JP6039855B1 - Piping inner wall lining method - Google Patents

Abstract

A pipe lining method capable of forming a robust liner layer on the inner wall of a pipe whose lower end is closed. A rear end of a coated running cross pipe 5 is connected to an upper end 11 of an outer pipe 1 of a heat pipe HP which is arranged in a vertical direction with a lower end 12 closed and an upper end 11 open, and the outer pipe is further connected from the upper end. In the piping lining method in which the impregnated lining cloth tube 30 that is inverted and turned to the outer peripheral side is brought into close contact with the inner wall 10, the lower end portion 13 of the outer tube 1 is constructed by a film tube. 4 is temporarily removed to form a ventilation gap between the inner wall 10 and the inside of the film tube 4 to be re-pressurized, so that the entire length of the impregnated lining cloth tube 30 is reduced to the inner wall 10 of the outer tube 1. In addition, the air remaining between the contact surfaces is completely removed, and a rigid liner layer L having no pinholes is formed. [Selection] Figure 2

Description

  The present invention relates to a lining method for forming a liner layer for repair or the like on an inner wall of a pipe which is installed in a vertical direction and whose lower end is closed.

  In buildings such as condominiums and rental buildings, in order to restore and rehabilitate the durability of piping such as water supply and drainage pipes, lining construction is performed in which a resin layer of a predetermined thickness is formed as a liner layer on the inner wall of the piping (for example, , See Patent Document 1 by the same applicant as the present application).

  The lining construction of Patent Document 1 is made of woven fabric, impregnated with a liquid lining paint into a lining cloth tube that can be reversed on both sides and made into an impregnated lining cloth tube, and surrounded by an airtight film tube with one end closed. A bag-like coated lining cloth tube is formed.

  Usually, the length of the covering lining cloth pipe is set somewhat longer than the length of the pipe to be repaired. One end of this covering lining cloth pipe is connected by a cable body, and the other end is coaxially inserted and fixed to the outer peripheral side of one end of the pipe. Then, by forming an initial reversal part in the fixed part of the coated lining cloth tube, vacuum suction is applied to the other end of the pipe, or pressure is applied to the one end with compressed air, so that the coated lining cloth pipe is connected to one end of the pipe. Due to the pressure difference between the other end and the other end, the inside of the pipe is continuously reversed while proceeding to the other end.

  Thereby, the impregnated lining cloth pipe adheres to the inner wall over the entire length of the pipe. Subsequently, high-pressure air is supplied into the pipe from one end side of the pipe to cure the liquid lining paint while maintaining the tight contact of the impregnated lining cloth pipe, thereby forming a liner layer on the inner wall of the pipe.

Japanese Patent No. 4181439

  The piping inner wall lining method described in Patent Document 1 is a construction method applied to piping having a structure in which both ends are open, and the impregnated lining cloth tube is piped by inverting the coated lining cloth tube inserted from one end of the piping. This is a simple and reliable construction method in which continuous reversal is carried out until it projects to the other end while being in close contact with the inner wall, and the coated lining cloth tube projecting from the other end is excised and constructed.

  However, in the case of a pipe whose one end is closed, it cannot be applied by projecting from the closed end while inverting the coated lining cloth pipe. That is, when the front end portion of the coated lining cloth pipe that is reversed on the front and back approaches the closed end portion, the air remaining in the pipe is compressed and the air pressure in the pipe increases. For this reason, the pressure of the high-pressure air supplied into the film tube from the one end side and the residual air pressure on the closed end side of the pipe are balanced, and the reversal and push-in construction of the coated lining cloth pipe cannot be performed smoothly. The impregnated lining cloth tube cannot be in close contact with the nearby inner peripheral wall.

