JP2685508B2 - Reinsurance method of lining steel pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a method for resuscitating an existing pipe for water or gas, particularly a steel pipe lined with a resin such as a hard vinyl chloride resin or an epoxy resin.

[Prior art]

Various methods are well known as resuscitation methods for existing pipes of this type. For example, there are conventional methods disclosed in Japanese Patent Publication No. 57-56391 and Japanese Patent Publication No. 58-14826. In the former method, sand for polishing and cleaning is supplied together with swirling air from one end side of the existing pipe, and after polishing and cleaning the inside,
This is a method in which paint having a relatively high viscosity is supplied together with swirling air in the same manner as described above, and the paint is revived by stretching the paint along the inner surface of the pipe. The latter method is a method in which after the inner surface of the pipe is ground and cleaned, the paint is atomized and supplied together with the swirling gas flow, and the atomized paint is sprayed onto the inner surface of the pipe by the swirling gas flow.

[Problems to be solved by the invention]

The existing pipes targeted by the conventional example are pipes that are not lined, and further, the work of cleaning and painting is performed only from one end side of the pipe, and sand or paint is continuously supplied. It is a thing. Technically, such a conventional resuscitation method cannot be applied to the resuscitation of a lining steel pipe. That is, in this type of lining steel pipe,
As shown in FIG. 4, in particular, a swelling phenomenon of the resin coating 3 lined inside the joint 2 connecting the straight pipes 1 to each other at a substantially right angle, a so-called blister 4, occurs, and the inner surface of the joint is sandwiched by the blister. Not only does it block the flow of water, but also at the connecting portion 5 between the straight pipe 1 and the joint 2, the steel pipe is exposed during the threading process, and water permeates into this portion. Then, rust is generated to form a rust bump 6 and push up the resin film 3, and a blister similar to the above is generated. Therefore, since the blister 4 thus generated is covered with the resin film 3, it cannot be removed by a scouring means only using sand as in the conventional example.
Even in the coating process, if the blister 4 cannot be removed by the scouring means, it is completely wasted, and there is a problem that the lining steel pipe cannot be revived substantially.

[Means for Solving the Problems]

As a specific means for solving the problems of the conventional example, the present invention is a method of rejuvenating an existing pipe of a lining steel pipe by a polishing step and a coating step, wherein the polishing step has a flow rate of 60.
With turbulent air of m / sec or more, Mohs hardness is 6.0 or more and it is performed by introducing a coarser silicon material than 20 mesh, and the coating process uses an epoxy resin with a viscosity that does not atomize due to the introduced air flow. A flow rate of 30 m / sec while using the main coating material and detecting the arrival of the coating material at each branch of the existing pipe.
Performed by blowing the inner surface of the pipe by the above air flow, at least the blasting and sweeping step is to perform primary blasting and sweeping from one direction and secondary blasting and sweeping from the other direction, and dry the inside of the pipe before blasting and blasting. In order to provide a method for resuscitating a lining steel pipe, the blister generated on the inner surface of the pipe can be removed by the specified drying step and scouring step, and the subsequent coating step can be performed smoothly. However, the existing pipe can be efficiently revived.

