JP2011163452A - Short pipe for buried pipe lines of water service business, buried pipe line using the same, and replacement method of intervention equipment of buried pipe line - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a short pipe for buried pipe lines of water service business, a buried pipe line using the short pipe, and a method of replacing an intervention equipment of the buried pipe line. <P>SOLUTION: In the short pipe relatively short in length which is cast iron pipe employed on the buried pipe line for the water service business and is connected to the intervention equipment in the buried pipe line, the short pipe is a tubular body which has a connection flange portion connected to the intervention equipment on one end and which has on the other end a trumpet-shapedly formed receptor into which the plug-fit end of the other buried pipe is inserted. Bore of the tubular body of the short pipe is determined to be an inside diameter which fittably swallows at least one part of the tubular body of the buried pipe which follows the plug-fit end of the buried pipe inserted into the receptor and the plug-fit end. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cast iron pipe used as a pipe (buried pipe) constituting a buried pipe for buried water, water transmission, water distribution, etc., buried in the ground in a water pipe business (generally used is a ductile cast iron pipe More specifically, replacement work for measuring devices such as gate valves and pressure reducing valves and metering devices (hereinafter referred to as valves and measuring devices are referred to as intervening devices) intervening in the conduit. The present invention relates to a novel structure of a short pipe (short pipe) used for convenience, an embedded pipe line configuration using the novel short pipe, and a method for replacing an intervening device.

  Hereinafter, the related art will be described with reference to FIGS. 3 and 4. 3 is a cross-sectional view of a buried pipe for a water supply business in which a conventional short pipe and a buried pipe are ductile cast iron pipes and a valve is interposed as an intervening device, and FIG. 2 is a cross-sectional view of the valve, the conventional short pipe and the buried pipe in FIG. It is an expanded sectional view which shows the connection part.

3 and 4, a conventional short pipe 1 is a flange portion that is bolted to one connection flange 21 of a valve 2 (an example of an intervening device) on one end side of a cylinder 11 that is a main body of the short pipe 1. 12 and swallows the insertion end 31 of a straight pipe 3A (hereinafter also referred to as straight pipes 3A, 3B...) Of a predetermined length used for most of the pipes on the other end side. The receiving port 13, the retaining ring 4 interposed on the outer periphery of the straight pipe 3 </ b> A on the outer peripheral edge of the receiving port 13, and the nut portion 14 that is bolted. The receiving length S (hereinafter also referred to as receiving length S) of the insertion end 31 is the receiving length S (receiving) of the receiving portion 32 of the straight pipe 3 (3A, 3B...) Used for most of the pipes. The length was very short, the same as S).

The buried pipes in the water supply plumbing business are underground, most of which are buried under the road for more than a few decades, so they are susceptible to not only vibration from the ground but also large external pressure due to crustal deformation and earthquakes. Sufficient flexibility is required for the pipe line to hold the water pipe line, which is one of important lifelines.
For this reason, the construction of buried pipes (3A, 3B, ...) by sequential connection of this kind of buried pipe is adopted because the so-called flange connection in which the flanges of the buried pipes are bolted together is not flexible at all. Can not do it.

As a water pipe, a method unique to the water industry (hereinafter referred to as a press ring connection) is used to connect the buried pipe before and after being sequentially connected using a retaining push ring 4 to give flexibility to the buried pipe. It is also called).
By connecting a retaining pusher 4 to each connecting portion of this pusher wheel connection, that is, in the example shown in the figure, “short pipe 1 + straight pipe 3A + straight pipe 3B...”, One receiving portion is provided between adjacent buried pipes. The buried tube 3 on the other insertion end portion 31 side inserted into the receptacle portion 13 in the short pipe 1 and the receptacle portion 32 in the straight pipe 3 is the buried tube on the receptacle portion (13, 32) side. For example, an inclination fluctuation of about 4 degrees (hereinafter also referred to as tilting) is allowed.

In order to allow such fluctuation (tilt), first, as shown in the drawing, the inner shape of each of the receiving port portions 13 and 32 has an inner diameter larger than the outer diameter of the insertion end portion 31 to be inserted. In addition, a trumpet shape in which the inner diameter gradually increases from the inner side of the receiving portions 13 and 32, that is, from the cylindrical bodies 11 and 33 toward the opening side of the receiving portions 13 and 32 (hereinafter also referred to as an enlarged diameter portion). It is necessary to form in.

