JPH0335550B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a high-pressure flexible pipe that is suspended in the sea to transfer high-pressure fluid, such as a pipeline connecting a seabed port and a manifold center in, for example, an undersea oil production system. (Prior Art) FIG. 1 is a cross-sectional view of an example of a high-pressure flexible pipe. In the drawings, 1 is a plastic pipe with a high-pressure fluid transfer passage 1a formed inside;
It is formed by extrusion molding of plastic materials such as polyethylene, polybutene, polyetheretherketone, and nylon. On the outer periphery of the plastic pipe 1, an internal pressure reinforcing layer 3 is provided by winding a metal tape such as iron tape or stainless steel tape through a seat cloth tape wrapping layer 2. A plastic sheath 5 made of extruded polyvinyl chloride, polyethylene, etc. is provided on the outer periphery with a pressure tape layer 4 interposed therebetween. On the outer periphery of the plastic sheath 5, double axial force reinforcing layers 7 and 9 are formed by winding a large number of iron wires through floor cushion tape wrapping layers 6 and 8 as reinforcement in the axial direction of the pipe.
is provided, and the outermost layer is a pressure tape layer 1.
An anti-corrosion layer 11 formed by extruding a plastic material such as polyvinyl chloride or polyethylene is provided through the anti-corrosion layer 11. Note that in the above, the presser tape layer 4 and the plastic sheath 5 on the internal pressure resistant reinforcing layer 3 are omitted, and the axial force reinforcing layer 7 is applied on the internal pressure resistant reinforcing layer 3 via the seat cloth tape wrapping layer 6. Moreover, the axial force reinforcing layer may be one layer if necessary. (Problem to be solved) As mentioned above, high-pressure flexible pipes that have been conventionally used in submarine oil production systems, etc., have metal tape such as iron tape or stainless steel tape as the internal pressure-resistant reinforcing layer 3 of the plastic pipe 1. Also, metal wires such as iron wire and steel wire have been used as the axial force reinforcing layers 7 and 9. When offshore oil production was conventionally carried out on the shallow seabed, such high-pressure flexible pipes could be hung from the sea to connect equipment on the seabed and transport the production fluid (crude oil) to the sea. . but,
As offshore oil production moves to the deep seabed (recently, the aim is to mine at depths of 300 meters or more), the following problems have arisen, and the development of lighter, more reliable, high-pressure flexible pipes is desired. It is rare. The underwater weight of high-pressure flexible pipes is determined by the metal body used, but conventional ones use iron for the internal pressure-resistant reinforcing layer and the axial force reinforcing layer, and have a large underwater weight, such as buoys, restraints, etc. The equipment requires large equipment and is difficult to hang. During maintenance and inspection, when the water depth exceeds 50 meters, it is difficult for divers to visually inspect the vessel, so it is necessary to remove it, but due to its large weight, it is time-consuming. Since a metal body such as iron is used, the metal parts of the internal pressure reinforcing layer and the axial force reinforcing layer are likely to break due to fatigue due to bending due to long-term oscillations in the sea, resulting in poor long-term reliability. (Means for Solving the Problems) The present invention provides a high-pressure flexible pipe that solves the above-mentioned problems, and has the following characteristics:
In the high-pressure flexible pipe shown in the figure, the internal pressure-resistant reinforcing layer has a plastic protective layer on the outer periphery of the fiber-reinforced plastic, and a tape with fitting grooves in opposite directions on the left and right is fitted into the fitting grooves. The axial force reinforcing layer is formed by winding a large number of filaments having a plastic protective layer on the outer periphery of fiber-reinforced plastic, and the tape and the filaments are uncured or semi-cured. The reason is that it is wound on a plastic pipe and then hardened by heating after winding. (Example) The overall structure of the high-pressure flexible pipe of the present invention is not particularly different from that shown in FIG. The internal pressure-resistant reinforcing layer 3 in the present invention is made of glass fiber, carbon fiber, polyamide fiber, etc., and thermosetting resin such as unsaturated polyester resin, epoxy resin, silicone resin, etc., as shown in FIG. 2A. Fiber-reinforced plastic impregnated with and hardened 3
A high tensile strength tape 30 having a plastic protective layer 32 formed by extruding a plastic material such as nylon resin on the outer periphery of the tape 1 and having fitting grooves 33 in opposite directions on the left and right sides is attached as shown in FIG. The above-mentioned fitting grooves 33 are fitted into each other and the seat fabric tape is wound on the plastic pipe 1 via the winding layer 2. In addition, the axial force reinforcing layers 7 and 9 are made of nylon resin or the like on the outer periphery of fibre-reinforced plastic filament bodies 71 and 91 made of the same material as described above, as shown in FIG. plastic protective layer 7
It is constructed by winding a large number of high tensile strands 70, 90 having a diameter of 2,92. Note that the high tensile strength tape 30 and the high tensile strength filament bodies 70, 90 are both wound with the fiber reinforced plastics 31, 71, 72 in an uncured or semi-cured state, and heated after winding to harden them. . This is because when winding an already cured fiber-reinforced plastic tape or filament, the tape or filament remains under stress due to the relatively high elastic modulus of the reinforced plastic. There is a problem that stress cracking may occur and accidents such as wire breakage may occur, making it difficult to guarantee long-term life.
This is to solve this problem. In the high-pressure flexible pipe as shown in FIG. 1, which is equipped with the internal pressure-resistant reinforcing layer 3 and the axial force reinforcing layers 7 and 9 constructed as described above, the pressure-wrap tape layer 4 and the plastic sheath 5 on the internal pressure-resistant reinforcing layer 3 are It goes without saying that the axial force reinforcing layer may be omitted or the axial force reinforcing layer may be a single layer, and each floor tape wrapping layer and the outermost plastic protective layer 11 may be omitted as necessary. Incidentally, the results of comparing the weight and bending resistance of high-pressure flexible pipes with an inner diameter of 6 inches and a normal pressure of 80 Kgf/cm ² are shown in the following table.

