JPH0338002B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The disclosed technology belongs to the technical field of liner lining of metal liner lined pipes of pipe bodies such as liquid transport pipes.

<Summary of the gist> Accordingly, the present invention includes a rectangular liner having a curved circular cross section inserted into the outer tube,
This invention relates to a method of manufacturing a liner-lined pipe in which a longitudinal straight joint formed by opposing edges is joined and fixed to each other at a slight inclination angle in the axial direction of the outer pipe, and in particular, On the other hand, one parallelogram-shaped liner flat plate is rolled up and curved,
After being inserted, the opposing edges are brought into close contact with each other and shifted longitudinally from each other with their entire lengths in contact, the diameter of the liner is increased, the entire area of the liner is compressed, and the liner is tightly pressed against the inner surface of the outer tube. This invention relates to a method of manufacturing a liner-lined pipe in which a joint between opposing edges or a joint between the joint and an outer pipe are joined and the joint is inclined with respect to the pipe axis direction.

<Prior art> As is well known, various types of piping are used to transport fluids such as factory waste liquids, water and sewage, and gas.
We lined the outer tube with a liner due to various conditions, such as having multiple functions such as heat resistance and corrosion resistance, as well as durability over time, and the need to manufacture it at low cost. Many tubes are used.

Therefore, when the liner-lined pipe is manufactured as a unit pipe of a predetermined length, it is required that the liner be lined tightly against the outer pipe during operation, so there have been various restrictions until now. Ta.

That is, in order to increase the degree of tightness of the liner lining to the outer pipe, as is well known, the shrink fitting method and the hydraulic pipe expansion method have been used for the liner lining.

<Problem to be solved by the invention> However, such conventional methods use complicated equipment, require high heat and high pressure, and have the disadvantage of high costs. The problem is that management is extremely cumbersome.
In addition, there were other inconveniences such as restrictions such as the outer tube being limited to a metal tube and a lack of freedom in design.

Furthermore, the liner inserted into the outer pipe is extremely expensive when a seamless pipe is used, and when a seam welded joint pipe is used,
Since tensile loads are applied to the joints during manufacturing, the strength of the joints is not sufficient, and in addition, stress corrosion cracks are likely to occur during operation, and defects may appear in the welds when water pressure and heat are applied to pipe expansion. There were also some negative points.

For example, there are techniques such as the invention disclosed in Japanese Patent Publication No. 48-24151, and a method for manufacturing a tube in which a thin plate is wound in a spiral shape has been devised; Although the diameter of the thin plate is reduced by pulling it in the axial direction for winding, it cannot be used as a liner and therefore cannot be used to form a liner-lined pipe. , it is not possible to meet the above-mentioned demand.

<Objective of the Invention> The object of the present invention is to solve the problems of manufacturing liner-lined pipes based on the above-mentioned prior art, and to solve the problems by rolling up a parallelogram-shaped flat plate for a substantially rectangular liner and joining opposing edges. By placing them close to each other, facing each other and shifting them in opposite longitudinal directions, the diameter can be expanded and easily pressed into contact with the outer tube, giving a compressed state to the liner lining, eliminating the need for a large liner thickness, and The material of the outer tube can be selected freely and can be easily tightened, and the entire liner, including the liner seams on the liner lining, is in a compressed state, which prevents stress corrosion cracking during operation and has great strength. It is an object of the present invention to provide an excellent method for manufacturing liner-lined pipes that can be used in piping technology application fields in various industries.

<Means/effects for solving the problem> In order to solve the above problem, the structure of the present invention, which is based on the scope of the above-mentioned claims, is as follows:
An outer tube of a material and thickness freely selected according to the design is combined with a parallelogram-shaped liner flat plate of a material and thickness also freely selected,
The flat plate for the liner is rounded into a cylindrical shape, has a diameter smaller than the inner diameter of the outer tube, and is inserted into the outer tube, and after insertion, the liner is tilted linearly at a slight inclination angle with respect to the axial direction of the outer tube when the liner is in a flat plate state. The opposing edges of the liner are brought into close contact with each other over their entire length, and they are slid and shifted from each other in a direction opposite to the longitudinal direction, and a liner is applied to increase the diameter.The liner is then compressed on its entire surface. Press it tightly against the inner surface of the outer tube, and then press the back side of the liner before and after that.
Alternatively, apply an adhesive to the inner surface of the outer tube, make the seam between opposing edges inclined linearly with respect to the axial direction, and fix the liner to the outer tube, or weld the liner seam to fix it. The liner, including the seams, is in a compressed state so that the joint length is long and has sufficient strength, and technical measures have been taken to prevent stress corrosion cracking etc. from occurring during operation. be.

