JPS6359376A - Method for repairing lining pipeline - Google Patents

Abstract

PURPOSE:To perfectly eliminate the metal exposed surface at an elbow part, by allowing a pig made of an elastic material and a lining material to advance through the non-joint part of a pipeline at a relatively low speed within the pipeline having a joint part in a closed state. CONSTITUTION:A pig 6 and a lining material 5 are integrally allowed to move forwardly by a pressurized fluid. At this time, in the non-joint part of a pipeline 1, the flow rate and pressure of the pressurized fluid are made low to allow the pig 6 and the lining material 5 to advance at a relatively low speed of 10m/min or less. As a result, the pig 6 made of an elastic material does not largely deform and the gap between the pig 6 and the inner wall surface of the pipeline 1 shows a small value near to a set value to form a thin film. When the pig 6 and the lining material 5 reaches a joint part 8, the gap between the pig 6 and the inner wall surface of an elbow becomes larger and, therefore, a lining film 5a is formed thickly and the end surface 9 of a pipe part is perfectly covered.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is used for repairing pipelines using lined pipes, and eliminates all exposed metal surfaces at elbows, etc. of pipelines. This invention relates to a method for repairing lined pipelines.

(Prior art) In order to prevent rust as much as possible in gas pipelines, hot water supply pipelines, etc., so-called lining pipes are used in which a film of synthetic grease or the like is formed with a certain thickness on the inner wall surface of the metal pipe. Generally widely used.

Therefore, when lining pipes are used to construct piping lines, so-called threaded piping is usually used, and the lining pipes are screwed together using sockets, elbows, etc. ing.

Figure 3 shows the bare hand section (elbow section) of this lined pipe.
2 is a vertical cross-sectional view of the elbow A, in which an external thread D formed at the end of the lined pipe C is screwed into the threaded hole B of the elbow A.

Thus, the inner wall surfaces of the elbow A and the lining pipe C are completely covered with the lining layers E and F.

However, in a case where the external thread D is formed after cutting the lining pipe C to a predetermined size, a metal portion is exposed on the cut end surface G of the pipe C.

In addition, when removing a lining IC screwed into the elbow A and screwing another lining pipe C into it, the lining layer formed on the inner wall surface of the screw hole of the elbow A will be peeled off and the metal surface will be exposed. That will happen.

By the way, if even a very small part of the metal surface of the inner wall of the pipe is exposed, the corrosion of the metal will gradually expand from the exposed part even if the exposed area is small, and the lining layer E will peel off and the corroded part will become (The problem that the invention aims to solve) As mentioned above, in conventional lined pipelines, exposed metal parts inevitably remain at joints such as elbows and sockets. Therefore, even if an expensive lining tube is used, there is a problem in that dirt is generated from the exposed portion and the eyebrows gradually expand. This is intended to fundamentally solve the problem of rusting, and in addition to forming a thick lining film on the inner wall surface of joints such as elbows and sockets of lining pipes, a lining layer is formed in advance. A lining that prevents the formation of a thick lining film on the non-joint parts of pipes, making it economical to consume less lining material, and completely eliminating rust on the inner wall of the pipes. The present invention provides a method for repairing pipelines.

(Means for Solving the Problems) The present invention includes laminating and filling a highly viscous lining material at one side open end of the lining pipe, and disposing a pig made of an elastic material behind the lining material. Then, pressurized fluid was supplied from behind the pig to cover the pig and lining material for 10 m.
The basic structure of the invention is to form a thick lining coating film on the inner wall surface of the joint part of the pipe by moving the non-joint part of the pipe forward at a speed of /Rtn or less.

(Operation) The pig and the lining material are moved forward together by the pressurized fluid. At that time, in the non-joint part of the pipe (straight part excluding the socket part), the flow rate = pressure of the pressurized fluid is made weaker so that the pig and lining material have an IQ m/I
Xf+! Proceed at the following relatively slow speed. As a result, the elastic material pig does not deform significantly due to the weak pressure applied by the working fluid, and the gap between the outer surface of the pig and the inner wall surface of the lining pipe is maintained at a set value (approximately 0.3 to 0.5
The resulting clay is extremely small, close to 0.3 to 0.5 mm in thickness, and the lining film formed is extremely thin, with a thickness of 0.3 to 0.5 mm.

When the pig and lining material reach the joint, the gap between the inner wall surface of the elbow or socket and the outer surface of the pig becomes larger, resulting in the formation of a thick lining film and the distal end surface of the pipe. is completely covered by the lining film. As a result, there are no exposed metal parts on the inner wall surface of the tube.

