JP3065723B2 - Pipe fitting repair method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing a pipe joint which prevents leakage of fluid in a pipe at a flange joint of a fluid conduit. The present invention relates to a pipe joint repair method for preventing leakage of a fluid flowing therein without changing the internal pressure of the pipe when the fluid leaks.

[0002]

2. Description of the Related Art Conventionally, this type of pipe joint repair method considers a large range of measures for preventing fluid leakage in the pipe from the flange joint, and extends to a part of the pipe before and after the flange joint in the longitudinal direction of the fluid conduit. The method was implemented by providing a joint cover. In one example, the joint cover is divided into two parts by the plane including the axis of the fluid conduit as the joint part cover, and the divided part and the cover are assembled together. A part of the fluid conduit to which the flange is attached and the flange joint part are provided in a wrapped form, and the joint part covers are connected to each other with bolts,
There was a fitting repair method to prevent fluid leakage.

[0003] The leakage of fluid in the pipe from the flange joint portion to be treated here is mainly due to deterioration of the sealability due to aging or the like of the seal or packing provided on the flange mating surface. In view of this, there is also known a method in which only the peripheral portion of the flange mating surface is packed. As an example, the outer peripheral surface of the butted flange is surrounded by lead packing, and the outer peripheral portion of the lead packing is wound around one entire ring material with one ring material and fastened. There is also known a method for repairing a pipe joint by injecting a sealing material into the pipe (see, for example, FIG. 1 of Japanese Utility Model Application Laid-Open No. 56-148187).

[0004]

However, of the above-mentioned conventional pipe joint repair methods, the former method includes a joint cover that wraps up a part of the fluid conduit to which the flange is attached in addition to the flange mating surface. Due to the provision method, the joint cover is inevitably large in size, so that it cannot be accommodated in the pipe joint in a narrow space or repair work is extremely difficult.

The shape and dimensions of the joint cover are as follows:
Considering that the shape and dimensions of the target pipe joint repair part vary depending on the site, it is necessary to prepare and prepare various types of joint part covers that meet these conditions, which is extremely time-consuming. There is a drawback that the cost is low and the cost is low. Furthermore, when the pipe portion to which the flange is attached is formed of a member having a complicated shape such as a valve, the fitting cover cannot be manufactured in accordance with the shape. A very extensive method of disassembling and repairing the flange and the fluid conduit together had to be taken.

[0006] In this regard, of the above-mentioned conventional pipe joint repair methods, according to the latter method, since only the peripheral portion of the flange mating surface is packed, the repair work becomes relatively simple, and the narrow space is reduced. The repair work is easy and economical, but the following disadvantages occur because the outer periphery of the lead packing surrounding the outer peripheral surface of the flange is tightened by winding it around the entire width with one ring material. was there. That is, the lead packing needs to contact the outer peripheral surface of the flange to prevent leakage of the sealing material from between the outer peripheral surface of the flange and the lead packing, and at the same time, allow injection of the sealing material between the butted flanges. There is. In this case, in the case where the outer peripheral portion of the lead packing is fastened with one ring material over the entire width, in order to reliably prevent leakage of the sealing material from between the outer peripheral surface of the flange and the lead packing, one lead member is used. If the ring material is strongly tightened, the injection of the seal material does not go smoothly, and conversely, if the tightening force of the ring material is weakened in order to smoothly inject the seal material, leakage of the seal material may occur. Become. In addition, between the butted flanges,
For example, if there is a slight difference in the outer diameter, it is difficult for one ring material to contact the lead packing with an equal tightening force to the outer peripheral surfaces of both flanges, and there is also a problem that leakage of the sealing material is caused. is there.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, so that repair work in a narrow space can be easily performed, and repair of flange joints having various shapes and dimensions can be easily performed. It is another object of the present invention to provide a pipe joint repair method capable of smoothly injecting a seal material between both flanges while reliably preventing leakage of the seal material from an outer peripheral surface of abutted flanges.

[0008]

In order to achieve this object, the present invention is characterized in that a rubber belt having a groove extending along a longitudinal direction at an intermediate portion in a width direction on an outer peripheral surface of an abutted flange is provided. Surrounding the groove with the groove inside, surrounding the both sides of the groove in the width direction of the rubber belt with a steel belt, separately winding and tightening, passing the rubber belt, and abutting the flange through the groove. A sealing material is injected under pressure between the holes, and the sealing material is injected under pressure until it leaks from a hole of a bolt connecting the flanges.

[0009]

According to the above-mentioned characteristic means, the rubber belt or the steel belt is surrounded by the outer peripheral surface of the butted flange, and the peripheral portion is wound around with a steel belt and fastened. Since the flange is limited to the outer peripheral surface and is not related to the shape of the pipe adjacent to the joint, repair can be performed at the joint where the above-described valve is juxtaposed, and further, the joint used in the conventional repair method described above. Since a large mounting space is not required unlike the case of the unit cover, repair can be performed in a place where space is small.
In addition, since the processing of the rubber belt only requires cutting to a length corresponding to the flange circumference of the joint part to be repaired and does not require any special processing, a repair part corresponding to a difference in flange diameter of the pipe joint to be repaired. Need not be made and prepared.

In addition, a rubber belt having a groove extending along the longitudinal direction at the middle of the width direction is used as the rubber belt surrounding the outer peripheral surface of the flange. In the peripheral portions on both sides, the rubber belts are separately wound and fastened by a steel belt, and in order to prevent leakage of the sealing material from between the outer peripheral surface of each flange and the rubber belt, each steel belt is Even if the rubber belt is fastened to the surface with a strong fastening force, the groove of the rubber belt is maintained in a state of maintaining its shape. Then, since the sealing material is injected under pressure between the butted flanges through the groove, the injection of the sealing material between the flanges becomes smooth,
As a result, it is possible to reliably inject the sealing material between the flanges while reliably preventing the leakage of the sealing material from between the flange outer peripheral surface and the rubber belt.

Further, between the butted flanges,
Even if there is a slight difference in the outer diameter of the two flanges, separate rubber belts are tightened on the outer peripheral surface of each flange with separate steel belts. And as a result,
Even if there is a slight difference between the outer diameters of the two flanges, as described above, it is necessary to reliably prevent leakage of the sealing material from between the outer peripheral surface of the flange and the rubber belt while maintaining the shape of the groove of the rubber belt. Can be.

In this manner, the seal material is prevented from leaking from between the outer peripheral surface of the flange and the rubber belt, and while the shape of the groove of the rubber belt is maintained, the seal is provided between the flanges butted through the groove. Since the material is pressurized and injected until the sealing material leaks from the holes of the bolts connecting the flanges, the gap between the flanges is reliably filled with the sealing material,
By leaking the sealing material from the hole of the bolt, it can be confirmed that the sealing material is reliably filled in the gap.

[0013]

Therefore, according to the pipe joint repair method of the present invention, repair in a narrow space becomes possible, and it is possible to easily and reliably cope with a flange joint portion of any size, and it is economical without labor. Repair can be performed, and the sealing material can be smoothly and reliably injected between the flanges while reliably preventing leakage of the sealing material from the butted flange outer peripheral surfaces.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a state in which a flange joint portion 2 of a gas pipe 1, which is an example of a fluid conduit, is repaired to prevent leakage of a fluid 3 in the pipe.

According to the repair method of the present invention, in the flange joint portion 2 in which the butted flanges 4 are connected to each other with bolts 5, first, a rubber belt 6 cut in accordance with the circumferential length of the outer peripheral surface of the flange 4 is provided. The steel belt 7 is surrounded by the rubber belt 6 so as to surround the periphery of the flange butting surface 4a.
And wrap it around both sides of it, and fasten it with a wringer.

Next, the flange 4 abutted through an injection hole 8 provided at a position located at a lower portion of the flange joint portion 2 at a substantially central position in the width direction of the rubber belt 6.
In the meantime, the sealing material 9 is injected under pressure by the injector P. The injection of the sealing material 9 is performed at a pressure approximately ² kg / cm ² higher than the gas pressure in the pipe, and is continuously performed until the injected sealing material 9 leaks from the bolt hole 10 on the side surface of the flange 4. This serves as an index for confirming the state in which the sealing material 9 is being filled between the butted flanges 4. The sealing material 9 leaking from the bolt holes 10 is hardened and increases in viscosity and elasticity. Leakage is stopped to close the bolt holes 10 with improved performance.

On the other hand, in addition to the injection hole 8, the rubber belt 6 is provided with a vent hole 11 at a position facing the injection hole 8 on the flange outer peripheral surface 4b. The gas stored between the butted flanges 4 is pushed out of the joint portion 2 through the vent hole 11,
Finally, like the bolt hole 10, the sealing material 9
The end of the filling can be known by leaking.

Thus, the sealing material 9 at the joint 2 is
Is completed, the injection hole 8 and the vent hole 11 are closed, and an aluminum collar (not shown) is installed on the peripheral surface for the purpose of protecting the outer peripheral surface of the repaired portion, thereby completing the repair. is there.

FIG. 2 shows the details of the flange joint 2 repaired by the pipe joint repairing method of the present invention.

An example of the rubber belt 6 surrounding the flange outer peripheral surface 4b of the pipe joint will be described below. A large groove portion 13 is provided on one surface in the middle in the width direction over the entire length, and on the back surface of one surface, At both ends in the width direction, small grooves 14 are respectively provided over the entire length, and the outer peripheral surface 4b of the flange is surrounded with the large grooves 13 inside. A sealing material 9 filling space 15 surrounded by the large groove portion 13 and the flange outer peripheral surface 4b;
And the packing part 16 between the butted flanges 4 is
It becomes a target space for injection of the sealing material 9, and the small groove portion 14
When the steel belt 7 is wound and fastened by the steel belt 7, the steel belt 7 is separately positioned on both sides of the large groove portion 13 in the width direction of the rubber belt 6 to prevent the steel belt 7 from coming off the rubber belt 6. Is provided as a guide.

Since the rubber belt 6 has a portion having a different role in its shape, the rubber belt 6 is formed with a different rubber material for that role. First, both protruding portions 17 of the large groove portion 13 which is located inside while surrounding the flange 4 and abuts on the flange 4 are made of a relatively soft material to improve the close contact with the flange outer peripheral surface 4b. The bottom portion 18 of the large groove portion 13 constituting the outer portion is made of rubber of a relatively hard material for the purpose of protection since the bottom portion 18 of the large groove portion 13 which constitutes the outer portion is similarly covered with rubber. It is built.

Further, the rubber constituting the bottom portion 18 of the large groove portion 13 is integrally formed so as to wrap nylon fibers 19 for reinforcement inside thereof, and is exposed to the outside while surrounding the flange 4. Nylon fiber 19 on the surface
Is coated.

The bottom portion 18 of the large groove portion 13 is provided with an embedded screw washer 20 for forming a female screw which can serve as both the injection hole 8 and the air vent hole 11. The screw washer 20 is provided with a flange-shaped projection 20a around its periphery to prevent it from coming off. Further, when closing the injection hole 8 and the air vent hole 11 formed by the screw washer 20, the male screw (not shown) screwed to the female screw of the screw washer 20 can be screwed. .

On the other hand, the sealing material 9 is formed of a special resin of a two-liquid mixture type. When the sealing material 9 is cured, it becomes a rubbery elastic body. The curing speed is adjusted by adding a catalyst. Can be adjusted arbitrarily.

[Another Embodiment] The pipe joint repair method of the present invention is as follows.
In addition to being applied to the prevention of leakage of the fluid 3 in the pipe at the flange joint portion 2 of the fluid conduit described in the previous embodiment, it also effectively acts to prevent leakage of the fluid 3 at the pipe portion of the fluid conduit.
The target fluid conduit and the fluid 3 flowing through the inside thereof are not limited to the above embodiment, and can be applied to both liquid and gas.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

Fig. 1 Flange joint repair situation diagram

FIG. 2 is a detailed view of a joint portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid conduit 2 Joint part 3 Fluid in pipe 4 Flange 4b Outer peripheral surface of flange 5 Bolt 6 Rubber belt 7 Steel belt 9 Sealing material 10 Hole 13 Groove

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16L 55/16

Claims (1)

(57) [Claims] 1. A flange joint (2) of a fluid conduit (1).
A method of repairing a pipe joint for preventing leakage of fluid in a pipe (3) in the above (1), wherein the outer peripheral surface (4b) of the butted flange (4) is
It has a groove (13) along the longitudinal direction at the middle of the width direction.
To rubber belts (6), and said groove (13) on the inside
In the width direction of the rubber belt (6).
Each side of the groove (13) with a steel belt (7)
Separately wound and fastened, passed through the rubber belt (6), and
A sealing material (9) is injected under pressure between the flanges (4) butted through the groove (13) , and the sealing material (9) connects the flanges (4) with bolts ( 5) A method of repairing a pipe joint in which pressure injection is performed until leakage from the hole (10) occurs.