JP4519781B2 - Pipe fitting - Google Patents

Description

The present invention relates to a pipe joint, and particularly to a pipe joint suitable for connecting relatively soft pipes such as copper pipes and resin pipes used for water pipes and the like.

Soldering or brazing is generally used to connect copper pipes for waterworks, but since the connecting work takes time and effort, pipe joints that are simple and can reliably prevent the pipe from being pulled out are required. Therefore, for example, as shown in Patent Document 1, a pipe joint using a nut having a tapered surface on the inner periphery and a split ring having a tapered surface on the outer periphery and a claw portion that bites into the outer peripheral surface of the pipe on the inner periphery is provided. Are known.

FIG. 5 shows an example of a conventional pipe joint.
In the case of this joint, the pipe P is inserted into the joint body 10 and the nut 11 is tightened with respect to the joint body 10, whereby the tapered surface 11 a of the nut 11 slides in the rotational direction with the tapered surface 12 a of the split ring 12. While pushing in the axial direction, the split ring 12 is contracted in the inner diameter direction, and the claw portion 12b on the inner surface of the split ring 12 bites into the outer periphery of the pipe P and is locked.

However, in the case of the joint, since the tapered surfaces 11a and 12a are friction-welded with each other when the nut 11 is tightened, a large amount of tightening torque is required. Further, since the pressure contact reaction force between the tapered surfaces acts in the direction in which the nut 11 is loosened, the nut 11 is likely to be loosened. Further, when the nut 11 is loosened due to vibration or external force, the split ring 12 is also loosened at the same time, so that there is a problem that the pipe P comes out of the joint body 10.
Further, when the O-ring 13 disposed on the inner periphery of the joint body 10 is replaced, if the nut 11 is loosened, the split ring 12 is also loosened with respect to the pipe P, so that the position of the split ring 12 with respect to the pipe P is shifted. . For this reason, when the nut 11 is tightened again, it is necessary to manage the insertion depth of the pipe P again, which is troublesome.
When rotational torque is applied to one end side of the pipe P, such as when the pipe P is cut, twisting torque is also applied to the other end side of the pipe P. In the conventional joint, since the joint body 10 and the pipe P are integrally fixed, the torsion torque of the pipe P is transmitted to another pipe connected through the joint, and the joint portion of the other pipe is loosened. There is a problem.
Furthermore, since the taper surface 11a of the nut 11 and the taper surface 12a of the split ring 12 move relative to each other in the axial direction while sliding in the rotational direction, a large abnormal noise (sliding noise) may occur. Such abnormal noise occurs when there is no difference in hardness between the nut 11 and the split ring 12 or when the material is similar.
JP-A-6-323474

Accordingly, an object of the present invention is to provide a pipe joint that can be easily connected and can solve the above-described problems.

In order to achieve the above object, the present invention has a joint body having an opening for receiving a tube and having a male threaded portion on the outer periphery, and a female threaded portion that is threadedly engaged with the male threaded portion on the inner surface at one end in the axial direction. A nut having an inner stepped portion projecting to the inner diameter side from the female thread portion on the inner surface on the other end side in the direction, and a claw portion that bites into the outer peripheral surface of the pipe on the inner peripheral surface, and a cylindrical surface on the outer peripheral surface on the one axial end side A split ring that has a tapered surface that gradually increases in diameter toward the cylindrical surface on the outer peripheral surface on the other end side in the axial direction and that has elasticity in the radial direction, and the split ring on the inner peripheral surface on the one end side in the axial direction. An outer step having a cylindrical surface continuous with the smallest diameter portion of the tapered surface on the inner peripheral surface on the other end side in the axial direction, and contacting the inner step portion of the nut on the outer peripheral surface. A cylindrical sleeve having a portion, and the nut is screwed onto the joint body By pulling the outer stepped portion of the sleeve toward the joint body side with the inner stepped portion of the nut, the sleeve taper surface comes into contact with the taper surface of the split ring, and the split ring is reduced in diameter. Provided is a pipe joint configured to ride on a cylindrical surface of a split ring.

When the nut is tightened with respect to the joint body, the sleeve is pulled toward the joint body by the inner stepped portion of the nut due to the screwing rotation of the nut. The split ring in contact with the sleeve via the taper surface is also deformed to reduce the diameter while moving relative to the sleeve in the axial direction, and the claw portion of the split ring bites into the outer periphery of the tube. The tapered surfaces slidably contact each other in the axial direction, but do not slidably contact in the rotational direction, so that the tightening force of the nut can be small. In the final tightening state, the tapered surface of the sleeve gets over the tapered surface of the split ring, and the cylindrical surface of the sleeve and the cylindrical surface of the split ring come into contact with each other. Since the tapered surfaces are not pressed against each other, loosening of the nut hardly occurs.
Even if the nut loosens due to vibration or external force, and the outer stepped portion of the sleeve and the inner stepped portion of the nut are separated, the sleeve and the split ring are pressed against each other on the cylindrical surface. Does not displace. Therefore, the state where the claw part of the split ring bites into the pipe is maintained, and the pipe does not come out of the joint body.

When replacing the O-ring arranged inside the joint body, even if the nut is loosened, the split ring and the sleeve do not loosen with respect to the pipe, so the position of the split ring with respect to the pipe does not shift. For this reason, when the nut is tightened again, it is not necessary to redo the management of the tube insertion depth. When removing the split ring from the pipe, the split ring can be easily removed from the pipe by pushing the sleeve in the axial direction and removing it from the cylindrical surface of the split ring.

Torque may be applied to the tube when cutting the tube. When this joint is used in the above pipe, the split ring and sleeve that bite into the pipe rotate together with the pipe, but the nut and joint body can rotate relative to each other, so another pipe connected via the joint can be used. Torque is not transmitted to. Therefore, the joint part of another pipe does not loosen.

When the nut is tightened, the inner stepped portion of the nut is only in contact with the outer stepped portion of the sleeve in the axial direction, and the frictional force is small, so that twisting of the tube due to co-rotation can be prevented. When the taper surface of the sleeve gets over the taper surface of the split ring, the cylindrical surfaces only come into contact with each other. Therefore, abnormal noise (sliding noise) generated when tightening the nut is in contact with the conventional taper surfaces. Small compared to the case.

In the case of the present invention, when the nut is tightened to some extent, the sleeve rides on the cylindrical surface of the split ring, and the tightening force does not increase. When the pipe is a relatively soft pipe, the tightening force increases in proportion to the tightening amount of the nut in the conventional method of tightening the split ring by the action of the tapered surface of the nut and the split ring. Deforms inward and causes pressure loss. On the other hand, in the present invention, since the pipe is not tightened more than necessary, it is possible to prevent the pipe from being deformed to the inside, and to keep the inner diameter of the pipe without causing pressure loss.

It is desirable to provide a stopper on the outer periphery of the joint body so as to abut against one end in the axial direction of the nut in a state where the nut is screwed until the cylindrical surface of the sleeve rides on the cylindrical surface of the split ring.
In this case, when the nut and the stopper portion are brought into pressure contact with each other, the function of preventing the loosening as the lock nut can be achieved. In addition, since the nut and the stopper portion come into pressure contact after the cylindrical surface of the sleeve rides on the cylindrical surface of the split ring, the stress in the loosening direction due to the tapered surface does not act, and the loosening of the nut can be reliably prevented.

A concave step that opens to the other end in the axial direction is formed on the inner periphery of the opening of the joint body, and a seal ring for sealing the outer periphery of the tube and an axial end of the sleeve abut on the concave step. A possible presser ring is arranged, and the sleeve can compress the seal ring in the axial direction via the presser ring.
It is possible to seal the outer periphery of the pipe only by arranging the seal ring on the inner peripheral portion of the joint body, but there is a possibility that the seal ring may be damaged when the pipe is inserted. In addition, sufficient sealing performance may not be obtained when there is a variation in tube diameter or the cross section of the tube itself is not a perfect circle. Therefore, if the seal ring has an inside diameter that allows easy insertion of the pipe, tightens the nut, and pulls the sleeve toward the joint body, compressing the seal ring in the axial direction via the retainer ring at the end face of the sleeve Swells in the inner diameter direction and adheres closely to the outer peripheral surface of the pipe, so that the sealing performance can be improved without damaging the seal ring. As the seal ring, a known seal material such as an O-ring can be used.

It is preferable to project a stopper portion that restricts the axial separation of the split ring on the inner peripheral surface on the other axial end side of the sleeve.
When a strong tensile force is applied to the tube with the nut tightened, the split ring that bites into the tube is pulled together with the tube. Since the split ring and the sleeve are only in contact with each other on the cylindrical surface, there is a possibility that the split ring comes off from the sleeve and the tube comes out together. Therefore, such a problem can be solved by providing a stopper portion for restricting the axial separation of the split ring in the sleeve.

