JP3228368B2 - Method for manufacturing flexible fluid transport tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a flexible fluid transport pipe used to transport a fluid such as petroleum, chemicals or water.

[0002]

2. Description of the Prior Art Flexible fluid transport tubes are typically manufactured as follows. First, an interlock tube is prepared by spirally winding a stainless steel tape having an S-shaped cross section and meshing with it, and an outer tube is extrusion-coated with a plastic tube to form an inner tube. The interlock pipe is for obtaining the external pressure strength or the side pressure strength of the inner pipe, and the plastic pipe is for preventing leakage of the fluid flowing inside.

Next, a circumferential reinforcing member made of, for example, a metal band is spirally wound at a short pitch around the outer periphery of the inner tube. This circumferential reinforcing member constitutes a reinforcing layer against hoop stress generated by the pressure of the transport fluid. Next, a plurality of axial reinforcing members made of, for example, a metal band are spirally wound around the outer periphery at a long pitch. This axial reinforcing member constitutes a reinforcing layer against tension applied to the fluid transport pipe. Finally,
The outer periphery of the axial direction reinforcing member is extrusion-coated with a protective sheath made of plastic to complete a flexible fluid transport tube.

[0004]

Conventionally, steel materials are generally used for the axial direction reinforcing member and the circumferential direction reinforcing member. For example, such as a flexible fluid transport pipe suspended from a deep sea offshore oil field or the like. In the case of a flexible fluid transport pipe which is subjected to a large tension due to its own weight, the thickness of the axial reinforcing member must be increased to withstand the tension. However, as the thickness of the axial reinforcing member increases, it becomes extremely difficult to spirally wind the axial reinforcing member during manufacturing.

When the thickness of the reinforcing member in the axial direction is increased, not only the weight of the fluid transport pipe is increased, but also the flexibility is reduced, so that it is difficult to handle and lay the fluid transport pipe. In order to reduce the weight of the fluid transport pipe, it is effective to use FRP (fiber reinforced plastic) or a metal having a higher strength than steel as the axial direction reinforcing member, but since these materials are less likely to deform than steel, , Spiral winding is difficult. A similar problem can occur with circumferential reinforcement members when the pressure of the transported fluid is high.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to easily spiral an axial reinforcing member or a circumferential reinforcing member when manufacturing a flexible fluid transport tube to which high tension or high internal pressure is applied. An object of the present invention is to provide a manufacturing method that can be wound.

[0007]

In order to achieve this object, the present invention is to spirally wind a circumferential reinforcing member at a short pitch around the outer periphery of an inner pipe through which a fluid passes, and to apply an axial reinforcing member around the outer periphery. Spiral winding at a long pitch, in a method of manufacturing a flexible fluid transport tube by covering the outer periphery with a protective sheath, when spirally winding at least one of the axial reinforcing member and the circumferential reinforcing member, a belt-shaped The reinforcing member is spirally wound with two or more layers laminated via an uncured adhesive layer, and after winding, the adhesive layer is cured to integrate the laminated reinforcing members.

[0008]

When the axial direction reinforcing member or the circumferential direction reinforcing member has a large thickness, it is difficult to perform spiral winding, but when the thickness is small, the spiral winding can be easily performed. Therefore, in the present invention, a reinforcing member having a required thickness is formed by laminating two or more layers of a thin band-shaped reinforcing member. When spirally wound, the reinforcing member having two or more layers is formed of an uncured adhesive layer. The layers were stacked so that the layers could be slipped from each other, so that the spiral winding could be easily performed. Then, after winding, the adhesive layer was cured by heating or the like, and the laminated reinforcing members were integrated to obtain a reinforcing member having a thickness necessary for strength. The material of the reinforcing member is not particularly limited, but it is desirable to use FRP when the weight of the flexible fluid transport pipe is required.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a flexible fluid transport pipe manufactured by the manufacturing method of the present invention. This flexible fluid transport tube is manufactured as follows.

First, an interlock tube 1 is prepared by spirally winding a stainless steel tape having an S-shaped cross section and meshing with it, and an outer tube is extrusion-coated with a plastic tube 2 to form an inner tube 3. The material of the plastic tube 2 is usually cross-linked polyethylene or polyamide. Next, a circumferential reinforcing member 4 is spirally wound around the outer circumference of the inner tube 3 at a short pitch. The circumferential reinforcing member 4 is formed by forming a steel strip into a concave cross section.
This is spirally wound into two layers at a short pitch so that the inner and outer layers mesh with each other.

Next, a plurality of first-layer axial reinforcing members 5A are spirally wound around the outer periphery of the circumferential reinforcing member 4 at a long pitch in one direction, and a plurality of second-layer axial reinforcing members 5B are formed thereon. Spiral winding in the opposite direction at the main pitch. The reason why the axial direction reinforcing member is wound in two layers with the winding direction reversed is to balance the torque.

As shown in FIG. 2, each of the axial reinforcing members 5A and 5B is formed by laminating two FRP bands 6 with an adhesive layer 7 therebetween so as to obtain a required strength.
The adhesive layer 7 is in an uncured state when spirally winding the axial direction reinforcing members 5A and 5B, allowing relative sliding of the two FRP bands 6 to facilitate winding. is there. After the winding, the adhesive layer 7 is cured by heating, and the two FRP bands 6 are integrated. As a result, the axial reinforcing members 5A and 5B are in the same state as when the thick FRP band is wound from the beginning.

The material of the FRP band 6 is, for example, glass fiber or aramid fiber (for example, Kevlar fiber manufactured by DuPont).
Alternatively, high-strength fibers such as carbon fibers are used as reinforcing fibers, and these reinforcing fibers are solidified with a resin such as an epoxy resin or a polyamide resin as a matrix. The material of the adhesive layer 7 is, for example, epoxy resin or epoxy resin. And the like.

Finally, a protective sheath 8 is extrusion-coated on the outer periphery of the axial direction reinforcing member 5B. The material of the protective sheath 8 is usually polyethylene or polyamide. This completes the flexible fluid transport tube.

Next, the results of a winding test of the axial reinforcing member will be described. The following three types of axial reinforcing members were tested. 2mm thick FRP band + 1mm thick adhesive layer + 2mm thick F
RP band 4 mm thick FRP band 3.5 mm thick FRP band + 1 mm thick adhesive layer + 3.5
FRP band of mm thickness The material of the FRP band used here is a material in which glass fibers are used as reinforcing fibers and an epoxy resin is used as a matrix. The reinforcing fiber volume content is about 60%, and the width is 12 mm.
The adhesive layer is a non-woven fabric impregnated with epoxy resin,
The width is the same as the FRP band.

These reinforcing members were spirally wound around a core having an outer diameter of 90 mm at an angle of 35 ° (angle with respect to the core axis). The results were as follows. Could easily be spirally wound. The reinforcing member was too thick, and when it was attempted to be spirally wound, cracking occurred, and spiral winding could not be performed under the above conditions. Although the reinforcing member of (1) could be spirally wound, the reaction force was large because the thickness of one FRP band was larger, which was the limit of the windable range.

[0017] The above test was carried out by measuring the thickness of the FRP band,
As a result of changing the combination of the winding diameter and the winding angle, assuming that the thickness t (mm) of one reinforcing member is t (mm) when the winding diameter is D (mm) and the winding angle with respect to the axis is θ °, t ≦ When the condition of 0.008πD / sinθ was satisfied, it was found that spiral winding could be easily performed.

If FRP or high-strength metal is used for the axial reinforcing member, the weight can be reduced as compared with the case where a steel strip is used, and a lightweight flexible fluid transport pipe can be constructed. In the above embodiment, the axial direction reinforcing member has been described, but the same applies to the circumferential direction reinforcing member.

[0019]

As described above, according to the present invention, two or more belt-like reinforcing members are spirally wound in a state of being laminated via an uncured adhesive layer, so that an axial reinforcing member or a circumferential reinforcing member is provided. The member can be easily spirally wound even when the thickness required for the strength is large, and after the winding, the laminated reinforcing member is integrated by curing the adhesive layer, so that the thickness having high strength from the beginning. The same condition is obtained as a thick axial or circumferential reinforcing member is spirally wound. Therefore, a high-strength flexible fluid transport pipe can be easily manufactured.

Further, the reinforcing member made of FRP or high-strength metal is hardly plastically deformed, and it has been considered that the spiral winding is difficult. However, even when such a reinforcing member is used, the spiral winding can be easily performed. By using a reinforcing member made of FRP or high-strength metal, a lightweight flexible fluid transport pipe can be manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a flexible fluid transport pipe manufactured by a manufacturing method of the present invention.

FIG. 2 is a perspective view showing an axial reinforcing member used in the fluid transport pipe of FIG. 1;

[Explanation of symbols]

 1: Interlock pipe 2: Plastic pipe 3: Inner pipe 4: Circumferential reinforcing member 5A, 5B: Axial reinforcing member 6: FRP band 7: Adhesive layer 8: Protective sheath

Continuation of the front page (56) References JP-A-3-49937 (JP, A) JP-A-2-225893 (JP, A) JP-A-50-24371 (JP, A) JP-A-5-508466 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 70/06-70/10 B29D 23/00-23/24 F16L 11/08

Claims (2)

(57) [Claims] 1. A circumferential reinforcing member is spirally wound at a short pitch around the outer periphery of an inner pipe through which a fluid passes, and an axial reinforcing member is spirally wound at a long pitch around the outer periphery thereof, and the outer periphery is covered with a protective sheath. In the method for manufacturing a flexible fluid transport pipe, when at least one of the axial direction reinforcing member and the circumferential direction reinforcing member is spirally wound, the belt-like reinforcing member is provided with two layers via an uncured adhesive layer. A method for manufacturing a flexible fluid transport pipe, comprising: spirally winding in a laminated state, curing the adhesive layer after winding, and integrating the laminated reinforcing members. 2. The method according to claim 1, wherein the thickness t (mm) of one of the belt-like reinforcing members is such that the winding diameter is D.
(Mm), when the winding angle with respect to the axis is θ °, t
≦ 0.008πD / sinθ.