JPS58193778A - Repairing method of inside surface of installed pipe - Google Patents

Abstract

PURPOSE:To execute the repair of coating to only a specified part, by adding a pressure difference to a feed pipe to which coating is not performed, when coating and repairing the inside surface of a specified part of an existing pipe such as a gas pipe, etc. compriping of a branch pipe from which a lot of underground feed pipes are made to branch. CONSTITUTION:The inside surface of a specified part of an existing pipe A such as a gas pipe, etc. comprising a branch pipe 30 having a lot of feed pipes 31 is repaired by coating it with a thermosetting resin, etc. First of all, the inside surface of the existing pipe A is cleaned by a gas containing a polishing material. The pipe is heated also by high temperature air and dried. Subsequently, a vacuum pump 23 is connected to the end of a necessary feed pipe 31 through collecting vessels 20a, 20b of the polishing material and a coating material, a coating material feeding head 8 is connected to an opening part on the ground provided on a suitable part of the branch pipe 30, and the inside surface of the branch pipe 30 and the feed pipe 31 is coated with a coating material. In this case, it is prevented that the coating material is accumulated in the connecting part with the branch pipe, by applying a small positive pressure or negative pressure to the feed pipe 31 which requires no coating.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for repairing the inner surface of existing gas pipes, water pipes, etc., when the inner surface of the pipe is coated with a resin.

Conventionally, various methods have been proposed to repair underground pipes or indoor pipes such as gas pipes and water pipes from the inside, but one method is to coat them with thermosetting resin such as epoxy resin. There is a method in which the agent is placed on a carrier gas and transported into the target existing pipe, where it adheres to the inner W surface and solidifies.

In this case, the problem is that a large number of underground supply pipes are branched from branch pipes within one group of the existing pipe system. Therefore, even if the coating agent is diffused into the carrier gas and sent from the opening at one end of the branch pipe into the above installation (a), it will be ensured that the entire branch pipe or supply pipe will be covered.
-Ting processing may not be possible. This is likely to occur at vents, junctions, and narrow supply pipes where flow resistance is high, and at branch pipes and supply pipes (where the coating agent accumulates and blocks the communication path, etc.). There is a same order.

The present invention has been proposed based on the above-mentioned circumstances. 1. In the above-mentioned coating method, the method 111 is to apply an appropriate gas pressure to the uncoated supply pipe and apply it to the branch section. Prevent the agent from accumulating and blocking communication between the supply pipe and the branch pipe [
The purpose is to provide a method for repairing the inner surface of the installation.

Hereinafter, the present invention will be explained based on an illustrated embodiment that incorporates the [h method].

First of all, FIG. 1 is a schematic diagram of the entire configuration, and in the figure, reference numeral 1
is a compressor, and its compressed air outlet side is connected to header 2.
is communicated with. The header 2 is connected to an air heater 4 via a governor 3, and the J air heater 4 uses steam supplied from the boiler 5 via the pressure reducing valve 6 and compressed air from the header 2. For example, 0; 3k
This generates a carrier gas with a low positive pressure of about g,/cs2. The carrier gas is brought to the resin coating head 8 via the airflow generator 1 in a desired airflow form, for example a vortex. On the other hand, the air heater 4 has a bypass path 9
Heated air is flowed to the coating head 8 through the bypass passage 9, and a thermosetting resin such as an epoxy resin is supplied as a coating agent from a resin injection means, for example a tank 10. The coating agent can be supplied from the tank 10 to the bypass path 9 by dropping the liquid into heated air or by spraying it. In this embodiment, the pressure of compressed air supplied from the header 2 via the pressure regulator 11 causes the valve 1 to open inside the tank 1o.
A method of injecting through 0a is adopted. Further, the coating agent is heated in the tank 10 by an electric heater 12 to lower the viscosity to an appropriate level.

In FIG. 1, reference numeral 13 is a safety valve provided downstream of the governor 3, 14 is a flow meter, 15 is a pressure gauge, and 16 is 1*1.

Further, in this embodiment, an abrasive charger 11 is connected to the downstream side of the airflow generator 7 via a valve 18, and compressed air is also supplied to the charger 17 from the header 2. When the valve 18 is opened, the abrasive can be supplied downstream of the airflow generator 1 with the compressed air.

The coating head 8 is the F! to be repaired. i
Installation! As shown in the embodiment shown in FIG. 2, the existing pipe A is a branch pipe 30 buried underground with a large number of supply pipes 31 branched from it. The end of the line 31 is exposed above the ground and is connected to a gas meter or the like in each household.