<Example> Next, an example of the present invention will be described below with reference to the drawings.

The embodiments shown in FIGS. 1, 2, and 3 are embodiments of the principle of the present invention, and as shown in FIG. Then, as shown in Figure 2,
The opposing edges 2, 2 are brought close to each other to form a liner 3 as an inner tube with a circular cross-section and a diameter l, and then
The opposing edges 2, 2 are brought into contact with each other along the entire length as a seam 4, and as shown in FIG. The diameter L gradually increases (L>l), and when it reaches a desired diameter that can be easily inserted into the outer tube, the opposite edges 2, 2 are inserted into the outer tube (not shown).
By shifting them in opposite directions, it is possible to apply a pressing force in the radial direction while increasing the diameter and tightly connect the inner surface of the outer tube in a compressed state, so that the successor part 4 can be sealed in a specified position. do.

However, as shown in FIG. 3, at both ends of the liner 3, the ends of the seam 4 will be misaligned in the circumferential direction.

Therefore, the seam 4 is substantially straight and does not have a spiral shape as in the invention of Japanese Patent Publication No. 48-24151.

Therefore, even if the liner is a strip in the spiral shape, it becomes a coil shape and is not just a single rectangular plate.Therefore, it cannot be made into the cylindrical shape shown in Figure 2, and it is difficult to set it inside the outer tube. It turns out.

Next, in the actual embodiment shown in FIGS. 4 to 9, as shown in FIG.
Also, although the other opposing edges 2', 2' are parallel,
In order to eliminate the misalignment between both ends of the seam 4 shown in Fig. 3 and to align them smoothly in the circumferential direction in the shifted state, the parallelogram is slightly inclined by θ with respect to the opposing edges 2 and 2 as shown in Fig. 4. Trimmed to shape.

Then, as shown in FIGS. 4 and 5, metal stiffeners 5, 5 are attached to the opposite edges 2, 2 of the flat plate 1 at close design distances, respectively, to the opposing edges 2, 2 of the flat plate 1. By applying an appropriate adhesive (not shown) to the entire surface, it is adhesively fixed in a releasable manner.

However, since each stiffener 5 is in a posture fixed to the inner surface of the liner with a circular cross section, it may be slightly curved by a designed amount in advance in a warped shape.

Therefore, each stiffener 5 has a large amount of adhesive in the length direction and is bonded with strong adhesive force to the flat plate 1, but the adhesive force in the direction perpendicular to the length direction is weak due to the small amount of adhesive. It is said that it can be easily removed by applying a light impact force in the lateral direction during the subsequent peeling operation.

Further, the amount of adhesion is determined in advance based on the design.

Therefore, as shown in Fig. 6, the stiffener 5,
A flat plate 1 having stiffeners 5 integrally fixed thereto is bent with the stiffeners 5, 5 inside, bent into a circular cross section, and opposing edges 2, 2 are brought close to each other in a straight line, similar to the embodiment shown in FIG. 2 above. to cylindrical liner 3 and 7th
As shown in the figure, it is inserted into an outer tube 6 made of a material such as concrete and having a thick wall.

In this case, before inserting the cylindrical liner 3 into the outer tube 6, the inner surface of the outer tube 6 to which the liner 3 is joined;
Alternatively, a predetermined industrial adhesive may be applied to the entire outer surface of the liner 3.

