JPH01189374A - Method for lining and repairing inside surface of pipe - Google Patents

Abstract

PURPOSE:To continuously execute an operation for pressing and moving a resin by a low-pressure gas without requiring the time for resin refilling by supplying the resin to be additionally packed into a pipe by a resin injecting means introduced into an existing piping from the lining end side of the piping. CONSTITUTION:The resin A is packed in the state of liquid into the pipe on one end side of the existing piping 1 so as to fill and close the inside of the pipeline over a required length from the aperture thereof. The packed resin is allowed to flow to form the film to a required thickness on the inside surface of the pipe from relative conditions such as pipe diameter, resin viscosity and length of the packed resin. The low-pressure gas for pushing and moving the packed resin A is supplied to the lining start side of the existing piping 1. Further, at least the resin A' to be additionally packed is supplied into the pipe by the resin injecting means 18 introduced into the existing piping from the lining end side thereof. As a result, the operation for pressing and moving the resin by the low pressure gas can be continuously executed without requiring the time for refilling of the resin and the workability is improved.

Description

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

The present invention applies a uniform resin lining to the inner surface of existing pipes such as gas pipes and water pipes installed underground, especially existing pipes called branch pipes or supply pipes. This article relates to a method for repairing the lining of the inner surface of a pipe.

[Conventional technology]

In general, with existing pipes such as gas pipes and water pipes installed underground, there is a risk of leaks due to corrosion holes and loosening of joints over time, so leak prevention and maintenance are necessary. Therefore, after construction, at a required time, the existing pipes are repaired by lining the inner surface of the pipes with resin while they are still installed. Conventionally known repair methods include the ``Vig transfer method'' and the ``vapor phase method.'' However, with the above-mentioned "VIG moving method", there is a risk that the VIG may get caught in the pipe's diameter changing section or bent pipe section, rendering it impossible to circulate or repair, and is limited to cases where the conditions are favorable. On the other hand, in the conventional "gas phase method", low viscosity (for example, 15.0
Due to the constraint that the resin must be used (less than 00 cps), the thickness of the coating film is mostly thin, less than 0.5n+m, and the lining coating film is thinner on the upper side of the pipe inner wall and thicker on the lower side. In particular, in curved pipes, it is difficult to avoid the phenomenon of thinning on the outer circumferential curved surface side of the pipe where r/X corrosion is likely to occur. For this reason, when attempting to implement the above-mentioned "vapor phase method" using a resin with as high a viscosity as possible during construction, a large amount of air is required, and a high-speed air flow of 2 kQ/cm2 or more is required. becomes. This not only results in an increase in the size of the equipment, but also poses a problem of noise in the working environment, making it unsuitable for residential areas. In addition, when using an air pressure of 2 ko/cn2 or more,
If there is already a pinhole-like corrosion hole in the pipe, air can be blown through the hole, enlarging the corrosion hole and even damaging the pipe. (Problems to be Solved by the Invention) Therefore, the present inventors have already filled a pipe at one end of the existing pipe with a liquid resin group so as to fill and block the inside of the pipe. We proposed a lining repair method for the inner surface of a tube, in which the inner surface of the tube is lined with the required film thickness by flowing a predetermined low-pressure gas.Here, the related conditions such as the tube diameter, resin viscosity, and length of the filled resin group inside the tube are considered. From this, the resin speed can be controlled appropriately and the resin film thickness on the inner surface of the tube can be set.
Linings of considerable thickness are possible. However, there is a limit to the length of the coating film formed by one can filled with the above-mentioned resin group, so in the case of existing piping with a long section to be repaired, the filled resin group decreases and Once the low-pressure gas for pressing has blown through in the forward direction, additional resin is filled from the lining start side, and the same low-pressure gas is carried to the lining end point of the existing piping, and lining is continued from there. There is. For this reason, it takes a considerable amount of time to bring the additional resin to the lining end point. Furthermore, in order to add resin, it is necessary to hold the previous resin group until the low-pressure gas blows through in the direction of travel, so when blowing through, the low-pressure gas in the existing piping is wasted, which is uneconomical. It is. The present invention has been made based on the above circumstances, and at least the additional resin is supplied into the existing piping by a resin injection means introduced from the end of the lining end of the existing piping, thereby replenishing the resin. It does not take time to
The object of the present invention is to provide a method for repairing the lining of the inner surface of a pipe, which improves workability by continuously performing a pressing and moving operation of the resin using low-pressure gas.

[Means to solve the problem]

゛For this reason, in the present invention, in the pipe at one end of the existing pipe,
The resin is filled in liquid form so as to fill and close the inside of the pipe for the required length from the opening, and by making the filled resin flow, the inner surface of the pipe is In order to form the required film thickness, low-pressure gas is supplied to push and move the filled resin to the lining start side of the existing pipe, and at least additional filling resin is introduced from the lining end side of the existing pipe. The resin is supplied into the pipe by means of resin injection means.

[Effect 1] Therefore, even if the resin mass moving in the existing piping is consumed and reduced for lining, it can be moved by adding additional resin, so -a allows lining work to be carried out in all target sections. can be realized efficiently and economically. [Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, FIG. 1 schematically shows an embodiment of the repair method according to the present invention, and reference numeral 1 indicates an existing pipe to be repaired. This existing piping 1 is an existing piping such as a gas pipe or water pipe installed underground or inside a building, and in particular, the existing piping 1 to be repaired by the present invention is
Regarding gas pipes, generally the diameter is 15-4011II.
Supply pipe of about l, branch pipe of about 50 to 100 mm in diameter,
This applies to existing piping called main pipes with a length of 1001 mm or more. This existing piping 1 is divided into repair sections of a predetermined length when repaired, and a launch 17-2 having a predetermined length is connected to an opening at one end via a flange 3. A resin injector 4 is connected to the launcher 2 via an electromagnetic closing valve 5 which is a resin supply means.
Liquid lining resin A is launched so as to fill and block the inside of the pipe to a predetermined degree. -2. Here, the lining resin A is a two-component curing resin at room temperature, which is a mixture of a main resin and a curing agent, and is a resin having thixotropic properties. In addition, for the resin injection 54, the resin mixed with the base resin and the curing agent in advance may be pumped and supplied using an air pressurized injector, or the resin injection process may be performed while the base resin and the curing agent are pumped using separate pumps (not shown). Both may be mixed and supplied using a static mixer. The launcher 2 also has a power supply 1if1 of the resin injector 4.
An electric current that operates in the opposite direction in conjunction with the on-off valve 5! & An on-off valve 1 is installed, and behind it there are flow regulating valves 11 and 16 which are computationally controlled by a computing device 6', a flow meter 9゜17 for measuring their gas flow, and a pressure gauge for measuring the gas supply pressure. A small compressor 12 is connected via a control device 6 consisting of 8.10, etc., and this compressor 12
The flow rate of the pressurized air from the launch 1 is controlled by the control device 6.
7-2, and is fed into the existing piping 1. Further, the compressed air from the compressor 12 is introduced into the launcher 2 via a three-way switching valve 13 controlled by a control device a6, and is also introduced into the resin injector 4 via a flow rate regulating valve 14. The lining resin A is introduced, and the lining resin A is controlled via the pressurized sliding plate 15 provided in the resin injector 4.
The electromagnetic on-off valve 5, which is opened in conjunction with the electromagnetic on-off valve 7 controlled by the I device 6, is opened in a liquid state at a constant pressure. -2 is extruded and filled to a specified extent. On the other hand, a resin injector 4' and a pressurizing sliding plate 15' similar to those described above are prepared on the other end opening side (the end side of the lining work) of the existing pipe 1, which is equipped with an electromagnetic shut-off valve. 5
A resin injection hose 18 is connected via '. Also,
Pressurized air is supplied from the combiner 912 to the resin injector 4' via a flow control valve 14' (although a separate compressor may be provided). In addition, the above-mentioned flow rate adjustment valve 14' and ? Control of the magnetic on-off valve Ii 5' is performed by a control signal from the control device i16, based on the calculation result of the calculation device 6'. Next, to explain the work process of repair work using the above-mentioned device, first, the electromagnetic on-off valve 7 is closed and the on-off valve 111 is opened in the launcher 2 connected to the starting end side opening of the existing piping 1. A predetermined amount of the lining resin 11FrA is injected from the resin injector 4 in a liquid state. The resin A is injected so that the lining resin A is filled rAM from inside the launcher 2 into the pipe line on the starting end side of the existing pipe 1 over a predetermined length. Next, when the filling of the resin described in 1 is completed, the electromagnetic on-off valve 5 is closed, and the electromagnetic on-off valve 7 on the side of the ventilation system is opened to transfer compressed air from the compressor 12 to the flow rate adjustment valve 11 by switching the three-way switching valve 13. and the launcher through the flow meter 9.
It is controlled so that it is fed into the tube from the end of No. 2. As a result, the pressurized air acts to suppress the rear end surface of the filled resin A from the rear, and the pressing force of the static pressure imparts fluidity to the lining resin A.
The particles flow in a columnar state from inside the launcher 2 through the existing piping 1 in the form of a lump. The pressing force applied to the resin at this time is such that the initial pressing force that gives fluidity to resin A is approximately 1.5 cm/cm2 relative to atmospheric pressure, and the pressure that gives fluidity to the resin is approximately 1.5 cm/cm2. When flowing through the existing piping 1, the pressure is reduced by the flow adjustment valve 16, and the pressure is lowered to approximately 0.6 kg 7 cm2 or less relative to atmospheric pressure. Due to the progress of the flow of resin A, the adhesion force to the wall surface when flowing while contacting the inner surface of the pipe causes the resin A to
The IA progresses while remaining on the inner surface of the tube, and after passing through the resin group, the remaining resin uniformly forms a lining coating film a of a required thickness on the inner surface of the tube. First, when the traveling speed V to the resin is constant and the resin viscosity is changed, the lower the resin viscosity, the more the end face shape of the resin will be bullet-shaped as shown in Figure 2, and the film thickness will be thicker. Moreover, the higher the viscosity, the more vertical the end face shape as shown in FIG. 3 and the thinner the film thickness. Further, when the resin viscosity is kept constant, when the compression force P is increased to increase the traveling speed of the resin A, the end face shape of the resin becomes a bullet shape as shown in FIG. 2, and the film thickness becomes thicker. Also,
When the compressive pressing force a is lowered and the running speed is lowered, the end face shape of the resin becomes a vertical end face shape as shown in FIG. 3, and the film thickness becomes thinner. In other words, in the relationship between resin viscosity and running speed (■), resin A should be
If the 3rd layer is flown, the film will be thicker.
Adjust the resin A so that it has a nearly vertical end face shape as shown in the figure.
It has been experimentally and theoretically confirmed that the film thickness becomes S film when the material is flown. Therefore, in the repair method according to the present invention, first, the thickness of the lining coating film to be formed on the inner surface of the target existing pipe 1 is selected, and the selection of the film thickness is Based on the repair-related conditions such as the diameter of the pipe to be repaired, the viscosity of the resin to be used, and the amount of resin filled, the flow rate of resin A necessary to form the desired film thickness is set, and this setting is The compressed air from the compressor 12 is controlled by the control device 6 to apply a required static pressure to the rear end surface of the filled resin A so that the amount of lining resin flows through the pipe at the flow rate. In this case, the resin A used is a dixotropic resin as described above, and when external force is applied to this type of resin, the coating structure is destroyed and a softening phenomenon occurs, and when the external force is removed, the resin becomes soft over time. Since the resin A has the property of recovering to its original state with the passage of time, the pressing force of the resin A is equal to the pressing force (approximately 0.6 kg 7c) when traveling in the pipe after flowing, as described above.
m2 or less), the initial pressing force for imparting fluidity is set at a somewhat higher pressure of about 1.5 kg/cm2. In the case of such a pressure setting, the initial pressing force acts on the inside of the tube of the launcher 2, causing F! It has almost no effect on the inside of the L installed piping 1, and the pressing force inside the existing piping 1 is
This has a slight pressure difference with respect to atmospheric pressure, approximately 0.
By being set at a low pressure of 6 kg 7 cm2 or less,
Even in the aged existing piping 1, the phenomenon of blowing out from corroded holes can be reliably avoided. In addition, due to the above pressing force, the amount of resin in the pipe increases to vle+, and the formation of a lining coating film progresses, and when the flow rate of resin A decreases due to the formation of the coating film, the above pressing force corresponds to the decrease in the amount of resin. The amount of air flowing into the pipe is controlled by the control device 6 and the flow ffi adjustment valves 11 and 16 so that the flow rate to the lining resin is attenuated and the flow rate to the lining resin is constant. In other words, as the resin group moves inside the pipe and the amount of resin decreases, the flow rate of resin A tends to increase accordingly. It changes in relation to the pressure, and the pressure inside the pipe is determined by the stirring of the pushing gas that has flowed into the pipe and the position of the resin mass, that is, the volume on the rear side of the resin mass. Pressure gas suspension flowmeter 9.1
1, and further measures the pressure inside the pipe at each point in time when the amount of gas inside the pipe is measured.
Accordingly, the velocity of the resin group can be calculated from the change in the volume of the gas in the pipe, that is, the change in the position of the resin. As a result, the flow rate adjustment valve 11 (R1) and the flow rate adjustment valve 16 (Rz) are controlled by the control device 6 on the starting end side so that the pushing force 11 that keeps the flow rate of the resin A constant is controlled. The pressing force of the tree [11A] is controlled to be automatically attenuated so that the flow rate of the resin group becomes constant as the amount of resin decreases. Hereinafter, the operation of the suppressor H mushroom 6 for keeping the flow rate of the resin A constant will be explained in detail. First, if ff1Q1 of the pushing gas that has flowed into the pipe and the pressure inside the pipe P1, then π/4・d2 ・It 1 ・PI −Ql ・Pa
Since the relationship is -.=(1), Ql at a certain time T1. By measuring Po and Pl, 11 can be determined from equation (1). The pushing gas Q1 that has flowed into the pipe is determined by the flow meter 9.
This is the difference between the 1st measurement value F1 and the 31st measurement value F2 by the flow meter 17. It is convenient to use a single mass flow meter as the flow meter 9.17 because it is not affected by the temperature of the gas. Here, Jtl is the resin position 4, P at time T1. is the measured value of the pressure gauge 10, Pl is the measured value of the pressure gauge 8, and d is the inner diameter of the lining in the existing pipe 1. Next, in order to detect the resin flow rate, for a certain period of time (in seconds)
If we stop the air supply and measure the change in pipe pressure PI → P2 with the pressure gauge 8, and if the resin position at this time is 12, then Jlz ・Pt = Az - Pz, and if we know R2, we can convert a certain time into seconds. The subsequent resin layer r1tAz can be known. Therefore, the resin flow rate V is Vl□−J! , becomes 1/j. In addition, if the air supply is not stopped and the constant inflow in the previous state is continued, the inflow mQ of the pushing gas at a certain time T1
z, measure the pressure PR in the pipe, π/4・d2・1□
・Pz-Qz'Po to Am =Qx ・Po/7r
/4 ・d 2 ・Pz, and the resin flow velocity V is V=j! z JLtn Tl It becomes Tl. In this way, the flow rate regulating valve 11 (R1) is controlled by the arithmetic unit 6' and the control device 6 so that the resin flow rate V is constant.
, controls the flow at adjustment valve 1G (R1). In this way, the lining resin A is filled with the launcher 2 of a predetermined length connected to the injection side pipe end of the existing pipe 1 so as to fill and close a predetermined length of the pipe while remaining in liquid state, and the filled resin has fluidity. The pressure of the pushing gas that gives the pressure can be calculated from the difference between the resin position obtained by measuring the mass flow rate of the pushing gas and the pressure inside the pipe at the starting end of the pipe and the resin position measured at predetermined time intervals. The calendar of the pushing gas in the pipe is adjusted to keep the calculated resin velocity constant, and a lining coating film a with a uniform required film thickness is applied to the inner surface of the existing pipe 1.
Form and go. On the other hand, in the repair method of the present invention, the resin injection boss 18 is inserted from the other end opening of the existing pipe 1, and as shown in FIG. As shown in the figure, the resin layer A is continuous on one side in the length direction.
The resin is supplied from the injection 1FJ4' to form LL. In the example of FIG. 1, the first resin group A is
It is desirable to supply the resin group A' at intervals of 1' so that the resin group A' decreases during the lining process and reaches the next resin group A' among the resin groups before the compressed air blows through the resin group A. . Therefore, such an interval L' is calculated by the calculation device 6' and controlled! In the IlI device 6, the insertion length of the resin injection hose 18 is controlled by an appropriate feeding means such as a winch 19.
control to adjust. Further, the control device 6 controls the opening degree of the flow rate regulating valve 14' and the opening/closing control of the electromagnetic on-off valve 5'. In addition, in the embodiment shown in FIG. 4, the resin supply is calculated so that the amount of resin per unit length of the resin layer A corresponds to the amount of resin used for the inner lining coating of the existing pipe 1 for that unit length. If it is realized by the functions of the device 6' and the control device 6,
After the first resin group A reaches the resin layer A I+, there is no change in the total amount of resin group moved, so the amount of air supplied per unit time is kept constant to keep the pressure of the pumped air constant. Since the transfer speed to the resin group can be kept constant, it is easy to obtain a uniform film thickness commensurate with this, and control is advantageous. In the embodiment shown in FIG. 5, a replenishment method is shown in which the next required additional resin mass A'' is supplied through the resin injection hose 18 after the compressed air has blown through the resin mass A. In addition, in the above embodiment, by limiting the filling m of resin in the pipe to a predetermined value of υ1, the gas pressure for pushing the resin can be suppressed to a low pressure, thereby preventing corrosion of the repaired pipe. Even if there is a hole, etc., good lining can be performed without causing a blowout.In addition, in the repair work according to the present invention, if there is a large corroded hole in the middle of the existing pipe 1, or if the valve is stopped at m. If a branch pipe that is not connected is connected, the pushing gas will be blown from there immediately after the resin group has passed, causing a sudden decrease in the pushing force and preventing the flow of resin A from proceeding any further. In this case, the pressure Ht8 in the control device 6 is detected by the flow meter 9, and the flow rate of gas per hour is calculated, so the flow layer is increased, The pushing speed of the resin group is maintained.In other words, when blow-by of the above-mentioned pushing gas occurs, the blow-by which is mapped immediately is calculated based on the previous pushing gas flow rate and the blow-through per time. The corrected flow rate calculated from the gas flow rate is added to the subsequent pushing gas at the blowout to return to the original push-off speed, causing the resin to flow again, and at the same time reducing the amount of resin moving inside the pipe. It is possible to control the pressing force of the static pressure so as to keep the flow #l speed of the lining resin constant correspondingly.In the above embodiment, the first resin group is released through the launcher 2. The resin was supplied from the front side (lining start end) of the existing piping 1 through the resin injection hose 18 mentioned above.
It may be supplied from the rear side (the end of the lining) and may also be supplied into the launcher 2 first. In this case, the 'S' position for supplying resin to the launcher 2, that is, the resin injector 4, electromagnetic opening valve 5, etc. can be omitted.

