JP4177311B2 - End fitting for fluid transport pipe - Google Patents

Description

  The present invention relates to a terminal fitting for a flexible fluid transport pipe used to transport a high-pressure fluid such as crude oil or natural gas.

  As shown in FIG. 4, this type of fluid transport pipe 10 reinforces the strength in the circumferential direction by spirally winding a steel concave reinforcing material at a short pitch around the outer circumference of a plastic inner pipe 11 such as a crosslinked polyethylene pipe. An internal pressure reinforcing layer 12, an axial force reinforcing layer 13 that reinforces the strength in the axial direction by spirally winding a flat steel reinforcing material at a long pitch, and an outer sheath 14 made of plastic. During use of the fluid transport pipe 10, gas contained in the high-pressure fluid transported through the transport pipe 10 penetrates the inner pipe 11, and the internal pressure reinforcing layer 12 between the inner pipe 11 and the outer sheath 14 and It stays in the gap of the axial force reinforcing layer 13. Although the amount of gas penetrating the inner tube 11 is very small, the gas pressure becomes high during long-term use, and the external sheath 14 may expand and be damaged by this pressure.

  Therefore, conventionally, it is possible to prevent the outer sheath 14 from being damaged by discharging the gas staying between the inner tube 11 and the outer sheath 14 of the fluid transport tube 10 from the longitudinal end of the fluid transport tube 10 to the outside. Terminal fittings that have been developed have been developed.

  This terminal fitting is configured as shown in FIG. That is, an end body 15 attached to the end of the inner pipe 11 of the fluid transport pipe 10 via the packing 16, a front part is held by the end body 15, and a rear part is fitted to the outer sheath 14 via the packing 18. An outer case 17 that is mounted so that each end of the inner tube 11, the internal pressure reinforcing layer 12, and the axial force reinforcing layer 13 is formed so as to form a space portion 19 therebetween, and the space portion 19. An axial force reinforcing layer holder 20 that is provided and fixes the end of the axial force reinforcing layer 13, a room temperature curable filler 21 made of an epoxy resin that is filled in the space 19 and solidified, and the inner tube 11. And a gas discharge means 22 for discharging the gas staying between the outer sheaths 14.

  More specifically, the axial force reinforcing layer holder 20 is made of an annular body made of steel, and the tip of the axial force reinforcing layer 13 is bent outward along the holder 20 and fixed to the holder 20 by welding. The gas discharge means 22 is disposed in the space portion 19 between the flange portion 17a integrally provided at the rear portion of the outer case 17 and the axial force reinforcing layer holder 20, and the end portion of the outer sheath 14 on the inner side. A degassing annular block 23 having a degassing space 24 opposed to the degassing hole 14a, a gas introduction hole 25 having an inlet side communicating with the degassing annular block 23, and an end. The gas outlet hole 26 provided in the side wall of the body 15 and one end portion are connected to the outlet side of the gas introduction hole 25 and the other end portion is connected to the gas outlet hole 26 and is piped to the space portion 19. , A plastic gas made of a long tetrafluoroethylene resin (PTFE) or the like that conducts and discharges the gas staying between the inner tube 11 and the outer sheath 14 from the gas introduction hole 25 side to the gas outlet hole 26 side. And a conduit 27. Reference numeral 28 denotes a packing for sealing between the gas venting annular block 23 and the outer sheath 14, and 29 is a packing for sealing between the gas venting annular block 23 and the flange portion 17a of the outer case 17 (see Patent Document 1).

Japanese Utility Model Publication No. 2-59393 (4th page, 1st line to 5th page, 16th line and FIG. 1)

  However, in the conventional terminal fitting, since the gas discharge means 22 requires the gas venting annular block 23, the number of parts of the terminal fitting increases, the structure becomes complicated, and it is not easy to assemble the terminal fitting. In addition, since the terminal fittings become long and large, it is not easy to install the terminal fittings at the laying site where there is not enough space for installation. There was a problem to up.

  Further, since the gas conduction pipe 27 of the gas discharge means 22 becomes long, it is not easy to connect the gas conduction pipe 27 to the narrow space 19 in the outer case, and the gas conduction pipe 27 is made of a flexible plastic. When the terminal fitting is used for a long time in a place where the usage environment is severe, there is a possibility that the gas conduction pipe 27 may be deteriorated or buckled, so that the gas cannot be discharged from the terminal fitting satisfactorily.

  Further, since the gas vent hole 14a is provided in the outer sheath 14 of the fluid transport pipe 10, the stress is concentrated on the gas vent hole 14a due to the longitudinal tension and elongation acting on the fluid transport pipe 10 and creep. As a result, there is a possibility that the outer sheath 14 may be fatigued and destroyed, and there is a problem that the quality and reliability of the terminal fitting are lowered.

  The present invention has been made in view of the above problems, and its object is to simplify the structure and reduce the size, improve the workability of assembly and installation, reduce the cost, and improve the gas. An object of the present invention is to provide an end fitting for a fluid transport pipe excellent in quality and reliability.

  In order to achieve the above object, an invention described in claim 1 of the present invention includes an internal pressure reinforcing layer for reinforcing the strength in the circumferential direction and an axial force reinforcing layer for reinforcing the strength in the axial direction on the outer periphery of the inner tube. An end body attached to the end of the inner pipe of the fluid transport pipe having an outer sheath, a front part held by the end body, and a rear part fitted into the outer sheath, the inner pipe, the inner pressure reinforcing layer, and the shaft An outer case mounted so that a space portion is formed between each end portion of the force reinforcing layer, and an axial force reinforcing layer holder provided in the space portion and fixing the end portion of the axial force reinforcing layer And a filler for filling the space, and a gas fitting for discharging a gas staying between the inner tube and the outer sheath. The gas guide is provided in the layer holder and communicates with the gap between the inner tube and the outer sheath. A hole, a gas outlet hole provided in the peripheral wall of the outer case in the vicinity of the outlet side of the gas inlet hole, one end connected to the outlet side of the gas inlet hole, and the other end connected to the gas outlet hole, or a gas A gas conduction pipe that is piped in the space portion so as to extend outward through the lead-out hole and that conducts the gas staying between the inner pipe and the outer sheath from the gas introduction hole side to the gas lead-out hole side and exhausts it. Prepare.

  According to a second aspect of the present invention, in the end fitting of the fluid transport pipe according to the first aspect, the gas outlet hole of the gas discharge means also serves as a filler injection hole for filling the space with the filler. It is characterized by this.

  The invention described in claim 3 of the present invention is the end fitting of the fluid transport pipe according to claim 1 or 2, wherein the outer peripheral surface of the internal pressure reinforcing layer of the fluid transport pipe, the inner peripheral surface of the axial force reinforcing layer holder, and A sealing material is provided so as to fill a gap formed between the axial force reinforcing layers.

  According to the terminal fitting of claim 1 of the present invention, the gas staying between the inner pipe and the outer sheath of the fluid transport pipe is led to the gas introduction hole provided in the axial force reinforcing layer holder, and the gas discharge An annular block for venting of the means becomes unnecessary, and the number of parts is reduced. In addition, by arranging the gas outlet hole in the vicinity of the outlet side of the gas inlet hole, the length of the gas conduction pipe piped in the space part in the outer case is shortened, and the structure of the terminal fitting is simplified. It becomes easy to assemble the terminal fitting. Further, the annular block for venting is not required, the length of the terminal fitting is shortened, and the terminal fitting is reduced in size. Therefore, it is easy to install the terminal fitting even in the laying site where the arrangement space is not sufficient. Therefore, the workability of assembling and installing the terminal fitting is improved, and the cost can be reduced.

  In addition, the length of the gas conduction pipe that is piped into the space in the outer case is shortened, and the bending of the gas conduction pipe and the portion that bends sharply are reduced. The flow resistance of the gas flowing through the gas conduit decreases and the gas flows easily, and the gas staying between the inner tube and the outer sheath can be discharged well from the terminal fitting. The quality and reliability of the metal fittings can be improved.

  In addition, since the gas conduit is short and less bent, it is possible to use a metal conduit that is more rigid than plastic and that is superior in strength and durability. The terminal bracket can be used stably even in severe locations.

  According to the terminal fitting according to claim 2 of the present invention, since the trouble of newly providing a gas outlet hole in the outer case can be omitted, the inner diameter of the gas outlet hole is formed to be relatively large in order to inject the filler. Connecting the other end of the conducting pipe to the gas outlet hole, or extending the gas conducting pipe to the space in the outer case so as to extend outward through the gas outlet hole, facilitates the terminal. The workability of the metal fitting can be further improved.

  According to the terminal fitting of claim 3 of the present invention, the filler filled in the space in the outer case includes the outer peripheral surface of the internal pressure reinforcing layer of the fluid transport pipe, the inner peripheral surface of the axial force reinforcing layer holder, and the shaft. Through the gap formed between the force reinforcement layers, it can be surely prevented from entering the gap between the inner pipe and the outer sheath of the fluid transport pipe, and the gas staying between the inner pipe and the outer sheath can be better discharged. it can. Further, since the sealing material is provided in the vicinity of the portion where it contacts the internal pressure reinforcing layer of the axial force reinforcing layer holder, the end of the axial force reinforcing layer fixed to the axial force reinforcing layer holder and the filler are blocked by the sealing material. Since the end of the axial force reinforcing layer and the filler are joined to the nectar and firmly fixed to each other, the end fitting is firmly fixed to the end of the fluid transport pipe, increasing the strength and reliability. Can be further enhanced.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an upper half sectional front view showing an embodiment of a terminal fitting of a fluid transport pipe 10 according to the present invention. In addition, the same code | symbol is attached | subjected to the thing of the same structure as what was described in the prior art (refer FIG. 4).

  As shown in FIG. 1, the terminal fitting of the present embodiment reinforces the strength in the circumferential direction in which a steel concave reinforcing material is spirally wound at a short pitch around the outer periphery of a plastic inner tube 11 such as a crosslinked polyethylene pipe. A flexible fluid transport pipe having an internal pressure reinforcing layer 12, an axial force reinforcing layer 13 for reinforcing the strength in the axial direction by spirally winding a flat steel reinforcing material at a long pitch, and an outer sheath 14 made of plastic. 10, an end body 15 attached to the end portion of the inner tube 11 via a packing 16, a front portion is held by the end body 15, and a rear portion is fitted to the outer sheath 14 via a packing 18, An outer case 17 that is mounted so that a space portion 19 is formed between the end portions of the tube 11, the internal pressure reinforcing layer 12, and the axial force reinforcing layer 13, and the space portion 19. Axial force reinforcement 13, an axial force reinforcing layer holder 20 that fixes the end of the space 13, a room temperature curable filler 21 made of an epoxy resin that is filled in the space 19 in a liquid state and solidified, the inner tube 11, and the outer sheath 14. And a gas discharging means 30 for discharging the gas staying therebetween.

  More specifically, a seal fitting 31 whose front end is pressed against the packing 16 is attached to the rear side portion of the end body 15 on the inner tube 11 side by a bolt 32 coaxially with the inner tube 11, and the bolt 32 is tightened. Thus, the front end of the seal fitting 31 is pressed against the packing 16 to seal the inner tube 11 and the end body 15 in an airtight and liquid tight manner.

  The axial force reinforcing layer holder 20 is made of a steel annular body, and a sheath holder made of a steel sleeve inserted into the end portion of the outer sheath 14 and the outer peripheral surface thereof by crimping into an enlarged diameter portion formed inside the rear portion. 33 is fitted. The front end of the axial force reinforcing layer 13 bent from the inside to the outside along the holder 20 is fixed by welding to the front end side of the holder 20.

  Moreover, in the clearance gap formed between the outer peripheral surface of the internal pressure reinforcement layer 12 of the fluid transport pipe 10, the inner peripheral surface of the axial force reinforcement layer holder 20, and the axial force reinforcement layer 13, as shown in FIGS. A sealing material 34 made of resin, compound material or the like is provided so as to fill the gap.

  When such a sealing material 34 is provided, the filler 21 filled in the space 19 in the outer case 17 is used as the outer peripheral surface of the internal pressure reinforcing layer 12 of the fluid transport pipe 10 and the axial force reinforcing layer holder 20. The inner tube 11 and the outer sheath 14 are reliably prevented from entering the gap between the inner tube 11 and the outer sheath 14 of the fluid transport tube 10 through the gap formed between the inner peripheral surface of the tube and the axial force reinforcing layer 13. The gas staying between them can be discharged better. In addition, since the sealing material 34 is provided in the vicinity of a portion where the sealing member 34 contacts the internal pressure reinforcing layer 12 of the axial force reinforcing layer holder 20, the end portion of the axial force reinforcing layer 13 fixed to the axial force reinforcing layer holder 20 and the filler 21 Is not interrupted by the sealing material 34, and the end of the axial force reinforcing layer 13 and the filler 21 are joined to the nectar and firmly fixed to each other. It is preferable because it can be fixed to increase the strength and the reliability can be further improved.

  A seal fitting 35 whose front end presses against the packing 18 is coaxial with the outer sheath 14 at the rear portion of the flange portion 17a provided integrally with the rear portion of the outer case 17 (see FIG. 1) or separately. By attaching the bolt 36 and tightening the bolt 36, the front end of the seal fitting 35 is pressed against the packing 18, and the outer sheath 14 and the flange portion 17a of the outer case 17 are hermetically and liquid-tightly sealed. .

  As shown in FIG. 1, the gas discharge means 30 is provided in the axial force reinforcing layer holder 20, and includes a gas introduction hole 37 communicating with the gap between the inner tube 11 and the outer sheath 14 of the fluid transport tube 10, and a gas introduction hole. 37 is provided on an arbitrary peripheral wall of the outer case 17 in the vicinity of the outlet side 37, preferably on the upper peripheral wall, and also serves as a filler injection hole 41 for filling the space portion 19 in the outer case 17 with the filler 21. The gas lead-out hole 38 is connected to a one-touch connection type pipe connector 39 (commercially available) having one end attached to the outlet side of the gas introduction hole 37, and the other end is extended outward by a predetermined length through the gas lead-out hole 38. As described above, the gas guide is connected to the space 19 in the outer case 17 and the gas staying between the inner tube 11 and the outer sheath 14 is conducted from the gas introduction hole 37 side to the gas outlet hole 38 side and discharged. And a tube 40. The gas conducting tube 40 is made of, for example, a plastic thin tube such as tetrafluoroethylene resin (PTFE), FRP, PE, PP, PVC, or a metal thin tube such as SUS, copper, or copper alloy. Connected to the other end of the gas conduit 40 is a gas discharge valve 42 such as a relief valve or a check valve that opens when the pressure of the discharged gas exceeds a predetermined pressure and discharges the gas into the atmosphere. Is done.

  Like the gas discharge means 30, the axial force reinforcement layer holder 20 is provided with the gas introduction hole 37, so that the gas staying between the inner tube 11 and the outer sheath 14 of the fluid transport pipe 10 is retained by the axial force reinforcement layer. Since the gas is introduced into the gas introduction hole 37 of the holder 20, the conventional gas venting annular block becomes unnecessary, and the number of parts is reduced. Further, the gas lead-out hole 38 is disposed in the vicinity of the outlet side of the gas introduction hole 37, so that the length of the gas conduction pipe 40 piped to the space 19 in the outer case 17 is shortened, and the structure of the terminal fitting is reduced. It becomes easy and it becomes easy to assemble the terminal fitting. Further, the annular block for venting is not required, the length of the terminal fitting is shortened, and the terminal fitting is reduced in size. Therefore, it is easy to install the terminal fitting even in the laying site where the arrangement space is not sufficient. Therefore, the workability of assembling and installing the terminal fitting is improved, and the cost can be reduced.

Since the annular block for venting is not required, the length of the terminal fitting is shortened and the size is reduced, it is easy to install the terminal fitting even in the laying site where there is not enough space for installation and the workability is improved. Cost can be reduced.

  Further, since the length of the gas conduction pipe 40 piped in the space portion 19 is shortened, and the bent portion of the gas conduction pipe 40 and a sharply bent portion are reduced, the gas conduction pipe 40 is connected to the narrow space portion in the outer case 17. In addition to facilitating piping, the flow resistance of the gas flowing through the gas conduction tube 40 is reduced and the gas flows easily, and the gas staying between the inner tube 11 and the outer sheath 14 is discharged well from the terminal fitting. Will be able to. Furthermore, it is possible to use a metal pipe excellent in strength and durability as the gas conduction pipe 40, and the selection range in which the gas conduction pipe 40 can be used has been expanded, so that the terminal fitting can be used even in a severe environment. Can be used stably.

  When piping the gas conduction pipe 39 to the space portion 19, after one end of the gas conduction pipe 39 is attached to the end body 15 and the outer case 17, the space portion 19 in the outer case 17 is filled with the filler 21. By inserting it into the gas outlet hole 37 (filler injection hole 40) of the outer case 17 and connecting it to the tube connector 38 attached to the outlet side of the gas inlet hole 36 of the axial force reinforcing layer holder 20, or Before the case 17 is attached to the end body 15, the case 17 is inserted in advance into the gas outlet hole 37 (filler injection hole 40) of the outer case 17 and connected to the pipe connector 38. The tube connector 38 may be attached in advance to the one end side of the gas conduction pipe 39 instead of the axial force reinforcement layer holder 20 side, and one end of the gas conduction pipe 39 is connected to the axial force reinforcement layer via the pipe connector 38. The holder 20 is connected to the outlet side of the gas introduction hole 37. The gas outlet hole 38 is sealed by packing (not shown) or the like after filling the space portion 19 with the filler 21.

  When the gas conduction pipe 39 is piped before the space portion 19 is filled with the filler 21, the other end portion does not extend outward through the gas outlet hole as described above, and as shown in FIG. You may make it connect directly to the lead-out hole 38 itself. In this case, the operation of connecting one end portion of the gas conduction pipe 39 to the gas introduction hole 37 may be performed at any time before or after the outer case 17 is attached to the end body 15, but the other end portion is connected to the gas outlet hole 38. The connection work is preferably performed after the outer case 17 is attached to the end body 15 in terms of construction. Also in this case, a gas discharge valve 42 (not shown) is connected to the other end of the gas conduction pipe 40.

  Further, when the other end portion of the gas conduction pipe 40 is directly connected to the gas outlet hole 38, the gas outlet pipe 40 and the gas outlet hole 38 are matched so that the diameters of the gas conduction pipe 40 and the gas outlet hole 38 are matched. It is desirable that the hole 38 not exclusively serve as the filler injection hole 41 but be dedicated to the gas outlet hole. In this case, the filler injection hole 41 can be provided at a location different from the location where the gas outlet hole 38 on the peripheral wall of the outer case 17 is provided, for example, at a lower location.

  If the gas lead-out hole 38 also serves as the filler injection hole 41, it is possible to save the trouble of newly providing the gas lead-out hole 38 in the outer case 17, and the inner diameter of the gas lead-out hole 38 generally injects the filler 21. Since it is formed relatively large, the other end portion of the gas conduction pipe 40 is connected to the gas outlet hole 38, or the gas conduction pipe 40 is disposed in the outer case 17 so as to extend outward through the gas outlet hole 38. It is preferable because the work of piping to the space portion 19 becomes easy and the workability of the terminal fitting can be further improved.

  In addition, 43 fills the space part 19 in the outer case 17 with the filler 21 and releases air remaining in the space part 19 and overflows the filler 21 filled in the space part 19 to the outside of the outer case 17. In order to prevent air from remaining in the space 19, the nipple hole is provided in the peripheral wall of the outer case 17. The nipple hole 42 is closed by a stopper (not shown) after the filling of the filler is completed. Reference numeral 44 denotes an inner pipe buckling prevention interlock pipe provided inside the inner pipe 11 of the fluid transport pipe 10.

It is an upper half section front view showing one embodiment of the end fitting of the fluid transportation pipe concerning the present invention. In the terminal fitting of FIG. 1, X shows a state in which a sealing material is provided to fill a gap formed between the outer peripheral surface of the internal pressure reinforcing layer of the fluid transport pipe, the inner peripheral surface of the axial force reinforcing layer holder, and the axial force reinforcing layer. FIG. FIG. 2 is an enlarged cross-sectional view showing a state in which the other end of the gas conduction pipe is directly connected to a gas outlet hole in the gas discharge means of the terminal fitting of FIG. 1. It is upper half sectional drawing of the terminal metal fitting of the conventional fluid transport pipe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fluid transport pipe 11 Inner pipe 12 Internal pressure reinforcement layer 13 Axial force reinforcement layer 14 Outer sheath 15 End body 16 Packing 17 Outer case 17a Flange part 18 Packing 19 Space part 20 Axial force reinforcement layer holder 21 Filler 30 Gas discharge means 31 Seal Metal fitting 32 Bolt 33 Sheath holder 34 Seal material 35 Seal metal fitting 36 Bolt 37 Gas introduction hole 38 Gas outlet hole 39 Pipe connector 40 Gas conduction pipe 41 Filler injection hole 42 Gas discharge valve 43 Nipple hole 44 Interlock pipe

Claims (3)

  An end attached to the end of the inner pipe of the fluid transport pipe having an inner pressure reinforcing layer for reinforcing the strength in the circumferential direction, an axial force reinforcing layer for reinforcing the strength in the axial direction, and an outer sheath on the outer circumference of the inner pipe The body and the front part are held by the end body, the rear part is fitted to the outer sheath, and a space part is formed between each end of the inner tube, the internal pressure reinforcing layer and the axial force reinforcing layer. An outer case to be mounted, an axial force reinforcing layer holder provided in the space portion and fixing an end portion of the axial force reinforcing layer, a filler filled in the space portion, and an inner tube and an outer sheath In the terminal fitting of the fluid transport pipe provided with the gas discharge means for discharging the gas to be discharged, the gas discharge means is provided in the axial force reinforcing layer holder, and a gas introduction hole communicating with the gap between the inner pipe and the outer sheath Installed on the peripheral wall of the outer case near the outlet side of the gas introduction hole The gas outlet hole and one end portion are connected to the outlet side of the gas inlet hole, and the other end portion is connected to the gas outlet hole or piped to the space portion so as to extend outward through the gas outlet hole. And a gas conduction pipe for discharging the gas staying between the inner pipe and the outer sheath from the gas introduction hole side to the gas outlet hole side and discharging the gas.   The terminal fitting for a fluid transport pipe according to claim 1, wherein the gas outlet hole of the gas discharge means also serves as a filler injection hole for filling the space with a filler.   The sealing material is provided so that the clearance gap formed between the outer peripheral surface of the internal pressure reinforcement layer of the said fluid transport pipe, the internal peripheral surface of an axial force reinforcement layer holder, and an axial force reinforcement layer may be provided. Or the terminal metal fitting of the fluid transport pipe of 2.

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