JPS5973691A - Method of repairing inner surface of pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention applies a coating agent to the inner wall of the pipe during the process of moving the VIG, mainly within existing pipes such as water pipes and gas pipes. This invention relates to a method for repairing the inner surface of a pipe.

As a method for repairing the inner surface of this pipe, the method shown in Figure 1 is known. That is, inside the existing pipe A, a pair of front and rear pipes 1 and 2 connected by a connecting cable 3 are installed with coating agent B filled between the two pipes, and atmospheric pressure P1 is applied to the rear pipe A. By adding Big 1.
While moving the pipe 2, the coating agent is pushed out from the circumferential surface of the rear big pipe 2, and the coating lIC is applied to the inner circumferential surface of the existing pipe A.

In this case, the problem is that when the amount of coating agent B filled between the two pigs decreases due to the movement of the bigs 1 and 2, a void is created in the upper part of the pipe, and this causes the upper part of the inner surface of the tube to This results in uncoated areas. In addition, since pressure P1 is applied to the treatment area where coating agent B has already been applied and coating film C has been formed, when there are corrosion holes etc. on the inner surface of existing pipe A, uncured coating agent may be There is a possibility that the coating film C may be torn or thinned due to leakage, and the original purpose of the inner surface treatment may be lost.

The present invention has been proposed to solve the above-mentioned disadvantages, and even if the filling IE range of the coating agent decreases due to the movement of the VIG, no voids will be created in the upper force of the filling part, and the coating process will not occur. The inner surface of the tube allows for the coating agent to be accurately formed on the entire inner surface of the tube by applying the necessary pressure to the coating agent to extrude it without applying pressure from the side to the VIG. The purpose of this paper is to provide information on repair methods.

For this purpose, the present invention connects the front and rear vigs with a connecting rope, installs a movable vig that can be moved between the vigs through the connecting rope, and fills a coating agent between the movable pig and the rear vig. However, when the front vig is moved, a desired pressure is applied to the =1-ting agent via the movable vig.

Hereinafter, one embodiment of the present invention will be explained in detail with reference to FIG. The front vig 11 is towed forward by a tow rope 14 or by negative pressure.

Furthermore, a movable vig 16 is arranged between the vigs 11 and 12, and the movable vig 16 is slidably slidable on the connecting cable 13 and has an insertion hole 15 through which the cable 13 is inserted in the center. A coating agent B such as a thermosetting resin, for example, an epoxy resin is filled between the front end and the rear big 12. The above-mentioned front big 11 and movable big 1G are connected to the existing pipe A
On the other hand, the rear big 12 has a slightly smaller outer diameter, and an outflow gap G for the coating agent B is formed between it and the inner surface of the tube.

In the existing pipe A, the front and rear vigs 11 and 12 are moved by the traction of the tow rope 14 or by negative pressure.

At this time, by moving the big 11 and 12, the movable big 16
moves backward due to its movement resistance P2, and the movable big 16
Since the pressing force P3 is applied to the coating agent B filled between the rear big 12 and the rear big 12, the coating agent B is pushed out from the peripheral gap G of the rear big 12, and after passing through the rear big 12. It is applied to the inner surface of the existing pipe A, forming a coating film C on the inner surface of the pipe.

In this case, since the pressing force P3 is acting on the coating agent B through the movable Vig 1G while the Vigs 11 and 12 are moving, even if the amount of the coating agent decreases as the coating process progresses, the No voids are formed above the filling part, and a coating film C of uniform thickness can be formed over the entire inner surface of the tube. In addition, since no positive pressure is applied inside the existing pipe after Vig 12 has passed, the existing pipe A
Even if there is a corrosion hole on the inner surface, the coating film C will not be torn or thinned because it is cured with the corrosion hole closed.

Note that the pressure P3 when extruding the coating agent B from the peripheral gap G of the rear big 12 affects the thickness of the coating film C, so it is desirable that it be as stable as possible. For this reason,
The internal pressure of the coating agent B may be adjusted by further applying air pressure to the front side of the movable big 16.

As detailed above, the present invention presses the coating agent filled between the movable vig and the rear vig with a pressing force applied between the movable vig and the rear vig while the vig is moving. At the same time, the coating process is performed by extruding it from around the rear big and applying it to the inner surface of the existing pipe, so there is no uncoated area like in the conventional method, and it is possible to form a coating film of uniform thickness over the entire inner surface of the pipe. Until the membrane is cured, there is no leakage to the outside from corrosion holes, etc., and a complete repair can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal side view showing a conventional coating method, and FIG. 2 is a longitudinal side view showing an embodiment of the present invention. 11...Front big, 12...Back big, 13...
Connecting cable, 15... Insertion hole, 16... Movable big, A.
...Existing pipe, B...Coating agent, C...Coating film. Patent applicant Hakko Co., Ltd. Agent Patent attorney Makoto Kobashi Ukiyo Patent attorney Susumu Murai 6-

Claims (1)

[Claims] The front and rear vig are connected by a connecting rope, and a movable vig is provided that can be moved between the vig through the connecting rope, and a nicoding agent is filled between the movable pig and the rear vig, and when the front vig is moved, the movable vig is moved. A method for repairing an inner surface of a pipe, characterized in that a desired pressure is applied to the coating agent through a pig.