As described above, there are the following cases in application examples in which the pipe is closed at one end.
As shown in FIG. 1, a heat fence HF is laid around the outer periphery of the underground cryogenic tank T for storing liquefied gas such as LNG in order to prevent the soil layer from freezing. The heat fence HF has a structure in which a large number of heat pipes HP are embedded in the vertical direction at predetermined intervals so as to surround the outer periphery of the underground cryogenic tank T. The heat fence HF is provided with a hot water supply device (not shown) for circulating hot water through each heat pipe HP. Warm water is supplied to the heat pipe HP to prevent the soil layer around the underground cryogenic tank T from freezing.

  The heat pipe HP has an outer pipe 1 that is open on the top and exposed to the ground, closed at the lower end and buried in the ground, and an inner pipe that is coaxially arranged inside the outer pipe and has an open upper end and a lower end (see FIG. Not shown). The circulated hot water is turned from the upper end to the lower end of the inner pipe and is discharged at the lower end of the outer pipe 1 and discharged from the upper end, or conversely, is injected from the upper end of the outer pipe 1 and turned to turn the upper end of the inner pipe. And return to the hot water supply device. The inner wall of the heat pipe HP deteriorates with time due to corrosion, accumulation of impurities, and the like. In order to operate the heat fence HF for a long period of time, it is necessary to repair by forming a robust liner layer on the inner wall of the outer pipe of the heat pipe HP.

  Thus, in the case of a pipe whose lower end is closed, such as an outer pipe of a heat pipe, air does not escape from the lower end and residual air exists. Accordingly, the reversing part of the coated lining cloth tube is pushed by the pressure of the high-pressure air supplied into the film tube while reversing the remaining air pressure inside the pipe, and reversely moves downward. There is a slight gap between the impregnated lining cloth tube and the inner wall of the pipe, and there is some air leakage. However, when the inversion movement distance to the inner wall of the pipe, that is, the close contact distance with the impregnated lining cloth pipe is increased or the pressure is applied, there is almost no way for residual air to escape. As a result, it is difficult to perform the reverse pushing operation of the impregnated lining cloth tube, and when the residual air exists in the impregnated lining cloth tube and hardens, there is a possibility that the liner layer becomes non-uniform and has pinholes.

  The object of the present invention is to insert from one end in order to form a robust liner layer including the lower end in a pipe arranged in the vertical direction and closed at the lower end, such as the outer pipe of a heat pipe of a heat fence. An object of the present invention is to provide a pipe lining method capable of reliably bringing an impregnated lining pipe into close contact with the inner wall in the vicinity of the closed lower end in a construction in which the coated lining cloth pipe is brought into close contact with the inner wall of the pipe while being inverted.

(About claim 1)
A pipe lining method in which a liner layer is formed on the inner wall of a pipe arranged in the vertical direction with the lower end closed and the upper end open, and a cylindrical lining cloth pipe that can be turned upside down is impregnated with a liquid lining paint. The impregnated lining cloth tube is surrounded by an airtight film tube with one end closed, and the outer peripheral side is a film tube, and the inner peripheral side forms a bag-like coated running cross tube with an impregnated lining cloth tube. The other end of the running cross pipe is coaxially inserted into the outer periphery of the upper end of the pipe, and an initial reversal part that enters the pipe from the opening is formed, and pressure is applied to the film tube side of this initial reversal part with compressed air. While the covered running cross pipe is moved in reverse into the pipe, the impregnated lining cloth pipe that has become the outer peripheral side after inversion adheres to the inner wall of the pipe. Have adopted a pipe lining method that.

  And the construction of the lower end of the pipe is after the inside of the film tube is depressurized to form a ventilation gap between the inner wall of the pipe and the impregnated lining cloth pipe, and the air staying at the lower end of the pipe is released from the ventilation gap. The pressurized fluid is injected into the film tube, the coated running cross pipe is inverted and moved into the pipe, and the impregnated lining cloth pipe is brought into close contact with the inner wall of the pipe.

