JP4540841B2 - Pipe inner surface painting method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pipe inner surface coating method for performing uniform coating without coating unevenness by reciprocating a coating pig inserted into a pipe body to be rehabilitated in painting for performing rehabilitation in a pipe.
[0002]
[Prior art]
When used for many years, water pipes and drainage pipes installed in buildings, condominiums, etc. will rust and corrode on the inner surface of the pipe, reducing its function and making it unusable. Therefore, it is desirable to replace the tube with a new one before the functional failure occurs. However, the replacement of the tube is accompanied by troubles such as a long-term water interruption, and the replacement requires an expensive cost. Therefore, a retreading method is adopted in which the rust and attached foreign matter inside the pipe are removed without moving the existing pipe, the inner surface is polished, and a rust-preventing coating film is formed on the inner surface of the pipe.
[0003]
Various methods are used for rehabilitation of these pipes. Extrusion methods using compressed air, that is, compressed air is introduced from one end, abrasives are introduced into this high-speed air stream, and pumped, or polishing pigs are attached. After removing rust and deposits by pressure feeding, there is a method in which painting is performed by inserting a paint pig into the paint and the rear part of the paint in the same way with pressure air and feeding them.
[0004]
In this extrusion method, since compressed air is used, the piping is subjected to a higher pressure than in normal use, so there is a risk of damage to the corroded and weakened part. The accumulated rust and deposits accumulate on the front of the pig, and finally the pig stagnates in the pipe, and it is necessary to remove the pig by applying pressure from the opposite direction. Since the amount of paint decreases as painting progresses, it is necessary to lower the pumping force accordingly, and adjustment is difficult and uniform painting cannot be performed.
[0005]
The applicant has repeatedly studied to overcome the problem of the above-described pig extrusion method, and the burden on the piping is small, and the operation and adjustment when transferring the pig are easy without the pig stagnating in the pipeline. Focused on the pig suction method. However, in this pig suction method, there is a problem that, when painting the inner surface of the pipe, since the pig moving in the pipe advances in only one direction in the concave portion such as a step of the pipe connection portion, unpainted remains.
[0006]
[Problems to be solved by the invention]
There is provided a coating method in which the rehabilitation pipe is less burdened, the operation adjustment when transferring the pig is easy, and further, the remaining coating of the stepped portion and the like due to pipe joining is prevented.
[0007]
[Means for Solving the Problems]
The present invention was devised in order to cope with this problem in view of a novel situation, and provided with paint supply portions on the left and right sides of the pipe, and accepts a pig insertion and a pig or paint at each of the open ends. A stop device is provided, which is connected to a suction device via a header equipped with an air intake opening / closing valve and a switching opening / closing valve, and a pig is inserted from one of the pig insertion portions of the pipe, and the traveling direction of the pig The paint is supplied to the pipe and the suction device on the other side is activated to make the inside of the pipe negative. After that, the air is introduced by operating the on / off valve on the pig insertion side, and the pipe is moved by the differential pressure before and after the pig. The pipe is received and coated on the inner surface of the pipe, and the suction device and the air intake on-off valve are switched, and the pipe is moved again in the opposite direction with negative pressure inside the pipe, and the pig is reciprocated in the pipe for painting. Is to provide.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An example of an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an explanatory view showing the entire piping of the present invention. Reference numeral 1 denotes a tubular body, and tanks 3 and 3a each having an on-off valve 2 and 2a for supplying paint into the tubular body 1 are provided on the left and right sides of the tubular body 1 on the tube end side. Also, at both open ends of the tube body 1, there are provided pig receiving ports 5 and 5a having pig insertion ports 4 and 4a and several surrounding holes, and the enormous portions 6 and 6a are arranged so as to receive paint. The receiving devices 7 and 7a are provided.
8 and 8a are headers, and the headers 8 and 8a are provided with suction pipes 10 and 10a provided with on-off valves 9 and 9a, pressurization regulating valves 11 and 11a, and on-off valves 12 and 12a, respectively, and the receiving device 7, 7a and connected to suction devices 14 and 14a through dust collectors 13 and 13a, respectively. The pig insertion ports 4 and 4a provided in the enormous portions 6 and 6a of the receiving devices 7 and 7a are provided with lids 15 and 15a that can be sealed, respectively, and provided with opening / closing valves 16 and 16a that appropriately remove residual paint at the bottom. It is.
In addition, what was shown here is one Embodiment, Comprising: As long as the function is fulfilled, it is not limited to this Embodiment.
