JP2002071065A - Method for joining pressure resistant pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joint in high pressure piping for liquid and gas in which highly reliable leakage prevention of internal fluid, a simple structure, excellent workability, and economical merits can be achieved, and furthermore, to prevent electrolytic corrosion in small diameter pipes. SOLUTION: The fundamental constitution of the joining method is a combination of a divided hetero coupling and a self seal type gasket of an internal mounting on the pressure receiving side, wherein a joint structure having flexibility is formed by a coupling whose both ends are loosely engaged with the outer diameter of the pipe, and the workability is enhanced in the small diameter pipe by using a plate spring, and an insulating material is used at least in one of the divided coupling of the external mounting and the gasket so as to enable assembling to provide a joining means by the pipe joint capable of preventing electrolytic corrosion for a composite metal piping.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION Liquid or air, or
The present invention relates to a method for joining a fluid such as a gas in pressure-resistant piping.

[0002]

2. Description of the Related Art In a conventional pressure-resistant pipe construction using a joint, various methods including a method of joining a flange welded to both ends of a pipe joint with a bolt using a high-strength material through a packing are used. Many construction methods such as packing and tightening methods using special couplings have been carried out, but many problems such as pressure resistance performance, flexibility performance, or workability, and reliability problems have been encountered. There were restrictions.

[0003]

SUMMARY OF THE INVENTION According to the joining method in the construction of pressure-resistant piping using the joint having the structure according to the present invention,
The sealing performance is enhanced in proportion to the increase of the internal pressure of the various internal fluids, so that the leakage of the fluid from the pipe joint is reliably prevented, the flexibility is excellent, and the workability and the economy are improved. It is intended to provide excellent joining means. In addition, in the case of a small-diameter joint, measures are taken to prevent electrolytic corrosion that may occur when joining different kinds of metal pipes.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention firstly provides a stopper having a pressure-resistant strength at the pipe outer diameter portions at predetermined positions at both ends of a pressure-resistant pipe joint of hydraulic or general fluid. Provided as a locking mechanism in which the ring is fixed by welding or screws, etc., a coupling that can be fitted loosely from the outside of the stopper ring in the axial direction and that can be loosely locked, mainly a steel cylinder with pressure resistance The shape, the central portion is expanded into a circumferential shape by expanding the diameter of the center portion, and a flange, or a coupling mechanism such as a screw is provided to form an approximately symmetrical different diameter in the axial direction, and in the coupled loose coupling, A tubular gasket made of an elastic material such as rubber or resin that is fitted over both ends of the outer diameter portion of the joint pipe is fitted and stored,
In this gasket shape, in the axial cross section, a liquid chamber portion in which the inside of the body portion is circumferentially expanded is provided, both ends are closely fitted to the outer diameter portion of the pipe, and the circumferentially inward direction is formed. The fin portion is provided in a self-sealing structure provided for liquid receiving pressure, and furthermore, a steel seal ring is mainly integrally joined to the shoulder at both ends of the body,
Alternatively, the composite gasket is formed as an abutting composite gasket, and the composite gasket is closely mounted on both outer diameter portions of the connecting portion of the pipe and the inner wall surface of the stopper ring. As the internal pressure of the internal fluid increases, the fins at both ends of the gasket receive pressure and the sealing performance increases,
It is formed as a self-sealing type with no fear of leakage of the internal fluid, and the loose coupling is variably locked to the stopper ring, so it absorbs bending due to thermal expansion and contraction of piping or vibration due to vibration etc. Have flexibility,
Further, the seal ring joined to the outer shoulder of the gasket prevents the gasket portion from flowing out of the gap generated when the pipe is bent. In the joint structure, the non-diameter side end of the different diameter neck portion of the external coupling is directly welded or fixed by screws or the like to the outer diameter portion of the pipe so that both flanges can be connected, and the gasket is included inside. It can also be formed. Further, the coupling can be replaced with another material depending on the pressure resistance condition.

