JP5683894B2 - Terminal structure of flexible tube for gas transportation - Google Patents

Description

  The present invention relates to a terminal structure of a flexible tube for gas transportation for transporting a gas such as a medium / high pressure natural gas.

  Usually, a steel pipe is used for piping for transporting a gas such as natural gas. A steel pipe can be applied regardless of the pressure of the gas used if it has pressure resistance. By the way, the gas pressure is determined according to the gas business method as low pressure (water column gauge pressure less than 0.1 MPa), medium pressure B (water column gauge pressure 0.1 MPa to less than 0.3 MPa), medium pressure A (water column gauge pressure 0.3 MPa). ˜less than 1.0 MPa) and high pressure (water column gauge pressure of 1 MPa or more).

  Further, according to JIS K6774, it is stipulated that a polyethylene base pipe (PE80) can be used as a gas pipe for low pressure to medium pressure B applications. For example, Patent Document 1 describes that a polyethylene pipe or a metal flexible pipe can be used as a gas pipe drawn into the primary side of a gas meter in a site. (Patent Document 1).

JP 2006-194349 A

  As described above, when the working pressure is lower than the medium pressure B, the amount of gas that permeates the resin (for example, methane gas) is not a problem level, but the amount of gas permeation increases in proportion to the gas pressure. However, it is known to be inversely proportional to the wall thickness of the tube. Therefore, if the resin pipe used at a low pressure (0.1 MPa) is used at a high pressure (1.0 MPa), the gas permeation amount becomes 10 times. However, increasing the wall thickness increases the unit weight, which is disadvantageous in terms of cost and handling.

  On the other hand, if resin piping can be used, it is not necessary to use a heavy steel pipe, and laying work is also easy. However, when resin piping is used, it is necessary to peel off the outer layer at the end portion of the piping that is a connecting portion between the piping, and a structure that suppresses gas permeation is required.

  The present invention has been made in view of such a problem. Even when used under conditions of medium pressure A to high pressure, the gas that suppresses gas permeation to the outside of the flexible tube and is lightweight and excellent in flexibility. It aims at providing the terminal structure of the flexible tube for transportation.

In order to achieve the above-described object, the first invention provides a flexible resin tube, a gas shielding layer provided on the outer periphery of the tube, and a reinforcing layer provided on the outer periphery of the gas shielding layer. And a gas pipe having a protective layer provided on the outer periphery of the reinforcing layer, a terminal member having a flange portion at the end is joined to the end of the tubular body, and the outer periphery of the terminal member The fixing member is provided, and the fixing member is pressed against the rear surface of the flange portion and joined to the connection target by the joining member, and the formation range of the fixing member with respect to the gas pipe is the reinforcing layer and the protection The terminal structure of the flexible tube for gas transportation in which a layer is peeled off and a sealing member is provided between the inner surface side of the fixing member and the gas shielding layer, and the end of the terminal member and the tubular body, Butt-fused or electro-fused and the gas barrier Layers are formed so as to cover the junction, the terminal structure of the gas transportation flexible tube, wherein a sealing member is provided between the tubular body the joining portion and the flange portion in the longitudinal direction of the It is.
According to a second aspect of the present invention, there is provided a flexible resin tube, a gas shielding layer provided on the outer periphery of the tube, a reinforcing layer provided on the outer periphery of the gas shielding layer, and an outer periphery of the reinforcing layer. A terminal member having a flange portion at the end portion is joined to the end portion of the tubular body, and a fixing member is provided on the outer peripheral portion of the terminal member. The fixing member is pressed against the rear surface of the flange portion and bonded to a connection target by a bonding member. The fixing member is formed on a gas pipe in a range where the reinforcing layer and the protective layer are peeled off. A gas transport flexible tube terminal structure in which a sealing member is provided between the inner surface side of the gas shielding layer and the gas shielding layer, wherein the fixing member includes a first fixing member and a second fixing member. And the first fixing member is disposed on the rear surface of the flange portion. And is joined to the connection object by a joining member and joined to the second fixing member via a packing, and the second fixing member is connected to the terminal member side in the longitudinal direction of the tubular body. The sealing member is provided between the inner surface of the second fixing member and the gas shielding layer on the outer periphery of the tubular body across the junction between the terminal member and the tubular body. It is the terminal structure of the flexible tube for gas transport.