As a result, in the final period of inversion of the coated lining cloth pipe, the contact area with the inner wall of the pipe is large, and even if the contact distance is long, the residual air with increased pressure can be released and the residual air at the lower end of the pipe is reduced. In addition, the pressure balance in the piping is maintained. Therefore, the reversal proceeds smoothly by re-pressurizing the inside of the film tube, and the impregnated lining cloth tube can be easily brought into close contact with the closed inner wall of the lower end of the piping.
As a result, a liner layer in which an impregnated lining cloth pipe made of a liquid lining paint having a lining cloth pipe as a core material is in close contact is also formed at the lower end of the closed pipe.

(About claim 2)
When the impregnated lining cloth pipe is long, it is characterized in that the inside of the film tube is repeatedly pressed and depressurized so that the impregnated lining cloth pipe is brought into close contact with the inner wall of the pipe.
Thereby, even if the piping is very long, a uniform and robust liner layer can be formed from the upper end to the lower end of the piping.

(Claim 3)
After the reversal movement is completed, the pressurized fluid to be injected into the film tube is hot water, and after the hot water is retained at the lower end of the pipe, gradually increase the water depth until the upper end of the pipe is full. The impregnated lining cloth pipe is closely attached to the inner wall of the pipe.
As a result, the air remaining at the lower end of the pipe and the foamy air (air bubbles) remaining in the air gap formed between the pipe and the inner wall of the pipe are pushed out by the water pressure of the staying hot water, and the water depth rises to full water. Accordingly, the water pressure can be discharged so as to push the air bubbles upward, so that the generation of pinholes can be prevented and a robust liner layer can be formed.

(About claim 4)
The hot water is characterized by being hot water having a temperature equal to or higher than a thermosetting temperature for curing the liquid lining paint when the liquid lining paint is thermosetting.
Thereby, a hardening process can be shortened and cycle time improves.

(Claim 5)
The end of the lining cloth pipe is characterized in that it is set higher than the lower end of the pipe by a distance equal to or greater than the wall thickness of the coated running cross pipe.
As a result, as in the conventional example, the impregnated lining cloth tube is protruded and reversed from one end side to the other end side, and thereafter the step of cutting off the protruding portion is not required, so that the construction is simple and the number of steps can be reduced.

(About claim 6)
Piping constitutes a heat fence arranged to surround an underground storage tank of liquefied gas, and is an outer pipe of a heat pipe buried vertically in the ground, and the pressurized fluid injected into the film tube is The hot water is supplied from a plant hot water source constituting the heat fence.

Due to this, a large amount of hot water can be used, so even pipes that are buried in the ground and have significant heat dissipation due to heat conduction can be heated without a temperature drop, easy to maintain above the heat curing temperature, shorten the curing process, and cycle time Will improve.

It is the schematic which shows the aspect which constructs a liner layer to the outer pipe of the heat pipe which comprises the heat fence of a liquefied gas storage tank (Example 1). (Example 1) which is the schematic of the apparatus which reversely inserts a covering lining cloth pipe | tube in an outer pipe | tube. It is a perspective view which shows the structure of a covering lining cloth pipe (Example 1). (Example 1) which is the first half process drawing which reversely inserts a covering lining cloth pipe into an outer pipe. (Example 1) which is a latter half process figure which reversely inserts a covering lining cloth pipe into an outer pipe.

  Embodiments of the invention will be described together with examples shown in the drawings.

[Example 1]
(Configuration of Example 1)
As shown in FIGS. 1 and 2, the liquefied gas underground storage tank heat fence device surrounds the liquefied gas (for example, liquefied LNG) storage tank T buried in the ground and the storage tank T to prevent the soil from becoming frozen. It is comprised from the heat fence HF installed in. The heat fence HF includes a large number of heat pipes HP arranged around the storage tank T at predetermined intervals. The heat fence HF is provided with a hot water supply device (not shown) for circulating hot water through the heat pipe HP.

