JP3421012B2 - Pig for cleaning inside the pipe - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pig used for cleaning gas pipelines, water pipelines, etc., and particularly to large diameter pipes to small diameter pipes or small diameter pipes to large diameter pipes having different diameters. The present invention relates to a pipe cleaning pig suitable for use in cleaning a pipeline having a portion.

[0002]

2. Description of the Related Art Iron pipes with different diameters used in pipelines for natural gas, industrial water, sewage, tap water, etc.
There is a problem that deposits will be deposited on the inner wall surface during long use and the fluid in the pipe will be contaminated, and the flow will be obstructed, reducing the feed rate. Cleaning is taking place.

As a method for cleaning the conduit having the different diameter portion, usually, the portion having the different diameter portion is cut and the pigs matching the inner diameters of the large diameter pipe and the small diameter pipe are inserted into the respective pipes. I am doing it. However, the position of the different-diameter portion may be obstructed by a building or the like in some cases, or it may not be cut due to the structure of the road. In such a case, cleaning could not be practically performed.

Therefore, a cylindrical or spherical pig made of a soft urethane foam which is compressed and deformed when it receives a pressure-feeding force of a pressure fluid is used. Although it has been proposed that the pig body can be cleaned by moving to a pipe, since the pig body is a soft urethane foam, it allows pressure fluid to pass therethrough, which may cause a stop during traveling.

Therefore, the inside of the pipe is cleaned by using a pig having a pressure fluid receiving surface coated with an impermeable synthetic resin that does not allow the pressure fluid to permeate on one end surface of the pig.

[0006]

However, in the case of this pig, since the uncoated portion has low strength in terms of material, when it comes into sliding contact with an attachment that accumulates on the inner wall surface of the pipe, the outer peripheral surface is damaged and the material is damaged. However, there is a drawback that the abrasion debris remains in the pipe.

Further, since the elasticity of the soft urethane foam is different from that of the non-permeable synthetic resin applied to one end face of the soft urethane foam, it is difficult for them to be familiar with each other when traveling in the pipeline, as shown in FIG.
As shown in FIG. 7, not only the joint portion between the soft urethane foam 21 and the synthetic resin film 22 is easily peeled off, but also creases 23 and dents 24 are generated in the soft urethane foam 21 to deteriorate the sealing performance against the inner wall surface of the pipe. Then, the crease 23
There is a problem that the back pressure of the pressure fluid is blown by the recesses 24 and the pig stops without traveling, which causes a problem.

The present invention was developed with the object of solving the above-mentioned problems, and it is connected via a pipe having a different diameter portion or a flexible pipe for earthquakes having a large diameter in the middle. It is an object of the present invention to provide an inside-pipe cleaning pig that is capable of smoothly traveling along an existing pipe line or the like and reliably cleaning the wall surface inside the pipe.

[0009]

As a means for solving the above-mentioned problems and achieving the object, the present invention is a pig for cleaning an inside of a pipe which is inserted into the pipe and runs by the pumping force of a pumping source. Foam density 0.02-0.06g / c
It is formed of a soft foam of m ³ and has a shrinkage and flexibility equivalent to that of the soft foam, and is made of a non-pressure fluid permeable foam resin and is crushed to a paste form of 0.05 to 0. We developed and adopted a pig for cleaning the inside of the pipe, which has a thickness of 0.8 mm and is coated on almost the entire circumferential surface of the pig body.

Further, in the present invention, with respect to the pipe cleaning pig having the above-described structure, the pipe cleaning pig having at least one hollow hole in the outer peripheral surface of the pig body has been developed and adopted.

The defoaming paste referred to here is a non-pressure fluid-permeable foamed resin having shrinkage and flexibility equivalent to that of the soft foam of the pig body. Then, it is like a state of glue in which flattened or open cells and closed cells are crushed to form a film.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings.
No. 1 is a thin cylindrical or spherical pig body made of soft urethane foam with a foam density of 0.02 to 0.06 g / cm ³ , and has an open cell structure, and has a low foam density and elasticity. Rich in sex. The foam density range is determined as described above, and it is not suitable when the foam density of the pig body 1 is a soft urethane foam of 0.02 g / cm ³ or less, because it is soft and does not deform so much that it does not maintain a constant shape. This is because when the soft urethane foam has a weight of 0.06 g / cm ³ or more, it is slightly hard and inferior in elasticity, and the adhesion to the inner wall of the tube is deteriorated.

