipe to block gas flow. And a pair of regulating members that define a section, and the inside and outside of the guide tube pass through a part of the section. The sealing member is made of a two-component mixed foaming resin, the regulating member is a parasol-like member, and the neck portion is sandwiched by a coating layer that is attached to the surface of the guide tube. The flow path closing tool according to claim 3. A confluence joint is attached to the first supply pipe, a second supply pipe is connected to the confluence joint, and at least the inside of the confluence joint is blocked from outside air, and then the first supply pipe is drilled. Through which the composite pipe is fed into the first supply pipe, pressurized fluid is supplied into the composite pipe from the fluid pumping means, and a part of the intermediate layer is expanded from the notch, and the expansion A method for renewing a supply pipe, wherein the section sandwiched between the expanded portions of the first supply pipe is cut off after the portion is brought into close contact with the inner surface of the first supply pipe. A confluence joint is attached to the first supply pipe, a second supply pipe is connected to the confluence joint, and at least the inside of the confluence joint is blocked from outside air, and then the first supply pipe is drilled. Through which the composite pipe is fed into the first supply pipe and the foamed resin composition is filled in the composite pipe, thereby blocking the gas flow inside the first supply pipe A supply pipe renewal method characterized in that after forming a member, only the section of the first supply pipe where the sealing member is formed is cut off.

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