JP4575481B2 - Tube connecting part sealing method - Google Patents

Description

The present invention relates to a tube connecting portion sealing method for sealing the connection of conduits formed by connecting tube bodies with resin coating, and more specifically, in an annular groove portion or an annular corner portion on the inner surface of the connecting portion. The present invention relates to a technique for forming a resin coating.
In this specification, the “tube body with resin coating” means a tube body in which at least the inner surface is covered with a resin including the connecting portion, and the end portion to be connected is a resin even if most of the inner surface is resin-coated. This does not apply to uncoated pipes. The presence or absence of resin coating on the outer surface does not matter.

  Various resin-lined steel pipes (tubes with resin coating) have been developed as suitable for transport pipes (pipe lines) for chemicals used in various chemical plants and power plants. Among them, polyethylene-lined steel pipes are widely used because they have the advantage of being excellent in corrosion resistance and economy. In that case, a flange joint is often used for the connection of the pipe bodies for piping. Mechanical joints other than flange joints (for example, Victoria joints) are often used. The connection means between the pipes using these joints or threaded joints, here, a butt connection in which the end faces of the two pipes are butted together and an end of one pipe is connected to the other pipe It is roughly divided into superposed connections that are inserted into and connected to hollows. In many cases, a gasket or tape is inserted or attached to the tube connecting portion in such a connection in order to strengthen the seal.

  Further, in such a pipe body, at least the inner surface is coated with a resin coating so that the transport fluid (contents) and the steel pipe (base material) do not come into direct contact with each other, and the resin coating is connected to the connecting portion. It is often extended continuously. For example, in a flange joint that can be said to be a typical butt connection, a continuous resin coating is applied from the inner surface of the steel pipe to the flange surface. Then, by tightening the flange bolt, the resin surface and the resin surface at the opposed end surfaces are compressed and pressed directly or with a gasket interposed therebetween, thereby preventing the transport fluid from entering and exiting the connecting portion.

  There is known a pipe connection joint that has both a flange joint for butt connection and a specific joint mechanism for overlapping connection (see, for example, Patent Document 1). The application is not limited to the connection of tube bodies with resin coating, but it is also possible to connect tube bodies with resin coating. And by the connection, an annular tube end facing portion that faces the inside of the tube is formed on the inner surface of the connecting portion between the tube bodies, and a stepped portion between the tube bodies that faces the inside of the tube can be formed in an annular shape by overlapping connection. . In addition, the pipe end facing part and the step part between the pipes are V-shaped due to the presence of a surface contour (design to avoid laceration of the coating) and a gasket following the chamfering of the end face of the base material. An annular groove having a U-shaped cross section is developed. And since it is behind the said annular groove seeing from the pipe inner side, the transport fluid can freely enter and exit this annular groove.

  In addition, although it is a plastic joint for resin pipe connection instead of the pipe body with resin coating, the thing which coat | covered and embedded the heater wire with the insulating heat-resistant fiber is also known (for example, refer patent document 2). Since the end of the heater wire is exposed, when an electric current is directly applied from there, the inner peripheral part of the joint and the outer peripheral part of the fitting tube are fused and connected. Also in this case, a gap or an annular groove appears in the annular tube end facing portion facing the inside of the tube and the step portion between the tubes facing the inside of the connecting portion, and sealing is performed on the outer peripheral side thereof.

  By the way, when the pipe ends are connected by welding, a pipe body in which most of the inner surface is coated with resin but the base material is exposed at the connection portion and the end portion in the vicinity thereof is used. A lining technique is also known in which a resin coating is formed after the surface of a base material exposed on the inner peripheral surface of a welded portion is trimmed (see, for example, Patent Document 3). In this case, the resin coating on the inner surface of the tube after welding is performed by setting a heating device on the outside of the tube, setting a lining device on the inside of the tube, and spraying the resin while heating or while heating. Done. By welding with resin after coating in this way, sealing is firmly performed up to the inner periphery, and the inner surface annular portion in the connecting portion (that is, between the annular tube end facing portion facing the inside of the tube and the tube body facing the inside of the tube) A conspicuous annular groove is not developed in the step portion.

JP 2000-274564 A (page 1-2) Japanese Utility Model Publication No. 3-91595 (first page) JP-A-60-110368 (first page, FIG. 2)

However, pipe connection by such welding requires that the base material and construction environment are limited to those that can be welded, that it is necessary to secure skilled welding technicians, and that not only welding equipment but also a lining device is required. And that the site conditions are such that external heating and internal spraying can be performed simultaneously.
In addition, the total resin tube has restrictions from the viewpoints of strength, price, and the like, and also exhibits an annular groove on the inner surface of the connecting portion.

For this reason, various connection methods are used properly for the configuration of the pipe line, and butt connection and superposition connection of resin-coated pipe bodies are also widely used.
However, as described above, the annular groove appears in the annular tube end facing portion facing the inside of the tube and the step portion between the tubes facing the inside of the tube in the connecting portion. Moreover, even at the bottom and back of the annular groove, the resin coating is not integrated between the connected pipes, and there is a division between the connected pipes even though it is microscopic. Therefore, it cannot be said that there is no gap due to the absence of the pressing force associated with the above, or the opening force that works on it disappears.

  And there are some inconveniences when such an annular groove or division is in the connecting portion. If a specific example is given, care will be needed, for example, in applying to high-pressure piping. In other words, it is usually used at a pressure of about 1 MPa or less, and if it is such a pressure, it can be used safely for a long period of time for fluid transportation, etc. However, when the pressure is about 3 MPa, a gap is formed in the connecting part and the fluid is removed. In order to prevent leaks, it is necessary to adopt a high-pressure flange, special gaskets, and tightening conditions such as tightening force. On the other hand, in the case of submarine piping or buried piping, for example, seawater or the like does not enter the high-purity transport liquid from the outside or contaminants from contaminated soil must not be connected properly. I must.

Or, for example, in the case of a chemical plant or the like, in particular, in the case of a pipe positioned overhead where people come and go, the leakage of the contents must never occur. In addition, even if people cannot enter after laying the piping, maintenance is a big deal and there should be no leakage. Fail-safe is eagerly desired for such applications.
Further, in the flange connection, if the flange tightening bolts are tightened too much for fear of an accident, in the case of resin lining, the load is directly applied to the resin coating of the flange. If a gasket is used, there is a portion that is absorbed by it, but in any case, if it is tightened too much, it is inevitable that the amount of deformation of the resin will increase. And excessive tightening causes the resin to undergo undesired permanent deformation. If the connecting part is integrated, there is no fear that you will be worried if you do not tighten it strongly, and you will not over-tighten and break the resin coating, but if it is not an integrated structure, it will induce over-tightening It's easy to do.

  Also, for example, when transporting a slurry mixed with solid matter, if there is an annular groove in the pipeline, the solid matter in the slurry tends to collide with the groove shoulder, and if there are many impacts, wear of the resin coating progresses quickly. It will end up.

In addition, for example, when a pipeline is used for transporting food and drinks, if there is an annular groove in the pipeline, the transported material tends to accumulate there, and if food or drinkable items stay for a long time, there will be Undesirable residues and spoilage may occur, and in order to prevent this, heat disinfection, cleaning the inside of the pipe, and in some cases, disassembly and cleaning must be performed frequently.
For example, in the case of seawater piping, if there is an annular groove on the inner surface of the piping, marine organisms often adhere to the groove. Since polyethylene is a nonpolar resin, there is almost no marine life adhering to polyethylene in the seawater flow, but due to fluid turbulence etc., marine organisms adhere to the flange connection.

Therefore, in order to eliminate these inconveniences, for pipes constructed by butt connection or superposition connection between pipes with resin coating, the resin coating of the connecting part is integrated to enhance the isolation between the pipe inside and outside Further, by eliminating or reducing the annular groove of the connecting portion, the annular tube end facing portion or the tube facing the inner side of the tube at the connecting portion so as to prevent the resin coating from being worn and to prevent the contents from staying and sticking. It is a technical problem to devise a method for improving the step portion between the tubes facing the inside.
However, application of resin coating that requires heating in a very narrow space where access within the pipeline itself is unintentional is due to heat deterioration and damage of the existing resin coating, but the construction itself is the conventional resin. It is almost impossible with the covering means.

  This invention was made in order to solve such a problem, and the division sandwiched between the tube end resin coatings existing in the tube connecting portion was sealed in a form such as filling the annular groove. It aims at realizing the pipe body connection part sealing method for making a pipe line.

In order to solve such a problem, the tube connecting portion sealing method according to claim 1 at the beginning of this divisional application is amended (the original application initial claim 7 which referred to the original application claim 5 was amended). The present invention succeeds claim 10 and succeeds the latter part of paragraph 0019 of the original specification of the original application), and an open loop energization heating element having a heat-sensitive adhesive resin disposed on the inner periphery and having an energization end on the outer periphery. This energization heating element has a length that satisfies one round, and one of the energization ends is not short-circuited and rubs against each other, and then a tubular body connecting portion that uses an annular gasket drawn out to the outside It is a sealing method, and if a butt connection is made in a direct contact state or in a gasket interposed state, pipes with resin coating in which an annular groove is formed in a pipe end facing part facing the inside of the butt connection part are connected to each other. upon butt perform connection as the body, the gasket der Thus , the butt connection is performed in such a manner that the annular groove is filled by energizing the energizing end after connecting both the connected pipe bodies butt across each other with an inner peripheral edge located where the annular groove is filled. The division of the part is sealed .

Further, the pipe body connecting portion sealing method according to claim 2 at the beginning of this divisional application (inheriting claim 9 after amending the original application initial claim 6 which referred to the original application claim 3) An annular gasket characterized in that a heat-sensitive adhesive resin is disposed on the inner peripheral edge and a closed loop energization heating element is disposed on the outer peripheral side of the original application. A tube with a resin coating in which an annular groove is formed in a tube end facing portion facing the inside of the tube of the butt connection portion when the butt connection is made in a direct contact state or in a gasket interposed state. When butt-connecting the bodies as connected pipe bodies, the two connected pipe bodies are butt-connected between the gaskets with the inner periphery located where the inner peripheral edge fills the annular groove. By induction heating the current-carrying body , The division of the butt connection portion is sealed in a form of filling the annular groove .

Further, the pipe body connecting portion sealing method according to claim 3 at the beginning of this divisional application (inheriting claim 8 after amending claim 1 of the original application and succeeding paragraph 0016 of the original specification of the original application) ), the annular groove of the extraordinary free pipe end face portion directly into the tube side of the butt junction of or gasket interposed state of the contact state between the resin coated tube which served as the coupled tube or resin coated tube The heat-sensitive adhesive resin faces the inner side of the pipe between the heat-sensitive adhesive resin and the closed-loop or open-loop current-carrying heating element in the annular groove of the step part between the pipes facing the inside of the pipe of the overlapping connection part between the bodies After the composite annular bodies are arranged in such a manner, the energization heating element is energized by electromagnetic induction or direct energization to heat the composite annular body, and the heat-sensitive adhesive resin portion of the composite annular body is connected to both connected pipes. Let the resin coating on the body heat-bond in the form of holding between the two The parting between them only the resin, characterized in that the sealing in a form and fill the annular groove in the form facing the tube side.

  Note that (the successor to the latter part of paragraph 0016 of the original specification of the original application), in the case of the present invention, the energization frequency at the time of electromagnetic induction is in the range of 10 kHz to 200 kHz, more preferably in the range of 20 kHz to 50 kHz. This is preferable from the viewpoint of induction efficiency.

In the tube connecting portion sealing method of the present invention described in claim 3 at the beginning of the division (inheriting the former stage portion of paragraph 0062 of the original specification of the original application), the inner annular portion of the connecting portion is provided. By placing the heat-sensitive adhesive resin in combination with the energization heating element, and then energizing and heating it to adhere to the resin coating, sealing the division between the connected body tubes, The sealing function is enhanced to a level where fluid leakage between the inside and outside of the pipe cannot occur, and the resin coating of the inner ring portion of the connecting portion can be made into a gentle shape with less undulations. it can.

Further, in the tube connecting portion sealing method of the present invention described in claim 2 at the beginning of division (inheriting the latter part of paragraph 0062 of the original specification of the original application), heating the heat-sensitive adhesive resin, A closed-loop energization heating element is arranged and configured to generate heat by induction heating to achieve a high degree of sealing with a closed-loop material and a resin coating with less undulations without skill. Can do. Specifically (when succeeding paragraph 0018 of the original specification of the original application), when such a tube connecting portion sealing method is executed, the annularly arranged heat-sensitive adhesive resin is thermally melted by heating after the arrangement. Or heat-denatured and bonded (thermally bonded) to the resin coating of the inner ring portion of the connecting portion (that is, the tube end facing portion or the step portion between the tube bodies facing the inside of the tube of the connecting portion). Thereby, the division existing between the pipe end resin coatings existing in the connecting portion is sealed and disappears in a form such as gently filling the annular groove, and the above-mentioned problem is solved. Moreover, in this case, the heat-sensitive adhesive resin can be easily heated by causing the energization heating element to generate heat by energization. And the resin coating of the inner surface annular portion of the connecting portion becomes a gentle integral with little undulation.
Therefore, according to the present invention, it is possible to easily make a pipe line that is sealed in a form such as filling the dividing groove sandwiched between pipe end resin coatings existing in the pipe connecting part.

Further, in the tube connecting portion sealing method of the present invention described in claim 1 at the beginning of division (inherited to paragraph 0064 of the original specification of the original application), it is replaced with a closed loop energized heating element. Although the configuration of the loop energization heating element requires the technical integration of the configuration, the most inexpensive material configuration and the simple equipment form that can be completed with only the commercial power source, there is little high sealing and undulation A resin-coated form can be realized. Specifically, in the case of using the gasket used in the tube body connecting portion sealing method according to claim 1 of the initial split (continuing from the second sentence of paragraph 0020 of the original specification of the original application), Since the end is out of the tube, when the current is directly supplied from there, the energization heating element generates heat, and the heat-sensitive adhesive resin is heated by the heat. Since this energization is for self-heating, non-high-frequency energization (energization not using a high-frequency power supply device such as an inverter) using commercial AC, a private generator, a secondary battery, or a primary battery is sufficient. In this case as well, the resin coating on the inner surface annular portion of the connecting portion becomes a gentle integral with little undulation. Thereby, when induction heating from the inside of the tube is difficult, heating can be easily performed by energization heating.
Therefore, according to the present invention, it is possible to easily make a pipe line that is sealed in a form such as filling the dividing groove sandwiched between pipe end resin coatings existing in the pipe connecting part.

About the pipe | tube connection part sealing method of such this invention, the specific form for implementing this is demonstrated by the following Examples 1-7.
And the first embodiment shown in FIG. 1, the second embodiment shown in FIG. 2, Example 3 shown in FIG. 3, Example 6 shown in FIG. 7, the original claim 3 divisional application of the present invention It is an embodiment. Further, the fourth embodiment shown in FIGS. 4 to 5 and the fifth embodiment shown in FIG. 6 embody claim 2 at the beginning of the divisional application, and the embodiments shown in FIGS. 7 embodies claim 1 at the beginning of the divisional application.

An embodiment of the tube connecting portion sealing method of the present invention will be described with reference to the drawings (paragraphs 0023 to 0031 in the original specification of the original application).
Fig.1 (a) is a longitudinal cross-sectional view of the butt connection part by a flange pipe joint, and the same figure (b) is a longitudinal cross-sectional view of the butt connection part by a Victorian pipe joint. (C)-(h) are all the principal part enlarged views of A part, and the joint etc. are abbreviate | omitted. In addition, (c) is an example with a gasket, and (d) to (h) are examples without a gasket.

  In the butt connection, both pipe flanges 10 and 20 to be connected have the same diameter, both in the case of flange fittings (see FIG. 1 (a)) and in the case of Victorian fittings (see FIG. 1 (b)). Since the end portions of both the tubular bodies 10 and 20 are connected by appropriate attachments such as bolts in a state where the end faces of the tubular bodies 10 and 20 are in direct contact with each other or faced closely to each other, the inner surface thereof An annular facing portion appears. In the annular tube end facing portion 30 facing the inside of the tube, the gasket 31 interposed between the end faces may be exposed (see FIG. 1C) or may not be exposed (see FIG. 1D). In any case, an annular groove or unevenness appears.

  Since the connection method between the tubular bodies 10 and 20 is defined in the JIS standard or the like, further explanation is omitted and the tubular bodies 10 and 20 will be described. Each of the tubular bodies 10 and 20 is a tubular body with a resin coating, and the inner surface is resin-coated including the connecting portion. Specifically, the tubular body 10 is obtained by applying a resin coating 12 to the inner surface and end face of the base material 11. Similarly, the tubular body 20 is provided with a resin coating 22 on the inner face and end face of the base material 21. Is. The base materials 11 and 21 are typically steel pipes such as steel pipes, stainless steel pipes, and ductile cast iron pipes, but may be pipes made of non-ferrous metals such as copper, and ceramic pipes such as alumina. Also good. In the case of a steel pipe, the outer diameter is generally 21.7 mm to 812.8 mm, but may be thinner or thicker. The wall thickness is generally 2.8 mm to 7.9 mm, but it may be thinner or thicker.

  The material forming the resin coatings 12 and 22 is typically polyethylene (PE), but may be other thermoplastic resins or further reaction curable resins, such as polypropylene (PP) or other materials. Polyolefin, polyamide (PA), polyvinyl chloride (PVC), ethylene vinyl acetate copolymer (EVA), ethylene acrylic copolymer (EEA, EAA, etc.), fluororesin (FEP, PFA, PVDF, ETFE, etc.), polyester Polyurethane, epoxy resin, phenol resin, etc. are also used. They may be used alone or in combination of two or more. In many cases, pigments such as carbon black and titanium oxide are blended with these resins in order to improve weather resistance. In the case of polyethylene, one having a melting point of 120 ° C to 130 ° C is usually used. In the case of polyethylene, the thickness of the resin coatings 12 and 22 is usually 1 mm to 3 mm.

For forming the resin coating, several methods are known, such as spraying resin powder on a heated base material, heating a resin sheet on a base material, and the like. These corners are usually rounded by 3 mmR or more, and an annular groove appears in the tube end facing portion 30 due to this roundness.
Since the butt connection between the tubular bodies 10 and 20 is performed by a known method, the subsequent additional steps will be described in detail, assuming that it has been completed.
In the additional step, the resin coating is formed so as to fill the annular groove with respect to the annular groove portion of the annular tube end facing portion 30 facing the inside of the tube in the butt connection portion.
In this example, the case where there is no gasket 31 in the pipe end facing portion 30 and the closed-loop energization heating element 32 is used will be described in detail as a specific example (see FIGS. 1D to 1H).

In this case, the energization heating element 32 and the heat-sensitive adhesive resin 33 are used, but the energization heating element 32 is previously arranged in an annular form with respect to the tube end facing portion 30 and then the heat-sensitive adhesive resin 33 is separated. The adhesive resin 33 may be annularly arranged to form a composite annular body on the spot (in the case of a large-diameter pipe into which a person enters), and a pre-complexed string-like body is disposed after being closed in a ring shape. It is good (regardless of pipe diameter). Here, the former form will be described. The heat-adhesive resin 33 is heated by causing the energization heating element 32 of the composite annular body thus arranged to generate heat by energization.
The heat-sensitive adhesive resin 33 is preferably the same resin as the resin coatings 12 and 22 or a modified body with enhanced thermal bonding performance (such as fusion bonding performance). Any material having adhesion performance and environmental resistance performance may be used.
The energization heating element 32 is made of, for example, a thin metal wire such as a thin nichrome wire, stainless steel wire, iron wire, or nickel wire, or a conductive ceramic fiber such as carbon fiber or silicon carbide fiber, and is formed in a wire shape. A conductive resin wire may be used.

  The annular arrangement of the current-carrying heating element 32 (see FIG. 1 (e)) is such that the wire-shaped current-carrying heating element 32 is pushed into the innermost part of the annular groove to energize the annular pipe end facing part 30 facing the inside of the pipe. The heating element 32 is made a round and the ends are closed to each other by a means such as brazing. Thus, the energization heating element 32 is annularly arranged in a closed loop shape at the tube end facing portion 30. In addition, since the appropriate rigidity and flexibility required for the energization heating element 32 differ depending on the use state of the tube diameter, the annular groove, etc., the energization heating element 32 may be a single wire or a plurality of lines. An appropriate one is selected and used from a bundle, a plurality of twisted or knitted pieces, and the like. Furthermore, a plurality of wires or wires of the energization heating element are wound, and an annular body constituting one closed loop electric circuit is arranged by securing conduction between the end portions and adjacent wires by brazing of the main part. Also good.

The annular arrangement of the heat-sensitive adhesive resin 33 (see FIG. 1 (f)) is arranged such that the heat-sensitive adhesive resin 33 previously formed in a string shape is overlaid on the energization heating element 32, or a high viscosity The base of the heat-sensitive adhesive resin 33 prepared in the form of a paint is applied to the energizing heating element 32 and the resin coatings 12 and 22 around it, and then applied once.
Heating of the heat-sensitive adhesive resin 33 using the current-generating heat generating body 32 (see FIG. 1G) is performed by temporarily arranging the annular conductor 34 in a mode that does not contact the heat-sensitive adhesive resin 33 immediately inside the current-generating heat generating body 32. Then, it is performed by applying high-frequency current to the conductor 34.

When the conductor 34 is energized with a high frequency, an induced current flows through the energization heating element 32 positioned on the inner periphery thereof, and the energization heating element 32 generates heat (that is, induction heating), and the heat is combined with the heat-sensitive adhesive resin 33. The heat-sensitive adhesive resin 33 and the surrounding resin are fused or bonded to the resin coatings 12 and 22 therearound.
In this way (see FIG. 1 (h)), the pipe end facing portion 30 of the pipe connecting portion where the pipe bodies 10 and 20 are butt-connected is the heat-sensitive adhesive resin whose resin coatings 12 and 22 hold between them. It is integrated by the bridge connection by 33, it becomes a continuous body, and the said division is sealed. And there is an energization heating element that performs the heating function for the bridge sealing, but it is not exposed to the inside of the pipe, which may adversely affect the flowed material. In addition to being absent, it functions as a reinforcing body that maintains the annular form of the heat-sensitive adhesive resin 33. The heat-sensitive adhesive resin 33 and the resin coatings 12 and 22 connected to the heat-sensitive adhesive resin 33 are integrated by fusion or the like, and fill the annular groove on the inner surface of the connecting portion and the energization heating element 32 to provide a gentle coating with less surface undulation. Has been reformed.

The embodiment of the tube connecting portion sealing method of the present invention will be described with reference to the drawings (paragraphs 0032 to 0035 of the original specification of the original application).
FIG. 2 (a) is a free state external view of the electrically fusible material 40 in which the tube body 42 of the heat-sensitive adhesive resin (thermoplastic resin in this example) and the electrically conductive heating element 41 are combined, and FIG. 2 (b). Fig. 2 is an enlarged cross-sectional view of the electrically fusible material, Fig. 3C is a side view of the annularly arranged electric fusible material, and Fig. 4D is a side view of a joining portion of cut ends. . 2E to 2H are cross-sectional views in which main portions (corresponding to the above-described A portion) of the butt connection portion are enlarged.

  That is, here, in order to simplify the construction, the electrically fused material 40 (see FIG. 2A) combined in advance is used. The energizing and fusible material 40 is a flexible string-like body in which an energizing heating element 41 is built in a hollow portion of a tube body 42 made of a heat-sensitive adhesive resin (see FIG. 2B). If it is formed in the shape of a ring from the beginning, it can be used immediately, but when making a closed loop from a long end (see FIG. 2 (c)), it is cut to an appropriate length and then the cut end 43 is cut. To make a ring. For the butted portion of the cut end 43 (see FIG. 2 (d)), the end portions of the energization heating element 41 are mutually connected by brazing, sleeve crimping, wire knitting, etc. (44) to form a closed loop circuit. Close to state. Further, the ends of the tube body 42 may be joined together by fusing, taping, or shrink tube / tape coating using a heat-sensitive adhesive resin.

Here (see FIG. 2 (e)), the case where the gasket 31 is provided in the annular pipe end facing portion 30 facing the inside of the pipe, and the case where the electrically fusible material is disposed in a previously closed state will be described as a specific example. To do.
In this case (see FIG. 2 (f)), first, the electrically fusible material 40 is formed into an annular body corresponding to the inner diameter of the tubular bodies 10, 20, for example, a single ring, which is also formed on the inner peripheral surface of the gasket 31. It arrange | positions in the cyclic | annular groove | channel of the pipe end opposing part 30 in the form which also contacts the resin coatings 12 and 22 of the pipe bodies 10 and 20. FIG.