Further, the present invention provides a joint structure for a pressure-resistant pipe, wherein a cylindrical central portion used for the joint portion is provided with a symmetrically provided axially different bowl-shaped neck portion having an enlarged diameter in the axial section. An open leg on both sides of a bowl with an axial cross section where the small diameter part at both ends is directly joined to the outer diameter part of the tube and the back part abuts in accordance with the shape of the inner surface of the bowl-shaped neck part. The mold is provided so that the end of the opening is in contact with the position of the inner wall surface of the bowl-shaped neck portion, and a bead ring is built in the inner periphery of the opening meat portion so as to be closely attached to the end to prevent fluid entrapment at the end. Alternatively, a gasket which is integrally formed by providing a flange on the circumference of the back portion may be provided, and the gasket may be sandwiched and joined to the flange of the coupling.

Further, the present invention is mainly applicable to a pipe joint such as a water pipe or a gas pipe. A gasket is formed in a self-sealing manner by providing a liquid chamber portion having an enlarged diameter in the central body portion and a circumferential fin portion inward at both ends, and a steel or resin bowl is formed at both ends of the gasket. A pipe-shaped retainer is formed so as to be fittable to the outer diameter portion of the pipe and abuts on the pipe. The gasket and the pipe at the outer positions on both ends of the bowl-shaped retainer are expanded, or a ring such as a split ring is used for groove processing. A locking mechanism is provided, which includes an external coupling formed from a steel- or resin-made cylindrical divided and coupleable by a screw mechanism or the like from the outside in the axial direction, and formed by providing locking portions at both ends. It can also be configured to be assembled.

The present invention also provides an elastic tubular gasket having a joint provided with a liquid chamber portion and a circumferential fin extending inwardly at both ends inside the body portion. A projection is formed on the periphery with a compression allowance, and a cylindrical retainer with a leaf spring is provided at one end of a spring steel, which is attached to the periphery of the projection, and has a plurality of slits in the axial direction. The inner diameter is integrally molded and provided as a circular leaf spring with slits that can bite into the outer diameter of the pipe.
Moreover, the tubular retainer with a leaf spring is press-fitted to the projection, the tubular portion slightly enlarged by the compression allowance is fixed by inserting a caulking sleeve externally, and the gasket thus mounted and both ends are fixed. It can also be assembled by a divided external coupling that includes the cylindrical retainer from the outside in the axial direction. The end leaf spring is provided as a circular leaf spring in which an inner diameter portion is bent at a predetermined angle inward in the axial direction of the cross section and is provided in a chrysanthemum flower shape having a plurality of radial slits. When force is applied, the inner diameter edge of this leaf spring cuts into the outer diameter of the pipe to prevent pulling out, and forms a joint that can be attached without applying a locking mechanism to the piping and coupling end. Can be done.
In addition, it is also possible to provide a cylindrical portion having a predetermined diameter for caulking in the external both end couplings without using the cylindrical portion caulking sleeve, and caulking can be performed. Also, the split coupling can be formed by combining the materials. Alternatively, the coupling may be formed by being split into two parts in the axial direction.

In the case where the joint is used at a low pressure, a gasket-shaped circular flat spring having a plurality of slits is provided on the outer surface of both ends of the gasket without mounting the protrusions on both ends of the gasket. To prevent this, a coupling can be formed by attaching a separately formed coupling to the outside.

Further, the joint according to the present invention has a liquid chamber portion in which both ends are fitted to the outer diameter portion of the pipe connection portion and the inside of the cylindrical central body portion for internal mounting is enlarged, An insulative elastic gasket formed by providing a circumferential fin portion is engaged with a chrysanthemum-shaped leaf spring on both outer end surfaces of the gasket, and the inner diameter portion is cut into the outer diameter surface of the pipe and locked. A locking mechanism is provided at a predetermined position on the outside of the pipe, for example, for expanding a pipe or performing groove processing to form a split ring. The gasket and a tubular external part including a leaf spring are provided on the locking mechanism. A coupling joint is mounted and attached, and the both ends of the coupling are provided with locking portions capable of locking from an axial direction. Or, at least one of which is provided by an insulating resin material or the like. Form, resulting in electrolytic corrosion prevention measures in the case of dissimilar metal piping can take.

