JP4093692B2 - Gas leak repair method for screw joints for gas piping - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas leak repairing method for a screw joint portion for a gas pipe that repairs a gas leak from a threaded portion of a screw joint section provided in a gas pipe in a live pipe state in which gas is passed.
[0002]
[Prior art]
As a gas leak repairing method for the above-mentioned gas pipe threaded joint part, conventionally, as shown in FIGS. 7 and 8, as shown in FIGS. As shown in FIG. 9, a method of infiltrating the passage C to be cured (hereinafter referred to as a first conventional method), or the outlet side of the gas leakage passage C formed at the threaded portion 1 of the screw joint portion B is a sealing material. 13 (hereinafter referred to as a second conventional method).
In the first conventional method, as shown in FIG. 7, a porous material 5 such as carbon fiber is wound around an existing sealing material 4 at the outer end portion of the screwing location 1, and the porous material 5 is uncured liquid. After impregnating the sealing material 6, as shown in FIG. 8, the rubber belt 14 wound so as to cover the porous material 5 is tightened with a tightening jig 15, so that the liquid sealing material 6 resists the gas pressure of the leaked gas. Then, pressure is applied so as to penetrate into the gas leakage passage C, and the rubber belt 14 is held while being tightened by the tightening jig 15 to cure the liquid sealing material 6 that has penetrated into the gas leakage passage C.
Further, in the second conventional method (FIG. 9), a temporary fixing material 16 such as clay or putty is applied to the outer end portion of the screwing portion 1 over the entire circumference and hardened, and the hardened temporary fixing material 16 is used. After temporarily fixing the gas leakage from the gas leakage passage C, the uncured sealing material 13 applied so as to cover the temporary fixing material 16 over the entire circumference is cured, and the outlet side of the gas leakage passage C is It is blocking.
[0003]
[Problems to be solved by the invention]
According to the first conventional method, the rubber belt 14 wound around the porous material 5 is tightened with the tightening jig 15 so that the liquid sealing material 6 penetrates into the gas leakage passage C against the gas pressure of the leakage gas. In order to pressurize the liquid sealing material 6 applied to the porous material 5, for example, the screw joint portion B is in a narrow place, or other pipes or walls are provided in the vicinity of the screw joint portion B. In the case where a wide working space in which the tightening jig 15 can be used cannot be ensured, there is a drawback that the gas leakage from the threaded portion 1 of the threaded joint B cannot be repaired.
Further, according to the second conventional method, since a special jig such as the tightening jig 15 is not used, gas leakage from the screwing portion 1 of the screw joint portion B can be prevented even when a large work space cannot be secured. The liquid sealing material 6 that has penetrated into the gas leakage passage C is not cured, but the outlet side of the gas leakage passage C is covered with the sealing material 13 that is cured so as to wrap the outer end portion of the screwing location 1. Since the sealing material 13 is closed, there is a drawback that it is easy to cause gas leakage again when the cured sealing material 13 is broken, and it is difficult to ensure reliability.
The present invention has been made in view of the above circumstances, and it is an object of the present invention to repair gas leakage from a screwed portion of a threaded joint portion with high reliability without requiring a large work space. And
[0004]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a gas pipe screw joint portion for repairing a gas leak from a screwed portion of a screw joint portion provided in a gas pipe in a live pipe state in which gas is passed. A gas leakage repair method, wherein the outer end of the screwed portion is covered with an air-permeable layer impregnated with an uncured liquid sealing material over the entire circumference, and an adhesive tape material wound around the air-permeable layer. Forming an airtight layer that hermetically seals the gas permeable layer over the entire circumference, allowing a leaked gas from the screwed portion to enter the gas permeable layer, and an uncured liquid sealing material impregnated in the gas permeable layer In the gas leak passage formed at the screwing point, the resin is penetrated and cured.
[Action]
The outer end of the screwed portion is covered with a ventilation layer impregnated with an uncured liquid sealing material over the entire circumference, and an airtight layer is formed with an adhesive tape material wound around the outer side of the ventilation layer. The gas leakage passage and the airtightness are sealed by sealing the gas leaking from the gas leakage passage formed at the threaded place into the ventilation layer and confining the leakage gas inside the airtight layer. By eliminating the pressure difference from the inside of the layer, the uncured liquid sealing material impregnated in the ventilation layer can be permeated into the gas leakage passage so as to replace the leakage gas that has entered the ventilation layer.
〔effect〕
Without using a special jig such as a clamping jig, the leaked gas that has entered the ventilation layer is sealed inside the airtight layer, and the liquid sealing material is infiltrated into the gas leakage passage so that the leaked gas is replaced. Therefore, it is possible to repair the gas leakage from the screwed portion of the threaded joint portion with high reliability without requiring a large work space.