Reference numeral 2 denotes a foam-breaking paste which coats substantially the entire circumferential surface of the pig body 1, and is made of a non-pressure fluid-permeable foam resin having the same contractility and flexibility as the soft urethane foam. . This foam-breaking paste 2 stirs and mixes two liquid urethane foaming liquids A and B, which have a long gelling time, in a free state, and the foam is broken by the rise time until gelling and gelation. It is in the form of a paste, and its thickness is optimal in the range of 0.05 to 0.8 mm because the same shrinkability and flexibility as the soft urethane foam can be obtained.

By applying the foam breaking paste 2,
As shown in FIG. 2, closed cells 3 in which open-celled bubbles are crushed or crushed and are crushed into a thin layer.
Then, the crushed and coated film 4 overlaps with each other so that the pumping fluid cannot pass through.

That is, in this foam breaking paste 2, even if the form of the bubbles changes, basically the bubbles remain, so that the density can be made closer to that of the soft urethane foam, and the coating portion has the soft urethane foam. It will have the same elasticity and integrity as the body. In addition, since the same material as the soft urethane foam is used as the coating material, it is easy to get familiar with the material, penetrates into the open-cell part of the soft urethane foam, closes the open-cells, and has excellent adhesiveness. improves.

The use state of the pipe cleaning pig thus constructed will be described together with its function and effect. As shown in FIG. 3A, in order to transfer the pig body 1 from the large diameter pipe 5 to the small diameter pipe 6, the pressure feeding fluid ( The back pressure indicated by the arrow) is received on one side and pressure is applied to clean the inner wall surface of the pipe. The different diameter portion 7 compresses and deforms the inner diameter of the small diameter pipe 6 and forcibly pushes it into the small diameter pipe 6. It removes and discharges the deposits that are pumped and attached to the inner wall surface for cleaning.

At this time, the outer peripheral surface of the pig main body 1 is covered with the defoaming paste 2 to impart abrasion resistance, so that abrasion debris will not be generated even if it makes sliding contact with the deposit attached to the inner wall surface. Adhesion with the inner wall surface of the pipe is good, and even if it enters the small diameter pipe 6, it is reduced while maintaining a constant shape, so that uniform cleaning can be performed over the entire circumference.
By the way, as a result of the test, even in the pipeline in which the diameter of the pipe changed from 200φ to 80φ, the pig body of 200φ passed without any problem and was not damaged or worn.

Further, as shown in FIG. 3B, when the small-diameter pipe 6 is transferred to the large-diameter pipe 5, the pressure-fed fluid is received on one side and urged to clean the inner wall surface. Since it is expanded and deformed to the size of the inner diameter of 5 and comes into close contact with the inner wall surface of the large-diameter pipe 5, backpressure blow-through is prevented, and the pig 1 is smoothly pumped to uniformly clean the entire circumference of the pipe. Can be done.

Further, as shown in FIG. 4, sleeves 9 and 9 are fitted to the ends of the sewage pumping pipes 8 and 8 buried in the ground,
Flexible tube 1 with a large diameter due to couplings 10 and 10
It can be used even in the case of pipelines where 1 is attached and measures are taken so that the joints will not be damaged even if an earthquake occurs.

That is, the spherical pig main body 1 having a diameter substantially equal to the inner diameter of the flexible tube 11 is reduced and inserted into the tube 8 and is fed under pressure to clean the inner wall surface. It expands to a size that contacts the inner wall surface of the flexible tube 11 due to the restoring force, and the flexible tube 11 runs while being in close contact with the inner wall surface.
To clean. When the flexible tube 11 is cleaned, the flexible tube 11 comes into contact with the end of the other tube 8 and receives a pumping fluid to be compressed and deformed to the size of the inner diameter of the tube 8 and forcibly inserted into the tube 8. It removes and discharges the deposits adhering to the inner wall surface of, and cleans it.