Next, after inserting the liner 3 into the outer tube 6, the stiffeners 5, 5 are used to connect the longitudinally substantially straight joint formed by the opposing edges 2, 2 to each other as shown in FIG. When the cylindrical liner 3 is brought into contact over its entire length and then shifted in the opposite direction of the longitudinal direction using, for example, a hydraulic jack, the diameter of the cylindrical liner 3 increases as described above, and the wedge force applied to the joint 4 increases the diameter of the cylindrical liner 3. A circumferential force is obtained, resulting in seam 4 of liner 3
A large compressive force is applied to the entire area including the outer tube 6 to prevent stress corrosion cracking during operation, and a pressing force is generated against the inner surface of the outer tube 6 to tightly adhere to the inner surface.

In this case, the edges 2', 2' are arranged in advance so that the length of the liner 3 and the length of the outer tube 6 match with each other, with the edges 2', 2' smoothly connected as a circle at opposing parts of the substantially straight joint 4. The angle θ is designed to generate a strong binding force.

Next, as shown in FIG. 8, the welding torch 7 is moved using the facing stiffeners 5, 5 as guides to perform a weld seal 8 on the seam 4.

Then, when the welding seal 8 is completed, the hydraulic jack is removed and a light impact force is applied inwardly or outwardly to the stiffeners 5, 5 from the lateral direction with respect to the length direction, and as described above, the stiffeners 5 and 5 have a small adhesive force due to a small amount of adhesive in the lateral direction, and are easily peeled off and removed, completing the lining of the liner 3 to the inner surface of the outer tube 6.

As shown in FIG. 9, since the liner 3 has a straight seam 4 and is inclined by θ with respect to the axial direction 10, the seam 4 is
The length of the joint 4 is long, so the joint length of the seam 4 is long, and the joint strength is more fully guaranteed.

Therefore, when designing, the length of the joint 4 can be designed and the inclination angle θ with respect to the axial direction 10 can be determined so that the liner 3 can be easily inserted into the outer tube 6.

In addition, to join the seam 4, as shown in FIG. 10, a predetermined adhesive 8' is poured using the stiffeners 5, 5 as a guide before and after the liner 3 is pressed against the outer tube 6 of the liner 3, and the seam 4 is bonded. It is also possible to simultaneously achieve joint sealing of the outer tube 6 and the outer tube 6.

It goes without saying that the embodiments of this invention are not limited to the above-mentioned embodiments; for example, the outer tube may be made of a variety of materials other than a concrete tube, such as a metal tube or a synthetic resin tube. Instead of a stiffener, a presser plate may be pressed against the seam to apply a displacement force from both ends of the liner, and adhesive may be applied between the liner and the outer tube in advance, or a flat plate for the liner may be applied. Various methods can be used, such as forming the liner into a rectangular shape, lining the inner surface of the outer tube with a liner, and then cutting and forming both ends of the liner.

Specific examples are as follows.

That is, first of all, as for the outer pipe, as shown in Figure 11, it is a high tensile strength carbon steel pipe for pipeline high pressure API 5L x 70. Dimensions: (10 inches, schedule 120) Outer diameter: D _P = 273.00 mm Plate thickness: t _P = 21.44mm Inner diameter: D _L = 273.00-2 x 21.44 = 230.12mm Length: a = 12.0m.

Next, for the liner plate, the material: SUS 316 L (Fig. 12) Thickness: t _L = 2.5 mm Width: b = 722.92 mm Inclination angle: θ = 1.97° = 0.034 rad Length: a = 12 m. (The upper and lower sides of the figure are curved as shown by the arrows.) Also, as shown in Figure 14, the liner plate is made into a cylindrical shape by shifting the joints (inner pipe).

Shift the end: Δ=100mm Perimeter: b′=b−Δθ=722.92−100×0.034 =719.52 Outer diameter: L=b′/π=719.52/π=229.15mm shall be.

And this Put it inside the outer tube.

Since L<D _L (229.15<230.12), it can be easily inserted into the outer tube.

next, Push in both ends with pushing force F to align them.

Here, the diameter of the inner tube increases (L'), but it is constrained by the inner diameter (D _L ) of the outer tube (which is considered rigid), and compressive stress σ _f in the circumferential direction is generated.