Further, the insertion end portion 31 should not be fitted into the diameters of the cylindrical bodies 11 and 33 at the back of the receiving portions 13 and 32 through the enlarged diameter portions of the receiving portions 13 and 32. That is, if the insertion end 31 is inserted into the cylinders 11 and 33 so as to form a double cylinder, the axis of the buried pipe that follows is automatically fixed in the axial direction. Therefore, tilting at the connection site becomes impossible, and if an external force that varies in a direction away from the axis acts on one of the adjacent embedded tubes, the embedded tube will be broken or damaged at the connection site. It is.

Therefore, the cylinder 11 of the conventional short pipe 1 and the cylinder 33 of the straight pipe 3 are arranged so that the insertion end 31 inserted into the receiving ports 13 and 32 cannot be inserted. The diameter is the same as the diameter of the portion 31. For example, as shown in the figure, the insertion tip surface of the insertion end 31 inserted into the receiving port 13 is formed so as to collide with the end surface of the cylinder 11 or the cylinder 33 and collide with each other. .

In the push wheel connection, a rubber ring 5 having a wedge-shaped cross section is fitted to the outer periphery of the cylinders 11 and 33 on the insertion end 31 side, and the rubber ring 5 is connected to the outer peripheral surfaces of the cylinders 11 and 33. The rubber ring 5 interposed between the receiving portion 13 and pushed in and compressed by the retaining push ring 4 (hereinafter also simply referred to as a push ring) has a repulsive force so that the inner peripheral surface of the rubber ring 5 has a cylindrical body 11, The outer peripheral surface of the rubber ring 5 is in pressure contact with the outer peripheral surface of the rubber ring 5, and the outer peripheral surface of the rubber ring 5 is pressed into contact with the inner peripheral surface of the receiving port portion 13, thereby preventing the insertion end portion 31 from coming off from the receiving port portion 13. 13 side buried pipe (short pipe 1 or straight pipe 3) is tiltably connected to the buried pipe end 31 side buried pipe (straight pipe 3), and at the same time, the inner peripheral surface of the receiving portion 13 at the connection site. And the outer peripheral surface of the plug-in end portion 31 are closed and connected in a watertight manner.

Now, for example, when the valve 2 is interposed as an intervening device in the buried pipe as the water pipe as described above, the connection flange 12 of the short pipe 1 is connected to at least one connection flange 21 of the valve 2. Then, the straight pipes 3 (3A, 3B...) Are sequentially connected to form the buried pipe line.

When the valve 2 is replaced, the fastening bolts of the connection flanges 21 and 21 on both ends of the valve 2 are removed, and the short pipe 1 and a retaining pipe of the buried pipe connected to the short pipe 1, that is, the straight pipe 3A. 4, the valve 3 is removed from the pipe line. As can be seen from FIG. 3, in the axial direction of the pipe line connected to both sides of the valve 3, There is almost no margin gap (hereinafter also referred to as a work gap) necessary for the detachment work, and even if forcibly creating a work gap, a few centimeters cannot be taken, which is not sufficient for work.

Even if a work gap of about several centimeters is likely to be obtained, in many cases, the gap is lost due to expansion due to secular deformation of the packing interposed between the left and right connection flanges 21 and 21 of the valve 2. It was not uncommon for them to end up.
Furthermore, even if the valve 2 can be removed with a large manual clearance, a sufficient working gap cannot be obtained even if a new valve (2) is interposed.

As described above, in the conventional replacement operation of the valve 2, a sufficient working gap was not obtained, and therefore, the cylinder 33 of the buried pipe (straight pipe 3A) connected to the short pipe 1 was cut and removed at an appropriate position. The working gap was obtained, and it was longer by the length corresponding to the length of the cut tube 33 when mounting the new valve (2) and connecting it to the existing pipeline. Another short pipe was newly prepared for replacement work.
In addition, the suitable place which cut | disconnects the cylinder 33 of a buried pipe (straight pipe 3A) is a site | part determined beforehand so that it may adapt to the length of the planned new short pipe (not shown).

Certainly, the cutting work of the cylinder 33 of the buried pipe (straight pipe 3A) provides a working gap in the removing work, so that the removing work is facilitated, but in the mounting work of the new valve (2), Since there is an existing pipe line extending to the left and right, a new valve (2) and a new short pipe (1), or in some cases, the original short pipe 1 are provided between the existing pipe lines extending to the left and right. (If the original short pipe 1 is used, a new buried pipe (straight pipe 3A) to replace the cut buried pipe (straight pipe 3A) must be prepared. This new buried pipe (straight pipe) 3A) can also be used to fit between existing pipe lines (the length of the cylinder must be cut so that the length can be adjusted to fit between existing pipe lines). It must be carried out in a state where there is almost no problem, and a great deal of labor and labor are required.

