JPS59228978A - Method for sealing and corrosion-preventing inside surface in broken part of buried conduit or the like - Google Patents

Abstract

PURPOSE:To repair and maintain a buried pipe to be maintained by digging said pipe at a suitable interval, feeding forcibly and successively a foamable and curable material as well as a lining material into the pipe and forming sealing and corrosion-preventive layers. CONSTITUTION:An underground buried pipe is dug at two points at about 100m interval and a foamable material A is forcibly fed into said pipe by a pig from one port thereof and is discharged from the other part. A material B such as aminals and water is forcibly fed therein by the pig to foam and cure the material A. Then the material A foams quickly in contact with the material B and cures with increase of its volume thereby sealing holes. After corroded holes 3, etc. are sealed in such a way, a lining material E is forcibly fed into the pipe by the pig to form the corrosion preventive lining integrally with sealing of holes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention can dig up only the moss at both ends without digging up an underground conduit, seal it and fill it with only a simple pig or the like and a foam generator. This is a corrosion-proofing method for sealing the inner surface of a defective part of a buried conduit, etc. by lining and preventing corrosion.

Conduits such as gas pipes and water pipes buried underground may become locally corroded over a long period of time due to chemical corrosion, electrical corrosion, etc., and holes may gradually form, causing leakage of fluid or gas. . Normally, to repair this, these pipes are dug up and replaced with new pipes, but this is not possible due to the location where digging is not possible or because it is not economically possible. There are many things. In such cases, the buried conduit can be easily and quickly repaired while remaining buried.
If there is a way to repair it, it would have great economic benefits.

The present invention has been made in view of the above circumstances, and specifically provides a method for sealing corrosion holes in branch pipes of gas piping (approximately JOmm diameter) while still buried, and providing long-term corrosion protection for the inner surface of the pipe. be.

As described above, the present invention does not involve digging up underground conduits, but excavates moss at intervals of about several/θθm, and from one of the openings, the foaming property (or swelling property, hereinafter omitted) of the present invention is used.
Sandwich substance (A) between simple pig moss, approximately θ, 3
Kg/'am2~0. It is pumped with an air pressure of r Kg/cJ. This foamable material (A) is a material that does not foam by itself and gradually hardens with moisture in the air.

The above-mentioned foamable substance (A) is a substance that itself swells and increases in volume or an adsorbent substance, such as a mixture of 7 to 2 of the following substances.

Urethane grebomer, dengun powder and dengan derivatives, certain natural gums, bulb powder, rice bran powder, water-swellable substances, gelling substances, zeolites, silica gel,
Synthetic water-swellable substances, etc.

It is advisable to add to the above-mentioned foamable material the following scaly material, that is, flake material, as a material that increases sealing properties.

Glass flakes, mica flakes, wood flakes,
Bulb flakes, PVC flakes, PVC flakes, aluminum flakes, or thin flakes of material.

The inclusion of these flaky substances improves the sealing performance and at the same time reduces the resistance of the pig during lining.

Furthermore, in order to prevent the foamed membrane formed from the foamed material (A) from sagging or from collecting on the bottom, it is preferable to add, for example, a material having rubber elasticity as shown below.

Synthetic rubber, natural rubber, 7'4 tux, plasticizers, polymeric substances, vinyl chloride, vinyl acetate copolymers, acrylic resins, acrylic rubber, and all other flexible elastic substances.

Note that it has been found that seven types of materials for the foamable substance (A) have sufficient effects, and the number of materials is not limited.

The foamable material (A) containing the above-mentioned components is pumped into a conduit using a pig and then discharged.

Next, in order to foam and harden the foam, a substance (B) such as amines or water is made into a foam and is sandwiched between similar pig moss and pumped into the conduit. The above substance (A) rapidly foams when it comes into contact with this substance (B), and the volume increases! It increases ~io times and hardens to seal the hole. At this point, the above-mentioned pumping pressure should be 300~ to avoid breaking the seal of the hole! O
Make the pressure as low as θmmH,O.

For example, a surfactant is added to an amine aqueous solution or simply water, foamed, and a foam pump is used to send pressure into the pipe at low pressure (300 to 30 mm) ('2 o) and discharge it to one side. Continue for 10-/ minutes. As a result, the foamable substance (A) undergoes a contact reaction, and after 7 to 2 minutes, it foams and hardens, expanding its volume by 3 to 10 times, thereby closing the corrosion hole and perfecting the sealing performance. Then excess foam <B
The work is completed by discharging at a low pressure of less than ay O,/Kg/am'. Then foam curing about ? Take 0 minutes.

The foam sealing material made in this way has a pressure resistance of 0, J
-~/Kg/cJ of air pressure does not cause rupture.

