JPH04337181A - Pulling method and renewing method for pipe - Google Patents

Abstract

PURPOSE:To provide a pipe pulling-off method and a pipe renewing method wherein a worn-out and deteriorated existing pipe can be completely removed without breakage and a new main pipe is smoothly installed, in a piping line where a main pipe is inserted through a disposed protecting pipe. CONSTITUTION:In a pipe line where a main pipe 1 is inserted through a disposed protection pipe, a traction wire 3 is inserted in the main pipe 1 and one end of the wire 3 is bound to one end of the main pipe 1. Thereafter, by conducting traction of the other end side of the traction wire 3, the main pipe 1 is pulled off from the disposed protection pipe 2. By intercoupling the one end of the wire 3 and the tip of a new pipe, the main pipe 1 is pulled off and the new main pipe 1 is inserted in the disposed protection pipe 2.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method for removing an old main pipe from a piping route in which a main pipe is passed through an installed protection pipe, and a method for extracting and renewing a pipe used for replacing the main pipe. It is useful for main renewal in pipelines.

0002

[Prior Art] In the sheath pipe type piping route used for piping inside buildings, the sheath pipe (protective pipe) is installed on the slab floor during construction of the building frame, and then inserted into the existing sheath pipe during equipment construction at a later date. main(
This method has the advantage that aging pipes can be dealt with by simply renewing the main pipes.

[0003] Conventionally, in renewal work for sheath pipe type piping, both ends of the main pipe, that is, between the main pipe and the header and between the main pipe and the use point (for example, a callan) are cut. After that, the old main pipe was pulled out by pulling on one end of the main pipe, and the new main pipe was passed through the area where it was pulled out.

0004

When the old main pipe is pulled out, a tensile force acts on the old main pipe due to the frictional force acting between the old main pipe and the installed protection pipe. In other words, the frictional force per unit length acting between the main pipe and the protection pipe is f
Then, a tensile force F=fx acts on the main pipe at a position x from the rear end of the main pipe (the rear end with respect to the direction in which the pipe is pulled out). However, the deterioration in the old main pipe mentioned above is not necessarily uniform over the entire length, but is usually localized, and these localized deterioration points are usually located in the middle of the length. , the above-mentioned tensile fracture rarely occurs at the point of maximum tensile stress, that is, at the tensile tip side of the main pipe, and often occurs in the middle of the old main pipe.

[0005] In this way, if a tensile break occurs in the middle of the old main pipe that is being pulled out, the broken pieces remain in the protective pipe, making it extremely difficult to pull in a new main pipe, that is, to renew the main pipe. Become.

An object of the present invention is to be able to completely remove old and deteriorated old main pipes without rupturing them in a piping route in which a main pipe runs inside a protection pipe, and also to quickly install a new main pipe. An object of the present invention is to provide a method for extracting and renewing a pipe that can be passed through a pipe.

[0007]

[Means for Solving the Problems] The method for pulling out a pipe of the present invention is to
Insert a traction wire into the main pipe, tie one end of the wire to one end of the main pipe, and then pull the other end of the traction wire to pull out the main pipe from inside the protective tube. This configuration is characterized by the following.

The pipe renewal method of the present invention involves inserting a pulling wire into the main pipe and connecting one end of the wire to one end of the main pipe in a pipe line in which the main pipe is passed through the installed protection pipe. Connect one end of the same wire to the tip of the new pipe, and then pull the other end of the traction wire to pull out the main pipe from inside the protective pipe and install the new main pipe. This structure is characterized by passing through the installed protection pipe.

[0009]

[Operation] Mechanically, it is equivalent to the main pipe being pushed from the rear end and removed, and the stress acting on the main pipe due to the frictional force between the main pipe and the installed protection pipe becomes compressive stress. . Therefore, the pipe is less likely to break due to the axial compressive force than the pipe due to the axial tensile force, and the main pipe can be removed smoothly without scratching between the main pipe and the protection pipe. Even if a break occurs, the broken pieces will not remain in the protective tube due to the pressure from the rear end, and the renewal work can be performed satisfactorily.

0010

Embodiments Hereinafter, embodiments of the present invention will be explained with reference to the drawings. FIGS. 1A to 1D are explanatory diagrams showing the tube drawing method of the present invention.

FIG. 1(a) shows the main pipe 1 (water supply and drainage pipe, hot water supply pipe, gas pipe) in the pipe line constructed by the sheath pipe method.
This figure shows a state in which both ends of the pipe are cut, that is, a state in which the main pipe and the header and between the main pipe and the use point (for example, the cutter) are cut.

According to the present invention, in order to pull out the old main pipe from inside the sheath pipe 2, as shown in FIG. 1(A), both ends of the main pipe 1 are cut, and then as shown in FIG. 1(B), The traction wire 3 is inserted into the main pipe 1 from one end (front end) to the other end (rear end) of the main pipe. The traction wire 3 is inserted through a so-called split bamboo thread, and the traction wire is inserted using the inserted split bamboo as a lead. A method can be used in which the main pipe is penetrated by blowing compressed air, and a pulling wire is passed through the thin wire as a lead wire.

After inserting the traction wire 3 into the main pipe 1,
As shown in FIG. 1(C), connect the fastening jig 4 to the rear end of the wire 3, pull the pulling wire 3 from the front end side A, and as shown in FIG. 4 is locked to the rear end of the main pipe 1, and the pulling wire 3 is continued to be pulled.