【Example】

Next, the present invention will be described in more detail with reference to the illustrated embodiment. For easy understanding, the same parts as those of the conventional example are denoted by the same reference numerals and described. In the figure, 10 is a floor of a building such as a condominium, and 11 is a wall. A water pipe, for example, is laid inside the floor 10 and the wall 11, and the water pipe is composed of a plurality of straight pipes 1 and a plurality of joints 2 bent in a substantially L shape. The end A side of the pipe is connected to the meter side, and the end B side is connected to, for example, a faucet. Inside the straight pipe 1 and the joint 2, a lining steel pipe lined with a resin such as a hard vinyl chloride resin or an epoxy resin is used. And, in such a pipe, blisters are likely to occur particularly inside the joint 2 as described in the conventional example. According to the present invention, such a lining steel pipe is revived by performing the specified cleaning and painting steps. The blasting step in the present invention is performed after first removing the equipment at both ends of the pipe, that is, the meter and the faucet, and then drying the inside of the pipe by blowing an appropriate drying means, for example, hot air. The compressor 12 and the silicon material storage container 13 are connected to one end, for example, the end A, from which the equipment is removed, and the compressor 12 introduces the silicon material into the pipe together with the compressed air. In this case, the compressed air has a flow velocity of approximately 60 m / sec or more depending on the pipe diameter of the pipe to be treated and is intermittently supplied in a turbulent flow state. Further, the silicon material used is, for example, silica or ceramic,
The Mohs hardness of the silicon material is 6.0 or more, and the particle size is selected to be coarser than 20 mesh. When the Mohs hardness is less than 6.0, the blister removing effect is poor, and even when the Mohs hardness is smaller than 20 mesh, the blister removing effect is poor. The supply of silicon material by air flow is the result of various experiments,
The intermittent supply is superior to the continuous supply in the blister removal efficiency. The reason for this is not clear, but in the case of continuous supply, if the flow of the air flow is continued, the air flow will flow regularly under certain conditions, whereby the silicon material located inside the air flow will be It is presumed that a part of the silicon material passes through the blister without colliding with the blister, although it is conveyed along the flow and is continuously supplied in large quantities. On the other hand, by supplying the air flow intermittently, the initial turbulence in the air flow works effectively, and the rectification is not always performed, so that the collision of the silicon material with the blister increases, and therefore the blister can be removed efficiently. It is supposed to be done. This first time, i.e., after the primary blasting step is completed, the next blasting, i.e., the secondary blasting step is performed, but the blister is destroyed in the previous primary blasting step, so that the inside of the blister The water that has accumulated in the pipe flows out and the inner surface of the pipe gets wet. In this wet state, the blister cannot be sufficiently removed by destruction, so a drying process must be performed so as to completely remove this moisture. This drying step is performed by blowing air, which has been dried by heating, into the pipe as described above. Further, the secondary polishing step is effective in that the silicon material is supplied from a different end portion of the existing pipe, that is, the other end portion B side in the same manner as the primary polishing step, and consequently the reciprocating polishing step is performed. A blast can be performed. That is, since the portion where blisters are likely to occur is a curved joint portion and the connecting portion between both ends of the joint and the straight pipe, only by supplying the silicon material from one direction,
It is difficult to remove the blister generated on the front side of the flow direction of the silicon material, and by supplying the silicon material together with the air flow from both sides of the one end A and the other end B, the blister is generated in any part. The blister that is present can be removed almost entirely. After the completion of the primary and secondary blasting steps, the inside of the pipe is cleaned with a dry air flow and then the coating step is performed. In this coating process, the paint used has a relatively high viscosity and is mainly composed of an epoxy resin. The paint is supplied by turbulent air from one end A side of the existing pipe. The velocity of the turbulent air in this case is almost
At least 30 m / sec, and the paint is known in advance for the length of the pipe to be painted, and the amount of paint that is more than the amount that can be applied is supplied all at once, and turbulent air is used. The inner surface of the tube is dragged or blown to form a coating film, which is then painted. By such supply, a continuous coating film can be uniformly formed with a predetermined film thickness from the straight pipe portion to the joint portion. Therefore, the viscosity of the paint is relatively high so as not to be atomized by the introduced turbulent air, and the viscosity is selected in the range of approximately 3000 to 35000 cp. When the viscosity is 3000 cp or less, not only the sprayed air flow causes the film to be sprayed, but also the formed coating film itself is thin and the adhesion strength is low, and a coating film having the intended strength cannot be obtained. On the other hand, if it is 35,000 cp or more, the viscosity is too high to be uniformly stretched or blown by a predetermined introduced air flow, and a coating film having a uniform film thickness cannot be formed. A preferable viscosity range is about 4000 to 30000 cp. In such a coating process, if necessary, similar to the above-mentioned blasting process, the coating material may be supplied from a different end portion, that is, the other end portion B side in the same manner as described above, and as a result, reciprocal coating may be performed. By performing the reciprocating coating in this way, almost complete coating can be performed. As shown in FIG. 2, when there are a large number of branch pipes in the existing pipe, the blasting step and the painting step are performed as follows. In the figure, is the meter mounting position, is the kitchen,
If the bathroom is the washroom, and the washroom is the toilet, first set the meter installation position to the dust collection position, keep the bathroom, washroom and toilet closed, and introduce the silicon material along with the airflow from the kitchen to install the meter. Clean the inside of the pipe that is located between the location and the kitchen. Next, the kitchen, washbasin and toilet are closed, and the bathroom is cleaned as described above. Then, the kitchen, bathroom, and washbasin are closed, and the toilet is cleaned as described above. After each of these cleaning steps, after drying the inside of the pipe, for the pipe part of the last remaining wash surface, set the kitchen to the dust collection position,
With the meter installation position, bathroom and toilet closed, clean from the wash surface in the same manner as above. By carrying out each of the above-mentioned blasting, the primary blasting from each direction is completed for the piping of each part, and the so-called secondary blasting is performed, in which only the piping part of the kitchen is reciprocated. Then, after completion of the primary cleaning in one direction, at least the pipe portion on the wash surface is dried. Next, for the part which has not been subjected to the secondary blasting from the other direction, by utilizing the fact that the blowing device of the air flow and the silicon material is set on the wash surface in the primary blasting operation,
The bathroom is set to the dust collecting position, the other meter mounting positions, the kitchen and the toilet are blocked, and the same cleaning as above is performed from the wash surface, so that the piping to the bathroom is secondarily cleaned, and then the bathroom is closed. By setting the toilet to the dust collecting position and performing the same blasting from the wash surface as described above, the piping to the toilet can be also secondary blasted. Finally, the wash surface is set to the dust collecting position, the kitchen, the bathroom and the toilet are closed, and the cleaning is carried out from the meter mounting position so that all the pipes are at least reciprocally ground, that is, the secondary cleaning is carried out. It will be. In this blasting step, blasting may be performed twice or more in the same direction for a certain part, but this can be done by making a blasting plan in consideration of the condition of the pipe. After the scouring step is finished, the inside of the pipe is cleaned or cleaned with a dry air flow, and then coating is performed. In this coating process, only the meter mounting position is left open, and the coating is performed sequentially from the branch pipe far from the meter mounting position. In the illustrated example, coating is performed from the wash surface, for example. In this case, block other kitchens, bathrooms, and toilets, grasp the length of the pipe from the branch of the tray to the wash surface in advance, and collect the amount of paint suitable for painting the pipe from the wash surface. Air flow and paint at least up to the next furthest branch of the toilet branch. Whether or not the paint to be coated has reached this branch can be detected or confirmed by detecting the fluctuation of the air pressure in the toilet. After the painting of the washbasin is completed, the paint is supplied from the furthest toilet by the air flow in the same manner as described above, and then the furthest branch of the bathroom is painted. Also in this coating, it can be confirmed by detecting the air pressure in the bathroom as described above. Subsequently, the paint and the air flow are supplied from the bathroom in the same manner as described above to paint the kitchen, and finally the kitchen to the meter mounting position. At the meter mounting position, the arrival of the paint can be visually observed. In short, the coating is performed after the arrival of the paint is not detected at each branch in the pipe. After the coating of each branch pipe is completed, only the air flow is blown into the pipe again to check the ventilation state of each pipe. In any of the above-mentioned coatings, the coating material is blown in or introduced with an air flow having a flow rate of 30 m / sec or more, and the coating material is spread substantially evenly for coating. In this case, since the paint has a relatively high viscosity and is supplied all at once, the paint is blown by being dragged by the air flow, so that a coating film having a substantially uniform thickness as a whole can be formed. Further, if necessary, reciprocal coating, that is, secondary coating can be performed for each branch portion in the reverse order of the above-mentioned coating order. By performing this secondary coating, the thickness of the coating film can be further increased, and the coating on the pipe joint portion can be made even more complete.