[0010] Therefore, since the joining joint of the present invention is formed as described above, the gasket inserted across both ends of the pipe joint prevents the internal pressure in the liquid chamber from increasing as the inside of the outer periphery of the pipe increases. Has a self-sealing function that can increase the sealing performance in proportion to the increase of the internal pressure, while the external pressure-resistant coupling is loosely locked at both ends. Because of the structure provided, very excellent flexibility can be expected. In addition, since the structure is very simple, it is possible to provide excellent workability in construction and to provide a joint which is very economical in terms of cost. In addition, in the case of medium and low pressures such as water pipes, it is possible to take measures to prevent electrolytic corrosion which occurs particularly when joining different kinds of metal pipes.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a loose-coupling type joint in a pressure-resistant pipe construction according to the present invention. As shown in FIG. In addition, a steel-made axially symmetrically divided, loosely-coupled coupling 3 having a flange 3A with an enlarged diameter at the center and a pipe 3 is welded to a predetermined position of an outer diameter portion at both ends of a joint portion of the pipe 2. A stopper ring 4 fixed by, for example, is provided to provide a locking mechanism for locking the non-diameter end of the coupling 3 and, as shown in FIG. A liquid chamber A is provided by enlarging a central body portion of a rubber cylinder to be formed, and both ends are closely fitted to the outer diameter portion of the pipe 2 and simultaneously a fin portion B in the axial direction is provided in a circumferential shape. In addition, a composite gasket 5 in which a steel seal ring 5a is integrally molded on both shoulders on the outer periphery of the trunk portion. First, a stopper ring 4 is welded or screwed to a predetermined position on both ends of the pipe 2 by fitting and inserting the outer diameter portions of both ends of the pipe 2 from the small-diameter end of the coupling 3. The two ends of the composite gasket 5 are fitted to the outer diameters of both ends of the pipe 2 between the stopper rings 4, and the coupling 3 is included from outside of the attached two axial directions.
Are assembled so that the small-diameter portion and the two stopper rings 4 are engaged with each other, and are loosely joined to each other to form a loose coupling type joint 1. The loose coupling type joint 1 thus formed is provided with pressure resistance by the coupling 3 and the stopper ring 4.
Since the composite gasket 5 has a self-sealing structure in which the liquid chamber portion A and the fin portion B enhance the sealing performance in proportion to the increase of the internal pressure, there is no fear of leakage of the internal fluid, and at the same time, the piping 2 and the cup Ring 3 is loosely connected,
And because the internal gasket has excellent followability,
Even if the pipe is greatly bent due to thermal expansion or contraction or vibration, it has a structure having excellent absorption capacity. The seal ring 5a completely prevents the material portion of the gasket 5 from flowing out of the gap between the coupling 3 and the stopper ring 4 which is deformed during the bending. The seal ring 5a can also abut. Incidentally, the initial molding of the fin portion B in the inner direction of the composite gasket 5 is provided to be smaller than the outer diameter of the pipe 2 and is formed as a tightening allowance, and a primer or an adhesive can be applied to the interface at the time of mounting. When the coupling 3 has a flange 3A joint structure, the structure of the composite gasket 5 may be such that the packing 6 is integrally formed around the center of the back. In the case of a low-pressure design, it can be formed without using the seal ring 5a. Further, as shown in FIG. 3, a fixed coupling type joint in which both ends of the different diameter neck portion 7A are fixed can be formed. In addition, the coupling 3 can be formed using a reinforced resin material depending on the pressure resistance condition. Further, although not shown, the different diameter coupling may be formed so as to be bisected in the axial direction so as to be connectable by a flange or the like.

As shown in FIG. 4, as a second embodiment of the present invention, a joint 8 with a bowl-shaped neck in a pressure-resistant pipe is provided.
The non-diameter side ends of the enlarged, different-diameter bowl-shaped neck portions 8B with flanges 8A used for the joint portion of the pipe 2 are joined to the outer diameter portions of both ends of the pipe, and the axial direction when the flange 8A is joined. Is formed in a bowl-shaped peripheral shape, and an elastic gasket 9 which is in contact with the inner surface of the bowl-shaped portion is formed by providing an opening C of an open-leg type having a bowl-shaped internal shape in cross-section, and a bead is formed circumferentially. Ring 9
a, and a flange 9A is provided around the back of the gasket 9 so as to be integrally formed.
The bead ring 9a is attached to the inner surface of the bowl-shaped neck 8B so as to be in close contact with the inner surface of the gasket B, and the back flange 9A is attached to the end of the gasket 9 to prevent the end of the gasket 9 from being lifted due to the internal fluid. It is also possible to form a pressure-resistant joint 8 with a bowl-shaped neck having self-sealing performance by being fixed by being sandwiched between the flanges 8A. Alternatively, in this case, although not shown, instead of incorporating the bead ring 9a having the peripheral portion of the opening C, the end portion of the opening portion C of the gasket 9 may be provided with a thick peripherally thick material to provide a sealing property. I can do it.

As a third embodiment of the present invention, as shown in FIG. 5, a self-sealing type pipe joint 10 and a resilient gasket 11 mounted inside are mainly used for pipes such as water pipes or gas pipes. Liquid chamber part A with expanded inside of cylindrical body
A self-sealing type is provided by providing inward circumferential fins B at both ends of the gasket 9 fitted to the outer diameter portion of the pipe 2 connection part, and steel is attached to both end faces of the gasket 9 fitted to the pipe 2. sex,
Or, a resin bowl-shaped retainer 12 is abutted and attached,
At the outer end portion, a locking mechanism such as a split ring type is provided by expanding a pipe D or a groove, and is made of steel or reinforced which can be divided into two or three from the outside and connected with screws or the like. Locking portions G are provided at the ends of the resin-made cylindrical male-female couplings 10A and 10B, and the gasket 11 and the bowl-shaped retainer 12 are externally connected to each other by being locked to the expanded portion D from the outside in the axial direction. It can also be configured. Therefore, also in the present invention, since the locking mechanism by the expanded tube D and the locking portion G and the liquid chamber portion A in which the diameter of the gasket 11 is increased are provided, the bending generated in the pipe 2 can be easily absorbed. I have.

As a fourth embodiment of the present invention, as shown in FIG. 6, a fixed end gasket type joint 13 is provided with a cylindrical body internal liquid chamber portion A as shown in FIG. A self-sealing gasket 15 having a peripheral fin B and a projection 15A with a compression allowance E at both ends is formed. A cylinder using a spring steel plate as shown in FIG. The cylindrical retainer 16 is provided with a plurality of axial slits F in a cylindrical portion so as to have flexibility, and is provided with an end surface 16B on one side. 16B is a circular plate provided with a predetermined angle θ in the axial direction, the inner diameter portion is fitted to the outer diameter portion of the pipe 2 so as to be able to bite, and a plurality of radial slits F are formed from the inner diameter portion of the circular plate. It is integrally formed and attached as a leaf spring provided in a chrysanthemum flower shape, One, a cylindrical portion 16A crimping sleeve 1
7, the projections 15A at both ends of the gasket 15 are fixed to the outer diameter portion of the pipe 2, and furthermore, a steel or reinforced resin cylindrical shape which can be divided into two or three parts and connected to the outside with screws or the like. The couplings 14A and 14B are externally included and connected to form a fixed end gasket type joint 13. Therefore, in this embodiment, the retainer 16 with a leaf spring is set at a predetermined position where both ends of the outer diameter portion of the pipe 2 are marked, and then the gasket 15 is inserted and fixed.
What is necessary is just to mount A and 14B, and the work of the conventional pipe expansion or the grooving can be made unnecessary. The cylindrical portion 16A of the retainer 16 and the crimping sleeve 17 are threaded, and the end face 1 of the coupling 14B is formed.
4a is provided at an angle at which the end surface 16B of the retainer 16 contacts the leaf spring. The marking is more preferably a creasing method. Further, although not shown, the end coupling 1 is not used without using the crimping sleeve 17.
A cylindrical projection having a predetermined diameter is provided at the outer end of 4B, and inserted into the outside of a cylindrical retainer 16 with a plate spring, and the projection 15A of the gasket is simultaneously caulked when the couplings 14A and 14B are connected to each other. Can be fixed to