  The heat pipe HP has a bottomed cylindrical outer tube 1 whose upper end 11 is open and whose lower end 12 is closed, and an inner tube which is coaxially arranged inside the outer tube 1 and whose upper and lower ends are both open. (Not shown). Prior to the formation of the liner layer L on the outer pipe 1, the inner pipe is taken out of the inner pipe, the inside is cleaned, and the deposits such as rust and scales that have flowed down are universal piping rehabilitation vehicles (not shown) )). After cleaning, the liner layer L is formed on the inner wall 10 of the outer tube 1 by the pipe lining method of the present invention.

  For the lining construction of the inner wall 10, as shown in FIG. 3, a flexible woven fabric (thickness 1 to 4 mm) containing chemical fibers such as glass fiber and polyethylene having excellent durability is formed into a cylindrical shape. A lining cloth tube 2 is used. The lining cloth tube 2 has an outer diameter commensurate with the inner diameter of the outer tube 1, can be turned upside down, and has a length slightly shorter than the length of the outer tube 1. The lining cloth tube 2 is impregnated with the liquid lining paint 3 to form an impregnated lining cloth tube 30 that can be reversed on the front and back sides. The liquid lining paint 3 is a liquid containing a coloring pigment or an epoxy resin, and a thermosetting one is often used.

  The outer circumference of the impregnated lining cloth tube 30 is covered over the entire length with a film tube 4 made of a flexible material such as a resin, so that a coated lining cloth tube 5 is formed. In the present embodiment, as shown in FIG. 3, the film tube 4 has a distal end 41 fastened to the distal end of the cable body G and closed in an airtight state, and the length is set longer than the lining cloth tube 2.

  The coated lining cloth tube 5 connects the distal end portion of the rope body G to the distal end portion 41 of the film tube 4. In this embodiment, the striatum G also serves as the hot water hose 6 for supplying hot water, but the striatum G and the hot water hose 6 may be separate. A showering nozzle 61 with a clamp for airtightly connecting the distal end portion 41 of the film tube 4 is attached to the distal end of the hot water hose 6.

  The warm water hose 6 and the covering lining cloth tube 5 are wound around the reel 71 of the reversing machine 7 from the warm water hose 6 side (see FIG. 2). The winding order is the hot water hose 6 followed by the tip 41 of the film tube 4 and the coated lining cloth tube 5. As shown in FIG. 1, a controller 72 is attached to the reversing machine 7, and a hot water source 73, a compressed air source 74, a power source 75, and the like are attached to the controller 72.

(Construction procedure of Example 1)
Next, the lining construction procedure of the inner wall of the pipe according to the present invention will be described with reference to steps 1 to 10 in FIGS. FIG. 4 shows the first half of steps 1 to 5 and FIG. 5 shows the second half of steps 6 to 10 separately.

  A lining cloth tube 2 having a predetermined length and made of glass fiber or chemical fiber such as vinylon is used as a woven fabric and can be reversed on the front and back sides. The lining cloth tube 2 is impregnated with the liquid lining paint 3 to form an impregnated lining cloth tube 30, and the outer periphery thereof is surrounded by an airtight film tube 4 having a closed tip, or the film tube 4 is used to Then, the front end is fastened to form a bag-like coated running cross pipe 5 having an outer peripheral side of the film tube 4 and an inner peripheral side of the impregnated lining cloth pipe 30 (step 1).

 The rear end of the covering running cross pipe 5 is connected by being inserted into the outer peripheral portion of the opening end of the pipe 1 arranged in the vertical direction where the lower end 12 is closed and the upper end 11 is opened. This connection is made so that the rear ends of the coated running cross tube 5 and the film tube 4 are put on the upper end 11 of the pipe, and there is no hermeticity so long as air leaks slightly (step 2). In addition, in a present Example, the piping arrange | positioned in the vertical direction includes the piping arrange | positioned in inclination other than perpendicular | vertical.

  Then, an initial reversing jig 8 is inserted coaxially with the inner wall 10 of the pipe 1 at the rear end connecting portion of the covered running cross pipe 5 to form an initial reversing section that is slightly recessed from the upper end 11 of the pipe 1. If the coated running cross tube 5 is long, it is crushed and flattened so that the coated running cross tube 5 is not twisted, and is temporarily wound around the reel 71 of the reversing machine 7 so that the reversal movement proceeds smoothly (step 3). ).

  Subsequently, compressed air such as a compressor is pressurized in the duct D connected to the outer periphery of the initial reversing jig 8. The coated running cross pipe 5 is pushed by the pressure of the pressurized air acting on the initial reversing part, and is pushed in while continuously reversing downward (closed end part). The impregnated lining cloth pipe 30 that is reversed and turned over to the outer peripheral side advances while closely contacting the inner wall 10 of the pipe 1 by the pressure of the pressurized air (step 4).

  In the reverse movement of the impregnated lining cloth tube 30 on the inner wall 10 of the pipe 1, the reverse movement position may not reach the end of the impregnated lining cloth pipe 30 depending on the magnitude of the pressure of the pressurized air. This is because the reversal movement follows the pressure difference, and the pressure difference is not generated by the pressure increase (back pressure) of the staying air at the closed lower end portion 13 of the pipe 1. Therefore, the construction of the closed lower end portion 13 of the pipe 1 requires sufficient exhaust of residual air at the lower end portion 13, and first the pressure in the film tube 4 is reduced. That is, all the pressurized air is released to the outside (atmosphere). As a result, a slight ventilation gap is formed between the impregnated lining cloth pipe 30 that has been in close contact with the inner wall 10 by the pressure of the pressurized air until now, and the residual air that has increased in pressure passes through this slight gap. 1 comes out to the outside (atmosphere) from the upper end 11 (step 5).

  Since the back pressure has disappeared, next, the inside of the film tube 4 is re-pressurized. Then, the reversal movement proceeds continuously, so that the coated running cross pipe 5 can be adhered (step 6). In the final stage of the reversal movement, the inside of the film tube 4 that has reached the lower end 12 of the pipe 1 is temporarily depressurized, a slight gap is provided between it and the coated running cross pipe 5, and then hot water is poured from the nozzle 61, Hot water is retained in the tube 4 (step 7). By this operation, the residual air staying at the lower end 12 of the pipe 1 is pushed out from the bottom to the inner wall corner by gravity (water pressure) acting on the hot water. It should be noted that the water poured in step 7 is not limited to hot water, and may be water at room temperature, or may be antifreeze if necessary.

  Thereafter, the water injection in the film tube 4 is continued until the water is gradually filled. In this way, the water pressure increases as the water depth becomes deeper, and in addition, the residual air present at the bottom or inner wall corner is lowered by this water pressure to show the behavior of increasing upward from the lower end 12 in order. From the upper end 11 of the pipe 1, it is discharged to the outside (atmosphere) (step 8). As a result, even air remaining between the inner wall 10 of the pipe 1 and the film tube 4 and even bubble-like air can be reliably deaerated over the entire length of the impregnated lining cloth tube 30. As a result, it is possible to form a robust liner layer L without pinholes.

  After the film tube 4 is filled with water in the above process, pressure is again applied to the film tube 4 with compressed air (process 9). As a result, the same air pressure pressing force is further applied to the lower end 12 of the pipe 1 having a deep water depth and a high water pressure, and also to the upper end 11 having a shallow water depth and a low water pressure. The inner wall 10 can be firmly adhered.

The film tube 4 in the above process is filled with water, and the liquid lining coating material 3 is cured for a predetermined time while applying pressurized air. When the curing is completed, the pressure application is stopped (depressurized), the full water is drained, and the film tube 4 is further pulled out from the pipe 1. A robust liner layer L having a uniform and uniform core material from the upper end 11 to the lower end 12 can be formed in the pipe 1 (step 10).
[Example 2]

  Although it is preferable to use warm water to accelerate the curing of the liquid lining paint, when the application target is an underground pipe for the heat fence HF, the temperature of the warm water decreases quickly and the curing promoting effect is low. From the showering nozzle 61 via the hot water hose 6, the discharge amount is small. Therefore, as a method of increasing the hot water supply amount, a method of supplying hot water from another hot water supply source into the film tube 4 can be adopted. For this purpose, a hot water supply device for circulating hot water through the heat pipe HP described above can be used effectively.

