JPS59150577A - Working method in existing pipe - Google Patents

Abstract

PURPOSE:To enable to inhibit the invasion of resin into a branched pipe, by detecting the change of atmospheric pressure inside said branched pipe, applying predetermined atmospheric pressure to the branched pipe, and making it possible to maintain the resulting condition until at least a rear pig has passed therethrough. CONSTITUTION:A space between a couple of front and rear pigs 11 and 12 is packed with resin B, said pigments are carried through an existing pipe A required, and the front pigment 11 is pulled and moved inside the existing pipe A while applying negative pressure to a space in front of the front pig 11 to repair the interior of the pipe A. In this working method, a part 18 of small caliber communicated to the outside air is provided at a branched pipe 17 divided from the existing pipe A toward a supply destination. When internal pressure inside the existing pipe A changes from a negative pressure state, before the front pig 11 passes through the part of the existing pipe A communicated to the branched pipe 17, to the atmospheric pressure, the change of pressure is detected by a pressure detector 21 to apply predetermined atmospheric pressure to the branched pipe 17 by a compressor 20 or the like. The resulting condition is maintained until at least the rear pig 12 has passed therethrough. Hence, the blocking of the branched pipe with the resin can be completely inhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a construction method for existing pipes such as water pipes and gas pipes, in which a coating agent is applied to the inner wall of the pipe during the process of moving the VIG. It is.

As a method for repairing this type of pipe inner surface, the method shown in FIG. 1 is known. That is, a pair of front and rear pigs 1.2 connected to each other by a connecting cable 3 is installed inside the pipe leading to the existing pipe, with coating agent B filled between the two pipes, and atmospheric pressure P1 is applied to the rear pig 2. By adding big 1,
The coating film C is applied to the inner circumferential surface of the existing pipe by extruding the coating agent from the circumferential surface of the rear pig 2 and stirring it for 1 hour.

In this case, the problem is that when the filling capacity of the coating agent B filled between the two Vigs decreases due to the movement of the Vigs 1 and 2, a void is created in the upper part of the Vig, and this causes the inner surface of the tube to This results in an uncoated area at the top. 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, if there are corrosion holes etc. on the inner surface of the existing pipe There is a possibility that the coating film C may be torn or thinned due to leakage, which may lead to a build-up that would lose the original purpose of the inner surface treatment.

Therefore, even if the filling of the coating agent decreases due to the movement of the coating agent, a void will not be formed on one side of the filling part, and the coated side will not have a gap (
) and apply pressure <><, the pressure necessary for the required extrusion is applied to the coating agent. A construction method for existing pipes has already been proposed so that a film of coating agent can be accurately formed on the entire inner surface of the pipe in just one step.

Here, the front and rear vig are connected by a connecting rope, a movable vig that can be moved between the pigs through the connecting rope is provided, a coating agent is filled between the movable vig and the rear vig, and the front vig is connected to a tow rope. And transfer by applying negative pressure to the front space! 11, the desired pressure is applied to the coating agent via the movable vibrator.

The present invention consists of 1. In the construction described below, the T1 coating agent
The purpose is to eliminate the inconvenience of branches branching from the existing pipe flowing into the pipe and clogging the branch pipe.In particular, this is because negative pressure is applied to the front big pipe during the above construction. By detecting changes in the pressure inside the pipe, the branch branches detect changes in the pressure inside the pipe, and while the resin between the big branches passes through the branch communication part of the pipe,
An object of the present invention is to provide a construction method for an existing pipe in which an air pressure higher than the filling pressure applied to the resin described in J- is applied to the pipe in the branch, and the branch can prevent the resin from entering the pipe. It is.

For this purpose, the present invention fills the space between the movable pig and the rear pig with resin, passes the said big into the required existing pipe, applies negative pressure to the front space of the front pig, and pulls it into the existing pipe. 11 + C, for those who carry out repairs within the pipe,
The branch that branches from the existing pipe to the supply destination has a small atmospheric communication part in the pipe, and when the front big branch changes from the negative pressure state to atmospheric pressure before passing through the branch communication part of the pipe, this It is characterized by detecting the pressure, applying the required pressure to the branch pipe, and maintaining that state at least until the rear VIG finishes passing.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 2 to 4. Here, the front pair of bigs 11. At the same time, the front big 11 is towed forward by a tow rope 14 or negative pressure. Also 1, J
1. A movable wire 16 is arranged between the wires 11 and 12 and has an insertion hole 15 in the center that allows the rope 13 to be inserted therethrough so as to be slidable relative to the rope 13. - A coating agent B such as a thermosetting resin such as an epoxy resin is filled between the movable vig 16 and the rear vig 12. The front h-vig 11 and the movable vig 1G have outer diameters that allow them to move airtightly against the inner surface of the existing pipe A. On the other hand, the rear vig 12 has a slightly smaller outer diameter and has a gap between the inner surface of the pipe and the inner surface of the pipe. An outflow gap G for the coating agent B is formed in the gap G.

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

At this time, by moving the big 11 and 12, the movable big 16
moves backward due to the movement resistance P3, and the movable big 16
Since the pressing force of Pl is applied to the coating agent B filled between the rear big 12 and the rear big 12, the coating agent B is pushed more than the peripheral gap G of the rear big 12.
It is sprayed out and applied to the inner surface of the existing pipe after passing through the Vig 12, forming a coating film 5-C on the inner surface of the pipe.