  It is desirable that the tube body and the terminal member are made of polyethylene, and the natural gas permeability coefficient of the gas shielding layer at room temperature is 1/2 or less than the natural gas permeability coefficient of polyethylene at room temperature.

  The fixing member is divided into a plurality of portions in the circumferential direction, is covered from the outer peripheral side of the gas pipe, and is fixed so that the inner surface side of the fixing member is pressed toward the outer peripheral surface of the gas pipe. Also good.

  According to the present invention, since the shielding layer for preventing the permeation of gas such as natural gas is provided up to the end portion of the pipe, the gas permeation is blocked by the gas shielding layer, and the gas leaks to the outside in the radial direction from the shielding layer. There is nothing. In addition, regarding the permeation of gas in the range where the gas shielding layer is peeled off, the gas does not leak out by the sealing member provided between the fixing member and the gas shielding layer.

  Moreover, since a fixing member can be joined with another fixing member (joining object), it can join piping. Further, when the fixing member is in contact with the rear surface of the flange portion of the terminal member and the ends of the pipes face each other, the fixing member can sandwich the flange portion of the terminal member between the terminal member and the fixing member. It is surely sealed during. Further, since the flange portion protrudes in the radial direction, when gas permeation is taken into consideration, gas can be prevented from permeating through the flange portion by the same effect as that of substantially increasing the thickness.

  In addition, if polyethylene pipes that are inexpensive and excellent in processability are used as the pipe body and terminal member, and the gas shielding layer has a gas permeability coefficient of 1/2 or less than that of polyethylene, the wall thickness is excessively increased. And gas can be shielded.

  Here, the gas permeability coefficient is determined by the material. In the present invention, when the shielding layer is a composite material (multilayer material), the thickness of each layer constituting the composite material and the respective gas permeability coefficient It is derived from the gas permeation amount of the entire composite material calculated from

  Further, in the case where the end portion of the terminal member and the tubular body are joined by butt fusion or electric fusion, a gas shielding layer is formed on the outer periphery of the electrical fusion socket, and the joint portion and the terminal member in the axial direction of the tubular body are formed. By providing a seal member on the outer peripheral side of the gas shielding layer between the flange portion and sealing between the fixing member and the shielding layer, gas leakage from the joint portion can be reliably shielded.

  The fixing member is composed of two members, and includes a first fixing member that contacts the rear surface of the flange portion, and a second fixing member that extends to the rear of the joint portion across the joint portion between the tube body and the terminal member. By doing so, the seal part between the gas shielding layer and the fixing member can be located behind the joint part. Even in this case, the gas can be reliably shielded by the fixing member and the gas shielding layer.

  Further, by dividing the fixing member into a plurality in the circumferential direction, it is easy to provide the fixing member on the outer periphery of the tubular body, and the fixing member can be pressed against the outer peripheral surface of the tubular body. And the gas shielding layer can be reliably sealed.

  According to the present invention, there is provided a gas transport flexible tube terminal structure that suppresses gas permeation to the outside of the flexible tube and is lightweight and excellent in flexibility even when used under conditions of medium pressure A to high pressure. can do.

It is a figure which shows the piping piping terminal structure 1, (a) is a general view, (b) is the elements on larger scale of (a). It is a figure which shows the piping 3 for gas, (a) is a perspective view, (b) is sectional drawing. The figure which shows the process of winding the shielding band 27 around the tubular body 15. FIG. The figure which shows the process of winding the shielding band 27 around the tubular body 15. FIG. The conceptual diagram which shows the function of the shielding layer 17. FIG. The figure which shows the shielding band 27a. The figure which shows the shielding band 27b. The figure which shows other embodiment of the piping terminal structure for gas.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1A and 1B are diagrams showing a gas piping terminal structure 1, FIG. 1A is an overall view, and FIG. 1B is a partially enlarged sectional view of a portion A in FIG. 2A is a diagram showing the structure of the gas pipe 3, FIG. 2A is a perspective view, and FIG. 2B is a cross-sectional view. The gas pipe terminal structure 1 mainly includes a gas pipe 3, a fixing member 5, a joining member 8, and the like, and is connected to a connection target 13.

  The gas piping terminal structure 1 is an end structure of a flexible tube for gas transportation and is a part connected to another connection target 13. The connection target 13 may have a configuration similar to that of the gas piping terminal structure 1 and may be a symmetrical structure with respect to the connection portion, or may be a steel pipe having a different structure.

  As shown in FIG. 2, the gas pipe 3 that is a gas transport flexible pipe mainly includes a tube body 15, a shielding layer 17, a reinforcing layer 19, a protective layer 21, and the like. The gas pipe 3 is, for example, a flexible pipe used for transporting natural gas or the like having medium to high pressure (1 MPa or more).

  The pipe body 15 is located in the innermost layer of the gas pipe 3. The tube body 15 is made of resin, for example, polyethylene (high density polyethylene). The tube body 15 is excellent in flexibility, and gas is allowed to flow inside.

  A shielding layer 17 is provided on the outer periphery of the tube body 15. The shielding layer 17 shields further gas permeation to the outer peripheral side when the gas flowing inside the tube body 15 permeates the tube body 15. The inner surface of the shielding layer 17 is configured to be in close contact with the outer surface of the tube body 15 so that no gap is formed.

The shielding layer 17 has a natural gas permeation coefficient (4.87 × 10 ^ (− 11) (cm ³ (STP) · cm) / (sec · cm ² · cmHG)) of polyethylene at room temperature or less. It is desirable to be made of a material having a natural gas permeability coefficient. Here, STP means the volume of gas at 0 ° C. and 1 atm.

  As the shielding layer, for example, EVA (ethylene-vinyl acetate copolymer resin), vinyl chloride, polymethacrylonitrile, polyacrylonitrile, polyvinylidene chloride (PVDC), stretched nylon 6 (ONY), PET (polyethylene terephthalate), etc. are used. it can. In addition, when a constant transmission coefficient is required regardless of changes in humidity, a hydrophobic resin such as PET or PVDC is desirable. In addition, in the case where a conventional pipe used at a pressure of about 0.3 MPa, which is the maximum value of the medium pressure B, is used at a pressure of about 1 MPa, which is a high pressure, as will be described later, When the shielding layer is wound and used, the gas permeation rate of the shielding layer is set to about 1/3 to 1/4 or less of the gas permeation coefficient of the tube so that the gas permeation amount can be reduced to medium pressure. Or less, more preferably, about 1/5 or less of the gas permeability coefficient of the resin constituting the tubular body.

  A reinforcing layer 19 is provided on the outer periphery of the shielding layer 17. The outer periphery of the shielding layer 17 means outside the shielding layer 17 in the cross section unless otherwise specified, and may have another layer structure between the shielding layer 17 and the reinforcing layer 19. Is included. In the following description, in the positional relationship of each layer, it is simply referred to as “periphery”, but it is needless to say that similarly, those having other layer structures between the respective layers are included.

