JP2002213646A - Water cutoff joint for pipe end - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm hydraulic resistance of a water cutoff joint and enhance reliability, by performing hydraulic test of a water cutoff portion of the water cutoff joint. SOLUTION: A ring-packing fixture 3 is mounted at the end of a pull-in steel pipe 2 pulled in an existing embedded pipe 1, a short pipe 6 is connected to the face of the packing fixture 3 opposite to the face attached to the pull-in steel pipe 2; a fastening hold ring 4 opposed to the packing fixture 3 is fitted slidably and arranged outside the short pipe 6, first and second ring rubber packings 5, 8 are opposed to each other between the fastening hold ring 4 and the packing fixture 3; a spacer 7 is arranged between the first and second ring rubber packings 5, 8 to form a gap between the existing embedded pipe 1 and the short pipe 6; so that, hydraulic test of the water cutoff portion is performed at a water filler 9 formed in a portion corresponding to the spacer 7 in the short pipe 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a watertight joint for hermetically connecting a pipe end of a drawn steel pipe drawn into an existing buried pipe and an existing buried pipe, for example, for rehabilitation of an old pipe.

[0002]

2. Description of the Related Art As one method of rehabilitating an old pipe, an old pipe rehabilitation method in which a steel pipe or an ordinary steel pipe is drawn into an existing buried pipe such as a cast iron pipe and used as a new pipe line. There is.

In the old pipe rehabilitation system, a certain gap is required between the outer peripheral surface of the new pipe drawn into the old pipe and the inner peripheral surface of the old pipe in order to facilitate the rehabilitation work. Therefore, when a part of the existing pipeline constituted by the old pipe is rehabilitated with a steel pipe (new pipe) as described above, a water stop joint is arranged at a joint between the old pipe end and the new pipe end. It is necessary to prevent the fluid flowing in the pipeline from leaking out of the pipeline.

[0004] As such a conventional watertight joint at the pipe end, there is, for example, one disclosed in Japanese Utility Model Publication No. 4-33513. This conventional pipe end water shutoff joint is shown in FIG. 7 which is a front view of FIG. 6 (a), a side sectional view of FIG. 6 (b), and an enlarged detailed view of a portion A in FIG. 6 (b). In addition, a ring-shaped packing press fitting 23 attached along the tip of the drawn steel pipe 22 drawn into the existing culvert (old pipe) 21, and a tightening attached to the packing press fitting 23 at regular intervals in the circumferential direction. Bolt 24 and the tightening bolt 24
, A ring-shaped clamping press wheel 25 slidable along the bolt 24, an existing culvert (old pipe) 21, and a packing press fitting 23. Rubber packings 26a and 26 provided in a ring shape in a space portion comprising a tightening bolt 24 and a tightening press ring 25.
b, and a nut 27 for tightening the rubber packings 26a and 26b in the direction of the packing press fitting 23 via the tightening press ring 25.

The outer diameter of the packing press fitting 23 and the tightening press wheel 25 is larger than the outer diameter of the drawn-in steel pipe (new pipe) 22, and the inner diameter of the packing press fitting 23 and the tightening press wheel 25 is set to the drawn steel pipe (new pipe). The inside diameter of the tube 22 is substantially the same.

The rubber packing 26a and the rubber packing 26b have inclined surfaces that come into contact with each other, and are configured to be deformed in the radial direction of the tube while sliding on the inclined surfaces by being compressed in the axial direction of the tube. Have been.

[0007] The watertight joint allows the existing culvert (old pipe) 21 to be used.
When stopping the connection of the drawn steel pipe (new pipe) 22, the packing presser 23 is welded to the pipe end of the drawn steel pipe (new pipe) 22 wrapped by the existing culvert (old pipe) 21. After that, the rubber packing 26a and the rubber packing 26b are inserted into the space formed by the existing culvert (old pipe) 21, the packing press fitting 23, and the tightening bolt 24 so that the respective inclined surfaces are in contact with each other.

Then, the hole into which the tightening bolt 24 is inserted is aligned with the tightening bolt 24 so that the tightening press wheel 2
5 is mounted on the packing retainer 23, the nut 27 is screwed into the tightening bolt 24, and the tightening press wheel 25 is pushed into the packing retainer 23.

When the tightening press ring 25 is pushed in, the rubber packings 26a and 26b are sandwiched between the packing press fitting 23 and the tightening press ring 25, and are compressed in the axial direction and expanded in the radial direction. The inner surface of the pipe 21 contacts the inner surface of the pipe 21, and the elasticity stops the water between the existing culvert (old pipe) 21 and the drawn steel pipe (new pipe) 22.

Further, a mortar 28 is cast around the water stop joint so that the inner diameter of the cable is smoothly drawn from the size of the steel pipe 22 to the size of the existing culvert (old pipe) 21. The mortar 28 is used to form a taper.

[0011]

However, in the water-stop joint at the pipe end disclosed in the above-mentioned Japanese Utility Model Publication No. 4-33513, the rubber packing is formed by the packing press fitting 23 and the tightening press ring 25. Since the water is stopped by directly sandwiching the water, the water pressure test of the water stop portion of the water stop joint cannot be performed, and it is difficult to determine whether the water stop joint can withstand the required water pressure.

A technical object of the present invention is to make it possible to perform a water pressure test on a water stop portion of a water stop joint so that the water pressure resistance of the water stop joint can be confirmed and reliability can be improved.

[0013]

According to a first aspect of the present invention, there is provided a watertight joint at a pipe end, which is larger than a steel pipe attached along an end of a steel pipe drawn into an existing buried pipe. A ring-shaped packing retainer with a diameter, a short pipe set to the same diameter as the drawn steel pipe and connected to the surface of the packing retainer opposite to the surface attached to the drawn-in steel pipe, and a sliding pipe outside the short pipe. A clamping press wheel movably fitted and opposed to the packing press fitting; first and second ring-shaped rubber packings disposed opposite to each other between the clamping press fitting and the packing press fitting; A spacer interposed between the second ring-shaped rubber packings to form a gap between the existing buried pipe and the short pipe, and a spacer formed in advance in a portion of the short pipe corresponding to the spacer, Water injection hole sealed after test , Those having a clamping member fixed to the short tube while urging the junk ring tightening the gland fitting, the.

According to a second aspect of the present invention, the first and second ring-shaped rubber packings are formed by combining a pair of ring packings each having a radially inclined surface and having a wedge-shaped cross section. It is composed.

According to a third aspect of the present invention, there is provided a watertight joint at a pipe end having a fastening means for fastening a fastening member in a direction of a packing presser fitting and removing the fastening member after fixing the fastening member to the short pipe. is there.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A watertight joint at a pipe end according to an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a side cross-sectional view showing a state at the time of packing tightening of a water stop joint at a pipe end according to the present embodiment, FIG. 2 is an enlarged detailed view of a portion B in FIG. 1, and FIG. Things
3 (a) is a side sectional view, FIG. 3 (b) is a sectional view taken along the line AA in FIG. 3 (a), and FIG. 4 is an enlarged detailed view of a portion C in FIG. 3 (a).

The watertight joint at the pipe end of the present embodiment is a ring-shaped packing press fitting 3 attached along the tip of the drawn steel pipe 2 drawn into the existing buried pipe 1.
And a clamping presser wheel 4 having substantially the same shape as the packing presser fitting 3, and disposed between the packing presser fitting 3 and the clamping presser presser 4, and when the clamping presser 4 is pressed against the packing presser fitting 3 side, A first ring shape that is compressed in the pipe axis direction, expands in the pipe radial direction, comes into contact with the inner peripheral surface of the existing buried pipe 1, and shuts off the connection between the existing buried pipe 1 and the drawn-in steel pipe 2. A rubber packing 5, a short pipe 6 which is set to have the same diameter as the drawn steel pipe 2 and is connected to a surface of the packing press fitting 3 opposite to the side connected to the drawn steel pipe 2, and a first ring-shaped rubber packing 5; A spacer 7 of a fixed length disposed between the spacer 7 and the pressing ring 4, a second ring-shaped rubber packing 8 disposed between the spacer 7 and the pressing ring 4,
A tightening member 10 which is connected orthogonally to the pressing surface of each of the above, and urges each ring-shaped rubber packing 5, 8 toward the packing press fitting via the tightening press ring 4, and a tightening force applied to the tightening member 10. And a tightening means, which will be described later, provided by a water injection hole 9 provided at a spacer portion of the short pipe 6 under a state where the tightening press wheel 4 is tightened by the tightening means via the tightening member 10. By injecting water between the located short pipe 6 and the existing buried pipe 1, a water pressure test of a water stop portion between the existing buried pipe 1 and the drawn-in steel pipe 2 can be performed.