Thereafter, as described in the above example (see FIG. 2G), an inductive current is generated in the energization heating element 41 in a non-contact manner using the conductor 34 or the like, and the energization fusion material 40 is generated by the generated heat. And the resin coatings 12 and 22 in the vicinity thereof are fused.
Then (see FIG. 2 (g)), in this pipe, the division of the pipe end facing portion 30 of the connecting portion is sealed with the heat-sensitive adhesive resin 42, and the closed loop energization heating element 41 is exposed to the inside of the pipe. It becomes the pipe buried in the ring without doing. In this case as well, the heat-sensitive adhesive resin 42 and the resin coatings 12 and 22 are integrated by fusion, and the annular groove on the inner surface of the connecting portion and the energization heating element 41 are filled to form a gentle coating with less surface undulation. Reformed. The arrangement of the annular body of the electrically fusible material 40 is not limited to a single ring, and a plurality of rings may be arranged concentrically in the tube axis direction or the tube diameter direction as necessary. Also good.

An embodiment of Example 3 of the tube connecting portion sealing method of the present invention will be described with reference to the drawings (paragraphs 0036 to 0038 of the original specification of the original application).
3A to 3D are cross-sectional views in which the main part (corresponding to the above-described A part) of the overlapping connecting part is enlarged.

  In the superposition connection (see FIG. 3 (a)), the outer diameter of the pipe body 10 having the smaller pipe diameter is equal to or slightly equal to the inner diameter of the pipe body 20 having the larger pipe diameter. Since the end portion of the tube body 10 is small and is fitted into the hollow end portion of the tube body 20, an annular stepped portion appears on the inner surface of the conduit. Regarding the inter-tube step portion 39 facing the inside of the tube, the step itself forms an annular groove, and the roundness of the resin coating 12 derived from the chamfering of the end corner of the inserted base material 11 The annular groove is emphasized at the back.

  Also in this case, although the tube connection part sealing method of each example mentioned above can be used, the usage example of the electrically-adhesive material 40 is demonstrated here. In this case, it is advisable to use an electrically fusible material 40 having a slightly smaller diameter than the step. An electrically fusible material 40 is annularly arranged in the throat portion of the step part 39 between the tubes (see FIG. 3B), and the conductor 34 is temporarily arranged inside (see FIG. 3C). The induction fusing material 40 is induction-heated by energizing the current. Then (see FIG. 3D), the step part 39 between the pipes of the connecting part is filled with the electrically fusible material 40, and the heat-sensitive adhesive resin that was the tube body 42 is replaced with the nearby resin coating 12, The surface of the inter-tube stepped portion 39 is flattened and leveled by being fused and integrated with 22 and simultaneously deforming. In this way, this pipe line is sealed in a gentle state with few undulations by the heat-sensitive adhesive resin 42 at the dividing portion 39 between the tube bodies, and the closed loop energization heating element 41 is not exposed to the inside of the tube. It will be buried.

An embodiment of Example 4 of the tube connecting portion sealing method of the present invention will be described with reference to the drawings (paragraphs 0039 to 0041 of the original specification of the original application).
4A is an external view of the gasket 50 with a heat-melting portion, FIG. 4B is an enlarged view of the BB cross section, FIG. 5A is a longitudinal cross-sectional view of the connecting portion in the pipe, and FIG. b) is an enlarged view of the main part (corresponding to the above-mentioned part A).

  The gasket 50 with a heat-melting portion (see FIG. 4) is a combination of an annular electrically fusible material 40 disposed on the inner peripheral edge and an annular plate-like body 52 so that it can be used as a gasket interposed at the pipe end. It is a simple shape. Therefore, one desirable form is that the annular plate-like body 52 is provided with a mechanical cushion function of a normal gasket by using a commercially available rubber-based gasket almost as it is. Then, on the inner peripheral edge, a current-welding material 40 in a closed loop shape is attached by a technique such as stepping-like partial fusion. Any material suitable for the gasket can be used for the annular plate-like body 52. For example, EPDM (ethylene propylene rubber), silicon rubber, fluorine rubber, neoprene rubber, soft natural rubber and the like are preferable. Wrapping packing covered with fluororesin is also good.

In this case (see FIG. 5), when the tubular bodies 10 and 20 are butt-connected to each other, a gasket 50 with a heat-melting portion is inserted in the connecting portion in advance. After the connection of the tube ends is fixed by bolt fastening or the like, a substantially annular conductor 34 is temporarily placed inside the connecting portion with an appropriate jig or tool, and this is supplied from an appropriate power supply unit for a predetermined time. A predetermined high-frequency energization is performed. If it does so, the heat-sensitive adhesive resin outer skin of the electrically fusible material 40 present at the inner peripheral edge of the gasket 50 with the heat fusion part will be heated by the induction heating heat generation of the energized heating element 41 , and the resin coatings 12 on both sides will be heated. , 22 are integrated with each other, so that the pipe end facing portion 30 facing the inside of the pipe is sealed with a heat-sensitive adhesive resin and a resin coating in a gentle state with little undulation. It becomes. In this case, since the annular arrangement of the members necessary for the re-formation / post-formation of the resin coating at the connecting portion is performed along with the mounting of the gasket, the construction is further facilitated.