Finally, after filling and sealing these corrosion holes, a lining agent (
K) is sandwiched between the pig moss and fed under pressure in the same manner as above. Since the viscosity of this lining agent is generally around 10,000 cps, the pumping pressure is θ,j ~/-OKg/am2.

This second inning agent is a durable synthetic resin, for example, the following substances.

Epoxy resin, urethane resin, acrylic resin, polyester resin, etc.

By coating the inner surface of the conduit with a lining agent such as epoxy, long-term corrosion resistance can be maintained.

In the present invention, if the hole is not completely sealed by the foamable material (A), the epoxy resin etc. will blow out into the corroded hole, making it impossible to seal it even if the lining is completed.

The present invention achieves its effects only when the hole seal and the corrosion-resistant lining are integrated.

Three preferred embodiments of the present invention will be described in detail below with reference to FIG.

Example / As shown in Figure 1 (a), the diameter is θφ and the length is ! A steel pipe with a diameter of θm is buried in ±2, and a 10 mm hole 3, 3...
of! 10 kg of foamable material (A1) is filled between the two pigs t and 4 in one log of this steel pipe /, and air pressure θ is applied to the log from the direction (a).
Apply r Kg/am2 and pig! , 6 in the (1) direction and discharged from 07 on the opposite side. /
Kg/am2 air is sent from the direction (a) for 1 minute to volatilize a small amount of the solvent inside. Note that 7 in the figure is an injection port for various substances.

Thereafter, as shown in Fig. 2 (B), the substance (AI) & the substance to be foamed and hardened (B,) are made into foam using the whisk 10, and then the log is heated at low pressure (3θθ~r (70mmH, O pressure)). Fill the steel pipe evenly and discharge in the direction (b). This filling was carried out for about io minutes. After that, the whisk 10 was stopped and the foam curing inside the steel pipe was maintained for about 3 minutes, and then 0-/Kg. The substance (B
,) was discharged. Immediately after that, I measured the leakage inside the pipe and found that it was θ at an initial force of 300 mmH20EE! l//
It was confirmed that the air that had been leaking within seconds turned to O and that the 10φ hole was completely blocked by the foaming properties of the foaming material (A). Then, as shown in Figure 1 (c), the epoxy compound (Ex) is filled between the two pigs //, /2 in the log, and the steel pipe / is heated with an air pressure of /, θKg/cm2.
After inner lining, two big //, /:1. was discharged from the lower side on the opposite side. Immediately after that 3θθmmH2O
The leakage was measured at a pressure of 0. Also, 3
θOmmH,O pressure was maintained for 2y hours, and the next day after the epoxy resin on the inner surface was semi-hardened, the pressure was increased to 30θmm in the same way as above.
It was 0 when measured at 0 pressure.

For further confirmation, the pipe was dug up and soapy water was poured into the hole to measure the leakage due to bubbles (with the naked eye), and the leakage was found to be 0.

At this time, as shown in Figure 1), there are 0,
A foamable material was applied thinly to a thickness of 7 to 01θjmm, and an epoxy resin (E,) of about 1000 yen was lined on top of it, resulting in a very good airtightness.

The composition of the foaming agent substance (A,) is as follows.O The composition of the foaming hardening agent (B1) is as follows.

The composition of the lining agent (El) is as follows.

Example Similar to Example 1, an experiment on sealing a corroded hole was conducted according to the steps (1) to (c) shown in Figure 1 (a), (b), and (c). The substance (A,), the hardening agent (B,), and the lining material (E2) have the following composition, and the initial leakage is 0.jl/θ, and the leakage becomes 0 after 2 seconds, and the corrosion hole seal and internal lining are completely sealed. It was successfully carried out.The lining material used was (E,).

Example 3 The work was carried out in the same way as in Example 1 through steps (1) to (ri) shown in Figure 1 (a), (b), (c), and (b). A3), curing agent (B8) and the final lining material (E3) are as follows.

Initially, the leakage from the steel pipe was 0.11/θ for 7 seconds, but the leakage immediately after the final lining was 3θOmmH10.
After that, even after holding at 30 θmmH for 2 hours, the leakage was θ and the corrosion hole sealing and lining were successful.Next, a comparative example will be explained with reference to FIG.

Comparative example / As shown in Figure 2 (a)! Oφ steel pipe/7. jOrn
I buried it in the ground at a depth of JOcm, and I made a 10φ hole in the pipe, assuming it was a corrosion hole, and measured the leakage with a flow meter. θ, ta110. It was a momentary omission.

This steel pipe is pigged 20.2 /
, 7.2. Q? , 2ri.

Corrosion hole sealing and internal lining were carried out using a blowing agent composition (Xl), a hardening agent (Y, ), and a lining agent E3 using 25 ml.

As a result, the hole seal failed due to a small amount of leakage.

The cause is foaming composition X1. This seems to be because a pig was used to pump the curing agent Y, tl: at high pressure, and the reaction foaming membrane was damaged by the pumping pressure.