In this case, since the pressing force P is acting on the coating agent B through the movable vig 16 while the vig 11 and 12 are moving, the coating agent charge (Ua) decreases as the coating process progresses. Also, no voids are formed above the filled part (A), and a coating film C having a uniform thickness can be formed over the entire inner surface of the tube. Furthermore, since no positive pressure is applied inside the existing pipe after the Vig 12 has passed, even if there is a corrosion hole on the inner surface of the existing pipe A, the coating film C will be
Since the corrosion pores are closed and the coating is cured in the state I, the coating film C will not be torn or thinned.

This J: Uni (), big 11.12.1 in the existing pipe A
On the other hand, branches such as the supply pipe branched from the above @membrane pipe A are pipes (the above supply pipe is branched into many branches and connected to the gas meter of each consumer). ) 17, the following actions are taken.

That is, the branch tube 17 is provided with an atmosphere communication section 18 having a restriction on the side, and is connected to a compressor 20 via the pulp 19. A pressure detector 21 is provided. The pressure sensor 21 does not issue a signal to open the valve 19 at the stage when f'lrF is indicated, and the pressure sensor 21 does not issue a signal to open the valve 19 at the stage when the specified negative pressure indicates the atmospheric pressure. A signal is issued, and a signal is connected to the output A1 calipulator 22, which closes the valve 19 when the pressure decreases to a predetermined atmospheric pressure. After receiving this valve occlusion No. 4g, the timer 23 operates and after a certain time delay, the 1-marker 22 is activated to change the timing for closing the valve 19. Like, I'm at 1no.

Therefore, the above-mentioned branch (the branch communication part of the J pipe 17 is connected to the big 11
In the situation where the branch is connected to the existing pipe in front of the pipe (see Figure 2), negative pressure is applied to the pipe 17, and the increase in air from the popular communication part 18 is extremely small, so the necessary 0 pressure is applied. Therefore, since the H-force detector 21 is detecting negative pressure, the valve 19 is in a closed state.

Next, when the VIG 11 passes through the branch communication section, the zero pressure applied to the front of the VIG 11 does not reach the pipe 17, so the residual negative pressure is removed with the atmosphere from the atmosphere communication section 18, and the branch Then, the valve 19 is opened by the action of the regulator 22, and the positive pressure P4 is supplied from the compressor 20. This positive pressure P+ is preferably slightly larger than or equal to the pressure P3 applied to the resin. Therefore, when the movable pig 16 and the rear pig 12 pass through the branch communication portion (see FIG. 3), the resin B does not enter the pipe 17 of the branch.

Then, when the rear big 12 finishes passing through the branch communication section (see Fig. 4), the pressure in the branch pipe 17 is reduced to atmospheric pressure because air is released into the V1 stage pipe A. significantly reduced to The pressure detector 21 detects this and sends a signal to the regulator 22. At this time, timer 23 works,
The operation instruction from the regulator 22 is delayed and the valve 1
9 and until the valve 19 is closed, air flow is blown out from the branch pipe 17 into the existing pipe A, completely keeping the branch communication part in communication with the existing pipe. It is possible to accelerate the curing of the coating agent around it and ensure a reliable communication state.

Note that J=Kt! In Example τ, the construction method of the present invention is applied when coating the inner surface of a pipe. It goes without saying that this method can also be used when adding a resin filling bar using a vig for filling agents, etc.

As described in detail above, the present invention tows the pig while applying negative pressure to the space in front of the pig, and performs this movement! When applying filling pressure to the resin filled between the previous pigs with FII overculm to repair the inner surface of the pipe or repair the pipe top, the branches branched from the existing pipe will be filled with resin to the pipe. Intrusion is prevented, and the branches can completely prevent the tube from being blocked with resin.

[Brief explanation of drawings]

Figure 1 shows an example of conventional pipe coating construction for an existing pipe, and Figures 2 to 4 show an example in which the construction method of the present invention is applied to pipe interior coating. It is shown in order of I: It is a longitudinal side view. 11...front pig, 12...rear big, 13...
Connecting cable, 159-... Insertion hole, 16... Movable pig, 17... Branch is pipe, 18... Atmospheric communication part, 19... Valve, 20...
...Compressor, 21...Pressure detector, 22...
Regulator, 23...Timer, △...Existing pipe,
B...Coating agent, C...Coating film. Patent applicant Hakko Co., Ltd. Agent Patent attorney Makoto Kobashi Ukiyo Patent attorney Susumu Murakata 10-

Claims (1)

[Claims] Fill the space between the front and rear Vigs with resin, and attach the above Vigs to the required number of parts.
! ! Pass it through the installed pipe, apply negative pressure to the space in front of the front big, and then be towed by a bar and move inside the existing pipe listed in J-. The branch is provided with a small [ ] diameter popular communication part in the pipe, and when the front branch passes through the branch communication part of the pipe and changes from the negative pressure state to the atmosphere It, A construction method for an existing pipe, characterized by detecting the required pressure, applying the required pressure to the branch pipe, and maintaining that state at least until the end of the passage of the rear big.