[0009]
Next, painting of pipe rehabilitation will be described.
For example, the application pig P is inserted from the pig insertion port 4 provided in the enormous portion 7, and the on-off valve 2 of the paint tank 3 is opened to paint the inner surface of the tube body 1, and a slightly excessive amount of paint is applied to the application pig. After supplying to the front side of P, the suction device 14a is activated. At this time, all open / close valves for releasing the negative pressure on the pig insertion side are closed. After the negative pressure in the pipe is obtained, the open / close valve 9 of the suction pipe 10 of the header 8 is slightly opened to introduce outside air while adjusting the intake amount. Adjustment of intake amount The pressure adjustment valve 11 is adjusted according to instructions from the controllers 17 and 17a.
The air introduced from the suction pipe 10 flows toward the suction device 14a and propels the application pig P toward the suction device 14a by the differential pressure action before and after the application pig P. At this time, the paint flows before the pig P, and the application pig P moves while painting the inner surface of the pipe and stops by hitting the receiving pipe 5a in the pig receiving apparatus 7a.
Further, when the pig stops, the suction device 14 is activated by switching the suction device 14a and the opening / closing valves 12 and 12a of the other suction device 14, the suction pipe 10 is closed, and the suction pipe 10a is opened and closed after the negative pressure is set as described above. The valve 9a is slightly opened and adjusted, the outside air is introduced from the suction pipe 10a, the application pig P is reversed and propelled toward the suction device 14, and stopped by the pig receiving device 7 while painting the inner surface of the pipe again. Then, the coating pig P is moved back and forth on the inner surface of the tube to uniformly coat the tube. At this time, excessive paint is received by the enormous portions 6 and 6a of the receiving devices 7 and 7a so as not to reach the dust collecting devices 13 and 13a and the suction devices 14 and 14a. Collected at.
When painting is completed in this manner, the suction device 14 is stopped, the on-off valve 11 is opened to release the negative pressure, the inside of the tube 1 is brought to normal pressure, the application pig P is taken out, and the excess paint is removed from the on-off valve 16. , 16a to complete.
[00010]
FIG. 3 describes the painting of the branch branch pipe provided in the pipe body.
The pipe body 1 has a plurality of branch branch pipes 21 branched (in FIG. 3, the branch technique pipe 21 shows one example), and each of the pipe body 1 and the branch branch pipe 21 of this pipe includes: Tanks 3, 3 a, 23 provided with opening / closing valves 2, 2 a, 22 for supplying paint into the pipe are provided on the pipe end side, and a pig insertion port, a huge portion 6 for receiving the pig and paint are received at each open end , 6a, 26, receiving devices 7, 7a, 27 are provided.
The receiving devices 7, 7 a, 27 are respectively provided with suction pipes 10, 10 a, 30 provided with on-off valves 9, 9 a, 29, pressurization regulating valves 11, 11 a, 31 and on-off valves 12, 12 a, 32, respectively. The dust collectors 13, 13a, 33 and the suction devices 14, 14a, 34 are connected via the headers 8, 8a, 28.
The enormous parts 6, 6a, 26 are provided with a receiving pipe for receiving the pig, a pig insertion / extraction port, and a paint removal opening / closing valve.
[00011]
In this configuration, in order to paint the selected branch pipe 21 of the branch branch pipe 21 to be rehabilitated, the coating pig P is inserted from the enormous portion 26 of the receiving device 27 provided on the branch pipe 21 and provided on the branch pipe 21. After opening the on-off valve 22 of the paint tank 23 and coating the inner surface of the target branch pipe 21 on the front surface of the insertion pig to supply a slightly surplus paint, all the on-off valves of the pipe are closed and the suction device 14 is started. After the inside of the pipe is set to a negative pressure, air is introduced from the suction pipe 30 while adjusting the on-off valve 29, the air flows in the suction direction, and the pig P is pushed in the suction direction by the differential pressure generated before and after the pig. Also, the paint flows before the pig P, moves while painting the inner surface of the branch pipe 21 with the pig P, and hits the receiving device 7 and stops. When the pig P is stopped, the on-off valve 12 of the suction device 14 and the on-off valve 32 on the other insertion side are switched, the air introduction of the suction pipe 30 is closed, and the suction apparatus 34 is activated to make the inside of the pipe negative again, Air is introduced from the tube 10 while adjusting the air, and the air flows in the suction direction. This operation is repeated to propel the pig P in the suction direction of the return path, and the paint film is uniformly applied by reciprocating the regenerated branch pipe 21. The surplus paint is received by the receiving devices 7 and 27 so as not to reach the suction device.