FIG. 9 shows a fifth embodiment of the present invention.
In the case of a low pressure as described above, a chrysanthemum-shaped flat spring 19 whose inner diameter bites into the outer diameter of the pipe 2 is attached to both ends of the gasket 18B, and the coupling 18A is connected to form the flat spring fixed joint 18. The tube 2 is configured to be prevented from being pulled out.

FIG. 10 shows a sixth embodiment of the present invention.
As shown in FIG. 2, as a joint 20 for preventing electrolytic corrosion generated at a joint of different kinds of metal pipes such as a pipe 2 such as a water pipe or a gas pipe, insulation of rubber or the like is provided at both ends of the pipe 2 at a predetermined gap. A gasket 21C made of a conductive material is fitted, and a flat spring 19 with a slit F is attached to prevent the pipe 2 from coming off to the outside.
1A is provided with an insulating resin or ceramics internally reinforced with a perforated pipe 21a or the like, and an end coupling 21B is provided with steel or an insulating material or the like so that they can be connected to each other. Piping 2 of coupling 21B
The fitting portion is formed by providing a locking portion H that faces outward in the axial direction.
A joint 20 for preventing electrolytic corrosion is formed in order to prevent inward contact between them. As described above, at least one of the divided couplings 21A and 21B can be insulated by using an insulating reinforced resin material or the like, and at the same time, the gasket 21C and the flat spring 19 are bonded in advance so that the joint 20 After assembly, insert the pipe. and,
The couplings 21A and 21B are connected to the insulating rubber cover 2
The effect is enhanced by coating with 2 etc. Further, it can be formed as shown in FIG.

[0017]

The pipe construction according to the present invention constructed as described above has not only been performed as far as the sealing performance is increased as the pressure of the fluid in the pressure receiving body is increased, so that there is no fear of leakage. There is no need to unnecessarily increase the strength of the flange of the pressure receiving body or the strength of the bolt, so that there is a great economic effect. In addition, bending due to thermal expansion, vibration, or the like of the pipe can be easily absorbed.
In addition, it is possible to take measures to prevent electrolytic corrosion in joining different kinds of pipes.

[0018]

[Brief description of the drawings]

FIG. 1 is an assembled front view of a loose coupling type joint in which a self-sealing type gasket is internally mounted, showing a sectional configuration view at an upper portion, and a state before assembly on one side.

FIG. 2 is a perspective view of a partially cutout of the composite gasket according to the first embodiment.

FIG. 3 is a view showing a state in which a coupling end is fixed to a pipe outer diameter portion;

FIG. 4 is a top view of a front cross-section with a beaded gasket of a bowl-type neck coupling.

FIG. 5 is a front cross-sectional top view of the expanded self-sealing joint of the embodiment of the present invention.

FIG. 6 is a sectional front view of an assembled front end fixed self-sealing joint of an embodiment of the present invention, and shows a state before assembly on one side.

FIG. 7 is a partially cut-away perspective view of a gasket having a circumferential interference on an end projection of the same internal mounting.