In the present invention, for such an existing pipe A, as is clear from FIG. 1, an above-ground opening is provided at an appropriate location of the branch pipe 30, and the coating head 8 is connected to this through a conduit to carry the coating agent. On the other hand, among the plurality of supply pipes 31 branched from the branch pipe 30, valves 21a and 21b are installed at the above-ground connection part (the connection point with the gas meter) at the end of some of the supply pipes 31. A coating agent recovery device 20a and a recovery device 20b for abrasive etc. are connected through a special pipe 19 having a
A vacuum pump 23 is connected downstream of Oa and 20b via a conduit 22. Furthermore, for supply pipes 31 on the coating route in the branch pipe 30 that are not coated, an appropriate positive pressure is applied from the header 3 of the compressor 1 to the above ground connection. Incidentally, the vacuum pump 23 performs a suction action on the existing pipe A at a low negative pressure of, for example, about 0.3 kg/cm2.

Next, repair of the inner surface of the existing pipe A will be explained step by step.

First, in the process of driving the compressor 1 and vacuum pump 23 and supplying the heated compatible gas (pressurized air) to the head 8 via air heating @ 4, the valve 18 is opened and the pressure regulator 11 is The abrasive is injected into the carrier gas from the injector 17 with the air pressure regulated through the abrasive. The injected abrasive was given to the carrier gas by the airflow generator 1.
For example, when passing through the existing pipe A on a vortex, the existing pipe A
The sludge, rust, etc. inside is scraped off, and this is placed on a compatible gas and guided to the conduit 19. The valve 21b is open, and the dust is collected together with the abrasive in the collector 20b.

When the inner surface treatment in the existing pipe A is completed, the valve 18 is closed, the supply of abrasive to the carrier gas from the injector 11 is cut off, and only the carrier gas is allowed to pass into the existing pipe A. Since the carrier gas is heated by air heating @ 4, the inner wall of the existing pipe A is humidified and moisture is removed by evaporation to make it dry.

Next, valve 10a is opened, valve 21b is closed, and valve 21a is opened. As a result, the coating agent is injected into the air flow passing through the bypass path 9 at the air pressure regulated via the pressure regulator 11, and is made into a mist, for example. The airflow that dispersed the coating agent in this way is
The coating agent is introduced into the existing pipe A on a carrier gas, and the coating agent collides with and adheres to the inner wall of the pipe due to the vortex flow, forming a resin coating B with a required thickness.

In this case, in the present invention, since the construction mode shown in FIG. 2 is used as described above, the compressor 1. When the vacuum pump 23 or the like is driven, the carrier gas carrying the coating agent flows from the branch pipe 30 to the supply pipe 31 on which the suction force is applied due to the suction action of the vacuum pump 23. Perform a 21-lining process on Ru [・.

During this time, positive pressure is applied to the other supply pipes 31, and the branch pipe 3
#1#i''!j prevents the coating agent from entering the branching part with #1#i''!j.

In the above example, low positive pressure is applied to the supported gas and it is supplied into the existing pipe, and low negative pressure is applied to suck it into the required route, but high positive pressure and high negative pressure When repairing the inner surface of existing pipes, it is also possible to preheat with a compatible gas. Alternatively, a system may be used in which only positive pressure or negative pressure is applied to the supported gas.

As described in detail above, the present invention involves transporting a coating agent into an existing pipe in a state in which it is diffused in a flow of compatible gas, adhering and solidifying the coating agent to the inner wall surface of the existing pipe, and repairing the inner surface.
Applying positive or negative pressure from the above-ground connection to the uncoated supply pipe that is branched off from the coated branch pipe to create a pressure difference between it and the carrier gas passing through the branch pipe. As this construction method is characterized by:

(1) Even in existing pipes that branch into a wide variety of complex areas, the direction of gas flow within the existing pipes is regulated in a constant manner.
The coating process inside the existing pipe can be reliably performed along the desired route of the existing pipe.

(2) Furthermore, since the above-ground connection at the end of the supply pipe is used as an opening and this opening is also used as the outlet for the carrier gas, there is less digging up of the existing pipe, and construction can be performed easily and efficiently.

(3) When coating inside existing pipes, use positive or negative pressure applied to the supply pipe to prevent the coating agent from leaking into the connection branch with the branch pipe and blocking the flow to the supply pipe; Because it does not cause coating agent deposition,
Prevents clogging of the supply pipe from occurring during coding processing.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an example of the method of the present invention, and FIG. 2 is a configuration diagram showing a construction IIS. 1... Compressuri, 4... Air heating machine, 7...
Airflow generator, 8...'' - Ting head, 10...
Tank, 23...vacuum pump.

Claims (1)

[Claims] The coating agent is transported into the existing pipe in a state in which it is diffused in the flow of the carrier gas, and the coating agent is transported into the existing pipe, and the I! Inside! ! Adheres to surfaces. When solidifying and repairing the inner surface, the existing underground pipe system targets a branch pipe buried underground and multiple supply pipes branching from this branch pipe, which is branched at the branch pipe where the coating is being applied. A method for inward repair of existing pipes, characterized in that positive or negative pressure is applied from an above-ground connection to an uncoated supply pipe to create a pressure difference between the supply pipe and the supported gas passing through the branch pipe. .