Comparative Example C: Similar to the previous example, a seal filling experiment was carried out in steps (1) to (4t) shown in Figure 1 (a), (b), (c), but at this time, foaming Composition (A) was made using only urethane prepolymer, and curing agent (B) was made only by foaming water, but as a result, the foamed film of urethane prepolymer sags and accumulates at the bottom of the steel pipe. , the upper hole was incompletely sealed, and the corrosion hole plugging failed. after that,
I lined the inside with epoxy resin (El), but the leakage did not stop. The reason for this failure was that the foaming composition did not have a rubber-like substance component, which caused sagging inside the steel pipe, and the foaming hardening was only a contact reaction on the surface of the water, so the foaming did not occur properly and the film did not have any strength. It is.

As described above, according to the present invention, the foamable substance (A) buried in the defective part of the conduit or the corroded hole can be replaced by a substance (B) such as amine or water.
Since it foams and hardens when it comes into contact with L and fills them, the sealability of corroded holes is improved and these can be reliably filled and sealed.

Further, according to the third invention of the present application, the foamable material (A) has a flake-like material and is itself a thin piece, so the foamable material (A) is blown out from the corrosion hole by the pumping pressure of the pig. The leakage of flakes into the soil should be minimized, and the leakage of air near corrosion holes should be minimized to prevent the pig from moving forward. The pig can be easily pumped and discharged at low pressure.

Furthermore, according to invention No. 7 of the present application, the foamable material (A) contains a substance that imparts rubber elasticity, such as synthetic rubber, latex, natural rubber, vinyl chloride, vinyl acetate, acrylic resin, acrylic rubber, etc. This serves to prevent the foamable substance (A) from sagging and to assist in its foaming, to minimize the amount blown out from the corrosion holes when it is pumped by the pig, and to provide strength to the film due to its rubber elasticity. Also, even if it is destroyed, it will return to its original state and make the hole that was destroyed smaller. Therefore, this has the effect of minimizing the amount of fluid or gas that has leaked.

[Brief explanation of drawings]

Figures 1 (a), (b), (c), and 2) are explanatory diagrams sequentially showing the steps of the embodiment of the present invention, and Figures 2 (a), (b),
(c) is an explanatory diagram sequentially showing the steps of the comparative example. /... Conduit, Ko... In the soil, 3... Corrosion hole,! 9g
... Pig, A... Foaming (or swelling substance) substance, B... Foaming and hardening substance, E... Lining agent. Procedural amendment (voluntary) 1. Description of the incident Kaku Showa 2016 Patent Application No. 104515 2 Title of the invention Corrosion prevention method for sealing the inner surface of defective parts of buried conduits, etc. Nozameya Jishino 4t Machiyo 1456 Hazama-cho, Hachioji-shi, Tokyo Three Bond Co., Ltd. Specification. (1) In the last line on the left on page 10 of the Specification Letter, in the 9th line on the left on page 12, and in the 4th line on the left on page 14, ``Kājorah'' is corrected to ``Kāshid.'' (3) ``Adeka EpVJ is corrected to ``Adeka EpUJ'' on page 14, line 3 on the left.

Claims (4)

[Claims] (1) While gas pipes, water pipes, and other conduits buried underground that have defects or corrosion holes, etc., are dug up in separated moss areas, and one of the openings is opened using foaming (or The swellable material (A) is coated by being pumped using a pumping pig, and then the foaming material (B) is reacted with the foaming material (A) to foam and harden for 300~! Air is blown into the conduit at a low pressure of 0.00 mm H20, and the substance (A) and substance (B) contact react and foam to harden, filling and sealing the defective part or corroded hole in the conduit, and then sending a lining agent into the conduit. A corrosion prevention method for sealing the inner surface of a defective part of a buried conduit, etc. by lining the inner surface of the pipe. (2) The above-mentioned foamable (or swelling) substances (A) include urethane prepolymers, starch powder and starch derivatives, certain natural gums, bulb powder, rice bran powder, water-swellable substances, gelling substances, and zeolites. , silica gel, synthetic water-swellable substances, and the like. (3) A patent characterized in that the above-mentioned foamable substance (A) contains glass flakes, mica flakes, wood flakes, pulp flakes, PVC flakes, PVC flakes, aluminum flakes, or thin film flakes. A corrosion-preventing method for sealing the inner surface of a defective part of a buried conduit, etc., according to claim 1. (4) The foamable material (A) above may be synthetic rubber, natural comb, latex, plasticizer, polymeric material, vinyl chloride, vinyl acetate copolymer, acrylic resin, acrylic rubber, or any other flexible elastic material. A corrosion-preventing method for sealing the inner surface of a defective part of a buried conduit, etc., according to claim 1, characterized in that it contains a substance or the like.