JP3541107B2 - Connection structure of fluid transport pipe - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is to connect and connect a fluid transport pipe such as a synthetic resin water pipe or gas pipe buried underground to a pipe connection port side on a connected body such as a connection flange, a gate valve or a branch pipe. More specifically, a fluid transport pipe having an external thread portion formed on the outer peripheral surface of the fluid transport tube to be screwed into a female thread portion formed on the inner peripheral surface of the pipe connection port portion on the connected body side. Connection structure.
[0002]
[Prior art]
In this type of fluid transport pipe connection structure, for example, as shown in FIG. 7, a cylindrical pipe connection port 01 is formed on an outer peripheral surface of an end portion of a synthetic resin fluid transport pipe P as an example of a connected body side. When connecting a flange joint F integrally formed with a connecting flange 02 on one end outer peripheral surface in the cylinder axis direction, conventionally, the wall thickness of the tube peripheral wall is configured to be constant in the tube axis direction and the circumferential direction. Each of the outer peripheral surfaces of the end portions of the fluid transport pipe P is provided with a male thread portion 07 which is screwed into a female thread portion 03 formed on the inner peripheral surface of the pipe connection port portion 01 of the flange joint F. 07 is formed in a state in which the outer diameter of the fluid transport pipe P is the same as or slightly smaller than the outer diameter of the fluid transport pipe P, and the external thread 07 of the fluid transport pipe P and the female thread 03 of the pipe connection port 01 are screwed. In some cases, the pipe connection port 01 was connected to each of the outer peripheral surfaces of the end portions of the fluid transport pipe P. Then, the connecting flanges 02 of the flange joint F screwed to each of the outer peripheral surfaces of the two fluid transfer pipes P made of synthetic resin which are opposed to each other in the pipe axis direction with bolts 014 and nuts 015. The two fluid transport pipes P, P were communicated and connected to each other (see, for example, Japanese Utility Model Laid-Open No. 59-54282).
In the connection structure of the fluid transport pipes configured as described above, since the fluid transport pipe P made of synthetic resin and the pipe connection port portion 01 are connected with a simple connection structure in which the fluid transport pipe P is screwed, the fluid transport pipe P and the fluid transport pipe P are connected to each other. It is possible to quickly and easily perform maintenance / inspection work of a connection portion with the flange joint F, and detachment work between the fluid transport pipe P and the flange joint F accompanying replacement work of the fluid transport pipe P or the flange joint F.
In addition, since the fluid transport pipe P is made of a synthetic resin, a tensile force in a pipe axis direction caused by an earthquake or uneven settlement, or a shearing force or bending in a direction intersecting with the pipe axis. Even if an external force such as a moment acts, the fluid transport pipe P is made of a synthetic resin, so that the external force can be absorbed by utilizing the elongation and bending deformation of the fluid transport pipe P itself. This is useful in that P can be prevented from being damaged by the external force.
[0003]
[Problems to be solved by the invention]
However, in the conventional connection structure of the fluid transport pipe, since the external diameter of the external thread portion 07 is formed to be the same as or slightly smaller than the external diameter of the fluid transport pipe P, Since the minimum wall thickness t3 of the pipe peripheral wall corresponding to the trough diameter of 07 is smaller by the thread height than the wall thickness t4 of the pipe peripheral wall other than the pipe connection region of the fluid transport pipe P, the male of the fluid transport pipe P The strength of the threaded portion 08 is lower than the strength of the peripheral wall of the pipe other than the pipe connection area. As a result, the pipe shaft between the fluid transport pipe P and the pipe connection port 01 caused by an earthquake, uneven settlement, or the like. When an external force such as a tensile force in a core direction or a shearing force or a bending moment in a direction intersecting with the pipe axis acts, the location 08 where the external thread portion of the fluid transport pipe P is formed becomes a pipe peripheral wall other than the pipe connection area. The fluid transport pipe P made of synthetic resin, There is not made a problem be sufficiently utilize the elongation and flexural deformation as a force absorption at long tube wall other than the region.
[0004]
The present invention has been made in view of the above circumstances, and its main problem is to provide a simple connection structure such as a screw connection similar to a conventional connection structure of a fluid transport pipe, and a fluid transport pipe and a connected body side. While improving the speed and ease of attaching and detaching work to and from the pipe connection port, the strength at the place where the male thread is formed in the fluid transport pipe has been improved, External force such as tensile force or compressive force, or shear force or bending moment in the direction intersecting with the pipe axis is effectively applied by using the elongation or bending deformation of the pipe peripheral wall other than the pipe connection area of the fluid transport pipe. Accordingly, the present invention provides a connection structure for a fluid transport pipe having a higher breaking strength against the external force than a conventional connection structure for a fluid transport pipe.
[0005]
[Means for Solving the Problems]
The characteristic structure of the connection structure of the fluid transport pipe according to the first aspect of the present invention is that a female screw portion formed on the outer peripheral surface of the synthetic resin fluid transport pipe on the inner peripheral surface of the pipe connection port on the connected body side. The external thread portion is formed so as to protrude, and the minimum wall thickness of the pipe peripheral wall at the location where the external thread portion is formed is equal to or larger than the wall thickness of the pipe peripheral wall other than the pipe connection region of the fluid transport pipe. In addition, a reinforcing cylindrical body is inserted into at least a part of the inner peripheral surface of the fluid transport pipe corresponding to the male screw portion forming portion in a closely contacted state.
According to the characteristic configuration, the pipe connection port and the fluid transport pipe can be connected only by screwing the male thread of the fluid transport pipe into the female thread formed on the inner peripheral surface of the pipe connection port. Since the minimum wall thickness of the pipe peripheral wall at the place where the male screw portion is formed is the same as or larger than the wall thickness of the pipe peripheral wall other than the pipe connection region of the fluid transport pipe, the peak portion where the male screw portion is formed The wall thickness of the pipe surrounding wall is larger than the wall thickness of the pipe surrounding area other than the pipe connection area of the fluid transport pipe. Or more.
Moreover, since the reinforcing tubular body is inserted into at least a part of the inner peripheral surface of the tube corresponding to the portion where the male screw portion is formed in a tightly contacted state, the shear strength at the portion can be increased at the same time. Due to tensile force or compressive force in the pipe axis direction due to settlement or external force such as shearing force or bending moment in the direction crossing the pipe axis, the pipe connection area of the fluid transport pipe, especially the male thread It is possible to prevent the formation location from breaking prior to the pipe peripheral wall other than the pipe connection area.
Therefore, with a simple connection structure such as a screw connection similar to the conventional connection structure of the fluid transport pipe, it is possible to speed up and facilitate the attachment / detachment work between the fluid transport pipe and the pipe connection port on the connected body side. At the same time, the external force such as the tensile force or the compressive force in the direction of the tube axis caused by the earthquake or the differential settlement, or the shearing force or the bending moment in the direction crossing the tube axis is transferred to the fluid transfer tube made of synthetic resin. Characteristics, in particular, it can be effectively absorbed by utilizing the elongation and bending deformation of a long pipe peripheral wall other than the pipe connection area, and the breakage against the external force as compared with the conventional fluid transport pipe connection structure. Strength can be increased.
[0006]
The fluid transport pipe connection structure according to claim 2 of the present invention is characterized in that a fluid transport pipe for the pipe connection port is provided at a position located on the inner peripheral surface of the pipe connection port on the inner side of the female screw portion. A sealing elastic seal material that is compressed radially outwardly as the screw is advanced to the connection side of the fluid transport pipe, and the reinforcing cylindrical body is provided with an elastic seal material on an inner peripheral surface of the fluid transport pipe. In that it extends to a site corresponding to.
According to the above-mentioned characteristic configuration, an elastic sealing material for sealing is used by using a screwing operation on the connection side of the fluid transport pipe with respect to the pipe connection port for connecting the pipe connection port and the fluid transport pipe. Can be brought into close contact with the inner peripheral surface of the pipe connection port and the outer peripheral surface of the fluid transport pipe in a compressed state. For example, the elastic sealing material is pressed by pressing the fluid transport pipe into the connection side of the pipe connection port. , The elastic sealing material can be reliably compressed with a smaller operation force.
In addition, the pipe peripheral wall of the fluid transport pipe receives stress concentration due to the reaction force against the compressive force of the elastic sealing material. This stress is received not only by the pipe peripheral wall of the fluid transport pipe but also by the reinforcing cylinder. Accordingly, it is possible to prevent the pipe peripheral wall of the fluid transport pipe from undergoing creep rupture over time due to the stress.
[0007]
According to a third aspect of the present invention, there is provided a fluid transport pipe connecting structure according to the first aspect of the present invention, wherein the reinforcing cylinder is cut at one location in a circumferential direction, and is reduced in diameter against an elastic restoring force toward an enlarged diameter side. In that it is inserted into the inner peripheral surface of the fluid transport pipe in a state where the fluid transport pipe is inserted.
According to the above-described characteristic configuration, the reinforcing cylinder can be inserted into the inner peripheral surface of the fluid transport pipe in a state where the reinforcing cylinder is forcibly elastically deformed to the reduced diameter side. The installation of the reinforcing cylinder on the inner peripheral surface of the fluid transport pipe can be performed quickly and easily compared to the case of press-fitting on the surface. By simply releasing the elastic deformation operation force to the reduced diameter side of the cylinder, the fluid in the state of reduced diameter against the elastic restoring force to the increased diameter side while the reinforcing cylinder elastically returns to the increased diameter side. Since it is in close contact with the inner peripheral surface of the transport pipe, it is not necessary to provide a special fixing means for fixing the reinforcing cylinder to the inner peripheral surface of the fluid transport pipe.
[0008]
The fluid transport pipe connection structure according to claim 4 of the present invention is characterized in that when the male thread of the fluid transport pipe is screwed to a predetermined position of the female thread of the pipe connection port, The plate-shaped stopper portion which comes into contact with the end face of the pipe in the axial direction of the pipe is integrally formed so as to protrude radially outward from the fluid transport pipe.
According to the above-mentioned characteristic configuration, not only can the screwed length of the male screw part of the fluid transport pipe and the female screw part of the pipe connection port part be always maintained at the set length, but also the stopper part for this purpose Is formed in a plate shape integrally formed with a synthetic resin fluid transport pipe, so that the screw is utilized by utilizing the elastic deformation of the stopper portion in the pipe axis direction accompanying the contact with the pipe connection port. It is possible to suppress relative rotation of the fluid connection pipe and the pipe connection port that are connected to each other to the loose side.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment]
FIGS. 1 to 3 show an example of a synthetic resin such as a fluid transport pipe (for example, a water pipe) P made of polyethylene. The fluid transport pipe of the present invention for communicating and connecting to the pipe connection port 1 of a flanged joint F made of cast iron, which is an example of a metal in which a connecting flange 2 is integrally formed at one end of the portion 1 in the cylinder axis direction. FIG. 4 shows a connection structure, in which a female screw portion 3 is formed on the other end side of the pipe connection port portion 1 of the flange joint F in the cylinder axis direction, and the inside of the pipe connection port portion 1 is formed. Two annular grooves 4a and 4b are formed in the peripheral surface at a position deeper than the female screw portion 3 (one end side in the cylinder axis direction) at predetermined intervals in the cylinder axis direction. Each of these annular grooves 4a and 4b is provided with an annular sealing elastic made of synthetic rubber (for example, styrene-butadiene rubber). Lumpur material 5a, are then fitted into and attached to 5b.
The connection flange 2 has a plurality of bolt insertion holes 6 formed therethrough along the circumferential direction.
[0010]
The inner diameter of the fluid transport pipe P is configured to be substantially constant along the axial direction of the pipe, and the outer peripheral surface of the fluid transport pipe P is provided with the pipe connection port 1 of the flange joint F. A male screw portion 7 screwed into the female screw portion 3 formed on the inner peripheral surface is integrally formed to protrude.
Further, the fluid transport pipe P is inserted into the open end side of the male screw part forming portion 8 from the opening at the other end of the pipe connection port 1 in the cylinder axis direction with respect to the pipe connection port 1. As the fluid transport pipe P is screwed toward the connection side, the two elastic seal members 5a and 5b are sequentially fitted into the inner peripheral surfaces of the elastic seal members 5a and 5b, respectively. A cylindrical portion 9 for compressing radially outward of the fluid transport pipe P is integrally extended between the inner bottom surfaces of the annular grooves 4a and 4b, and an outer peripheral surface on the distal end side of the cylindrical portion 9 is provided on the outer peripheral surface. A tapered surface 9a for guiding the cylindrical portion 9 to be fitted into the inner peripheral surfaces of the elastic sealing members 5a and 5b is formed. When the screwing operation is completed, the two elastic sealing members 5a and 5b are in contact with the inner peripheral surface of the pipe connection port 1 and the fluid. Close contact in a compressed state and an outer peripheral surface of the cylindrical portion 9 of the flue P, it is possible to seal the gap between the inner and outer circumferential surfaces of the fluid transport pipe P of the pipe joint port 1.
[0011]
On the outer peripheral surface of the fluid transport pipe P, when the male thread 7 of the fluid transport pipe P is screwed to a predetermined position of the female thread 3 of the pipe connection port 1, the cylindrical shaft of the pipe connection port 1 The substantially triangular plate-shaped stopper portion 10 which comes into contact with the end face on the other end side in the core direction from the pipe axis core direction and regulates the further screwing operation of the fluid transport pipe P is formed by the diameter of the fluid transport pipe P. A tool or the like for rotating the fluid transport pipe P is hooked between the adjacent stopper portions 10 when the fluid transport pipe P is screwed, while being integrally formed in a state of protruding outward in the direction. Projection 11 is integrally formed so as to protrude.
Further, the stopper portion 10 is slightly elastically moved to the side opposite to the pipe connection port 1 side in the pipe axis core direction by contact with the end face of the pipe connection port 1 on the other end side in the cylinder axis direction. It is configured to be able to bend and deform.
In addition, the pipe connection region of the flange joint F with respect to the pipe connection port portion 1 is configured by the male screw portion forming portion 8 and the cylindrical portion 9, and the stopper portion 10 and the projection 11 forming portion.
[0012]
As shown in FIG. 1, the portion corresponding to the valley portion of the male screw portion 7 at the male screw portion forming portion 8 is a portion of the peripheral wall of the male screw portion forming portion 8 having the thinnest wall thickness in the pipe radial direction. The wall thickness in the pipe diameter direction of the pipe peripheral wall of the portion corresponding to the valley portion of the male screw portion 7 (the minimum thickness in the pipe diameter direction of the pipe peripheral wall at the male screw portion forming portion 8) t1 is the fluid transport pipe. It is configured to be larger than the wall thickness t2 of the pipe peripheral wall other than the pipe connection region of P, in other words, the pipe peripheral wall of a long pipe portion protruding outside from the pipe connection port 1.
[0013]
As shown in FIGS. 1 and 2, a stainless steel reinforcing cylinder 12, which is an example of a metal, is closely attached to a portion corresponding to the male screw portion forming portion 8 on the inner peripheral surface of the fluid transport pipe P. The reinforcing cylindrical body 12 is further extended from a portion corresponding to the two elastic sealing members 5 a and 5 b on the inner peripheral surface of the fluid transport pipe P to an open end of the cylindrical portion 9. is there.
The outer diameter of the reinforcing cylinder 12 is configured to be larger than the inner diameter of the fluid transport pipe P in a natural state, and the reinforcing cylinder 12 is provided at one location in the circumferential direction thereof. A state in which the gap 12a is inclined with respect to the cylinder axis, that is, the cross section of the reinforcing cylinder 12 in a direction perpendicular to the cylinder axis is substantially C-shaped, and the gap is formed along the cylinder axis direction. It is cut so that the forming position is shifted in the circumferential direction.
The reinforcing cylinder 12 can be reduced in diameter against the elastic restoring force due to the existence of the gap 12a, and the outer diameter of the reinforcing cylinder 12 in the state of the most reduced diameter is larger than the inner diameter of the fluid transport pipe P. Is also configured to be small.
[0014]
As shown in FIGS. 1 to 3, the reinforcing cylindrical body 12 is formed such that an outer diameter of the reinforcing cylindrical body 12 is smaller than an inner diameter of the fluid transporting pipe P with respect to an inner peripheral surface of the fluid transporting pipe P. Can be inserted in a state where the diameter is forcibly reduced against the elastic restoring force, and the forced diameter reduction is released in this inserted state, whereby the inner peripheral surface of the fluid transport pipe P is released. The diameter of the fluid transport pipe P is increased by the elastic restoring force while the diameter is reduced until the outer peripheral surface of the reinforcing tubular body 12 comes into close contact with the outer peripheral surface of the reinforcing cylinder 12. Closely fixed to the peripheral surface.