More specifically, the packing press fitting 3 is in the shape of a ring, and the inner diameter of the ring is set to be substantially the same as the inner diameter D1 of the steel pipe 2 so as not to cause resistance of the fluid flowing in the pipe. The outer diameter of the ring is set to be close to the inner diameter D2 of the existing buried pipe 1 within a range that does not hinder the operation.

First and second ring-shaped rubber packings 5,
Numeral 8 is a combination of a pair of ring packings 5a, 5b and ring packings 8a, 8b each having a wedge-shaped cross section having a radially inclined surface, and is fastened by a fastening means in the radial direction along the inclined surface. Also moves to contact the inner peripheral surface of the existing buried pipe 1 and the outer peripheral surface of the short pipe 6 at the same time, so that water can be stopped.

The spacer 7 is disposed in a space formed by the existing buried pipe 1, the short pipe 6, and the first and second ring-shaped rubber packings 5, 8, and has a H-shaped cross section in the pipe axis direction. It consists of a ring-shaped member, the inner diameter and the outer diameter of the ring,
The spacer 7 is set to such a size that it can slide easily between the existing buried pipe 1 and the short pipe 6 in the pipe axis direction.

The tightening press wheel 4 has a ring-like shape like the spacer 7, and the inner and outer diameters of the ring are set to dimensions that allow easy sliding between the existing buried pipe 1 and the short pipe 6. Have been.

The tightening means for tightening the tightening press wheel 4 toward the packing press fitting 3 via the tightening member 10 includes an inner diameter ring-shaped connecting member 11 mounted orthogonal to the tightening member 10. A ring-shaped fixing member 12 in the inner diameter direction attached to the short pipe 6, a through bolt 13 penetrating a through hole provided in the connecting member 11 and a through hole provided in the fixing member 12, and connection of the through bolt 13 The connecting member 1 which is a movable member is constituted by nuts 14, 14 attached to both ends penetrating the member 11 and the fixed member 12. The nuts 14, 14 are screwed into the bolts 13 and screwed.
A tightening force is applied to the tightening press wheel 4 via the tightening member 1 and the tightening member 10.

In the water stop fitting at the pipe end of the present embodiment,
In order to conduct a water pressure test of the water stop section, the water injection hole 9 provided in the short pipe 6 is required.
Water of a predetermined water pressure is injected from (FIG. 2). Thereby, it is possible to confirm whether or not there is water leakage from the water stop portion.

If it is confirmed in the water pressure test that the water stopping portion can withstand a predetermined water pressure, the water injection hole 9 is welded 9a.
(FIG. 4), and, after the fastening member 10 is welded to the short pipe 6 as shown in FIGS. 3 and 4, the connecting member 11 and the fixing member 12, which are the resistance of the fluid flowing in the pipe, are cut and threaded. The bolt 13 and the nuts 14, 14 are removed together.

After that, the stepped portion between the short pipe 6 and the existing buried pipe 1 is polished with mortar around the water-stop joint to finish it smoothly, and then painted to increase the water-stopping property. desirable.

In the case where the existing buried pipe 1 is a cast iron pipe in which mortar is cast on the inner surface, the inner mortar of the portion where the water-blocking joint is disposed is removed, and the unevenness of the inner peripheral surface of the cast iron pipe is smoothly finished. It is desirable to apply a top coat to increase the water stoppage.

Further, here, the ring-shaped fastening member 10 has been described as an example of the fastening member to be welded to the short pipe 6 after the hydraulic test, but these are arranged at equal intervals as shown in FIG. 5, for example. A plurality of shaft members 15 may be used.