An embodiment of Example 5 of the tube connecting portion sealing method of the present invention will be described with reference to the drawings (paragraph 0050 of the original specification of the original application).
FIG. 6 is a BB cross-sectional view of the gasket 50 with a heat-melting portion, corresponding to the above-described FIG. 4B, and is a cross-sectional view schematically shown in the outline.
This is because the inner peripheral portion is formed in a tapered shape when viewed in cross section, and the innermost peripheral corner portion 81 is wide. Therefore, it is suitable when the inside of the tube in the annular groove of the tube end facing portion 30 has a reverse V groove shape or a reverse U groove shape, and the annular groove can be filled accurately.

An embodiment of Example 6 of the tube connecting portion sealing method of the present invention will be described with reference to the drawings (paragraphs 0051 to 0052 of the original specification of the original application).
FIG. 7 is a longitudinal sectional view showing a butt connection portion using the electric pipe fitting 300, and FIG. 7A is a view showing that the electrically fusible material 40 adjusted in an endless annular shape is provided in the pipe end facing portion 301. (B) shows the state of the pipe end facing portion (in this example) by bridging and fusing the above-mentioned electrically fusible material 40 to the resin coatings 12 and 22 on both sides by induction heating. This shows a state in which a gap having a width of several mm is sealed in a form in which resin coatings are continuously connected.

The electric pipe fitting 300 is a pipe connecting means that does not use a gasket, and the pipe end facing portion 301 has the gap extending to the outer peripheral edge of the pipe (however, the outside of the pipe is outside the gap. The lip seal rubber body 302 is sealed).
In this case (see FIG. 7 (a)), the electrically fusible material 40 that is slightly thicker than the width of the gap is selected and made into an annular body. Then, the pipe end faces on both sides are opposed to each other with the annular body sandwiched therebetween, and in this state, a pair of metal half housings (not shown) of the pipe joint 300 are arranged on the outside of the rubber body 302. Close with bolts.

Next, induction heating of the electrically fusible material 40 is performed from the inside of the tube by the same method as described above, and this is bridged and fused to the resin coatings 12 and 22 on both sides to seal the gap 301 (FIG. 7). (See (b)).
One of the characteristics of the Victorian pipe joint is that it has a slight flexibility at the connecting part. Therefore, the flexibility is not essentially lost, but rather provides the advantage of functioning as a bending limit means.

Regarding Example 5 of the tube connecting portion sealing method of the present invention, first, the structure of the gasket 100 with a heat fusion portion used for the implementation will be described with reference to the drawings (paragraph 0053 of the original specification of the original application). (Succession).
8A is an external perspective view of the gasket 100 with a heat-melting portion, and FIG. 8B is an enlarged view of a lead-out portion of the current-carrying ends 103 and 104.

  This gasket 100 includes an annular plate-like body 101 similar to the above-described annular plate-like body 52, and an electrically fusible material 40 equivalent is disposed on the inner peripheral edge. However, this electrically fusible material 40 equivalent is not in a closed loop shape but in an open loop shape, and further, an electric current corresponding to the energization heating element 41 in the electrically fusible material 40 is formed from a pair of ends thereof. The heating element 102 is drawn out to the outer peripheral side as the current-carrying ends 103 and 104 in a manner in which an insulating coating is applied. One end 103 and the other end 104 of the end portion are not short-circuited and rubbed against each other, and then are distributed to one surface side and the other surface side of the annular plate-like body 101 and drawn to the outside. In addition, as long as the drawer | drawing-out to the exterior of the electricity supply ends 103 and 104 is a form in which mutual short circuit is avoided, forms other than the said distribution form may be sufficient.

An embodiment of the tube connecting portion sealing method of the present invention performed using such a gasket 100 with a heat melting portion will be described with reference to the drawings (paragraphs 0054 to 0055 of the original specification of the original application). .
FIG. 9A is an external view of a butt connection portion by a flange pipe joint, FIG. 9B is a partially enlarged view of the longitudinal section (corresponding to the above-mentioned portion A), and FIG. It is.

  The gasket 100 with a heat fusion part is suitable for a pipe line that an operator cannot enter (see FIG. 9A). In this case, when the pipe bodies 10 and 20 are butt-connected to each other, the gasket 100 with a heat-melting portion is inserted in the connection portion in advance. After the connection is fixed by bolt fastening or the like, the current-carrying ends including the inner peripheral edge of the gasket 100 with the heat-melting portion are connected to the current-carrying ends 103 and 104 that are outside and connected to the current-carrying power. The heat-sensitive adhesive resin (42) corresponding to the adhesive material 40 can be fused to the resin coatings 12 and 22 on both sides (see FIGS. 9B and 9C). The energization of the open loop energization heating element 102 is direct energization rather than electromagnetic induction energization, so it is sufficient to energize from a simple power source such as commercial AC, portable generator or battery, not high frequency energization. .