In addition, cutting of a tubular body of an embedded pipe, which is a cast iron pipe and most of which is a ductal cast iron pipe, is extremely different from a resin pipe, and the cutting is not an easy operation.

  The present invention provides a short pipe having a novel structure capable of easily exchanging intervening equipment interposed in the buried pipe in order to solve the above-mentioned problems in a buried pipe of a cast iron pipe used in a water pipe business. An object of the present invention is to provide a new buried pipeline configuration using the short pipe and a new replacement method for intervening equipment.

The invention of the short pipe according to claim 1 is a cast iron pipe used for a buried pipe for a water service business, and is a short pipe connected to an intervening device interposed in the buried pipe,
The short pipe has a connecting flange portion connected to the intervening device at one end, and a tubular body having a receptacle portion formed in a trumpet shape into which the insertion end portion of another buried pipe is inserted at the other end. In this case, the diameter of the tube of the short tube can be freely inserted into the insertion end of the embedded tube inserted into the receiving port and at least a part of the tube of the embedded tube following the insertion end. It is characterized by the inside diameter swallowed.

  According to a second aspect of the present invention, in the short pipe of the first aspect, the diameter of the cylindrical body is such that the diameter of the tubular pipe is honey-fitted with the insertion end of the buried pipe and at least a part of the cylindrical body following the insertion end. It is characterized by that.

According to a third aspect of the present invention, in the short pipe according to the first or second aspect, the diameter of the tubular body of the short pipe is such that the insertion end of the buried pipe and the insertion end are inserted into the receiving part. It is characterized by being formed over the entire length of the cylinder with an inner diameter that allows the cylinder of the buried pipe to be swallowed so as to be freely inserted.

  According to a fourth aspect of the present invention, in the short pipe according to any one of the first to third aspects, the other buried pipe is a straight pipe, a bent pipe, or other deformed pipe longer than the short pipe. Features.

  The invention of a buried pipeline for water supply business according to claim 5 includes the short pipe according to any one of claims 1, 2, 3, or 4.

The invention of the method for exchanging the intervening equipment in the buried pipeline for the water supply business according to claim 6 is for water supply business including the short pipe according to any one of claim 1, claim 2, claim 3 or claim 4. In the replacement work of the intervening equipment in the buried pipeline,
At least the fastening at the connection site between the intervening device and the short pipe and the fastening at the connection site between the short pipe and the buried pipe inserted into the short pipe are each released, and the short pipe serves as the buried pipe. Working gap setting in which the short pipe is pushed into the buried pipe side so as to be swallowed into a double cylinder state, and a working gap corresponding to the pushed length is provided between the intervening device and the short pipe Including a process.

The invention of the method for exchanging the intervening equipment in the buried pipeline for the water supply business according to claim 7 is for a water supply business including the short pipe according to any one of claim 1, claim 2, claim 3 or claim 4. In the replacement work of the intervening equipment in the buried pipeline,
At least the fastening at the connection site between the intervening device and the short pipe and the fastening at the connection site between the short pipe and the buried pipe inserted into the short pipe are each released, and the short pipe serves as the buried pipe. A work gap setting step in which the short pipe is pushed into the buried pipe side so as to be swallowed into a double cylinder state, and a working gap corresponding to the pushed length is provided between the intervening crisis and the short pipe. When,
An intervening device separating step for unfastening at all other required connection sites except for fastening at the connection site with the short pipe so that the interstitial device can be removed from the buried pipeline;
The process of fastening the connection at all other required connection parts except the fastening at the connection part with the short pipe, the replaced new intervening device,
A short pipe drawing step of drawing out the short pipe pushed into the buried pipe in order to connect the short pipe to the new intervening device;
And a step of fastening each connection at a required connection site between the drawn short pipe and the new intervening device and a required connection site between the short pipe and the buried pipe.