The mechanical state in this case is equivalent to applying a pressing force to the rear end of the main pipe 1 to move the main pipe 1 into the sheath pipe 2, and the relationship between the main pipe 1 and the sheath pipe is The main pipe 1 only receives compressive stress due to the friction between them, and if the frictional force per unit acting between the sheath pipe 2 and the main pipe 1 is f, then the position at a distance y from the front end of the sheath pipe The axial compressive force at the main pipe location is
It is given by W=fy.

[0015] During the removal of the main pipe 1, the axial stress acting on the main pipe 1 is substantially only compressive stress, and usually
Because axial compression fractures of pipes are less likely to occur than axial tension fractures (for example, if a crack exists in a pipe, tension tends to widen the crack and cause rupture, but compression is less likely to cause it). Breaking of the main pipe 1 during removal can be well prevented, and the main pipe 1 can be removed without scratching between the main pipe 1 and the sheath pipe. Therefore, removal can be carried out smoothly, and the sheath pipe 2
It will not damage the inside of the body.

Even if the main pipe 1 is cut, no cut pieces remain in the sheath pipe 2, and the main pipe 1 can be completely removed. Any suitable fastening jig 4 can be used as long as it can be firmly attached to the main pipe. For example, in Figure 2 (
As shown in (a), there is one (made of metal) that is caulked and tied to the end of the main pipe, one that fits in the groove 41 as shown in (b) of Figure 2, and one that fits in the groove 41 as shown in (c) of Figure 2. Alternatively, a tapered core type or a screw-in type as shown in FIG. 2(d) can be used.

It is preferable to use a structure for connecting the jig 4 and the pulling wire 3 that can be connected with one touch. For example, as shown in (a) and (b) of Figure 3,
A jig 4 provided with a hook-shaped or ring-shaped hook 42,
As shown in FIG. 3(c), a bolt 43 is attached and the rear end of the traction wire 3- is tightened with this bolt 43, and as shown in FIG. 3(d), a screw hole is inserted into the jig 4. 44, a screw terminal 31 is attached to the rear end of the traction wire 3, and the screw terminal 31 is screwed into the screw hole 44, as shown in FIG. , and this central hole 4
5, insert the rear end of the traction wire 3 through the stopper 3
2 and which locks this stopper 32 on the front surface of the jig 4. stopper
32 can be inserted from the side).

Further, as shown in FIG. 3(f), when the jig 4 is provided with an arm 45 for tying the traction wire, this arm 45 is made flexible by elasticity or by a universal joint structure. By imparting this flexibility, it is possible to reliably eliminate rotational moment from acting on the jig 4 even when passing through the bends at both ends of the sheath tube.
This is effective in maintaining a safe connection between the jig and the rear end of the main pipe.

Next, in order to replace the old main pipe in the sheath pipe with a new main pipe according to the present invention, as shown in FIG. The tip of the new main pipe 10 is tied with the jig 4, and the tip of the new main pipe 10 is connected to the traction wire 3, and the old main pipe 1 is removed from the sheath pipe 2 by pulling the traction wire 3, and the new main pipe 10 is inserted. It is pulled into the sheath tube 2.

In this case, if the pipe line is long, it is desirable to push the new main pipe 10 into the sheath pipe 2 from the rear end side B of the sheath pipe 2 and to pull it in by the pulling force of the pulling wire 3. , if the conduit is relatively short, pull wire-3
It can be pulled in using only the pulling force.

[0021] In the above main update, a new main 1
The tip of the new main tube 10 can also be connected to the traction wire 3 by tying the tip of the new main pipe 10 to the jig 4, as shown in FIGS. (a) in Figure 5
In to (d), 1 refers to the new main, 1 refers to the old main,
4 represents a jig, 3 represents a pulling wire, and 32 represents a stopper.

[0022]

[Effects of the Invention] According to the tube pulling method of the present invention, since the tube axial stress acting on the tube is compressive stress rather than tensile stress, tube breakage can be well avoided and scratches with the inner surface of the protective tube can be avoided. The tube can be removed smoothly with good protection, and damage to the inner surface of the protective tube can be prevented. Even if the tube breaks, it can be completely removed without leaving any broken pieces inside the protective tube.

Furthermore, according to the pipe renewal method of the present invention, a new pipe can be replaced at the same time as the old pipe is removed, ensuring excellent workability. Since damage can be well eliminated, pipes can be renewed with good reliability.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the working procedure of the tube drawing method of the present invention.

FIG. 2 is an explanatory diagram showing different examples of fastening jigs used in the present invention.

FIG. 3 is an explanatory view showing different examples of connection structures between a fastening jig and a pulling wire used in the present invention.

FIG. 4 is an explanatory diagram showing an embodiment of the pipe renewal method of the present invention.

FIG. 5 is an explanatory diagram showing different examples of fastening jigs used in the pipe renewal method of the present invention.

[Explanation of symbols]

1 Main 2 Protection tube 3 Traction wire 4 Fastening jig

Claims (2)

[Claims] Claim 1: In a piping path in which a main pipe is passed through an installed protection pipe, a traction wire is inserted into the main pipe, one end of the wire is tied to one end of the main pipe, and then, A method for pulling out a tube, characterized in that the main tube is pulled out from inside the protective tube by pulling the other end of the traction wire. Claim 2: In a piping path in which a main pipe is passed through a protective pipe, a traction wire is inserted into the main pipe, one end of the wire is tied to one end of the main pipe, and the wire is connected to the other end of the main pipe. Connect one end to the tip of the new pipe, and then pull the other end of the traction wire to pull out the main pipe from inside the installed protective tube and pass the new main pipe into the installed protective tube. A method for renewing a pipe, characterized by: