JPH0718096U - Flexible fluid transport tube end structure - Google Patents

Abstract

(57) [Summary] [Constitution] In the case where the terminal unit 11 is attached to the end of the flexible fluid transport pipe 1, the casing 21 of the terminal unit 11 is extended from the outer periphery of the protective sheath 9 of the flexible fluid transport pipe 1. The heat shrinkable tube 29 was covered over the outer circumference of the. [Effect] The external seal 25 is not directly subjected to water pressure, seawater or the like can be prevented from entering the inside of the terminal unit, and the reliability and life of the terminal structure of the flexible fluid transport pipe are significantly improved. be able to.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 TECHNICAL FIELD The present invention relates to a terminal structure of a flexible fluid transportation pipe used for transporting high-pressure fluid such as crude oil and natural gas mined from an offshore oilfield.

[0002]

[Prior art]

 A conventional flexible fluid transport tube terminal structure is shown in FIG. A flexible fluid transport pipe 1 for transporting a high-pressure fluid such as crude oil or natural gas is provided on the outer circumference of a plastic inner pipe 3 so that the circumference of a steel strip or steel strip can withstand the circumferential stress generated by the internal fluid pressure. The direction reinforcing body 5 is spirally wound at a short pitch, and the axial direction reinforcing body 7 made of metal or fiber reinforced plastic is spirally wound around the outer circumference at a long pitch so as to withstand tension, and a plastic protective sheath is provided around the outer circumference. It has a structure in which 9 is covered.

A terminal unit 11 is attached to the end of the fluid transport pipe 1 of this type for connection with other devices and pipes. The terminal unit 11 has a connecting fitting 13 attached to the end of the plastic inner tube 3. An internal seal 15 is arranged between the connection fitting 13 and the plastic inner pipe 3 to prevent leakage of fluid in the pipe, and is fixed by tightening with an internal clamp 17. A fixing ring 19 is arranged on the outer periphery of the end of the axial reinforcing body 7, and the end of the axial reinforcing body 7 is bent and fixed to the fixed ring 19 by welding or the like.

The fixing ring 19 and the connecting fitting 13 are integrated by bringing the inward flange portion of the rear end of the casing 21 into contact with the rear end surface of the fixing ring 19 and screwing the tip end of the casing 21 into the connecting fitting 13. Has been converted. The space inside the casing 21 is filled with a thermosetting resin 23, whereby the end of the circumferential reinforcing member 5 is fixed. Further, an outer seal 25 is arranged between the casing 21 and the protective sheath 9 to prevent invasion of seawater or the like, and is fixed by being tightened by an external fastener 27.

[0005]

[Problems to be solved by the device]

 In the conventional structure, a gap is formed between the outer seal 25 and the protective sheath 9 due to the variation in the outer diameter of the flexible fluid transport pipe 1, or when the flexible fluid transport pipe 1 is used on a deep seabed, the flexible fluid transport pipe 1 has a hydraulic pressure. The diameter of the outer seal 25 is reduced due to the shrinkage of the outer seal 25, seawater enters the terminal unit 11, and the metal reinforcements 5 and 7 of the flexible fluid transport pipe 1 and various terminals in the terminal unit 11 There was a problem of causing corrosion to the metal fittings. An object of the present invention is to provide a terminal structure of a flexible fluid transport pipe that is resistant to external water intrusion.

[0006]

[Means for Solving the Problems]

 In order to achieve this object, the present invention is for connecting the end of a flexible fluid transportation pipe provided with a mechanical reinforcement layer and a protective sheath to the outer end of a plastic inner pipe to other equipment. Connection fitting, an inner seal that seals between the connection fitting and the plastic inner tube, a fixing ring that fixes the end of the mechanical reinforcement layer, a casing that integrates the fixing ring and the connection fitting, and a casing. A terminal unit including an external seal for keeping a liquid-tight space between the protective sheath and the protective sheath is attached, and a heat shrinkable tube is covered from the outer periphery of the protective sheath to the outer periphery of the casing.

[0007]

[Action]

 In this case, the heat-shrinkable tube is pressed from the outside by water pressure against the protective sheath and the casing, and water pressure is not directly applied to the outer seal portion, so that it is difficult for water to enter the terminal unit.

[0008]

【Example】

 Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. A feature of the terminal structure of the flexible fluid transport pipe is that the heat shrinkable tube 29 is covered from the outer circumference of the protective sheath 9 to the outer circumference of the casing 21. In order to facilitate the coating of the heat-shrinkable tube 29, the end portion of the casing 21 and the outer peripheral surface of the outer fastening member 27 are tapered, and the taper ring 31 is brought into contact with the end surface of the outer fastening member 27. Since the configuration other than the above is the same as that of the conventional terminal structure shown in FIG. 2, the same parts are designated by the same reference numerals and the description thereof will be omitted.

The taper ring 31 may be formed integrally with the external fastener 27. Further, in order to further enhance the water infiltration prevention ability, it is effective to put a sealant such as putty between the casing 21 and the external fastening member 27, between the external fastening member 27 and the protective sheath 9, and the like. Furthermore, in order to protect the heat-shrinkable tube 29 from external damage, it is advisable to wrap a plastic tape, a metal tape (such as stainless steel tape) or a metal wire around the outer circumference of the heat-shrinkable tube 29.

In order to confirm the effect of the present invention, a flexible fluid transportation pipe having an inner diameter of 101 mm and an outer diameter of 155 mm was cut into a length of 3 m, and the terminal structure of the present invention shown in FIG. The sample was subjected to an external pressure resistance test for 24 hours at an external water pressure of 65 kg / cm ² . After the test was completed, the protective sheath near the terminal structure was peeled off to confirm the presence or absence of water intrusion, and no trace of water intrusion was observed.

For comparison, the same external pressure resistance test was performed on a sample in which the conventional terminal structure shown in FIG. 2 was attached to both ends of the same 3 m flexible fluid transport pipe, and after the test, protection near the terminal structure was performed. When I peeled off the sheath, a lot of water gushed out. From these results, it was confirmed that the terminal structure of the present invention is effective in preventing water infiltration.

[0012]

[Effect of device]

 As described above, according to the present invention, by covering the outer periphery of the protective sheath with the outer periphery of the casing with the heat-shrinkable tube, invasion of seawater or the like into the terminal structure can be prevented, and the flexibility can be improved. The reliability and life of the terminal structure of the fluid transportation pipe can be significantly improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a terminal structure of a flexible fluid transportation pipe according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a terminal structure of a conventional flexible fluid transport pipe.

[Explanation of symbols]

 1: Flexible fluid transport pipe 3: Plastic inner pipe 5: Circumferential reinforcement 7: Axial reinforcement 9: Protective sheath 11: Terminal unit 13: Connection fitting 15: Internal seal 19: Fixing ring 21: Casing 25: External seal 29: Heat shrink tube 31: Tapered ring

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[Procedure amendment]

[Submission date] November 26, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

Claims (1)

[Scope of utility model registration request] 1. A connection fitting for connecting a pipe end to another device or the like is connected to an end of a flexible fluid transport pipe provided with a mechanical reinforcing layer and a protective sheath on the outer circumference of a plastic inner pipe. An internal seal that seals between the metal fittings and the plastic inner tube,
In a case where a terminal unit including a fixing ring for fixing the end of the mechanical reinforcing layer, a casing integrating the fixing ring and the connection fitting, and an external seal for keeping the casing and the protective sheath liquid-tight is attached. A terminal structure for a flexible fluid transport pipe, characterized in that a heat-shrinkable tube is covered from the outer circumference of the protective sheath to the outer circumference of the casing.