  The reinforcing layer 19 is a reinforcing layer against the internal pressure of the gas flowing through the tube body 15. Therefore, the pressure resistance strength of the reinforcing layer 19 is set according to the internal pressure used. For example, the reinforcing layer 19 is formed of a reinforcing tape. As the reinforcing tape, for example, a tape made of polyarylate fiber or aramid fiber is wound. A tape using Vectran (registered trademark) manufactured by Kuraray, which is a super fiber, can also be used. The polyarylate fiber tape may be wound, for example, by wrapping ends in the tape width direction, or may be wound with a slight gap. Further, the reinforcing layer 19 may be formed by winding a plurality of times, such as winding a polyarylate fiber tape in a forward and reverse manner. The winding method of the polyarylate fiber tape is appropriately determined according to the strength of the polyarylate fiber tape and the required internal pressure resistance.

  A protective layer 21 is provided on the outer periphery of the reinforcing layer 19. The protective layer 21 is a layer for preventing the reinforcing layer 19 from being damaged during laying or handling, and preventing water from entering the reinforcing layer or the like. The protective layer 21 is made of, for example, low density polyethylene. As described above, each layer constituting the gas pipe 3 follows the bending deformation of the gas pipe 3 and has flexibility.

  For example, the gas pipe 3 is provided with a 1 mm-thick shielding layer 17 (PET) on the outer periphery of a high-density polyethylene tube 15 having an outer diameter of 180φ and a thickness of 13.3 mm, and is made of polyarylate fiber. What provided the protective layer 21 of thickness 2.5mm made from a low density polyethylene in the outer periphery of the reinforcement layer 19 of thickness 1mm can be used.

  As shown in FIG. 1 (b), in the gas pipe terminal structure 1, the protective layer 21 and the reinforcing layer 19 in a predetermined range at the end of the gas pipe 3 are peeled off. Therefore, a part of the shielding layer 17 is exposed in a range where the protective layer 21 and the reinforcing layer 19 of the gas pipe 3 are peeled off. A terminal member 23 is joined to the end of the tube body 15. The tube 15 and the terminal member 23 can be joined by a known method such as butt fusion or electric fusion. In this embodiment, an example of joining by butt fusion will be described.

  The terminal member 23 is made of, for example, the same resin as the tube body 15. A flange portion 24 protruding in the radial direction is formed at the end portion of the terminal member 23. In addition, the fixing member 5 is provided on the outer periphery of the joint so as to cover the area where the protective layer 21 and the reinforcing layer 19 are peeled off and straddle the joint between the tubular body 15 and the terminal member 23. That is, in the range where the reinforcing member 19 is peeled off, the fixing member 5 bears the internal pressure resistance. For this reason, it is desirable that the entire inner peripheral surface of the fixing member 5 is reliably in contact with the outer peripheral surface of the tubular body 15 (terminal member 23) directly or through a shielding layer and the like so that there is no gap (in the drawing, simple Therefore, an example shown with a gap between the inner peripheral surface of the fixing member 5, the outer peripheral surface of the shielding layer, and the outer peripheral surface of the tubular body 15 (terminal member 23) is shown). The fixing member 5 is a ring-shaped member, for example, made of metal. Note that the fixing member 5 is preferably divided into a plurality of parts in the circumferential direction. For example, when a member divided into two parts is used, a pair of semicircular members are put on the outer periphery of the joint part, and the end parts of each other What is necessary is just to join so that it may tighten. By doing in this way, it can fix so that the inner peripheral surface of the fixing member 5 may be pressed to the outer peripheral surface direction of the pipe body 15 (terminal member 23).

  One end of the fixing member 5 (the longitudinal direction of the tube body 15 and the direction opposite to the connection target (hereinafter referred to as the rear of the joint portion)) is the tube body 15 and the terminal member 23 from the terminal member 23 side. It extends to the back across the joint. The fixing member 5 has an end on the rear side located in a portion where the shielding layer 17 is exposed and in contact with the outer periphery of the shielding layer 17 in a range where the reinforcing layer 19 and the protective layer 21 are peeled off. 5 is provided with an O-ring 25 which is a seal member. That is, the O-ring 25 is provided behind the joint between the tubular body 15 and the terminal member 23 and is sandwiched between the fixing member 5 and the shielding layer 7. As described above, since the fixing member 5 is tightened in the center direction of the tube body 15, the O-ring 25 can be pressed and reliably sealed between the fixing member 5 and the shielding layer 17.