The diameter of the pipe 8 is 200φ and the extension is 8k.
m, the test was performed by inserting the 350φ pig main body 1 into a pipe line in which eight 350φ flexible tubes were provided in the middle, and it was passed through the entire line without damage.

FIG. 5 shows another embodiment of the present invention, which differs from the first embodiment only in that a vertical hollow hole 12 is provided in the upper end surface of the pig body 1. The other points are exactly the same as those of the first embodiment. Although the figure shows an example in which one hollow hole 12 is provided on the upper end surface,
It may be provided on the side surface portion or the bottom surface portion, or a plurality thereof may be provided, and in short, it may be provided on the outer peripheral surface.

The use of this pig body 1 improves the flow of fluid through the hollow holes 12, so that even if the inner diameter difference between the large-diameter pipe and the small-diameter pipe is large and the inner diameter is rapidly reduced,
The elastic recovery from the expansion of the pig body 1 from the contraction to the expansion or the contraction from the expansion is quickened, and the pig body 1 can be held in a desired shape to be closely attached to the wall surface in the pipe.

Although the main embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the objects of the invention can be achieved and the scope of the invention is not deviated. It goes without saying that various design changes are possible with.

[0025]

As described above, according to the first aspect of the present invention, a cleaning pig that is inserted into a pipe and runs by the pumping force of the pumping source, has a foam density of 0.02 in the pig body. ~ 0.06 g / cm ³ of a soft foam, and a foam breaking paste made of a non-pressure fluid permeable foam resin having shrinkage and flexibility equivalent to that of the soft foam is 0.05 ~.
The present invention has the following excellent effects because it is related to a pipe cleaning pig having a thickness of 0.8 mm and coated on substantially the entire circumferential surface of the pig body.

Since the pig main body shrinks or expands in accordance with the diameter of the small diameter pipe or the large diameter pipe, a pipe passage having a different diameter portion composed of the large diameter pipe and the small diameter pipe or a flexible pipe having a large diameter. Even if the pipes are connected with each other, the pig can be smoothly fed under pressure, and the deposits and the like adhering to the inner wall surface of the pipe can be removed and discharged for easy cleaning without damage or wear.

Further, the pig main body is coated with the foam breaking paste on substantially the entire peripheral surface thereof, so that the pig main body has excellent wear resistance and eliminates the generation of abrasion debris, and the pig can be reduced while maintaining the shape of the pig main body. Since it expands, it adheres to the entire inner wall surface of the pipe, which ensures uniform cleaning.

Further, according to the second aspect of the present invention, in addition to the effect of the first aspect, the flow of the fluid is improved through the hollow hole 12, so that the elastic recovery of the diameter reduction and the expansion of the pig body 1 is much faster. Become.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a pig showing a first embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of a foam breaking paste.

FIG. 3 is a partial cross-sectional view showing a usage state in a different diameter pipe.

FIG. 4 is a partial cross-sectional view showing a usage state of a flexible tube.

FIG. 5 is a vertical sectional view of a pig showing another embodiment of the present invention.

FIG. 6 is a partially longitudinal front view showing a conventional use example.

FIG. 7 is a partially longitudinal side view showing a conventional use example.

[Explanation of symbols]

1 pig body 2 foam breaking paste

Claims (2)

(57) [Claims] 1. A pig for cleaning an inside of a pipe which is inserted into the pipe and runs by a pumping force of a pumping source, wherein the pig body is formed of a soft foam having a foam density of 0.02 to 0.06 g / cm ³ , It has the same contractility and flexibility as soft foam,
Breaking paste made of non-pressure fluid permeable foam resin,
A pig for cleaning the inside of the pipe, which has a thickness of 0.05 to 0.8 mm and is coated on substantially the entire circumferential surface of the pig body. 2. The pipe cleaning pig according to claim 1, wherein the pig body is provided with at least one hollow hole in an outer peripheral surface thereof.