[Table] (Effects of the Invention) The above-described high-pressure flexible pipe of the present invention provides the following effects. It is extremely lightweight because it does not use metals as a constituent material and is made of plastic with a specific gravity of about 0.95 to 1.3. As a result, the buoy, restraining device, etc. can be made smaller and easier to hang, as well as easier to retrieve. Since no metal material is used, there is no risk of component breakage due to fatigue or damage due to corrosion due to long-term bending, etc. Since the internal pressure reinforcing layers are wound so as to fit into the fitting grooves provided in the high tensile strength tape, the tape has good internal pressure resistance. The fiber-reinforced plastic that constitutes the internal pressure-resistant reinforcing layer and the axial force reinforcing layer is wound in an uncured or semi-cured state, and then heated and cured after winding.
There is no risk of stress cracking,
Long-term lifespan can be guaranteed.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of an example of a high-pressure flexible pipe, Figure 2-A is a cross-sectional view of a high tensile strength tape used in the present invention, Figure 2-B is a partial vertical cross-sectional view showing the rolled state, and Figure 3 is a cross-sectional view of a high tensile strength striatum. FIG. 4 is a schematic diagram of the bending test device. 1... Plastic pipe, 3... Internal pressure resistant reinforcing layer, 7, 8... Axial force reinforcing layer, 30... High tensile strength tape, 31... Fiber reinforced plastic, 32...
Reinforcement layer, 33... Fitting groove, 70, 90... High tensile strength filament, 71, 91... Fiber reinforced plastic, 72, 92... Reinforcement layer.

Claims (1)

[Claims] 1. An internal pressure-resistant reinforcing layer formed by winding a high tensile strength tape and an axial force reinforcing layer formed by winding a large number of high tensile strength filaments on the outside of a plastic pipe having a high pressure fluid transfer passage inside. In the high-pressure flexible pipe, the internal pressure-resistant reinforcing layer has a plastic protective layer on the outer periphery of the fiber-reinforced plastic, and a tape with fitting grooves in opposite directions on the left and right is wound by fitting the fitting grooves into each other. The axial force reinforcing layer is made by winding a large number of filaments having a plastic protective layer around the outer periphery of fiber-reinforced plastic, and the tape and the filaments are wrapped around the plastic in an uncured or semi-cured state. A high-pressure flexible pipe characterized by being wound around the pipe and hardened by heating after winding. 2. The high-pressure flexible pipe according to claim 1, wherein the fiber-reinforced plastic is a glass fiber-reinforced epoxy resin, and the protective layer on the outer periphery is a nylon resin coating layer.