  A flange portion 7 is provided at the end of the other side of the fixing member 5 (the connection target side, hereinafter referred to as the front of the joint portion). The flange portion 7 projects in the radial direction and contacts the rear surface side of the flange portion 24 of the terminal member 23. The flange portion 7 protrudes further in the radial direction than the flange portion 24, and a hole is provided in the protrusion portion, and a joining member 9 such as a bolt is inserted. The joining member 9 is a member for joining with the connection target 13.

  The packing 11 is provided on the front side of the flange portion 24. The packing 11 seals between the connection surface on the connection target 13 side. The gas pipe 3 is joined to the connection target 13 by facing the connection target 13 and tightening the joining member 9 with the packing 11 being sandwiched, and at this time, the packing 11 is pressed on the contact surfaces of each other. Thus, the connecting portion can be reliably sealed.

  In the gas piping terminal structure 1, the gas that has permeated through the tubular body 15 and the terminal member 23 made of resin is sealed with an O-ring 25 behind the joint portion between the tubular body 15 and the terminal member 23. Further, the fixing member 5 is made of metal and hardly transmits gas. Further, the contact surface between the fixing member 5 and the terminal member 23 is reliably sealed via the O-ring 25 by the flange portion 7 being pressed against the rear surface of the flange portion 24. Further, the contact surface between the end surface of the terminal member 23 and the connection target 13 is sealed by the packing 11. Therefore, the gas flowing inside does not permeate outside in the vicinity of the connecting portion.

  Although there is a risk that gas may permeate through the flange portion 24 of the terminal member 23, since the flange portion 24 protrudes in the radial direction, the thickness is substantially reduced with respect to permeation of the gas in the radial direction. The same effect as thickening can be obtained. That is, if the protruding length in the radial direction of the flange portion 24 is sufficiently larger than the thickness of the tube body 15 and the terminal member 23 (for example, 5 times or more), the gas permeation amount is inversely proportional to the thickness. , Gas permeation can be shielded.

  Next, the construction method of the shielding layer 17 will be described. FIG. 3 is a diagram illustrating a process of providing the shielding layer 17 on the outer peripheral portion of the tube body 15. The shielding layer 17 is formed by a shielding band 27. The shielding band 27 is a film-like member and is made of a material having a permeability coefficient smaller than that of natural gas at a normal temperature of polyethylene as described above. The width of the shielding band 27 is slightly larger than the outer peripheral length of the tube body 15.

  As shown in FIG. 3A, the shielding band 27 is sent to the tube body 15 so that the longitudinal direction of the shielding band 27 is substantially the same as the axial direction of the tube body 15. Both sides of 27 are bent in a U shape so as to wrap the entire tube body 15. Further, the tubular body 15 is wrapped by the shielding band 27 (FIG. 3B). That is, both end portions of the shielding band 27 are wrapped around the outer periphery of the tubular body 15, and the tubular body 15 is wrapped with the shielding band 27. That is, the lap portion 29 is formed along the axial direction of the tube body 15. As described above, the shielding band 27 is wound around the tube body 15 to form the shielding layer 17. A method of winding the shielding band 27 around the tubular body 15 as shown in FIG.

  Here, the winding method of the shielding body 27 is not limited to the vertical accessory winding, but can be spirally wound so that the end portion wraps in the axial direction of the tube body 15 as shown in FIG. In this case, since the gas permeation can be prevented by forming an adhesive or pressure-sensitive adhesive layer having high adhesive strength on the inner peripheral surface of the spirally wound shield 27, the spirally wound shield is provided. 27 configurations are also applicable. In the following description, an example of vertical side winding will be described.

  Next, a method for manufacturing the gas pipe 3 will be described. The shielding band 27 is supplied to the outer periphery of the tubular body 15 from a shielding band supply machine or the like to the resin tubular body 15 manufactured in advance by extrusion, and the shielding band 27 is formed while being formed as shown in FIG. 15 is wound around the outer periphery. The lap portion is appropriately selected such as fusion or adhesion.

  Next, a reinforcing tape is wound around the outer periphery of the tubular body 15 around which the shielding band 27 is wound by a reinforcing tape winding machine or the like to form a reinforcing layer. Further, the tubular body 15 provided with the reinforcing layer is sent to an extruder, and the extruder extrudes the resin to the outer peripheral portion to form the protective layer 21. Thus, the gas pipe 3 is manufactured.

  Next, the function of the shielding layer 17 will be described. FIG. 5 is a view showing a part of a cross section of the gas pipe 3. A gas such as natural gas flows in the tube body 15. Natural gas (mainly methane gas) permeates through the resin pipe 15 (in the direction of arrow B in the figure). A shielding layer 17 is formed on the outer periphery of the tube body 15. As described above, the shielding layer 17 has a permeability coefficient smaller than the permeability coefficient of the natural gas of the resin constituting the tube body 15. Therefore, the shielding layer 17 shields the natural gas that has passed through the tube body 15. Therefore, natural gas does not permeate out of the piping and leak out.

  As described above, according to the gas piping terminal structure 1 according to the first embodiment, the O-ring is provided on the shielding layer 17, the fixing member 5 is pressed against the terminal member 23, and the terminal member 23 Since the end surface of the flange portion 24 is sealed with the packing 11, natural gas flowing inside can be prevented from leaking outside at the connection portion of the gas pipe 3. Since the shielding layer 17 is disposed on the inner peripheral side of the reinforcing layer 19, the outer peripheral reinforcing layer 19 is responsible for the tension in the tube circumferential direction caused by the internal pressure. It is not necessary to consider the strength. Further, since the shielding layer 17 is disposed on the inner peripheral side of the reinforcing layer 19, natural gas or the like does not accumulate in the gap with the reinforcing layer 19.

  Further, since the O-ring 25 is pressed against the shielding layer 17 by the fixing member 5, the sealing can be surely performed, the flange portion 7 is pressed against the flange portion 24, and the packing 11 is pressed against the connection target. The gas can be reliably sealed, and gas leakage from the gas piping terminal structure can be prevented. In addition, if the shielding belt | band | zone 27 is wound side by side, there will be little clearance gaps between the shielding belt | band | zones 27, and natural gas can be shielded reliably.

  Next, a second embodiment will be described. In the following embodiments, constituent elements that perform the same functions as those shown in FIGS. 1 to 5 are assigned the same reference numerals as in FIGS.

  FIG. 6 is a diagram showing a shielding band 27a used in the second embodiment. The shielding band 27a is obtained by laminating a metal film 33 with resin films 31a and 31b. The metal film 33 should just be thin and easy to process on the film. For example, aluminum, stainless steel, clad steel clad with a material having good corrosion resistance on the outer surface, or the like can be used. The metal film has a thickness of about 0.05 mm, for example, and the entire shielding band 27a may be about 0.2 to 0.3 mm, for example. Here, as will be described later, the adhesive film or the adhesive may be coated on the resin film side of the laminate film.

  In the shielding band 27a, since the metal film 33 shields the permeation of natural gas, the resin films 31a and 31b may have a natural gas permeability coefficient equivalent to that of the tubular body 15. Further, similarly to the shielding band 27, the shielding band 27 a is preferably wound around the outer periphery of the tubular body 15.

  If the shielding band 27a is used, the permeation of natural gas can be more reliably shielded by using the metal film 33. Moreover, flexibility is not impaired by the shielding layer. Further, by laminating with the resin films 31a and 31b, it is possible to prevent the metal film 33 from being bent, torn, or wrinkled when the reinforcing tape is wound. The metal film 33 and the resin films 31a and 31b can use known techniques such as adhesion and pressure bonding.

