JPH0637956B2 - How to repair a gas conduit - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for repairing corrosion holes and the like generated in a gas conduit by using a heat shrinkable sheet.

[Prior art and its problems] As a method of repairing gas leakage due to corrosion holes or cracks generated in a gas conduit, there is a method of cutting this leakage section and replacing it with a new pipe. However, this method has a problem that it is necessary to stop the gas, and the repair is troublesome and expensive. Therefore, a repair method has been adopted in which the leaked portion is covered with a heat shrinkable sheet to prevent gas leakage.

FIG. 3 shows a repairing method using this heat-shrinkable sheet. 01 is a gas conduit, 02 is a corrosion hole, 03 is a heat-shrinkable sheet, and the heat-shrinkable sheet 03 is clamped at both ends by a chuck 04 or the like. To fix the reaction force in the circumferential direction.

In this way, when the corrosion hole is covered from the outside of the pipe for repair, the distance L between the corrosion hole 02 and both ends 03 of the heat shrinkable sheet 03 in the pipe axial direction must be sufficiently secured from the viewpoint of sealing property. I have to.

Usually, the width of the heat-shrinkable sheet 03 used in this way is such that the above L can be sufficiently secured when the corrosion hole 02 is at one place.

However, when there are two corrosion holes close to each other as shown in FIG. 4, if they are repaired with one heat shrinkable sheet by the same method as shown in FIG. 3, as shown in FIG. The distance L from the corrosion hole 02 to the end 03 of the heat-shrinkable sheet 03 becomes very small, which causes a problem that the seal width in the tube axis direction cannot be sufficiently secured.

As a solution to this problem, there is also a method of using two heat shrinkable sheets 03 as shown in FIG. However, the corrosion hole 02
If they are close to each other, the heat-shrinkable sheets 03 will overlap each other in the middle. As a result, on the side that partially overlaps the upper side,
There is a problem that the distance of direct contact with the surface of the pipe is insufficient and the repair cannot be completed completely. In particular, in the case of a system in which the heat-shrinkable sheet is stopped by a chuck or the like to fix the reaction force in the circumferential direction, this chuck or the like portion does not have airtightness, and thus the problem is serious if the distance is insufficient.

An object of the present invention is to propose a method for sufficiently securing airtightness when repairing a plurality of holes to be repaired that are approached by using a heat-shrinkable sheet that is stopped by an opening / closing device to fix a reaction force in the circumferential direction. is there.

[Structure of the Invention] The repair method of the present invention is as follows.

A method for covering and repairing a plurality of holes to be repaired close to each other with a heat-shrinkable sheet of a constant width with an opening / closing device, in which the heat-shrinkable sheet for repairing the holes is adjacent If the sealing distance in the pipe axis direction that overlaps each other and directly contacts the pipe surface cannot secure the specified distance, first wrap the heat-shrinkable wrap sheet under the overlapping part of the heat-shrinkable sheet, and then heat the heat-shrinkable wrap sheet. This heat-shrinkable wrap sheet is brought into close contact with the tube by heating, and then the first heat-shrinkable sheet is coated on either the left or right side so that a part of the end overlaps the surface of the heat-shrinkable wrap sheet. By heating this, the first-layer heat-shrinkable sheet is brought into close contact with the surface of the tube including the hole to be repaired and the surface of the partially-overlapping heat-shrinkable wrap sheet, and then the first-layer heat-shrinkable sheet. On the opposite side, the second-layer heat-shrinkable sheet is covered so that the edges of the first-layer heat-shrinkable sheet overlap with each other, and this is heated to cause the heat-shrinkage of the pipe including the hole to be repaired. A method for repairing a gas conduit, in which a second-layer heat-shrinkable sheet is brought into close contact with a part of a surface, a heat-shrinkable wrap sheet, and a first-layer heat-shrinkable sheet that partially overlap each other.

[Embodiment] An embodiment of the present invention will be described in detail below with reference to Figs.