When the pig comes close to the joint, if the Xff1 pressure of the pressurized fluid applied to the pig is increased, the pressing force applied to the pig increases, the pig deforms into a rugby ball shape, and the outer surface of the pig and the joint The distance between the inner wall surfaces is further increased. As a result, the thickness of the lining film formed on the inner wall surface of the joint becomes thicker.

(Example) Hereinafter, the present invention will be specifically described based on an example of the present invention shown in FIGS. 1 and 2.

FIG. 1 is an implementation system diagram of the present invention, and FIG. 2 is a longitudinal sectional view of the elbow portion after repair. In the figure, 1 is a pipe to be treated such as a gas pipe or water pipe formed using a so-called lining pipe, lc is a steel pipe section, and ld is a lining layer.

Further, 2 is a compressor, 3 is a flow rate pressure regulator, 4 is a working fluid, 5 is a highly viscous lining material, 6 is a pig made of an elastic material, and 7 is a lining material supply valve.

When repairing lining pipes, first repair the pipe by 30 to 5
It is divided into suitable lengths of about 1,000 m, and the inlet end 1a and outlet end 1b are opened.

Next, as shown in Figure 1, connect each of the five pots, and
At the same time as inserting the inner pig 6, the lining material supply valve 7 is opened and the lining material 5 of a predetermined viscosity is injected into the front of the pig 6.

The lining material 5 is excellent in agricultural properties and has high viscosity (40
The most suitable material is a liquid or gel-like material with a fluidity of 00 to 8 QOOOCPS), less dripping, and properties required as a lining material (corrosion resistance, safety, etc.). Specifically, epoxy resin paints with high viscosity (thickness limit for sagging of the coating film is 3 to 7 rrvn) and cement-based lining materials with high viscosity are most suitable.

In this embodiment, -C is used as the lining material 5, an epoxy resin paint having a sagging limit thickness of 7 mm (working fluid temperature: 25 DEG C.).

The pig is made of a flexible and deformable soft elastic material such as rubber or plastic, and its outer diameter is selected to be slightly smaller than the inner diameter of the tube 1 to be treated. The pig 6 is for causing the highly viscous lining material 5 to flow forward, and is used to flow the working fluid 4 while maintaining a predetermined gap (0.3 to 0.5wn) between it and the pipe wall. is pushed forward along the tube wall.

In this embodiment, the pig 6 is a solid ball made of elastic plastic, but a hollow ball made of rubber,
Alternatively, it may be a hollow rubber ball filled with fluid to inflate it.

The amount of lining material 5 to be injected into the pipe to be treated 1 is calculated from the length of the pipe, t, the number of joints, the thickness of the coating film to be formed, etc., and is usually 1.1 of the required calculation amount. About 1.2 times the amount of lining material 5 is injected. As shown in FIG. 1, the lining material 5 is injected into the pipe so that a layer of the lining material 5 is accumulated in the pipe and the pipe is closed.

When the injection of the required amount of lining material 5 is completed, the flow rate/pressure regulator 3 is adjusted to supply the working fluid 4 at a predetermined flow rate and pressure into the pipe, and the lining material 5 injected into the pipe via the pig 6 is adjusted. at the exit end 1 at a speed below 10 m/trin
Proceed in direction b. As the working fluid 4 to be supplied into the pipe, gases such as air and nitrogen, water, etc. can be used, and in this embodiment, the working fluid 4 is circulated around the compressed air from the compressor four times. When supplied into the pipe, the pig 6 and the lining material 5 injected into the pipe and accumulated in a plug-like layer flow in the direction of the arrow, and a very thin layer (approximately 03 to 0 .5 rran) The lining film 5a is formed.

It is desirable that the traveling speed of the pig 6 be 10 m/min or less. The traveling speed of Pig 6 is 10 m/t
If the thickness exceeds 1.5 in., the lining film formed on the non-portable portion of the pipe becomes thick, and the amount of lining material used increases, which becomes uneconomical.

In the present invention, the distance between the outer circumferential surface of the pig 6 and the inner wall surface of the lining pipe 1 is set to about 0.3 to 0.5 mm, and the moving speed of the pig 6 is 10 m/ wn
The lining film 5a is hardly deformed because it is held at the low speed below, and as a result, the lining film 5a is formed on the inner wall surface of the non-joint part.
The result is an extremely thin film of 0.3 to 0.4 mm.