The invention of the method for exchanging the intervening equipment in the buried pipe for the water supply business according to claim 8 is the replacement work of the intervening equipment in the buried pipe for the water supply business in which the conventional short pipe is connected to the intervening equipment.
The intervening device is unfastened at the connecting portion between the intervening device and the conventional short tube and the fastening at the connecting portion between the conventional short tube and the buried tube connected to the conventional short tube, respectively. And the conventional short pipe removing work step for removing the conventional short pipe from the buried pipeline,
The conventional short pipe is replaced with the short pipe according to any one of claims 1, 2, and 3, and the replaced new short pipe swallows the buried pipe to be in a double cylinder state. The working gap setting step of pushing into the buried pipe side and providing a working gap corresponding to the pushing length between the installation space of the interposed device and the short pipe,
The process of fastening the connection at all other required connection parts except the fastening at the connection part with the short pipe, the replaced new intervening device,
A short pipe drawing step of drawing out the short pipe pushed into the buried pipe in order to connect the short pipe to the new intervening device;
And a business process for fastening each connection at a required connection portion between the drawn short pipe and the new intervening device and a required connection portion between the short pipe and the buried pipe. .

  A ninth aspect of the present invention is the short pipe according to any one of the first to fourth aspects, wherein the short pipe and the buried pipe are ductile cast iron pipes.

  The invention of claim 10 is characterized in that the short pipe and the buried pipe are ductile cast iron pipes in the buried pipe for the water supply business according to claim 5.

Invention of Claim 11 is the replacement | exchange method of the intervening apparatus in the buried pipe line for water supply businesses in any one of Claim 6 thru | or 8, The short pipe and the buried pipe are ductile cast iron pipes, To do.

  According to each of the inventions of claims 1 to 4 and claim 9, in any of the inventions, by using the short pipe as a buried pipeline for a water supply business, replacement work for intervening equipment in the buried pipeline is performed. In this case, at least the fastening at the connection part between the intervening device and the short pipe and the fastening at the connection part between the short pipe and the buried pipe inserted into the short pipe are each released, and the short pipe is connected to the buried pipe. By pushing the short pipe into the buried pipe side so that a double cylinder state is swallowed, a working gap corresponding to the pushed-in length is easily provided between the intervening device and the short pipe In addition, when connecting the short pipe to the new intervening equipment that has been replaced, the short pipe pushed into the buried pipe can be easily removed by simply pulling it out to the new intervening equipment. it can.

  According to the inventions of claims 5 to 7, claim 10, and claim 11, in any of the inventions, in the replacement operation of the intervening equipment in the buried pipeline, at least the connection site between the intervening equipment and the short pipe Each of the short pipe and the short pipe and the buried pipe inserted into the short pipe are respectively unfastened and the short pipe swallows the buried pipe to form a double cylinder state. By pushing the pipe toward the buried pipe, a working gap corresponding to the pushed-in length can be easily provided between the intervening device and the short pipe.

According to the invention of claim 7, at least the fastening at the connection part between the intervening device and the short pipe and the fastening at the connection part between the short pipe and the buried pipe inserted into the short pipe, respectively, By pushing the short pipe toward the buried pipe so that the short pipe swallows the buried pipe into a double cylinder state, a working gap corresponding to the pushed-in length is provided between the intervening device and the short pipe. In addition, when connecting the short pipe to the replaced new intervening device, it is only necessary to pull out the short pipe pushed into the buried pipe to the new intervening device side. It can be done easily by work.

According to the eighth aspect of the present invention, the conventional short pipe removing work step for removing the intervening device and the conventional short pipe from the buried pipeline must be performed by the conventional method, but the new short pipe replaced. By using this, the new short pipe can be pushed into the buried pipe side so as to be in a double cylinder state, and a working gap corresponding to the pushed length can be easily provided between the installation space of the intervening equipment and When connecting the new short pipe to the replaced new intervening device, it can be easily done by simply pulling out the new short pipe pushed into the buried pipe.
At the time of replacement of the intervening device after the dredging, as in the effect of the invention of claim 7, at least fastening at the connecting portion between the intervening device and the short pipe, and embedment inserted into the short pipe and the short pipe Unfastened at the connection part with the pipe, and the short pipe swallowed the buried pipe and pushed the short pipe into the buried pipe side so as to be in a double cylinder state. It is possible to easily provide a working gap between the intervening device and the short tube, and when the short tube is connected to a new intervening device that has been replaced, it is pushed into the buried tube. It is possible to easily complete the operation by simply pulling out the short pipe to the new intervening device side.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention will be described below based on the embodiments shown in FIGS. 1 is a cross-sectional view of a buried pipe for a water supply business in which a short pipe and a buried pipe are ductile cast iron pipes and a valve is interposed as an intervening device, and FIG. 2 is a connection portion between the valve, the short pipe and the buried pipe in FIG. It is an expanded sectional view shown.

(Short pipe)
1 and 2, reference numeral 10 denotes a short tube according to the present invention.
The short pipe 10 has a connection flange portion 120 connected to one connection flange portion 21 of the valve 2 as an intervening device at one end of the cylinder 110, and is connected to the other end of the cylinder 110. A receiving portion 130 formed in a trumpet shape into which the insertion end 31 of the embedded tube 3A is inserted.

Here, the short pipe 10 is a straight pipe having a relatively long length that is usually used as a buried pipe for a water supply business, that is, the buried pipe in this example. It is called a short pipe in that it is shorter than the length of the 3A cylinder 33, and the interposer 2 whose connection port is constituted by the connection flange portion 21 and the buried pipe 3A not provided with the connection flange portion are provided. It is a kind of connecting pipe that intervenes for connection.

The short tube 10 of the present invention is different from the conventional short tube, ie, the conventional short tube 1 described above, in that the diameter of the cylindrical body 110 excluding the receiving portion 130 of the short tube 10 is the receiving portion of the short tube 10. The insertion end portion 31 of the embedded tube 3 </ b> A to be inserted into 130 and the cylindrical body 33 of the embedded tube following the insertion end portion 31 are formed to have an inner diameter that can be swallowed so as to be fitted.

The inner diameter of the tube 110 of the short tube 10 that can be swallowed is formed over the entire length of the tube 110 in the illustrated example, but it is not necessarily formed over the entire length, and a part of the tube 110 is not necessarily formed. (Not shown), it suffices if the length is sufficient to ensure a required working gap required for the replacement work of the valve 2 described later.
This will be explained with reference to the drawing. An appropriate length is formed from the receiving portion 130 side of the short tube 10 in the back direction of the cylindrical body 110, that is, in the direction of the connecting flange 120 on the other end side of the short tube 10 (see FIG. (Not shown).

The inner diameter of the tube 110 of the short tube 10 that swallows the insertion end 31 and the tube 33 of the embedded tube 3A is made to correspond to the outer diameter of the embedded tube 3A that is swallowed. The insertion end 31 of the buried pipe 3A that is swallowed or relatively pulled out, and the outer peripheral surface of the cylinder 33 following the insertion end 31 and the inner peripheral surface of the cylinder 11 are honey-fitted. The diameter is preferably watertight.

  In the example shown in the figure, the embedded pipe 3A connected to the short pipe 11 via the push ring 4 is a straight pipe longer than the short pipe, but is not necessarily a straight pipe, and depending on the pipe configuration, It may be a curved pipe or other deformed pipe.

(Replacement method of intervening equipment in the new short pipe interposer)
When a short pipe (also referred to as a new short pipe) 10 configured as described above is newly installed in a buried pipe for a water supply business, an intervening device (valve) 2 interposed in the buried pipe from the beginning as shown in the figure If a pipe line attached by flange connection is provided (this pipe line is also called a new short pipe intervening buried pipe line),
In the replacement operation of the intervening device (2), at least the fastening of the connection flange portion 21 that is fastened by using a fastening bolt at the connecting portion between the intervening device (2) and the short tube 10, and the short tube 10 When the short pipe 10 is pushed into the buried pipe 3A side after the fastening at the connection portion of the push ring connection by the push ring 4 with the buried pipe 3A inserted into the short pipe 10 is released, the short pipe 10 is The buried pipe 3A is swallowed and fitted so as to be in a double cylinder state, and the short pipe 10 is pushed into the buried pipe 3A side, that is, pushed in from the buried pipe 3A side. The space between the connection flange portion 120 of the short pipe 10 and the connection flange portion 21 of the intervening device (2) is long in the tube axis direction, and the working space, that is, the intervening device, is vacant there. Providing a work gap necessary for the replacement work in (2) Kill.

(Work gap setting process)
As described above, at least the fastening at the connection part between the intervening device (2) and the short pipe 10 and the fastening at the connection part between the short pipe 10 and the buried pipe 3A inserted into the short pipe 10 are respectively released. After that, the short pipe 10 swallows the buried pipe 3A and pushes the short pipe 10 toward the buried pipe 3A so that it becomes a double cylinder state (this pushing process is referred to as a short pipe pushing process)). A working gap is provided between 2) and the pressed short pipe 10. This process is called a work gap setting process.