Further, the cylindrical portion 9 of the fluid transport pipe P is inserted into the pipe connection port 1 from the other end side of the pipe connection port 1 of the flange joint F in the cylinder axis direction, and the stopper 10 is connected to the pipe connection port. One end of the fluid transport pipe P and the pipe connection port 1 of the flange joint F are communicated by screwing the fluid transport pipe P until the fluid transport pipe P comes into contact with the end face on the other end side in the cylinder axis direction of the section 1. Are screwed together.
[0015]
As described above, by connecting the flange joint F, which is an example of the connected body side, to the end of the fluid transport pipe P by screwing, as shown in FIG. The connection flanges 2, 2 of the flange joints F, F, which are screwed to the respective portions, are opposed to each other in the pipe axis direction, and a sealing elasticity is provided between the opposed end faces of the two connection ports 1. With the sealing material (packing) 13 interposed, a bolt 14 is inserted through each of the opposed bolt insertion holes 6, 6 of the two connection flanges 2, 2, and a nut 15 is screwed into the bolt 14. By tightening the two flange joints F, F, these fluid transport pipes P, P can be connected and connected in a sealed state.
Note that FIG. 4 shows a state in which two fluid transport pipes P, P having different inner diameters are connected and connected, and a flange joint F which is an example of a connected body side which is screwed and joined to the small diameter fluid transport pipe P. An annular protruding portion 16 that protrudes toward the cylinder axis of the pipe connection port 1 is integrally formed at the open end of the pipe connection port 1 at one end side in the cylinder axis direction. An inner peripheral surface of the tapered surface 16 is formed on a tapered surface 16a having a larger diameter toward the opening. More specifically, the minimum inner diameter of the tapered surface 16a of the protrusion 16 on the small-diameter fluid transport pipe P side is substantially the same as the inner diameter of the reinforcing cylindrical body 12 mounted on the inner peripheral surface of the small-diameter fluid transport pipe P. And the maximum inner diameter of the large-diameter fluid transport pipe P is substantially the same as the inner diameter of the reinforcing tubular body 12 mounted on the inner peripheral surface of the large-diameter fluid transport pipe P. It is.
[0016]
As shown in FIG. 4, the other end of the fluid transport pipe P (the end opposite to the threaded connection portion of the flange joint F) is provided with a fluid transport made of polyethylene having the same outer diameter and inner diameter. A pipe P1 is provided, and the two fluid transport pipes P, P1 are externally fitted with a polyethylene cylinder 17 over a connection portion thereof, and are connected to the outer peripheral surfaces of the two fluid transport pipes P, P1. The inner peripheral surface of the cylindrical body 17 is connected to the inner peripheral surface by heat fusion.
[0017]
[Second embodiment]
In the first embodiment, the connection structure of the fluid transport pipe of the present invention is adopted for connection between the fluid transport pipe P and the flange joint F which is an example of the object side. As shown in FIG. 5, the fluid transport pipe P may be used for connection with the pipe connection port 1 of a T-type pipe T made of cast iron, which is an example of the connected body side. In this case, the pipe connection port 1 of the T-shaped pipe T is configured in the same manner as the pipe connection port 1 of the flange joint F of the first embodiment, and is the same as the component described in the first embodiment. The components having the same structure or the same function are assigned the same reference numerals as in the first embodiment, and the description thereof is omitted.
[Other embodiments]
{Circle around (1)} In the first embodiment described above, the two fluid transport pipes P are connected via the flange joint F, which is an example of the connected object side, connected to the fluid transport pipe P with the fluid transport pipe connection structure of the present invention. , And P are described by way of example, but as shown in FIG. 6, the connecting flange 2 of the flange joint F, which is an example of the connected body side, and the pipe connecting portion 18 of the gate valve V are formed. The connecting flange 19 may be fastened with bolts 14 and nuts 15 to connect and connect the gate valve V to the fluid transport pipe P. Although not shown, the connecting flange 2 of the flange joint F and the cast iron The bolts and nuts are used to fasten the connection flange integrally formed on the pipe shaft core opening side end of the fluid transport pipe made of stainless steel with the fluid transport pipe made of synthetic resin and the fluid transport pipe made of cast iron. May be.
{Circle around (2)} The connected object side is not limited to the flange joint F or the T-shaped pipe T, but may be cast iron or poly steel if the pipe connection port 1 is provided. A bent pipe made of vinyl chloride or the like, a gate valve, a branch valve, or the like may be used.
{Circle around (3)} In each of the above-described embodiments, a water pipe is exemplified as the fluid transport pipe P. However, the present invention is not limited to this, and the fluid transport pipe P may be a gas pipe, an oil transport pipe, or the like.
{Circle around (4)} In each of the embodiments described above, the fluid transport pipe P made of polyethylene is exemplified as the fluid transport pipe P made of synthetic resin. However, the fluid transport pipe P is not limited to this. Is also good.
{Circle around (5)} In each of the above embodiments, the pipe connection port 1 is made of cast iron. However, the material of the pipe connection port 1 is limited to cast iron if the material is higher in strength than the fluid transport pipe P. It is not done.
{Circle around (6)} In each of the above-described embodiments, the wall thickness in the pipe radial direction of the pipe peripheral wall of the portion corresponding to the valley portion of the male screw part 7 of the male screw part forming part 8 (the pipe peripheral wall of the male screw part forming part 8) The minimum wall thickness t1 in the radial direction) may be the same as the wall thickness t2 of the pipe peripheral wall other than the pipe connection region of the fluid transport pipe P.
{Circle around (7)} In each of the above-described embodiments, the portion of the inner peripheral surface of the pipe connection port 1 located on the inner side of the female screw section 3 is connected to the connection side of the fluid transport pipe P with respect to the pipe connection port 1. The two elastic sealing materials 5a and 5b for sealing, which are compressed radially outward with the screwing, are installed, but the number of elastic sealing materials is not limited to two, and if necessary. It may be changed as appropriate.
{Circle around (8)} In each of the above embodiments, the reinforcing cylinder 12 is made of stainless steel, but the material of the reinforcing cylinder 12 is higher in shear stress than the fluid transport pipe P, that is, the material of the fluid transport pipe P. For example, when the fluid transport pipe P is made of polyethylene, the reinforcing cylinder 12 may be made of polyvinyl chloride or polyacetal, which is stronger than polyethylene.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of a connection structure for a fluid transport pipe of the present invention. FIG. 2 is a sectional view taken along the line II-II of FIG. 1. FIG. 3 is an exploded sectional perspective view. FIG. 5 is a cross-sectional view showing a state in which two fluid transport pipes are connected to each other via a pipe. FIG. 5 is a partial cross-sectional view showing a second embodiment of the fluid transport pipe connection structure of the present invention. FIG. 7 is a partial cross-sectional view showing a state in which a gate valve is communicatively connected to a fluid transport pipe via a joint flange in the first embodiment of the connection structure shown in FIG. Description】
P Fluid transport pipe t1 Thickness (minimum thickness)
t2 Thickness 1 Pipe connection port 3 Female thread 5a Elastic sealing material 5b Elastic sealing material 7 Male thread 8 Male thread forming location 10 Stopper 12 Reinforcing cylinder

Claims (3)

On the outer peripheral surface of the fluid transfer pipe made of synthetic resin, a male screw part to be screwed with a female screw part formed on the inner peripheral surface of the pipe connection port part on the connected body side is formed so as to protrude. The minimum thickness of the peripheral wall is equal to or larger than the thickness of the pipe peripheral wall other than the pipe connection region of the fluid transport pipe, and the external thread portion is formed on the inner peripheral surface of the fluid transport pipe. At least a part of the portion corresponding to the location, a reinforcing cylindrical body is inserted in close contact with the portion, and further, on the outer peripheral surface of the fluid transport tube, a male thread portion of the fluid transport tube is provided with a female thread portion of the pipe connection port portion. When screwed to a predetermined position, a stopper that contacts the end face of the pipe connection port from the pipe axis direction and a projection for rotating the fluid transport pipe are connected to the male screw section. The connection structure of the fluid transport pipe formed of . The connection structure for a fluid transport pipe according to claim 1, wherein the stopper portions and the rotation operation protrusions are alternately arranged in a circumferential direction . The connection structure for a fluid transport pipe according to claim 1 , wherein the stopper portion is formed so as to project radially outward from an outer peripheral surface of the pipe connection port .

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