[0005]
According to a second aspect of the present invention, the ventilation layer is provided so as to be compressible and deformable, and the adhesive tape material is made of a stretchable elastic material, and the adhesive tape material is elastically stretched to allow the ventilation. The point is to wrap around the outside of the layer.
[Action]
Since the airtight layer is formed of the adhesive tape material that is elastically stretched and wound around the outer side of the ventilation layer, the pressure-sensitive adhesive tape material pressurizes the ventilation layer, and the ventilation layer is compressed and deformed. A cured liquid sealing material is extruded from the vent layer.
〔effect〕
Uncured liquid sealing material easily penetrates into the gas leakage passage.
[0006]
According to a third aspect of the present invention, a primary pressure-sensitive adhesive tape material having adhesion to the gas permeable layer and releasability from a cured sealing material obtained by curing the liquid sealing material is formed on the gas permeable layer over the entire circumference. A secondary adhesive tape material having adhesion to the primary adhesive tape material and an elongation rate higher than that of the primary adhesive tape material is wrapped around the primary adhesive tape material wound around the air-permeable layer. The airtight layer is formed by wrapping over.
[Action]
The primary adhesive tape material that is easily peeled off from the cured sealing material is wound around the entire circumference so as to be in close contact with the air-permeable layer, and has a higher elongation than the primary adhesive tape material. A secondary pressure-sensitive adhesive tape material that can be easily deformed along the air flow is wound around the primary pressure-sensitive adhesive tape material wound around the air-permeable layer so as to be in close contact with the entire circumference, thereby forming a highly airtight layer.
〔effect〕
Leakage gas that has entered the ventilation layer can be securely sealed with a highly airtight layer, and the liquid sealing material can easily penetrate into the gas leakage passage, while being easily peeled off from the cured sealing material when the airtight layer is peeled off. Can do.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the parts indicated by the same reference numerals as those in the conventional example indicate the same or corresponding parts.
Referring to FIGS. 1 to 6, the gas pipe threaded joint for repairing the gas leakage from the threaded portion 1 of the threaded joint B provided in the gas pipe A in the state of the live pipe in which the gas is passed. The gas leak repair method for the part will be explained.
[0008]
FIG. 1 shows a threaded joint B between a straight pipe 2 and an elbow 3 provided in a gas pipe A for city gas. As shown in FIG. A description will be given of a case where the gas leakage passage C is formed and the gas leakage from the gas leakage passage C is repaired.
After the outer end of the threaded joint 1 of the threaded joint B is cleaned over the straight pipe 2 side and the elbow 3 side, as shown in FIG. 3, the existing sealing material 4 at the outer end is covered. A porous material 5 is wound, and the porous material 5 is impregnated with an uncured liquid sealing material 6 by spraying or brushing. Cover over.
The porous material 5 is preferably a liquid sealing material 6 or a fiber that can absorb and retain a large amount of moisture, such as carbon fiber or pure wool yarn.
The liquid sealing material 6 is preferably an acrylic silicone resin, but may also be an aqueous urethane resin, cyanoacrylate, or the like.
[0009]
Next, as shown in FIGS. 4 and 5, the outer side of the air-permeable layer 7 is air-tightly closed over the entire periphery with the air-tight layer 8 and is restrained by pressure.
The airtight layer 8 elastically extends a primary adhesive tape material 11 having adhesion to the air-permeable layer 7, peelability to the cured sealing material 9 obtained by curing the liquid sealing material 6, and self-shrinkage, As shown in FIG. 4, after the air-permeable layer 7 is air-tightly wound on the entire circumference of the air-permeable layer 7, the adhesiveness to the primary adhesive tape material 11, the higher elongation rate than the primary adhesive tape material 11, and self-shrinkage The secondary pressure-sensitive adhesive tape material 12 having the property of being stretched elastically and wound on the primary pressure-sensitive adhesive tape material 11 wound around the air-permeable layer 7 as shown in FIG. Wrap around and configure.
[0010]
Since both the primary adhesive tape material 11 and the secondary adhesive tape material 12 have self-shrinking properties, the primary adhesive tape material 11 is deformed so as to conform to the outer peripheral shape of the ventilation layer 7 and is brought into close contact therewith. In addition, while the secondary adhesive tape material 12 is deformed so as to conform to the winding shape of the primary adhesive tape material 11, it is wound with a strong winding force so as not to loosen, and the outer side of the air-permeable layer 7 is subjected to a strong force. Therefore, even when the gas pressure in the gas pipe is high, the leaked gas that has entered the gas-permeable layer 7 can be reliably contained in the gas-tight layer 8 having high air-tightness.
[0011]
The primary adhesive tape material 11 is preferably a butyl rubber-based (copolymer obtained by blending isobutylene and a small amount of isoprene in a rubbery form) having an elongation of about 400%, but in addition, acrylic rubber (ACM) or Polyisobutylene rubber (particle size average molecular weight 900,000 or more) or the like may be used.
In addition, as the secondary adhesive tape material 12, an adhesive material made of butyl rubber compound is applied almost uniformly to a base material based on EPM (ethylene propylene rubber) or EPDM (ethylene propylene terpolymer). A tape having a combined elongation of about 800% is preferable, but isoprene rubber (IR), chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR), etc. may also be used.
[0012]
And it hold | maintains for about 15 to 20 minutes in the state shown in FIG. 5, and while letting the leaked gas from the gas leak path C enter the ventilation layer 7, the pressurization restraint of the airtight layer 8 with the leaked gas The uncured liquid sealing material 6 impregnated in the air-permeable layer 7 is maintained by maintaining the inside of the air-tight layer 8 at the same pressure as that in the gas pipe A by being sealed inside the air-tight layer 8 by force. In order to replace the leaked gas that has entered 7, the gas leaks from the gas leak passage C and is cured by being penetrated into the gas leak passage C extending over the screw joint 1.
In addition, since the primary adhesive tape material 11 and the secondary adhesive tape material 12 are elastically stretched and wound, the ventilation layer 7 is compressed and deformed, and the uncured liquid sealing material 6 is pushed out of the ventilation layer 7. Since the compressed and deformed ventilation layer 7 is maintained in a pressurized state, the extruded uncured liquid sealing material 6 can easily penetrate into the gas leakage passage C at a high pressure.
Thereafter, as shown in FIG. 6, the primary adhesive tape material 11, the secondary adhesive tape material 12, and the porous material 5 are all peeled off, and repair of gas leakage is completed.
[0013]
[Other Embodiments]
1. According to the present invention, a gas leakage repair method for a threaded joint for a gas pipe includes a repair tape in which a porous material for forming a ventilation layer and an adhesive tape material for forming an airtight layer covering the porous material are combined in advance. It is also possible to use a repair tape in which a porous material is impregnated with an uncured liquid sealing material just before use, and cover the entire periphery of the end of the screwed portion.
2. According to the present invention, a gas leak repair method for a threaded joint for a gas pipe is performed by infiltrating an uncured liquid sealing material only into a gas leakage passage made of an existing sealing material, curing the liquid sealing material, May be repaired.
[Brief description of the drawings]
[Fig. 1] Perspective view of gas piping [Fig. 2] Partial cross-sectional side view explaining gas leak repair method [Fig. 3] Partial cross-sectional side view explaining gas leak repair method [Fig. 4] Gas leak repair method Partial cross-sectional side view explaining the gas leak repairing method. FIG. 6 Partial cross-sectional side view explaining the gas leak repairing method. FIG. 7 Conventional screw joint for gas piping. Explanatory drawing of the gas leak repair method for the gas pipe [Fig. 8] Explanatory drawing of the gas leak repair method for the conventional screw joint for gas piping [Fig. 9] Explanatory drawing of the gas leak repair method for the conventional screw joint for gas piping [ Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Threading place 6 Liquid sealing material 7 Venting layer 8 Airtight layer 9 Hardening sealing material 11 Primary adhesive tape material 12 Secondary adhesive tape material A Gas piping B Screw joint part C Gas leak passage

Claims (3)

A gas leakage repair method for a gas pipe threaded joint for repairing a gas leak from a threaded joint of a threaded joint provided in a gas pipe while maintaining the state of an active pipe through which gas has passed,
The outer end of the screwed portion is covered with a ventilation layer impregnated with an uncured liquid sealing material over the entire circumference, and the ventilation layer is covered with the adhesive tape material wound around the ventilation layer over the entire circumference. To form an airtight layer
Leakage gas from the screwed portion enters the vent layer, and an uncured liquid sealing material impregnated in the vent layer penetrates into the gas leak passage formed at the screwed portion and is cured. Gas leak repair method for screw joints for gas piping. The gas according to claim 1, wherein the gas-permeable layer is provided so as to be compressible and deformable, and the pressure-sensitive adhesive tape material is made of a stretchable elastic material, and the pressure-sensitive adhesive tape material is elastically stretched and wound around the gas-permeable layer. Gas leak repair method for piping threaded joints. A primary pressure-sensitive adhesive tape material having adhesion to the air-permeable layer and releasability to a cured seal material obtained by curing the liquid sealing material is wound around the gas-permeable layer over the entire circumference, and is adhered to the primary pressure-sensitive adhesive tape material. A secondary pressure-sensitive adhesive tape material having a property and a higher elongation rate than the primary pressure-sensitive adhesive tape material is wound around the primary pressure-sensitive adhesive tape material wound around the ventilation layer over the entire circumference to form the airtight layer. A gas leakage repair method for a threaded joint for gas piping according to claim 1.

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