  Next, a third embodiment will be described. FIG. 7 is a diagram showing a shielding band 27b used in the third embodiment. The shielding band 27 b is obtained by applying a coating 37 on at least one surface of the resin film 35. The coating 37 is an inorganic material, and may be vapor deposition or plating of metal or the like, or DLC (Diamond Like Carbon) or the like.

  Even in the shielding band 27b, the resin film 35 may have the same natural gas permeability coefficient as that of the tube body 15 because the coating 37 shields the transmission of natural gas. Further, similarly to the shielding band 27, it is desirable that the shielding band 27b is wound around the outer periphery of the tubular body 15 with a collar.

  By using the shielding band 27b, the coating 37 can more reliably shield natural gas permeation. Moreover, since the thickness of the coating 37 is very thin, the thickness of the shielding layer 17 can be made thinner. Moreover, flexibility is not impaired by the shielding layer.

  Next, another embodiment will be described. Fig.8 (a) is a figure which shows the piping terminal structure 1a for gas. As shown in FIG. 8 (a), the gas piping terminal structure 1a is substantially the same as the gas piping terminal structure 1, but the shape of the fixing member 5a is different, and the position of the O-ring 25 is thereby changed to the gas piping. Different from the terminal structure 1.

  The fixing member 5 a has a shorter length in the direction corresponding to the axial direction of the tube body 15 than the fixing member 5. That is, the end portion of the fixing member 5 a does not straddle the joint portion between the tube body 15 and the terminal member 23. Therefore, the O-ring 25 is disposed on the front side of the joint portion between the tubular body 15 and the terminal member 23 and is pressed against the outer periphery of the shielding layer 17 disposed across the joint portion.

  Also in the gas piping terminal structure 1a, since the O-ring 25 is pressed against the outer periphery of the shielding layer 17, it is possible to suppress the permeation of gas from the vicinity of the terminal, and the same effect as the gas piping terminal structure 1 is obtained. be able to.

  Moreover, it can also be set as the gas piping terminal structure 1b shown in FIG.8 (b). The same configuration can be applied even when the pipe body 15 and the terminal member 23 are joined by electrofusion as in the gas piping terminal structure 1b. That is, the electrofusion socket 39 is provided on the outer periphery of the joint portion between the tube body 15 and the terminal member 23. In this case, the reinforcing layer 19 and the protective layer 21 are provided so as to cover the outer periphery of the electric fusion socket 39, and the reinforcement layer 19 and the protective layer 21 are peeled off at the front side of the electric fusion socket 39, and the shielding layer 17 is formed. Exposed. On the outer periphery of the shielding layer 17, an O-ring 25 provided on the inner surface of the fixing member 5a is disposed.

  Also in the gas piping terminal structure 1b, since the O-ring 25 is pressed against the outer periphery of the shielding layer 17, it is possible to suppress the permeation of gas from the vicinity of the terminal, and the same effect as the gas piping terminal structure 1 is obtained. be able to.

  Moreover, it can also be set as the gas piping terminal structure 1c shown in FIG.8 (c). In the gas piping terminal structure 1c, the fixing member is divided into two fixing members 5b and 5c. The fixing member 5b that is the first fixing member is a ring-shaped member, and the front surface contacts the flange portion 24, and the rear surface contacts the fixing member 5c that is the second fixing member via the packing 11a. The fixing member 5 c has substantially the same configuration as the fixing member 5, has a flange portion 7, and the joining member 9 is inserted therethrough. That is, the packing 11a is sandwiched between the flange portion 7 and the fixing member 5b. A hole is formed in the fixing member 5b similarly to the fixing member 5c, and the joining member 9 penetrates the flange portion 7 and the joining member 5d and is joined to the connection target side.