(Intervening device separation process)
When the work gap is provided in the above-described work gap setting step, the replacement work of the intervening device (2) can be performed quickly and easily.
That is, in order to be able to detach the intervening device (2) from the buried pipe line, first, the connecting flanges of the intervening device (2) are connected to each other at the connecting portion with the other connecting flange portion 21 (left side in the figure). The fastening bolt of the part is removed and the fastening is released, and the fastening of the connection at the required connection site with the other place is released, and the intervening device 2 is detachably separated from the pipe line. This process is called an intervening device separation process.

(New intervening equipment preliminary connection process)
The intervening equipment 2 to be replaced is replaced with a new intervening crisis 2 by the above-described intervening equipment separating step. First, the replaced new intervening equipment 2 (also referred to as the new intervening equipment 2 or simply the intervening equipment 2) Except for fastening of the connection flange portion 21 of the intervening device 2 and the connection flange portion 120 of the short pipe 10, the connection at all other required connection sites is fastened. This process is called a new intervening equipment preliminary connection process.

(New interposer final connection process)
After the above-described new intervening equipment preliminary connection step, the short pipe 10 that has been pushed into the buried pipe 3A to connect the connecting flange portion 120 of the new intervening equipment 2 to the connecting flange portion 120 of the short pipe 10 is connected. (This drawing process is referred to as a short pipe drawing process), and the new intervening equipment 2 at the required connecting portion between the drawn short pipe 10 and the new intervening equipment 2, that is, the connecting flange portion 120 of the short pipe 10. Of the connecting flange portion 21 and the required connecting portion of the short tube 10 and the buried tube 3A, that is, the fastening portion of the receiving portion 130 of the short tube 10 and the press ring 4 interposed in the buried tube 3A. Make a conclusion. This process is called a new intervening equipment final connection process.

As described above, the replacement operation of the intervening equipment in the new short pipe interposing buried pipe is performed by the work gap setting process as the first process → the intervening equipment separation process as the second process → the new intervening equipment spare as the third example process. The replacement process can be completed easily and quickly in the four steps of the new intervening device final connection step as the connection step → the fourth step.

(Replacement method of intervening equipment in conventional short pipe interposing buried pipe)
Based on FIG.1 and FIG.3, the replacement | exchange operation | work of the intervening apparatus in the underground pipe line for water supply businesses in which the conventional short pipe was connected to the intervening apparatus 2 is demonstrated.

(Conventional short pipe removal work process)
In the replacement work of the intervening equipment 2 in the buried pipe for water supply business to which the conventional short pipe 1 is connected, first, the conventional short pipe 1 is separated from the buried pipe and removed or removed. A process (this is called a conventional short pipe removing operation process) is required as a premise.
The contents of the conventional short pipe removal work process may be specifically a fastening method for connecting each of the intervening equipment 2, the conventional short pipe 1 and the buried pipe 3A, that is, a connecting method. For the sake of convenience, here, an explanation will be given taking an existing buried pipeline connected as shown in FIG. 3 as an example.
Therefore, the conventional short pipe removing operation process referred to in the present specification and claims is a general content that separates the conventional short pipe 1 from the buried pipe line and makes it removable or removable. The definition is not limited to the work contents of the conventional short pipe removing work process described below.

In the replacement operation of the intervening device 2 in the connection example shown in FIG. 3 and FIG. 4, first, a connection that is fastened by using a fastening bolt at least at a connection portion between the intervening device 2 and the conventional short pipe 1. It is necessary to release the fastening of the flange portion 21 and the fastening at the connection part of the pusher wheel connection by the pusher wheel 4 between the short pipe 1 and the embedded pipe 3A inserted into the short pipe 1.
Of course, in order to enable not only the connection portion but also the intervening device 2 to be separated from the pipe line, it is necessary to explain the fastening of other connection portions of the intervening device 2 at an appropriate work stage.

However, as can be seen from the figure, the tube 11 of the short tube 1 and the tube 33 of the embedded tube 3A have the same diameter on the insertion tip side of the embedded tube 3A inserted into the receiving portion 13 of the short tube 1. Yes, because the cylinder ends of the cylinder 11 and the cylinder 33 are connected in the receiving portion 13 in a state where the end faces of both cylinders are abutted (FIG. 4). Even if all of the fastenings are released, the intervening device 2 cannot be removed only by releasing all the fastenings as described in the section of the background art.

Therefore, in the conventional construction method, the insertion side of the cylindrical body 33 of the embedded pipe 3A inserted into the short pipe 1 is cut. This cutting process is called a buried pipe cutting process.
In this buried pipe cutting process, a cast iron buried pipe having a relatively large diameter and a considerably thick wall, particularly a ductile cast iron buried pipe, must be cut, and the cutting operation is performed in a state where the buried pipe is buried. The work to do is a work that requires a lot of time and is not easy.

For example, in order to cut the buried pipe 3A, the soil must be dug up to the cutting site, and the surrounding space necessary for the cutting work must be dug up to a relatively large size. Is required.
In addition, since the length of the cylindrical body 33 of the cut buried pipe 3A is shortened, it is often necessary to use a new buried pipe (new buried pipe) 3A. The operation of cutting the new buried pipe 3A to the required length becomes necessary, and in order to replace the existing buried pipe 3A with the new buried pipe 3A, the existing buried pipe 3A and the buried pipe are used. The soil must be dug up to the part where the pusher 4 of the buried pipe 3B connected to the pusher 3A can be removed, and the pusher 4 and the rubber ring 5 of the buried pipe 3B must be removed and attached.

Thus, in the buried pipe cutting step, the buried pipe 3A is cut, and by removing the separated cylindrical body part and the short pipe 1 simultaneously from the pipeline, the removal work space of the intervening device 2 is A space (work space) similar to the work space is obtained as a space between the connection flange 21 of the intervening device 2 and the cut portion of the embedded pipe 3A.

As described above, at least at the connection portion between the intervening device 2 and the conventional short tube 1 and at the connection portion between the conventional short tube 1 and the embedded tube 3A connected to the conventional short tube 1 Each of the fastenings is released, and the intervening device 2 and the conventional short pipe 1 are separated from the buried pipe line so that they can be removed or removed (conventional short pipe removing operation process).

After the above-described conventional short pipe removing operation process is completed, the conventional short pipe 1 is replaced with the new short pipe (new short pipe) 10 of the present invention, and the replaced new short pipe 10 is replaced with the buried pipe 3A. Embedded tube so that the tube portion 33 (or the tube portion 33 of the newly embedded tube 3A after the new embedded tube 3A is connected to the embedded tube B by pushing a wheel) from the cutting portion side is swallowed into a double tube state. The working gap corresponding to the pushing length is pushed into the 3A side, and the working space, that is, the working gap, is provided between the installation space of the intervening equipment, that is, the connecting flange portion 21 of the intervening equipment and the connecting flange portion 120 of the pushed new short pipe 10. Is provided. Since this process is substantially the same as the work gap setting process, it is also referred to as a work gap setting process.

The steps after the work gap setting step are the same as the new intervening device preliminary connection step → the new intervening device final connection step.

As described above, the replacement operation of the intervening equipment in the conventional short pipe interposing buried pipe is performed as the conventional short pipe removing work process as the 0th process, the work gap setting process as the first process → the second process. The replacement operation can be completed easily and promptly in five steps of the intervening device separation step → the new intervening device preliminary connecting step as the third step → the new intervening device final connecting step as the fifth step.

In the replacement work of the intervening equipment in the conventional short pipe interposing buried pipe, the conventional short pipe removing as the 0th process is compared with the first to fourth processes of the interposition equipment replacement work in the new short pipe interposing buried pipe. The external work process will be increased by one process as a premise process. Once this 0th process is performed, the first replacement work of the intervening equipment in the new short pipe interposing buried pipe will be performed at the time of replacement work after dredging. There is an advantage that only the work for performing the fourth step is required.

INDUSTRIAL APPLICABILITY The present invention can be widely used in underground pipes that are buried in the ground, such as water conveyance, water transmission, and water distribution, in pipes that include valves and intervening equipment such as measurement equipment.

It is sectional drawing of the buried pipe line for water supply businesses in which the intervention apparatus interposes (Example). It is an expanded sectional view of the short tube part of Drawing 1 (example). It is sectional drawing of the conventional buried pipe line for water supply businesses which intervene equipment interposes (conventional example). It is an expanded sectional view of the short tube part of Drawing 3 (conventional example)

1 Short pipe (conventional type)
11 Cylinder (conventional short pipe)
12 Connection flange (conventional short pipe)
13 Receiving part (conventional short pipe)
10 Short pipe (new type)
110 Tube (New short tube)
120 Connection flange (new short pipe)
130 Receptacle (New short pipe)
2 Valve (intervening equipment)
21 Connection flange (intervening equipment)
3A buried pipe (straight pipe)
3B buried pipe (straight pipe)
4 Push ring (Retaining push ring)
5 Rubber ring

Claims (11)