First, in the gas conduit 1, two corrosion holes 2 and 3 are generated close to each other, and both holes are covered and repaired with a heat shrinkable sheet. In this case, first, the heat-shrinkable wrap sheet 4 made of a material such as plastic or rubber is wound under the heat-shrinkable sheets overlapping with each other and heat-shrinked by using a gas burner or the like. At the time of this winding, an adhesive may be applied to the inside of the heat-shrinkable wrap sheet 4. However, this adhesive does not necessarily have to be applied. After the heat-shrinkable wrap sheet 4 is wound in this manner, the first-layer heat-shrinkable sheet 5 is wound around the corrosion hole 3 side, and the chuck 6 is closed. The winding position of the first-layer heat-shrinkable sheet 5 must be such that the distance from the corrosion hole 3 to the right end in FIG. 1 is a sufficient seal width. Then, the left end on the opposite side overlaps with the heat-shrinkable wrap sheet 4 which has been wound in advance.

When the winding is completed, heat shrinkage is performed using a gas burner or the like. As a result, the first-layer heat-shrinkable sheet 5 adheres to the tube surface and the surface of the heat-shrinkable wrap sheet 4.

Next, the second layer heat shrinkable sheet 7 is wound around the corrosion hole 2 side, and the chuck 8 is closed. At the winding position of the second layer heat shrinkable sheet 7, the distance from the corrosion hole 2 to the left end in FIG. The right end on the opposite side overlaps with the first-layer heat-shrinkable sheet 5 that has been previously wound.

When the winding is completed, heat shrinkage is performed using a gas burner or the like. As a result, the second-layer heat-shrinkable sheet 7 comes into close contact with the tube surface and the surfaces of the first-layer heat-shrinkable sheet 5 and the heat-shrinkable wrap sheet 4.

When the corrosion holes 2 and 3 are closer to each other, the heat-shrinkable wrap sheet 4 may cover the corrosion holes 2 and 3.

[Advantages of the Invention] The present invention, when the hole to be repaired approaches and is repaired as described above, heat shrink sheets overlap each other, and when the seal width in the pipe axis direction cannot be sufficiently secured, Since the heat-shrinkable wrapping sheet is wound under the overlapping portion of the shrinkable sheets, the following effects can be expected.

a. The airtightness in the tube axis direction, which is reduced by the heat-shrinkable sheets partially overlapping each other, can be secured by the close contact action of the heat-shrinkable wrap sheet.

b. The heat-shrinkable wrap sheet, the tube surface, and the adjacent surfaces of the heat-shrinkable wrap sheet are closely adhered to each other and integrated, so that the sealing strength is increased and the drawback of the heat-shrinkable wrap sheet having a small shear deviation resistance in the circumferential direction of the tube. Is reinforced by the tightening force of the heat shrink sheet.

c. The present invention can be applied not only to repairing corrosion holes, but also to repairing corrosion of pipes.

[Brief description of drawings]

FIG. 1 is an explanatory view of the method of the present invention, FIG. 2 is a sectional view taken along the line AA, and FIGS. 3, 4, 5 and 6 are explanatory views of a conventional repair example using a heat shrinkable sheet. 1 ... Gas conduit, 2, 3 ... Corrosion hole, 4 ... Heat shrinkable wrap sheet, 5 ... First layer heat shrink sheet, 6 ... Chuck, 7 ... Second layer heat shrink sheet, 8 ... Chuck.

Claims (1)

[Claims] 1. A method for repairing a plurality of holes to be repaired close to each other by covering them with a heat-shrinkable sheet having a constant width with an opening / closing device, and repairing the holes to be repaired. When the heat-shrinkable sheets overlap each other and are in direct contact with the pipe surface, and the prescribed sealing distance in the tube axis direction cannot be secured, first, wrap the heat-shrinkable wrap sheet under the overlapping portion of the heat-shrinkable sheets, and then The heat-shrinkable wrap sheet is brought into close contact with the tube by heating the heat-shrinkable wrap sheet, and then one of the left and right sides of the heat-shrinkable wrap sheet is partially overlapped with the surface of the heat-shrinkable wrap sheet to further shrink the heat. By covering the sheet and heating it, heat shrinkage is caused to adhere to the surface of the tube containing the hole to be repaired and the surface of the partially overlapped heat shrinkable wrap sheet, and then the first layer heat On the side opposite to the side where the contraction sheet is adhered, the second layer heat contraction sheet is covered by overlapping a part of the edge of the first layer heat contraction sheet, and this is heated to cause heat contraction to form the hole to be repaired. A method of repairing a gas conduit, which comprises contacting a second-layer heat-shrinkable sheet with the surface of the tube, the heat-shrinkable wrap sheet, and the first-layer heat-shrinkable sheet that partially overlap each other.