[0028]

As described above, according to the present invention, the spacer for forming the gap between the existing buried pipe and the short pipe is disposed between the first and second ring-shaped rubber packings. Since a water injection hole that is sealed after the water pressure test of the water stop section is provided at a portion corresponding to the spacer in the short pipe, it is possible to stop the connection between the existing buried pipe and the drawn steel pipe,
In addition, a water pressure test of the water-end portion of the pipe was made possible, and the reliability of the water-stop joint was improved.

Further, since the first and second ring-shaped rubber packings are composed of a pair of ring packings each having a radially inclined surface and having a wedge-shaped cross section, the first and second ring-shaped rubber packings are formed by a fastening member via a fastening press ring. By urging the first and second ring-shaped rubber packings toward the packing presser, the first and second ring-shaped rubber packings are
It was possible to press against the inner peripheral surface of the existing buried pipe and the outer peripheral surface of the short pipe, thereby improving the water stoppage.

Further, the fastening means for fastening the fastening member in the direction of the packing presser via the fastening member is removed after the fastening member is fixed to the short pipe, so that the resistance of the fluid flowing in the pipe can be reduced. Can be eliminated.

[Brief description of the drawings]

FIG. 1 is a side cross-sectional view showing a state at the time of packing tightening of a water stop joint at a pipe end according to an embodiment of the present invention.

FIG. 2 is an enlarged detail view of a portion B in FIG.

FIGS. 3A and 3B show a state at the time of rehabilitation of a pipe end according to the present embodiment at the time of completion of a water-tight joint, wherein FIG. 3A is a side sectional view, and FIG. It is.

FIG. 4 is an enlarged detailed view of a portion C in FIG.

FIG. 5 is an explanatory view of another example of the fastening member in the water-end joint at the pipe end according to the present embodiment.

6 (a) is a front view, and FIG. 6 (b) is a side sectional view, showing a conventional pipe end water stop joint.

7 is an enlarged detailed view of a portion A in FIG. 6 (b).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Existing buried pipe 2 Pull-in steel pipe 3 Packing press fitting 4 Tightening press ring 5 First ring-shaped rubber packing 5a, 5b Ring packing 6 Short pipe 7 Spacer 8 Second ring-shaped rubber packing 8a, 8b Ring packing 9 Water injection hole 10 Tightening member 11 Connecting member (Tightening means) 12 Fixed member (Tightening means) 13 Through bolt (Tightening means) 14, 14 Nut 15 Shaft member (Tightening member)

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Sakae Ishiyama 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Yoshikazu Nakajima 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Date (72) Inventor Ichiro Kasahara 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Japan In-tube (72) Inventor Takashi Arakawa 2-6-1, Otemachi, Chiyoda-ku, Tokyo New Japan Inside Steel Works Co., Ltd. (72) Inventor Shozo Kikuchi 12 Nishikicho, Naka-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Heavy Industries, Ltd.

Claims (3)

[Claims] 1. A ring-shaped packing presser having a diameter larger than that of the drawn steel pipe attached along the tip of the drawn steel pipe drawn into the existing buried pipe, and having the same diameter as the drawn steel pipe. A short pipe connected to a surface of the packing press fitting opposite to the face attached to the drawn steel pipe; a tightening slidably fitted outside the short pipe and facing the packing press fitting; A pressing ring, first and second ring-shaped rubber packings disposed opposite to each other between the tightening pressing ring and the packing presser, and interposed between the first and second ring-shaped rubber packings. A spacer that forms a gap between the existing buried pipe and the short pipe; a water injection hole that is formed in advance in a portion of the short pipe corresponding to the spacer, and that is closed after a water pressure test of a water stop section; Tightening A watertight joint at the end of the pipe, comprising: a fastening member fixed to the short pipe in a state where the attached pressing ring is urged toward the packing press fitting. 2. The pipe end according to claim 1, wherein the first and second ring-shaped rubber packings are formed by combining a pair of ring packings each having a wedge-shaped cross section and having a radially inclined surface. Water stop fittings. 3. The pipe end according to claim 1, further comprising a fastening means for fastening the fastening member in the direction of the packing presser fitting, and removing the fastening member after fixing the fastening member to the short pipe. Water stop fittings.