【The invention's effect】

As described above, the method of rejuvenating the lining steel pipe according to the present invention is a method of rejuvenating the existing pipe of the lining steel pipe by a blasting step and a coating step, wherein the blasting step is performed by turbulent air having a flow velocity of 60 m / sec or more. , Mohs hardness is 6.0 or more and it is performed by introducing a silicon material coarser than 20 mesh,
The coating process uses a paint whose main component is an epoxy resin having a viscosity that does not cause mist by the flow of introduced air, while detecting the arrival of the paint at each branch of the existing pipe, the flow rate is 30 m /
The inner surface of the pipe is blown out by an air flow of sec or more, and at least the blasting and cleaning step performs primary blasting and cleaning from one direction and secondary blasting and cleaning from a different direction, and the inside of the pipe is dried before blasting and cleaning. In particular, the primary and secondary polishing steps are performed, and the inside of the pipe is dried before the polishing step, and the size and hardness of the silicon material are specified and introduced. By specifying the flow velocity of the air flow, it is possible to remove blisters and rusty cobs generated in the lining steel pipe and its pipe joint part and to revive it in a substantially complete state. By using it and identifying the flow velocity of the air flow while detecting the arrival of paint at each branch of the existing pipe, the connection between the pipe joint and the straight pipe can also be coated with a continuous coating film. , After resuscitation In the tube, so as not to give a room for the occurrence of blisters and rust Cobb, an excellent effect that it can be prolonged use.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of an existing pipe for carrying out the method of the present invention, FIG. 2 is a schematic diagram for explaining a scouring process and a coating process in an existing pipe having a large number of branch pipes, and FIG. Sectional drawing which shows the generation | occurrence | production state of the blister of a pipe joint part in an existing piping, FIG. 4 is an expanded sectional view of the principal part which shows the generation | occurrence | production state of rust in the same pipe joint part. 1 …… Straight pipe, 2 …… Pipe joint, 3 …… Resin coating 4 …… Blister, 5 …… Connecting part, 6 …… Rust bump 10 …… Floor, 11 …… Wall, 12 …… Compressor 13 …… Storage container for silicon materials.

Claims (4)

(57) [Claims] 1. A method of rejuvenating an existing pipe of a lining steel pipe by a blasting process and a painting process, wherein the blasting process uses turbulent air with a flow velocity of 60 m / sec or more, and has a Mohs hardness of 6.0 or more and 20 mesh or more. In addition, a rough silicon material is introduced, and in the coating process, the arrival of the paint is detected at each branch of the existing pipe by using a paint whose main component is an epoxy resin whose viscosity does not atomize due to the introduced air flow. While the flow velocity
Performed by blowing the inner surface of the pipe with an air flow of 30 m / sec or more, at least the blasting step performs primary blasting and sweeping from one direction and secondary blasting and sweeping from the other direction in the pipe before blasting and sweeping. A method for resuscitating a lining steel pipe, characterized by being dried. 2. The lining steel pipe rejuvenation method according to claim 1, wherein the introduction of the silicon material by the turbulent air in the polishing step is performed intermittently. 3. The method for rejuvenating a lining steel pipe according to claim 1, wherein the coating step is carried out after sufficiently drying after the scouring step. 4. The method for reactivating a lining steel pipe according to claim 1, wherein the viscosity of the paint is 3000 to 35000 cp.