  Also in the gas piping terminal structure 1c, since the O-ring 25 is pressed against the outer periphery of the shielding layer 17, it is possible to suppress the permeation of gas from the vicinity of the terminal, and the same effect as the gas piping terminal structure 1 is obtained. be able to. Further, since the space between the fixing members 5b and 5c is sealed with the packing 11a, gas does not leak.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs.

  For example, the structure of the gas pipe is not limited to the above-described example, and the configuration of each layer is appropriately set as long as a shielding layer is formed on the outer periphery of the tube and a reinforcing layer and a protective layer are formed on the outer periphery.

1, 1a, 1b, 1c ......... Gas piping terminal structure 3 ......... Gas piping 5, 5a, 5b, 5c ......... Fixing member 7 ......... Flange portion 9 ......... Junction member 11, 11a ... …… Packing 13 ……… Connected 15 ……… Tube 17 ……… Shielding layer 19 ……… Reinforcing layer 21 ……… Protective layer 23 ……… Terminal member 24 ……… Flange portion 25 ……… O Ring 27, 27a, 27b ......... Shielding band 29 ......... Lap part 31a, 31b ......... Resin film 33 ......... Metal film 35 ......... Resin film 37 ......... Coating 39 ......... Electric fusion socket

Claims (4)

A resin-made tubular body having flexibility;
A gas shielding layer provided on the outer periphery of the tube;
A reinforcing layer provided on the outer periphery of the gas shielding layer;
A protective layer provided on the outer periphery of the reinforcing layer;
Using a gas pipe comprising
A terminal member having a flange portion at the end is joined to the end of the tubular body,
A fixing member is provided on an outer peripheral portion of the terminal member, and the fixing member is pressed against a rear surface of the flange portion and bonded to a connection target by a bonding member,
The forming range of the fixing member with respect to the gas pipe is such that the reinforcing layer and the protective layer are peeled off, and a gas transporting flexible tube terminal is provided between the inner surface side of the fixing member and the gas shielding layer. Structure,
The end portion of the terminal member and the tube body is butt-fused or electro-fused, and the gas shielding layer is formed so as to cover the joint portion, and the joint portion in the longitudinal direction of the tube body and the A terminal structure for a flexible tube for gas transportation , wherein the sealing member is provided between the flange portion and the flange portion . A resin-made tubular body having flexibility;
A gas shielding layer provided on the outer periphery of the tube;
A reinforcing layer provided on the outer periphery of the gas shielding layer;
A protective layer provided on the outer periphery of the reinforcing layer;
Using a gas pipe comprising
A terminal member having a flange portion at the end is joined to the end of the tubular body,
A fixing member is provided on an outer peripheral portion of the terminal member, and the fixing member is pressed against a rear surface of the flange portion and bonded to a connection target by a bonding member,
The forming range of the fixing member with respect to the gas pipe is such that the reinforcing layer and the protective layer are peeled off, and a gas transporting flexible tube terminal is provided between the inner surface of the fixing member and the gas shielding layer. Structure,
The fixing member includes a first fixing member and a second fixing member, and the first fixing member is pressed against a rear surface of the flange portion and joined to a connection target by a joining member. The second fixing member is joined to the second fixing member via a packing, and the second fixing member straddles the joining portion between the terminal member and the tubular body from the terminal member side in the longitudinal direction of the tubular body. The terminal structure of the flexible tube for gas transportation , wherein the sealing member is provided between the inner surface of the second fixing member and the gas shielding layer on the outer periphery of the tubular body . The tube body and the terminal member are made of polyethylene, and the natural gas permeability coefficient of the gas shielding layer at room temperature is 1/2 or less than the natural gas permeability coefficient of polyethylene at room temperature. The terminal structure of the flexible tube for gas transport according to claim 1 or 2 . The fixing member is divided into a plurality in the circumferential direction, is covered from the outer peripheral side of the gas pipe, and is fixed so that the inner surface side of the fixing member is pressed in the outer peripheral surface direction of the gas pipe. The terminal structure of the flexible tube for gas transport according to claim 1 or 2 , characterized by these.

Images