  In this way, the pipes 10 and 20 are also sealed in a gentle state in which the annular pipe end facing part facing the inside of the pipe is less undulated with the heat-sensitive adhesive resin (42) and the resin coatings 11 and 12. . An open-loop energization heating element with an energization end is left buried in the connecting portion of the pipe line. The open loop-shaped portion 102 of the energization heating element has a length that fills one round, and the energization end portion of the energization heating element has one 103 and the other 104 distributed to both tube ends 10 and 20 side. It is drawn out to the outside.

About Example 1 of the pipe body connection part sealing method of the present invention, (a) is a vertical cross-sectional view of a butt connection part by a flange pipe joint, (b) is a vertical cross-sectional view of a butt connection part by a Victorian pipe joint, (C)-(h) are all the principal part enlarged views of A part. About Example 2 of the pipe body connection part sealing method of the present invention, (a) is a free state external view of an electrically fusible material, (b) is a cross-sectional view thereof, and (c) is a side view of an annular arrangement state (D) is a side view of the joining part of a cut end, (e)-(h) is sectional drawing which expanded all the principal parts of the butt | matching connection part. About Example 3 of the tube connection part sealing method of this invention, (a)-(d) is superposition | polymerization, All are sectional drawings which expanded the principal part of the connection part. About Example 4 of the pipe body connection part sealing method of this invention, the structure of the gasket with a heat fusion part to be used is shown, (a) is a gasket external view, (b) is BB sectional drawing. The tubular body connection situation using the gasket with a heat fusion part is shown, (a) is a longitudinal cross-sectional view of a connection part, (b) is a principal part enlarged view. It is BB sectional drawing of a gasket about Example 5 of the pipe body connection part sealing method of this invention. About Example 6 of the pipe body connection part sealing method of this invention, (a) and (b) are sectional drawings which expanded all the principal parts of the butt connection part. About Example 7 of the pipe body connection part sealing method of this invention, the structure of the gasket with a heat fusion part to be used is shown, (a) is an external appearance perspective view of a gasket, (b) is an enlarged view of the extraction | drawer part of an electricity supply end It is. The pipe connection state using the gasket with the heat fusion part is shown, (a) is an external view of the butt connection part by the flange pipe joint, (b) is a partially enlarged view of the longitudinal section, and (c) is the main part thereof. It is an enlarged view.

Explanation of symbols

10 ... Tube body, 11 ... Base material, 12 ... Resin coating,
20 ... Tube, 21 ... Base material, 22 ... Resin coating,
30 ... Pipe end facing part, 31 ... Gasket, 32 ... Current heating element,
33 ... heat-sensitive adhesive resin, 34 ... conductor, 39 ... step between pipes,
40 ... electrically fusible material, 41 ... electric heating element,
42 ... tube body of heat-sensitive adhesive resin,
50 ... Gasket with heat fusion part, 52 ... Circular plate
100 ... Gasket with heat fusion part, 101 ... Circular plate,
102: Energizing heating element, 103, 104: Energizing end

Claims (3)

A heat-sensitive adhesive resin is disposed on the inner peripheral edge, and an open loop energization heating element with a current-carrying end is disposed on the outer peripheral side. The current-carrying heating element has a length that satisfies one round and has one of the current-carrying ends. A tube connecting portion sealing method using an annular gasket drawn out to the outside after being rubbed without short-circuiting with the other ,
If butt connection is made in a direct contact state or in a gasket interposed state, butt connection is performed using pipes with resin coating that form annular grooves in the tube end facing part facing the inside of the butt connection part as connected pipes. At the time, the annular groove is filled by energizing the energized end after connecting both the connected pipe bodies with each other with the inner peripheral edge of the gasket positioned at a position where the annular groove is filled. A tube connecting portion sealing method , wherein the division of the butt connecting portion is sealed in a form. A tube connecting portion sealing method using an annular gasket , characterized in that a heat-sensitive adhesive resin is disposed on the inner periphery, and a closed loop energization heating element is disposed on the outer periphery thereof ,
If butt connection is made in a direct contact state or in a gasket interposed state, butt connection is performed using pipes with resin coating that form annular grooves in the tube end facing part facing the inside of the butt connection part as connected pipes. upon, by the inner peripheral edge a said gasket induces heating said energizing member from the connecting butt the both the coupled pipe bodies across the one located at filling the annular groove, the annular groove A tube connecting portion sealing method , wherein the division of the butt connecting portion is sealed in a filling form . The annular groove of the extraordinary free pipe end face portion directly into the tube-side of the butt junction of or gasket interposed state of the contact state between the resin coated tube which served as the coupled tube or resin coated tube bodies The heat-sensitive adhesive resin and the closed-loop or open-loop current-carrying heating element face the inner side of the pipe in the annular groove of the step part between the pipes facing the inner side of the superposed connecting part. After the combined annular body is arranged, the energization heating element is energized by electromagnetic induction or direct energization to heat the complex annular body, and the heat-sensitive adhesive resin portion of the composite annular body is connected to both the connected pipe bodies. A tube connecting portion seal characterized in that the resin coating is thermally bonded in such a way as to hold between the two, and the division between the two is sealed so that only the resin faces the inside of the tube and fills the annular groove. Stop method.

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