Cast iron pipes used for buried pipes for water supply business, in a short pipe connected to the intervening equipment interposed in the buried pipes,
The short pipe has a connecting flange portion connected to the intervening device at one end, and a tubular body having a receptacle portion formed in a trumpet shape into which the insertion end portion of another buried pipe is inserted at the other end. In this case, the diameter of the tube of the short tube can be freely inserted into the insertion end of the embedded tube inserted into the receiving port and at least a part of the tube of the embedded tube following the insertion end. A short tube characterized in that it has an inner diameter that is swallowed.   2. The short pipe according to claim 1, wherein a diameter of the cylindrical body is a diameter that fits into at least a part of the insertion end portion of the embedded pipe and the cylindrical end portion following the insertion end portion. The diameter of the tube of the short tube is the full length of the tube to the inner diameter of the embedded tube inserted into the receiving port and the inner diameter of the tube embedded in the embedded tube following the plug-in end. The short pipe according to claim 1 or 2, wherein the short pipe is formed over the entire length.   The short pipe according to any one of claims 1 to 3, wherein the other buried pipe is a straight pipe, a bent pipe, or other deformed pipe longer than the short pipe.   A buried pipe for a water supply business, comprising the short pipe according to claim 1, claim 2, claim 3, or claim 4. In the replacement work of the intervening equipment in the buried pipeline for the water supply business including the short pipe according to any one of claims 1, 2, 3, or 4,
At least the fastening at the connection site between the intervening device and the short pipe and the fastening at the connection site between the short pipe and the buried pipe inserted into the short pipe are each released, and the short pipe serves as the buried pipe. Working gap setting in which the short pipe is pushed into the buried pipe side so as to be swallowed into a double cylinder state, and a working gap corresponding to the pushed length is provided between the intervening device and the short pipe A method for exchanging intervening equipment in a buried pipeline for a water supply business characterized by including a process. In the replacement work of the intervening equipment in the buried pipeline for the water supply business including the short pipe according to any one of claims 1, 2, 3, or 4,
At least the fastening at the connection site between the intervening device and the short pipe and the fastening at the connection site between the short pipe and the buried pipe inserted into the short pipe are each released, and the short pipe serves as the buried pipe. A work gap setting step in which the short pipe is pushed into the buried pipe side so as to be swallowed into a double cylinder state, and a working gap corresponding to the pushed length is provided between the intervening crisis and the short pipe. When,
An intervening device separating step for unfastening at all other required connection sites except for fastening at the connection site with the short pipe so that the interstitial device can be removed from the buried pipeline;
The process of fastening the connection at all other required connection parts except the fastening at the connection part with the short pipe, the replaced new intervening device,
A short pipe drawing step of drawing out the short pipe pushed into the buried pipe in order to connect the short pipe to the new intervening device;
And a step of fastening a connection at a required connection portion between the drawn short pipe and the new intervening device, and a required connection portion between the short pipe and the buried pipe. To replace the intervening equipment in the buried pipeline. In the replacement work of the intervening equipment in the buried pipe for the water supply business in which the conventional short pipe is connected to the intervening equipment,
The intervening device is unfastened at the connecting portion between the intervening device and the conventional short tube and the fastening at the connecting portion between the conventional short tube and the buried tube connected to the conventional short tube, respectively. And the conventional short pipe removing work step for removing the conventional short pipe from the buried pipeline,
The conventional short pipe is replaced with the short pipe according to any one of claims 1, 2, and 3, and the replaced new short pipe swallows the buried pipe to be in a double cylinder state. The working gap setting step of pushing into the buried pipe side and providing a working gap corresponding to the pushing length between the installation space of the interposed device and the short pipe,
The process of fastening the connection at all other required connection parts except the fastening at the connection part with the short pipe, the replaced new intervening device,
A short pipe drawing step of drawing out the short pipe pushed into the buried pipe in order to connect the short pipe to the new intervening device;
And a step of fastening each connection at a required connection portion between the drawn short pipe and the new intervening device and a required connection portion between the short pipe and the buried pipe. Replacement method for intervening equipment in commercial buried pipelines.   The short pipe according to any one of claims 1 to 4, wherein the short pipe and the buried pipe are ductile cast iron pipes.   The short pipe and the buried pipe are ductile cast iron pipes, and the buried pipe for water service according to claim 5. 9. The method for exchanging intervening equipment in a buried pipe for a water supply business according to claim 6, wherein the short pipe and the buried pipe are ductile cast iron pipes.

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