FIG. 8 is a perspective view of a tubular retainer with a leaf spring fitted to an end projection of the gasket.

FIG. 9 is an upper partial cross-sectional view of the flat spring fixing type joint according to the embodiment of the present invention.

FIG. 10 is a cross-sectional top view of a joint for preventing electrolytic corrosion, and one side is a configuration diagram before assembly.

FIG. 11 is a partially enlarged view showing that the expansion and contraction of the pipe is fixed by drawing at the end of the coupling without using the flat spring;

[Explanation of symbols]

1: Loose coupling type joint 2: Piping
3; Loose coupling 3A; Flange 4; Stopper ring 5; Composite gasket 5A; Gasket without seal ring 5a; Seal ring 6; Packing 7; End fixed coupling 7A; Neck 8; 8A; same coupling 9; same leg type gasket 9A; same flange
9a; bead ring 10; pipe expansion self-sealing joint 10A;
Split male coupling 10B; female coupling 11; gasket for bowl-shaped retainer 12; bowl-shaped retainer 13; end-fixing self-sealing joint 14A; Gasket with projection 15A; projection 16; tubular retainer with leaf spring 16A;
16B; end face 17; crimping sleeve 18; flat spring type joint 18A; same coupling 18B; same gasket 19; flat spring 20; electrolytic corrosion prevention type fitting 21A; insulating body coupling 21B; End coupling 21C; same gasket 21D; rear drawing end coupling 21a; reinforcing holed pipe 22; rubber cover 23; bolt 24; nut A; enlarged liquid chamber B;
C: Opening D: Expanded pipe E: Compression allowance F: Slit G: Internal locking H: External locking I: Drawing processing θ: Angle provided inward

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16L 23/036 25/02

Claims (6)

[Claims] The present invention relates to a joining means for connecting a pressure-resistant pipe connection for hydraulic or general fluid, wherein the joint structure comprises a pressure-resistant coupling lockable to locking mechanisms provided at both ends of the pipe connection. The coupling comprises a gasket for sealing housed in the coupling, and the coupling is made of mainly steel, whose both ends can be fitted to both ends of the outer diameter of the pipe connection portion, and has a cylindrical central portion whose diameter is enlarged. Direction, and provided with a coupling mechanism such as a flange or a screw by dividing the central portion into a peripheral shape, and forming the coupling with the outer diameter of both ends of the pipe connection portion. A locking mechanism such as a stopper ring provided at a predetermined position of the portion fixed by welding or a screw or the like from outside in the axial direction so that the locking mechanism can be loosely locked, and the gasket is made of rubber or resin. Provided in a tubular shape made of an elastic material such as The internal circumferential shape enlarged the liquid chamber is provided, at both ends is fitted under the pipe outer diameter and cross-section,
A circumferential pressure receiving fin in the axial direction is provided, and a steel or resin seal ring is joined to or abutted on the shoulder of the outer periphery of the body of the gasket, or formed as a composite gasket in contact with the gasket. Then, the composite gasket is fitted to both ends of the outer diameter portion of the pipe, and the outer end thereof is mounted in contact with the inner wall portions of the stopper rings, and the coupling is externally attached to the outside of the composite gasket in both axial directions. A loose coupling type pressure-resistant piping constructed so that the stopper ring can be connected to the stopper ring by externally engaging the stopper ring. 2. The pipe joint structure according to claim 1, wherein said pipe joint structure has a cylindrical central portion whose diameter is enlarged and divided axially symmetrically so as to be provided with a flange. When the two flange portions are connected to each other and fixedly formed at a predetermined position, the axial cross-sectional shape of the neck portion is formed into a bowl-shaped peripheral shape, and the inside of the bowl-shaped neck portion is formed. An elastic gasket is provided on the surface, and the back is in contact with the back as an open-leg type with a bowl-shaped opening on both sides,
In addition, both ends of the opening portion are in contact with the inner wall surface of the bowl-shaped neck portion, and a bead ring is built in the circumference, and a flange is provided in the circumference of the back portion to be integrally formed and mounted. ,
2. A bowl-shaped neck having a flange configured to be connectable by sandwiching the flange with a central flange of the coupling.
The joining method in the pressure-resistant piping construction described. 3. In a joint structure mainly used for a pipe connection part such as a water pipe or a gas pipe, the pipe is fitted on an outer diameter part of a pipe provided with a locking mechanism such as a pipe expansion at predetermined positions at both ends of the pipe. A bowl-shaped retainer made of steel or resin is provided at the outside of both ends of an elastic gasket provided with an expanded liquid chamber in the cylindrical body and a circumferential pressure receiving fin in the axial cross section at both ends. From the outside in the axial direction to the gasket mounted, and the locking mechanism provided on the piping at both ends external positions of the bowl-shaped retainer. A self-sealing pipe expansion type, which is made of steel or resin and can be connected by a screw mechanism or the like, and can be assembled including a cylindrical external coupling formed by providing locking portions at both ends. The joining method in the construction of a pressure-resistant pipe according to claim 1. 4. A joint structure used for the pipe connection portion, wherein both ends of a cylindrical shape for internal mounting are fitted to the outer diameter portion of the pipe, and a fin portion which is circumferentially formed inward and a liquid is formed in the body portion. The elastic gasket provided with the chamber portion is further formed by providing a cylindrical projection in the outer direction at both ends with a compression allowance at the outer peripheral portion, and the both end projections are made of spring steel, and one end face is formed by a plate. A tubular retainer integrally provided as a spring is provided with a plurality of slits in the axial direction in the tubular portion, and the inner diameter portion of the end face cuts into the outer diameter portion of the pipe, and the inner diameter portion is formed in the axial cross section. And provided at a predetermined angle inward, and provided as a chrysanthemum flower-shaped circular leaf spring with a plurality of radial slits, and the tubular retainer with the leaf spring is pressure-mounted on the gasket both-end projections,
And, using a caulking sleeve on the outside of the cylindrical portion, the protrusions on both ends of the gasket are fixed to the outer diameter portion of the pipe, and the gasket and the cylindrical retainer with a leaf spring are made of steel from the outside in the axial direction. Or a gasket end fixed type which is divided into two or three cylindrical shapes made of resin, and each of which can be assembled by being enclosed by an external coupling formed so as to be connectable by a screw mechanism or the like. Item 1. The joining method in pressure-resistant piping construction according to items 1 and 3. 5. In the joint structure used for the pipe connection part, the gasket is formed by providing a liquid chamber part in a cylindrical body part and a circumferential fin part inward at both ends. A plurality of radially slit chrysanthemum-shaped circular flat springs made of spring steel are attached and bite and fixed to the outer diameter portion of the pipe, and the gasket, and both end leaf springs are formed separately from the outside in the axial direction. 5. The joining method in the construction of a pressure-resistant pipe according to claim 1, wherein the leaf spring is fixed and includes a coupling so as to be connectable. 6. A joint structure used for a pipe connection part such as a water pipe or a gas pipe, wherein a liquid chamber part inside a body part and an inward circumferential fin part at both ends are formed. A cylindrical elastic gasket for internal mounting is provided using an insulating material such as rubber, and, on the outer surface of both ends in the axial direction of the gasket, an inner diameter portion is in contact with the outer diameter portion of the pipe. A flat plate spring is mounted, and a locking mechanism such as an expanded pipe is provided at a predetermined position at an end of an outer diameter portion of the pipe, and both ends of a cylindrically formed coupling externally including the gasket and the plate spring. Can be formed by providing the pipe locking mechanism with a locking portion that can be locked from the shaft and inward direction, and at least one of the divided couplings can be assembled using an insulating resin material or the like. Claims 1, 3, and 5 for preventing electrolytic corrosion, which are configured as follows. In the bonding method into a pressure pipe construction of the mounting.