When painting is finished, the suction device 24 is stopped, the introduction of air is stopped, the pressure adjusting valve 31 is opened, the negative pressure is released, the inside of the pipe is brought to normal pressure, the pig P is taken out, and the excess paint is taken out and selected. The painting in the branch pipe is completed.
[00012]
Further, when the inner surface finish in the pipe is further required, the application pig P used in the one-way reciprocating coating is taken out, and if the application pig P is softer than the application pig P (for example, the coating pig P has a hardness index 100, 70 By repeating the same reciprocating coating operation as described above, a coating film having a uniform thickness with no coating unevenness can be obtained, and more complete coating is possible.
[00013]
【The invention's effect】
The pipe inner surface painting method of the present invention is a suction method, which is easy to operate and has little burden on the pipe. It is easy to work just by installing it at both open ends of the pipe, and the suction device is opened and closed at both ends of the pipe. By connecting the valve and switching the suction device, the pig moves in the tube toward the suction side and reciprocates. Painting is done. In addition, the coating distance of the pipe is also supplied with paint from both open and closed ends of the pipe, and the coating pig is reciprocated in the pipe to apply many excellent effects such as long distance, shortening the painting time and controlling the drying temperature. Can demonstrate.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an overall explanatory view in which a part of one embodiment of the present invention is cut away.
FIG. 2 is an enlarged view of the receiving device of FIG. 1;
FIG. 3 is an explanatory diagram of another embodiment of pipe coating having a branch branch pipe according to the present invention.
[Explanation of symbols]
1 Tubing 2, 2 a, 22 Open / Close Valve 3, 3 a, 23 Tank 4, 4 a Pig insertion port 5, 5 a, 25 Pig receiving tube 6, 6 a, 26 Expanding part 7, 7 a, 27 Receiving device 8, 8a, 28 Header 9, 9a, 29 Open / close valve 10, 10a, 30 Suction pipe 11, 11a, 31 Pressurization adjustment valve 12, 12a, 32 Open / close valve 13, 13a, 33 Dust collector 14, 14a, 34 Suction device 15, 15 a Lid 16, 16 a, 36 Open / Close Valve 17, 17 a, 37 Adjustment total 21 Branch branch pipe

Claims (2)

A paint supply unit is provided on the left and right sides of the pipe body, and each of the open ends has a pig insertion and a receiving device for receiving the pig and the paint, and this device has a header including an air intake opening / closing valve and a switching opening / closing valve. Connected to the suction device, and the pig is inserted from one of the pipe insertion portions of the tube body, the paint is further supplied to the surface of the pig in the traveling direction, and the suction device on the other side is activated to bring the inside of the tube to a negative pressure. After that, air is introduced while adjusting the amount of intake by operating the on-off valve on the pig insertion side, and the pipe inside the pipe is moved in the suction direction by the differential pressure generated before and after the pig, and the pipe inner surface is painted and received. The stop device receives the pig, switches the suction device, closes the open / close valve of the air intake suction pipe, makes the inside of the pipe negative again, introduces air from the air open / close valve on the opposite side, and repeats the above operation to repeat the pig Is moved in the suction direction of the return path, and the pig in the pipe is reciprocated. Inner surface coating method characterized by performing the coating of the inner wall. In a pipe composed of a pipe body having a plurality of branch branch pipes, the pipe body and the branch branch pipes are respectively provided with a paint supply section on the pipe end side, and a pig insertion section and a pig on each open end. And a receiving device having an enormous portion for receiving paint, each receiving device having a suction pipe provided with an on-off valve, a piping configuration connected to the suction device via a header provided with the on-off valve, All the on-off valves provided in this pipe are closed, a paint pig is inserted from the receiving device of one selected branch branch pipe to be rehabilitated, and paint is supplied to the pig traveling direction surface in the branch pipe. After starting the suction device on the other side of the receiving device and making the inside of the pipe negative pressure, air is introduced from the suction pipe on the pig insertion side while adjusting the on-off valve, and the pig is sucked in by the differential pressure generated before and after the pig To paint the inner surface of the pipe and receive the pig with the suction side receiving device , Switch between the suction device on-off valve and the insertion-side suction device on-off valve, stop the air introduction, make the inside of the pipe negative again, repeat the above operation by introducing the front and rear air, move the pig in the suction direction of the return path, and regenerate A pipe inner surface painting method characterized in that painting is performed by reciprocating the inside of the pipe.

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