L′=b/π=722.92/π=230.23mm σ _f =EL′−D _L /L′=2.1×10 ⁴ 230.23−230.12/230.23=10.0Kg/cm/mm
^2The pushing force F is composed of the wedge force F _W and the friction force F _f of the joining line (the friction coefficient μ between the liners, ignoring the friction force with the outer tube, is 0.4). Surface pressure p=
2ρ _f t/D=2×10×2.5/230.12=0.217Kg/
cm/mm ² (since the surface pressure between the inner and outer tubes is small) F=F _W +F _f =σ _F atθ+σ _F atμ =σ _F at(θ+μ) =10.0×12×10 ³ .4) = 13.0×10 ⁵ Kg = 130ton (push the stiffener from both sides with hydraulic jacks).

Next, the joints of the liner plates are welded (TIG welding) to integrate them.

Remove the liner plate edge stiffener (not shown).

In addition, seal welding is applied to the joints of the liner-lined pipes at both ends of the completed tight double pipe before shipping.

<Effects of the Invention> As described above, according to the present invention, basically a parallelogram-shaped flat plate is rolled into a cylindrical shape to form a liner,
Insert the liner into the outer tube and slide the opposing linear edges close together in the longitudinal direction while shifting them in opposite directions to increase the diameter of the liner and bring it into pressure contact with the inner surface of the outer tube. By sealing the joint with a seam that is inclined linearly at a slight angle to the direction, liner lining can be easily applied to the inner surface of the outer tube. , it is possible to obtain a large compressive force without using much heat, and therefore a large compressive force is applied to the liner including the seams to prevent stress corrosion cracking during operation;
The size and material of both the inner and outer tubes can be freely selected, and the excellent effect of obtaining a liner-lined tube that can withstand practical use is achieved.

By bringing the opposite straight edges of the parallelogram liner material into contact and offsetting each other, it is possible not only to control the degree of fit of the liner to the outer tube, but also to prevent The entire area, including the inner tube, is compressed during manufacturing, so stress corrosion cracking does not occur during operation as mentioned above, and welding defects are less likely to occur, which increases the bonding strength of the liner and the outer tube. It has excellent effects in that it can be made larger and can prevent displacement and peeling during operation.

In addition, since it is only necessary to join and tighten the liner to the outer tube at the time of manufacture, there is no need to strain the material afterwards. By making the diameter
Furthermore, there are also effects such as obtaining a strong tight fitting margin.

By providing an auxiliary part such as a stiffener on the linear opposing edge of the liner, it is possible not only to ensure that the opposing edge is shifted, but also to serve as a guide for welding and adhesion.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and Figures 1, 2, and 3 are perspective views of the principle of liner formation, Figure 4 is a plan view of a flat plate, and Figure 5 is a partial perspective view of a flat plate with a stiffener. , Fig. 6 is a curved perspective view of liner formation, Fig. 7 is a perspective view of the liner lining, Fig. 8 is a sectional view of the seam welding, Fig. 9 is a vertical sectional view of the liner-lined pipe, and Fig. 10 is Fig. 8. 11 to 15 are corresponding views of the design example, in which FIG. 11 is a perspective view of the outer tube, FIG. 12 is a perspective view of the liner plate, and FIGS. The figure is a perspective view of liner formation, and FIG. 15 is a perspective view of completed liner. 1... Flat plate, 3... Liner, 4... Seam, 6
...Outer pipe, 8, 8'...Joining, 10...Pipe axis direction,
θ...Inclination angle.

Claims (1)

[Claims] 1 In a liner-lined pipe manufacturing method in which a rectangular flat plate is curved and inserted into the outer pipe with a circular cross section, and the opposing joints are joined at an angle in a straight line with respect to the pipe axis direction. A parallelogram flat plate with opposing parallel edges inclined at a slight angle to other parallel edges is curved, the opposing edges are placed close to each other and the cross section is circular, and the plate is inserted into the outer tube. After inserting the liner, the opposing edges are in contact with each other along their entire length, and then shifted in opposite directions to press against the inner surface of the outer tube to create a liner in which the entire area is in a compressed state, and in this state, the joints of the opposing edges are joined. A method for manufacturing a liner-lined pipe, characterized in that: