JP2957249B2 - Sponge for lining inner wall surface of pipe and lining method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention fills a pipe with a fluid lining material such as paint, inserts an elastic sponge behind the pipe, and supplies compressed air from the rear. The present invention relates to a method for forming a lining film on the inner wall surface of a pipe by moving resin forward, and relates to an improvement in a sponge for lining the inner wall surface of the pipe and a lining method itself.

[Conventional technology]

Conventionally, as a rehabilitation method for existing pipelines, after removing the scale on the inner wall of the pipe, insert one or two pigs into the pipe and fill the paint before or between the pigs and fill the pig with air etc. A method of pressure feeding is known, and many patents have been filed in which the structure of the pig, the pressing method, the number of times the pig is moved, and the like are devised.

 For example, JP-A-60-172383 JP-A-61-18474 JP-A-63-69576 JP-A-63-162076 JP-A-63-31578 JP-A-63-4885 JP-A-63-31577 JP-A-63-274474 JP-A-63-59376 JP-A-1-224072 JP-A-55-44320 JP-A-52-78250 Japanese Patent Publication No. 40-25273.

In these conventional methods, the shape of the pig is spherical or shell-like and the material is plastic rubber or rubber having elasticity, and the outer diameter is slightly smaller or larger than the inner diameter of the pipe. When the lining material is placed in front of these pigs during lining and the pig is pushed by air pressure etc. and run, the pig is slightly deformed by the running speed and a certain gap is created between the pig and the inner surface of the pipe, and the lining is This is a method for determining the thickness and performing lining.

Japanese Patent Application Laid-Open No. 63-270580 describes a method of expanding a pig with air as a "lining method for an inner wall surface of a reduce pipe".

[Problems to be solved by the invention]

Conventionally, when the amount of deformation of the pig is increased, the stress of the pig increases in proportion to it, and when the stress increases, the thickness of the lining becomes thin, so that the pig can only be deformed within a very limited range. Was thought.

Therefore, the biggest problem of these methods is that the applicable pipe diameter is 1
It is limited to the type, and different diameter pipes must be separately constructed for each size.

Further, in the `` Method of lining the inner wall of a reduce pipe '' of JP-A-63-270580, the lining of different diameter pipes is possible by inflating the pig with air, but the adjustable range is as follows. JIS nominal diameter 100A → 90A
It is not suitable for use in actual piping because the width of 50A → 40A is narrow. It is also difficult to pressurize and hold the pig at an appropriate pressure.

An object of the present invention is to solve the conventional problems described above and to provide a sponge and a lining method as a pig for lining a pipe inner wall surface that can efficiently line even pipes of different diameters having a large difference in diameter. .

[Means for solving the problem]

In order to solve the above problems, the present invention has taken the following measures.

The sponge for lining the inner wall surface of the pipe according to the present invention is made of an elastic material made of synthetic resin and having open cells. In the load-deflection characteristic, the load at the time of 70% deflection is 60 kg or less, and the load at the time of the compressibility is 70%. There below 6 times the load when the compression rate of 10%, measuring 2-fold following minimum inner diameter d ₁ of the diameter D of the tube, and when the maximum inner diameter of the tube and d _2, D is 1.1 × d ₂ or more Yes, cylindrical with a length of 0.5D-3D, or a diameter of 1.1
In × d ₂ or more, and 2d ₁ is a sponge formed into a spherical shape is less.

In the lining method of the inner wall surface of the pipe of the present invention, the pipe is filled with a flowable lining material, an elastic sponge is inserted behind the pipe, compressed air is supplied from the rear, and the flowable lining material travels in the pipe together with the sponge. This is a method of lining the inner wall surface of a pipe with a fluid lining material, and using a sponge having the above-described configuration as a sponge.

 Hereinafter, the present invention will be described in more detail.

The elastic material constituting the sponge of the present invention has the above-described load-deflection characteristics. Here, as the synthetic resin-made elastic material to be used, a flexible polyurethane foam, a vinyl foam or a latex foam can be exemplified, but it goes without saying that other materials may be used as long as the load-deflection characteristics are satisfied.

Also. When the density of the sponge is about 10 to 70 kg / m ^3, it is preferable to exhibit the effects of the present invention.

The sponge preferably has a load at the time of 70% deflection of 60 kg or less in load-deflection characteristics. When the load at the time of 70% deflection satisfies the condition of 60 kg or less in the load-deflection characteristic, when the sponge is inserted into the pipe, the stress generated in the radial direction of the sponge is small. The compression ratio is 70
% Load is less than 6 times the load at 10% compression ratio,
Within this range, the change in load due to deformation is small.

Therefore, when the above conditions are satisfied, the lining when the pipe diameter changes can be deformed according to the pipe diameter from a thick pipe to a thin pipe, and the stress on the pipe wall is sharp even if the pipe becomes thin. Therefore, the entire pipe can be lined uniformly.

Here, the load-deflection characteristics are as follows: compression speed 50 mm / min, compression plate 200 mmφ, sample size 50 mm x 300 mm x 300 mm, A
It shall be measured according to STM D3574.

When the sponge is cylindrical, its dimensions are its diameter D
In There less than twice the minimum inner diameter d ₁ of the tube, and the maximum inner diameter of the tube
When d _2, D is 1.1 × d ₂ or more, a length may is 0.5D～3D.

When the sponge is spherical, its dimensions are 1.1
Xd ₂ or more and 2d ₁ or less.

Under these dimensional conditions, the lining of the inner surface of the different diameter pipe can be performed while the sponge is appropriately deformed.

If the outer shape of the sponge is cylindrical, molding becomes easier,
It may be cheap to produce.

The type of the fluid lining material to be charged into the different diameter tube together with the sponge does not matter in particular, but a two-component mixed type epoxy resin is preferable. The viscosity of the fluid lining material is
5000 cP to 20000 cP is desirable. The amount of the flowable lining material used for the lining treatment is preferably increased by 10 to 40% of the calculation amount required for forming the specified film thickness on the pipe to be treated.

[Action]

Although the sponge of the present invention is formed of an elastic material made of synthetic resin and having open cells, by having open cells,
A large amount of lining material can be contained inside, and when this sponge is run, it is in the same state as the inside of the tube is painted with a so-called sponge brush, and no extra lining material is attached to the tube wall. Further, in the elbow portion, when the sponge changes direction, it is strongly pressed against the tube wall, so that the lining material contained in the sponge is excessively extruded to form a thick coating film.

If necessary, the sponge may be impregnated with a lining material in advance.

INDUSTRIAL APPLICABILITY The present invention is suitably applied not only to a straight pipe but also to a manifold pipe in which a plurality of branch pipes are branched from a main pipe when connecting different-diameter pipes in series. In particular, when applying the sponge to the manifold pipe by air pressure from the end of the branch pipe, open the inlet of the main pipe and send a small amount of backflow prevention air from the end of the other branch pipe to send the sponge to the main pipe. It is good to guide to the entrance. {See FIG. 3, where 1 is the main pipe and 1A is the branch pipe (10A to 10D in FIG. 2)}.

〔Example〕

 Hereinafter, embodiments of the present invention will be described.

<Example 1> Fig. 1 shows an example of a load-deflection curve of an elastic material constituting the sponge of the present invention. This figure is 300mm x 3mm
FIG. 3 is a diagram showing the amount of deflection when a compression plate having a diameter of 200φ is placed on a soft urethane foam having a size of 00 mm × 50 mm in height and a load is applied thereon at a compression speed of 50 mm / min, as a percentage.

From this figure, it can be seen that the load of this elastic material increases in proportion to the amount of deflection up to a deflection amount of 10%, but the load increase rate is very small up to a deflection amount of about 50% when the deflection amount exceeds 10%. %, The load gradually increases up to about 70%, and when it exceeds 70%, the load rapidly increases.

In the present invention, the load at the time of 70% deflection is 60 kg or less in the load-deflection characteristic, and the load at the time of the compression ratio of 70% is the compression ratio.
6 times the load at 10% or less, the size twice or less the minimum inside diameter d ₁ the diameter D of the tube, and the maximum inner diameter of the tube and d _2, D is 1.1 × d ₂ or more, the length Using a cylindrical sponge having a length of 0.5D to 3D, combining with a lining material having a viscosity of 5,000 to 20,000 cP, filling the lining material into the pipe, then inserting the sponge into the pipe, and pressing the sponge with air. Moved. At this time, when the outer diameter of the sponge is D, the minimum inner diameter of the pipe is d ₁ , and the maximum inner diameter of the pipe is d ₂ , if D is in the range of 2d ₁ ≧ D ≧ 1.1d ₂ , the lining thickness is substantially constant. Has been found to show.

This is completely different from the conventional idea that the sponge diameter is slightly larger or smaller than the inner diameter of the tube,
From a practical point of view, in the conventional concept, a single sponge can be applied only to the same pipe diameter, but as a result of the present invention, it is possible to line pipes having different inner diameters with one sponge within the range described above. Was.

When this is displayed, as shown in Table 1, it can be understood that one sponge can cope with three stages of tube size changes.
In the table, SGP is a steel pipe for gas specified by JIS.

<Example 2> Next, as shown in Fig. 2, the present invention was applied to a pipe assembled according to a water supply pipe of an apartment.

In the figure, a main pipe 1 of a water supply pipe is provided at its end with a pipe 5 which is a kind of branch pipe, and between the pipe 5 and the other end 2 of the main pipe 1, a branch pipe 10A, 10B, 10C and 10D are connected.

As preparation for lining, the other end 2 of the main line 1 is detached from the water meter, and one end 6 of the line 5 and the branch lines 10A to 1A.
Remove the faucet from the ends 11A to 11D of 0D, and remove one end 6 and end 11
In A to 11D, a connecting pipe having an opening facing upward is added, and this opening is formed so that an air hose can be attached and detached.
A pressure gauge 24 and a valve 23 are connected to an air hose 25 connected to one end 6 of the air hose 25, and a pressure gauge 24A is connected to the air hoses 25A to 25D connected to ends 11A to 11D of the branch pipes 10A to 10D. ~ 2
Connect 4D to valves 23A to 23D, and each valve 23, 23A to 23D
2. It is connected to the air compressor 20 via the dehumidifier 21 in order.

The size of each pipe is 2A to 12A of the main pipe with a nominal diameter of 25A according to JIS, and the branch pipes 5 and 10A to 10D are JIS20A with a JIS15A different diameter elbow attached to the end of the faucet.

Lining In injects conduit 5 and 10A~10D required amount of lining material in the measuring cup from the connection tube attached to the end of a density 20 Kg / m ³ of flexible polyurethane foam in the formed diameter 30 mm, length 50mm Was inserted into the connecting pipe used for injecting the lining material at the end of the pipe line 5, the hose 25 was connected, and air was fed toward the main pipe side to perform coating.

That is, the other end 2 of the main pipeline is opened and the other branch pipelines 10A to 10D are opened.
A small amount of backflow prevention air is supplied by opening the valves 23A to 23D. Next, as a lining material of the main pipes 6 to 2, a value obtained by multiplying the inch size and the length (m) of the pipe between them by 30 to 120 cc, preferably 50 cc, per inch-m.
When the sponge is inserted after inserting the lining material of about 100 cc into the connecting pipe of the pipe 5, and the valve 23 is slightly opened to send air to the pipe 5, the sponge advances in the pipe and is discharged from the other end 2 of the main pipe. You.

Next, the same sponge and lining material are inserted into the connecting pipe at the end 11A of the branch pipe 10A, backflow preventing air is injected into the other branch pipes, and the sponge is sent in the same procedure and collected from the pipe 2. In this case, the amount of the lining material is calculated by calculating the amount of the lining material necessary for lining from the end 11A of the pipe 10A to the branch point 12A with the main pipeline 5 in the same manner as described above. Thereafter, all branch pipes were lined using a sponge in the same manner.

As a result, only the airflow method without using a sponge had a part where the coating thickness of the elbow part was 0.3 mm or less.However, by using a sponge, the thickness was reduced for all pipe lengths including the entire elbow. 0.3mm or more could be secured.

In addition, the movement of the sponge to the main pipeline opening 2 was extremely smooth, and no anxiety was felt.

Although a cylindrical sponge was used in this embodiment, the same effect can be expected even with a spherical sponge because it is easy to mold.

〔The invention's effect〕

Since the present invention is configured as described above, it is possible to efficiently line even different diameter pipes and various pipes having considerably different diameters.

[Brief description of the drawings]

FIG. 1 is an experimental graph showing a load-deflection curve of a flexible urethane foam, FIG. 2 is a schematic diagram showing an example in which the present invention is applied to a pipe assembled according to a water supply pipe of an apartment, and FIG. 3 is a branch pipe. It is a figure showing a method of moving a sponge from a road to a main pipeline. (P)… sponge 1… main pipe, 5,10A-10D… branch pipe, 5B… lining material.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B05C 7/00-7/08 B05D 7/22 F16L 55 / 26,55 / 16

Claims (4)

(57) [Claims] 1. A load made of an elastic material having open cells made of synthetic resin and having a load-deflection characteristic in which a load at the time of 70% deflection is 60 kg or less and a load at a compression ratio of 70% is 10%.
% When 6 times in the following load, measuring 2-fold following minimum inner diameter d ₁ the diameter D of the tube, and when the maximum inner diameter of the tube and d _2,
D is 1.1 × d ₂ or more, a cylindrical shape having a length of 0.5D to 3D,
Alternatively, a lining sponge having a diameter of 1.1 × d ₂ or more and 2d ₁ or less. 2. The lining sponge according to claim 1, wherein said synthetic resin elastic material is made of a flexible polyurethane foam, vinyl foam or latex foam. 3. A fluid lining material is filled in a pipe, a sponge made of an elastic material is inserted behind the pipe, compressed air is supplied from the rear, and the fluid lining material is caused to travel in the pipe together with the sponge to make the fluid lining. A method of lining the inner wall surface of a pipe with a material, wherein the sponge is made of an elastic material made of synthetic resin and having open cells, and has a load-deflection characteristic in which a load at the time of 70% deflection is 60 kg or less, and a compressibility. in load at 70% or less 6 times the load at 10% compression rate, dimensions when the diameter D is less than 2 times the minimum inside diameter d ₁ of the tube, and the maximum inner diameter of the tube and d _2, D is 1.1 There × d ₂ or more, cylindrical length is 0.5D～3D, or a diameter of 1.1 × d ₂ or more, and the lining method of pipe wall using a sponge formed into a spherical shape is 2d ₁ or less. 4. When the sponge is applied by pneumatic pressure from an end of a branch line, the inlet of the main line is opened, and the sponge is applied to a manifold pipe in which a plurality of branch lines branch from the main line. 4. A lining method according to claim 3, wherein the sponge is guided to the main pipeline inlet by sending a small amount of backflow preventing air.