When the pig 6 and the lining material 5 reach a joint such as an elbow or a socket of the conduit, the highly viscous lining material 5
As shown in FIG. 2, the lining film 5a adheres thickly to the inner wall surface of the elbow portion 8, and the metal tube end surface 9 and the like are completely covered with the lining film 5a.

In addition, since a highly viscous lining material is used as the lining material 5, and the lining distance at the joint is relatively short, the lining material can be used even if the lining film 5a has a thickness of 6 to 10 m+. Due to the surface tension of the film, almost no sagging occurs, and a thick film with a substantially uniform thickness is formed.

Moreover, if it is desired to make the lining film 5a near the joint part thicker, the flow rate and pressure of the working fluid 4 are increased, and the moving speed of the pig 6 is increased. When the speed of the pig 6 is increased, the resistance force of the highly viscous lining material 5 applied to the pig 6 increases, and the pig 6 deforms from a spherical shape with a circular cross section to a rough pole shape with an elliptical cross section. As a result, the gap between the inner wall surface of the pipe and the outer surface of the pig increases, resulting in the formation of a thicker coating film.

According to the test results, the temperature of the working fluid 4 is 40 to 45°C;
Atmospheric temperature 20~25°C1 Sponge spherical pig, lining material 5 (sag limit thickness 6 questions, epoxy sphere paint) flow velocity U = 9 m/Nn, diameter 50~6
With a pipe of 00 mm, it is possible to obtain a coating film thickness of t = 9 to 10 points at the key end, and the end surface 9 of the pipe is coated with a lining coating film 5.
Complete coverage was possible with a.

In addition, when the present invention is put into practice, even if a crack should occur in the lining I'J1d of the lining pipe, it goes without saying that the crack can be filled and repaired with the lining material 5.

Further, in this embodiment, the pig 6 is made to flow through the pipe only once, but after the lining material 5 is attached to the inner wall surface of the handle part, the pig 6 alone or the pig 6 and the lining are passed through the pipe. It is also possible to circulate the material 5 again to shape and increase the thickness of the outer surface of the lining film 5a.

(Effects of the Invention) (1) In the present invention, since the pig 6 made of an elastic material and the lining material 5 are moved forward at the non-joint portion of the pipe at a speed of 10 m/rIin or less, the lining The lining film at the non-joint part of the pipe where the layer 1d is pre-swaged can be made into an extremely thin film of about 0.3 to 0.5 parts, and the lining film at the joint part can be made into an extremely thin film of about 7 to 0.5 parts.
10rrr! The coating can be as thick as nth, and the tube end face is completely covered by the lining coating.

As a result, it is possible to completely prevent rust from forming on the inner wall surface of the pipe, and also to reduce the amount of lining material required for repair, thereby reducing repair costs.

(2) In addition, since the pipeline is closed with the lining material, the flow rate of the working fluid required is significantly reduced compared to previous lining methods, resulting in a significant reduction in energy consumption and The capacity of the supply device can be reduced, and large-diameter pipes can be easily lined.

(3) Furthermore, if cracks occur in the lining layer 1d of the lining pipe that forms the groove in the non-joint part of the pipe, the cracks will be filled with the lining material, and the lining layer 1d will need to be repaired. can be done at the same time.

As mentioned above, the present invention has excellent practical utility.

[Brief explanation of the drawing]

FIG. 1 is an implementation system diagram showing one embodiment of the present invention. FIG. 2 is a longitudinal sectional view showing the state of repair of the elbow portion according to the present invention. FIG. 3 is a longitudinal cross-sectional view showing the state of lining of the elbow portion by the conventional lining method. l Pipe to be treated 1c Metal pipe part 1d Lining layer 3 Flow 1/pressure regulator 4 Working fluid 5 Lining material 6 Elastic material pig 8 Pipe joint part 9 End face of metal pipe part Patent issuer: Kiyoshi Shinno

Claims (2)

[Claims] (1) A highly viscous lining material is laminated and filled at one side open end of the lining pipe, and a pig made of an elastic material is arranged behind the lining material, and then pressurized fluid is supplied from behind the pig. supplying pigs and lining materials at 10m/mi
1. A method for repairing a lined pipeline, the method comprising forming a thick lining coating film on an inner wall surface of a joint part of a pipeline by moving a non-joint part of the pipeline forward at a speed of less than m. (2) By adjusting the flow rate and pressure of the pressurized fluid, the pressing force applied to the pig at the joint of the pipe line is increased and the moving speed of the pig is increased. A method for repairing a lining pipe according to scope 1.