JPH01293168A - Method for repairing lining of inner surface of pipe - Google Patents

Abstract

PURPOSE:To uniformly repair a lining by using a high-viscosity resin to repair the inner surface of a pipeline, connecting an existing pipeline, purging the pipeline, making an ignition test, and restoring the pipeline. CONSTITUTION:A launcher 1 is connected to an existing pipeline A through an end connection body 2 provided with a clamp. Compressed air is passed through the existing pipeline A and supply pipe D to remove dust, etc., in the pipes. A resin injector 3 is connected to the launcher 1 through a solenoid valve 4, and a requisite amt. of a lining resin E is introduced into the launcher 1. An ordinary-temp. two-pack curing resin consisting of the main agent and a curing agent is used as the lining resin E. A solenoid valve 5 is provided to the launcher 1, and a low-pressure gas feeder 7 controlled by a control unit 6 is connected. The solenoid valve 4 is closed by the control unit 6, the solenoid valve 5 is opened, hence the resin body is fluidized, and the inner surface of the pipeline A is lined.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a lining repair method for the inner surface of an existing gas pipe installed underground, in which a uniform resin lining is applied to the inner surface of the pipe while the pipe is still installed.

[Conventional technology]

In general, existing gas piping installed underground can develop corroded holes or loosen joints over time, leading to leakage. At the required time, the existing pipes will be installed inside the pipes as they are installed. The surface has been repaired with resin lining. Therefore, as published in Japanese Patent Application Laid-open No. 63-65983,
The inside of the pipe at one end of the existing pipe is filled with a liquid resin group so as to fill and block the inside of the pipe, and the resin group is made to flow with a predetermined low-pressure gas to line the inner surface of the pipe with the required film thickness. A surface lining repair method was proposed. here,
A launcher is connected to one end of the opened existing piping, and a resin for lining is filled from a resin tank connected to the launcher to form a resin mass inside the launcher, which is then supplied with low-pressure gas from the free end of the launcher. (for example, low-pressure air) is supplied into the existing piping. Then, the resin group flows within the IPt installation pipe under the pressure of the low-pressure gas, lining the inner surface of the pipe. If the resin is consumed during the lining, the launcher is again filled with resin from the resin tank, a resin mass is formed in the launcher, and the resin mass is sent into the existing piping using low-pressure gas. By repeating this process, the inner surface of the existing pipe is repaired for a predetermined length.

[Problem to be solved by the invention]

The problem here is that since most of the existing piping to be repaired is still in use, there are severe restrictions on construction time. Normally, this type of repair work is subject to a time constraint of approximately eight hours from the time the gas supply is stopped until restoration is complete. However, during this period, preliminary preparations such as road surface excavation at both ends of the repair section, cutting of exposed parts of existing piping, removal of supply pipe meters, and gas purge are essential. Since post-processing such as an ignition test is required, the work time for repairing the inner surface is only about two hours. A particular problem that arises during restoration is that if the lining resin is uncured, when gas is passed through, the pressure will cause the resin to flow from the loosened gap in the threaded joint or from the corrosion hole, causing the lining membrane to rupture. be. Therefore, when the resin curing time is taken into consideration, the pot life is further shortened. Furthermore, depending on the situation, the entire construction time may have to be extended, causing inconvenience to users. The present invention has been made based on the above circumstances, and the composition of the resin used for the lining is taken into consideration so that it does not flow even in an uncured state under the pressure of the gas used in the existing piping. The present invention aims to provide a method for repairing the lining of the inner surface of a pipe, which eliminates the need to wait for the resin to harden, and substantially extends the usable life.

[Means to solve the problem]

Therefore, in the present invention, a liquid resin group is filled into the pipe of the existing pipe so as to fill and block the inside of the pipe, and the resin group is made to flow with a predetermined low-pressure gas to form a film with a required film thickness on the inner surface of the pipe. In the lining repair method for the inner surface of the pipe,
The resin used in the resin group has a high viscosity composition with a thixotropy value that does not flow under the gas pressure used in the pipe, and after repairing the inner surface of the pipe, the existing pipe is immediately connected, A purge 1 ignition test will be performed to restore the system.

[Effect 1] Therefore, by considering the composition of the resin used for lining so that it does not cause fluidity even in an uncured state under the gas pressure used in the existing repaired piping, the time required for resin curing can be reduced. It is possible to eliminate waiting time and extend pot life. [Example] Hereinafter, an example of the present invention will be specifically described with reference to the drawings. In the figure, reference numeral A indicates the existing piping to be repaired. This existing pipe A generally has a diameter of 50 to 801I! This applies to gas branch pipes with a diameter of about 100 yen, or gas main pipes with a larger diameter. During repair, this existing piping A is divided into repair sections of a predetermined length and both ends are opened. Tatewaza B and C are excavated at the locations corresponding to both ends of this lick. and,
A launcher 1 is connected to the existing pipe A, which has been opened by cutting or other means, via a connection port 2 with a clamp. Furthermore, regarding the service pipe connected to the existing pipe A, the meters 'are removed and the above-ground end is opened. Then, pressurized air is passed through the existing pipe A and the service pipe to remove dust and the like inside. Further, a resin injector 3, which is a resin supply means, is connected to the launcher 1 via an electromagnetic on-off valve 4, and a liquid is supplied from the resin injector 3 over a predetermined length so as to fill and block the inside of the existing piping A. A required amount of lining resin E is introduced into the launcher 1. The above-mentioned lining resin E is a two-residue curing resin at room temperature, which is a mixture of a base resin and a curing agent, of which the base resin is a composition mainly composed of unsaturated polyester resin, vinyl ester resin, epoxy resin, urethane resin, etc. By adding pigments, thixotropic agents, etc.,
The thixotropy value (T I
) -6 and other compositions with high viscosity and high tingetropy. For example, a blending example of a composition in which the lining resin E is mainly composed of an epoxy resin is as follows. (Composition) (Parts by weight) (% by weight) Epoxy resin 100 76.9 Scale-like filler
15 11.5 Pigment
53.8 Thixotropic agent 43.1 Other additives 64.6 The above-mentioned scale-like filler may be made of, for example, aluminum, silver, clay, mica, molybdenum disulfide, talc, glass, graphite, etc. as raw materials. For example, it has a thickness of 1 to 5 μm and a diameter of 0.5111 mm.
~3nn, and the generally used single grain of fine powder is just used as an extender, and has very little clogging effect on pressure, but it is possible to add one formed into a circumferential piece. As a result, they become tangled with the resin, forming scale-like or overlapping arrangements in the gaps of threaded joints or corrosion holes, and appear to be beneficial. Further, the thixotropic agent used here is added to ensure the above-mentioned thixotropy. Note that the resin injector 3 may be supplied with a resin in which a base resin and a curing agent are mixed in advance using an air pressurized injector. In the process, both may be mixed and supplied using a static mixer. Further, the launcher 1 is equipped with an electromagnetic on-off valve 5, and is connected to a low-pressure gas supply device 7 controlled by a control unit 6. The above low pressure gas supply device 7
is compressor 8. Air tank 9. Flow rate adjustment valve 10.
11. It is equipped with a flow meter 12.13 and a pressure gauge 14.15, and in particular, in this embodiment, the resin injector 3
A three-way switching valve 16 is provided on the outlet side of the compressor 8 to supply pressurized air to the resin inlet 33 through a conduit 17. A flow rate regulating valve 18 is provided in the pipe line 17,
It is controlled by the control unit 6 mentioned above. The control unit 6 includes the flowmeter 12 and 13.
and pressure gauge 14. +5 and the control program to adjust the opening degrees of the flow rate regulating valves 10 and 11, and also to control the opening and closing of the electromagnetic on-off valves 4 and 5. Therefore, when the control unit 6 closes the electromagnetic on-off valve 4 and opens the electromagnetic on-off valve 5 to direct the low-pressure gas to the existing piping A via the launcher 1, the pressing force of this low-pressure gas causes The resin mass flows and is sent while lining the inner surface of the existing pipe A with the required thickness. In this case, the calculation basis in the control unit 6 depends on the following formula. First, 1Q of the low pressure gas flowing into the existing pipe A (diameter D)
1. If the pressure P1 (for example, 0.6 days/an''), π/4 ・D2- Jll-P1=Q1- Po-(
Since the relationship is 1), if Ql, Po, and Pl are measured at time T1 when the resin group starts to be fed by low-pressure gas,
21 can be found from equation (1). Furthermore, here,
iQh of the gas flowing into the existing pipe A is the flowmeter 12.
It is obtained by the difference between the 13 measured values F1 and F2. In this case, if the mass flow rate 31 is used for the flowmeter 12.13,
It is easy to calculate because it is not affected by the temperature of the gas. In addition, here 11 is the position of the resin and resin group at time T1, Po, Pl
is the measured value of the pressure gauge 14.45, and D is the inner diameter of the lining of the existing pipe A. Similarly, pressure P2 and inflow amount Q at time T2
If the position of the resin group obtained by measuring and calculating 2 is 12, then the flow velocity V of the resin group is ∆=Δ1/Δt. However, ΔJl=J1.2-1.1 Δt=T2-T1. Therefore, the predetermined time interval Δt is set by the taro clock of the oscillator in the control unit 6, and each time the flow meter 1
2. Amount of gas flowing into the pipe from 13 and pressure gauge 14.
Each pressure is measured from 15, and the :a amount adjustment valves 10 and 11 are controlled so that each instantaneous resin flow rate (2) is maintained at a constant predetermined value. In the existing pipe A, the length of the resin aggregate decreases as it is consumed by lining the inner surface of the pipe, but since the flow rate remains constant, the pressure of the pressurized gas decreases approximately linearly (Fig. 3). reference). If the resin in the resin aggregate is consumed before the resin lining of the inner surface of the existing pipe A is completed over the entire length of the pipe, the resin aggregate length will gradually become shorter, and at the same time the pressure gas to maintain the resin flow rate constant will be reduced. The pressure also decreases approximately linearly, and when the resin aggregate reaches 0, the pressure of the pressurized gas naturally becomes atmospheric pressure. The amount of gas inflow Q up to this point, the length up to the position where the resin lining is finished 1. The elapsed times t, o, etc. are stored in the memory, and the electromagnetic on-off valve 5 is closed. - On the other hand, the control unit t-e detects that the pressing pressure has decreased to atmospheric pressure, opens the electromagnetic on-off valves 4, 4, and supplies and fills the launcher with lining resin from the resin injector 3 to a predetermined amount. The formation of a resin group is examined. Then, the electromagnetic on-off valves 4 and 5 are closed, and the electromagnetic on-off valve 5 is closed.
is released, and the existing pipe A is lined again while controlling the speed of the resin group ■ as before. At this time, while the lining resin group moves at a predetermined speed in the previously lined pipe, the film thickness of the lining inside the pipe remains unchanged, so the length of the resin group does not decrease, and the pressure of the pressing gas increases. is also held at a substantially constant value. After the resin mass reaches the unlined position at the end of the pipe A, the resin is consumed by the lining, the length of the resin mass decreases, and the pressure of the pressurized gas gradually decreases. The progress of lining is the same as described above. In this case, the resin aggregate head becomes approximately 0 and the pressure of the pressurized gas becomes atmospheric pressure again, but the elapsed time up to this point becomes approximately 2to, and the length to the end position of the lining also becomes approximately 21. In this way, the lining length is successively extended by repeating resin filling and compression lining. When the lining of the existing pipe A is completed and the resin block reaches the receiver 19 connected to the connection with the main pipe or the opposite end of the existing pipe A with the length of the resin block still remaining, the resin block is removed from the existing pipe A. As it flows out, the flow resistance of the resin group in the pipe A rapidly decreases, so that the pressing force controlled by the control unit 6 also rapidly decreases to atmospheric pressure. The elapsed time until the pressing force decreases to atmospheric pressure was also scheduled (nXt,
) is shorter than (n-1)tmo7' (where 7'< shi) (see Figure 3). That is, based on the sudden decrease in the pressing force and the difference between the elapsed time and the predicted elapsed time, it is determined that the resin mass has reached the outside of the existing pipe A, and the lining repair for the corresponding A-installed pipe A is completed. In this way, it can be determined that the repair lining of pipe A has been completed, but if the resin is injected and the lining is performed once again using pressurized gas, the time required to reach the branch pipe will be the same as before, <n-1 )t+t'. In this way, since the repair lining time has become the same each time, it is also possible to determine whether the resin aggregate has reached the end of the existing arrangement 'f, 1 m. In the figure, reference numeral 20 is a receiver tank that receives the remaining resin discharged into the receiver 19 at the end of resin lining. In addition, in the service pipe that branches off from the existing pipe A above, it should be lined with resin in advance, and then appropriate measures to prevent resin intrusion should be taken in preparation for lining the existing pipe A. good. Furthermore, it goes without saying that the pipe inner lining repair method of the present invention can also be applied to the above-mentioned service pipes. Once the lining repair is completed in this way, immediately install a meter to the service gD in the repaired section, connect the pipes at the open end of the existing pipe A, purge, conduct an ignition test, etc., and backfill the excavated part. , restore it. Even at this point of restoration, the lining resin remains uncured, but even if gas is supplied here, the gas pressure is very low, generally around 0.025 kg/cn'. By doing so, the resin with high viscosity and high thixotropic value does not flow, so there is no fear that the lining will break. Effects of the Invention 1 The present invention has been described in detail above, and by considering the composition of the resin used for the lining, the pressure of the gas used in the existing piping causes flow even in an uncured state. This eliminates the need to wait for the resin to harden, making it possible to substantially extend the pot life. Also,
It can also be effective in shortening the overall construction time.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing an aspect of a repair method according to an embodiment of the present invention, Fig. 2 is a configuration diagram regarding the supply and control of low-pressure gas, and Fig. 3 is a time chart showing the repetition status of resin lining. It is. DESCRIPTION OF SYMBOLS 1... Launcher, 2... Connection port body, 3... Resin injector, 4.5... Solenoid on-off valve, 6... Control unit, 7... Low pressure gas supply device. Patent Applicant: Hakko Co., Ltd. Agent Patent Attorney: Nobuko Ko Takayuki Patent Attorney: Susumu Murai Figure 2

Claims (1)

[Claims] The inside of the existing pipe is filled with a liquid resin mass so as to fill and block the inside of the pipe, and the resin mass is made to flow with a predetermined low-pressure gas to line the inner surface of the pipe with a desired film thickness. In the lining repair method, the resin used for the resin group has a high viscosity composition with a thixotropic value that does not flow under the gas pressure used in the pipeline,
After repairing the inner surface of the pipe, immediately connect the existing pipe, purge,
A pipe lining repair method characterized by conducting an ignition test and restoring the lining.