【Effect of the invention】

As explained above, according to the braze lining repair method of the present invention, at least the additional resin can be supplied into the existing pipes by the resin injection means introduced from the end of the lining end of the four existing pipes. The workability can be improved by continuously performing the operation of suppressing and moving the resin using low-pressure gas without requiring time to replenish the resin.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view schematically showing an example of the repair method according to the present invention, and Figs. 2 and 3 show the relationship between resin pressing force during resin flow, film thickness, and running speed according to the present invention. FIGS. 4 and 5, which are explanatory diagrams of the shape of the resin end face, are sectional views of main parts of another embodiment. 1... Existing piping, 2... Launcher 14, 4'...
・Resin injector, 5.5'...Electric lit! Open/close valve, 6.
...control device, 6'...computing device, 7...electromagnetic on-off valve, 8...pressure gauge, 9...fluid meter, 10...pressure gauge, 11...flow rate adjustment valve , 12... compressor,
13... Three-way switching valve, 14. 14'... Flow rate adjustment valve, 15... Pressure activation plate, 16... Flow rate adjustment valve, 17
...Rhyphenometer, 18... Branch pipe, 19... Automatic shutoff valve, 18... Resin injection hose.

Claims (1)

[Claims] Fill resin in liquid form into the pipe at one end of the existing pipe over the required length from its opening so as to fill and close the pipe, and by flowing the filled resin, the pipe diameter and resin viscosity can be adjusted. , in which a required film thickness is formed on the inner surface of the tube based on related conditions such as the length of the filled resin, and in addition to supplying low-pressure gas to push and move the filled resin to the lining start side of the existing piping, at least additional filling of the resin is performed. A method for repairing the lining of the inner surface of a pipe, characterized in that the resin is supplied into the pipe by a resin injection means introduced from the lining end side of the existing pipe.