  In this case, since it is not a method of supplying hot water from a hot water source (shown in FIG. 1) via the reversing machine 7, a valve is attached to a ferrule joint which is one of joints for guiding the coated lining cloth pipe 5 to the outer pipe 1. A method of supplying hot water directly into the film tube 4 by switching the valve is possible.

  According to the present invention, a lining construction of a pipe installed in a vertical direction with a closed lower end is possible, and a robust liner to an outer pipe of a heat pipe constituting a heat fence arranged so as to surround an underground storage tank of liquefied gas The formation of the layer can be carried out reliably.

1 Outer pipe (pipe) of heat pipe
2 Lining cloth pipe 3 Liquid lining paint 4 Film tube 5 Coated lining cloth pipe 6 Hot water hose 7 Reversing machine 10 Inner wall of outer pipe 11 Upper end opened of outer pipe 12 Lower end closed of outer pipe 13 Lower end part 30 Impregnated lining cloth pipe
L Liner layer T Underground storage tank for liquefied gas HF Heat fence HP Heat pipe

Claims (6)

A pipe lining method for forming a liner layer (L) on an inner wall (10) of a pipe (1) arranged in a longitudinal direction in which a lower end (12) is closed and an upper end (11) is opened,
A cylindrical lining cloth tube (2) that can be turned upside down is impregnated with a liquid lining paint (3) to form an impregnated lining cloth tube (30), and an airtight film tube (4) with one end closed. Surrounding, forming a bag-shaped coated running cloth pipe (5) of the outer peripheral side is a film tube (4) and the inner peripheral side is an impregnated lining cloth pipe (30),
The other end of the coated running cross pipe is coaxially inserted into the outer peripheral side of the upper end of the pipe, and an initial inversion part is formed that enters the pipe from the opening, and the initial inversion part is formed on the film tube side. In the piping lining method in which the impregnated lining cloth pipe that has become the outer peripheral side after inversion is brought into close contact with the inner wall while applying pressure with compressed air and inverting the coated running cloth pipe into the pipe,
The construction of the lower end (13) of the pipe is to reduce the pressure in the film tube to form a ventilation gap between the inner wall and the impregnated lining cloth pipe, and to store the air retained at the lower end of the pipe. After escape from the air gap, a pressurized fluid is injected into the film tube, the coated running cross pipe is inverted and moved into the pipe, and the impregnated lining cloth pipe is brought into close contact with the inner wall. Piping lining method.   2. The pipe according to claim 1, wherein when the impregnated lining cloth pipe is long, the inside of the film tube is repeatedly pressed and depressurized so that the impregnated lining cloth pipe is in close contact with the inner wall. Lining method.   After the reversal movement is completed, the pressurized fluid injected into the film tube is hot water, and the water injection is accumulated at the lower end of the pipe, and then the water depth is gradually increased, and the upper end of the pipe is filled with water. The pipe lining method according to claim 1 or 2, wherein the impregnated lining cloth pipe is kept in close contact with the inner wall until the end.   The pipe lining method according to claim 3, wherein the warm water is warm water at a temperature equal to or higher than a thermosetting temperature for curing the liquid lining paint when the liquid lining paint is thermosetting.   5. The pipe lining according to claim 1, wherein an end of the lining cloth pipe is set higher than the lower end of the pipe by a distance equal to or greater than a thickness of the coated running cross pipe. Method.   The pipe constitutes a heat fence (HF) arranged so as to surround an underground storage tank (T) of liquefied gas, and is an outer pipe of a heat pipe (HP) embedded in the vertical direction in the ground, The piping lining method according to claim 1, wherein the pressurized fluid injected into the film tube is hot water supplied from a plant hot water source constituting the heat fence.