In the present invention, the one axial end side and the other axial end side refer to the axial arrangement order of the features provided in the component, and only the axial one end portion and the other axial end portion of the component. Not limited to. For example, when looking at the cylindrical surface and the tapered surface in the split ring, the cylindrical surface may be positioned on one end side in the axial direction from the tapered surface, and the cylindrical surface may be the central portion in the axial direction. Similarly, the tapered surface may be positioned on the other axial end side from the cylindrical surface, and may be the central portion in the axial direction. The same applies to the relationship between the female thread portion and the inner stepped portion of the nut, and the relationship between the tapered surface and the cylindrical surface of the sleeve.

As described above, in the pipe joint according to the present invention, when the sleeve is interposed between the nut and the split ring and the sleeve is pulled toward the joint main body by tightening the nut, the taper surface of the sleeve becomes the taper of the split ring. Since the split ring is deformed in diameter reduction in contact with the surface, and the cylindrical surface of the sleeve rides on the cylindrical surface of the split ring, the tightening force on the pipe does not increase when the nut is tightened to some extent. Therefore, when applied to a relatively soft pipe such as a copper pipe or a resin pipe, deformation to the inside of the pipe can be prevented, and the inner diameter of the pipe can be maintained without causing pressure loss.
Also, since the tightening is completed when the cylindrical surface of the sleeve and the cylindrical surface of the split ring are in contact with each other, the nut is loosened compared to the conventional pipe joint that is tightened when the tapered surfaces are in pressure contact with each other. Even if the nut is slightly loosened, the sleeve and the split ring are kept in pressure contact with each other on the cylindrical surface, so the claw part of the split ring keeps biting into the pipe and the pipe comes out of the fitting body. There is nothing.
Further, when the seal member disposed inside the joint body is replaced, even if the nut is loosened, the split ring and the sleeve do not loosen with respect to the pipe, so that the position of the split ring with respect to the pipe does not shift. Therefore, when the nut is tightened again, it is not necessary to manage the insertion depth of the pipe again, and the tightening operation is facilitated.

Hereinafter, preferred embodiments of the present invention will be described with reference to examples.

1 and 2 show a first embodiment of a pipe joint according to the present invention, and this pipe joint shows an example used for connecting a general water pipe P. FIG.
The pipe joint 1 according to this embodiment includes a joint body 2 made of a cylindrical body that opens in both directions, and two pipes P are inserted to face the joint body 2. The pipe P is made of a metal pipe such as a copper pipe (for example, an outer diameter of 9.5 to 54 mm, a thickness of 0.8 to 1.8 mm). Since the pipe joint 1 has a left-right symmetric structure, only the structure on one end side will be described below. In FIG. 1, the left side from the center is before tightening, and the right side from the center is after tightening.

The joint body 2 is made of a metal material such as a copper alloy. As shown in FIG. 2, the inner peripheral surface of the opening 2a at both ends is formed with a recessed step 2b that opens to one end in the axial direction. A guide surface 2c for guiding the outer peripheral surface of the pipe P is formed on the peripheral surface, and a stopper wall 2d for defining the insertion depth of the pipe P is formed at the center of the guide surface 2c. An O-ring 3 is fitted to the concave step 2b, and one axial side surface and the outer peripheral surface of the O-ring 3 are held. A presser ring 4 that supports the other side surface of the O-ring 3 in the axial direction is disposed in the recessed step portion 2b so as to be movable in the axial direction. An external thread portion 2e is formed on the outer peripheral surface of the opening 2a of the joint body 2, and an outer flange portion (stopper portion) that defines a tightening limit position of a nut 5 to be described later is formed on the outer peripheral surface on the center side of the joint body 2. ) 2f is formed. Although not shown, a tool engaging surface with which a tool such as a wrench engages may be formed on the outer peripheral surface of the central portion of the joint body 2, or a tool engaging surface may be formed on the outer peripheral surface of the outer flange portion 2f. It may be formed.

A nut 5 made of a metal material such as a copper alloy is screwed into the male thread portion 2 e of the joint body 2. As shown in FIG. 2, an internal thread portion 5 a that is screwed into the external thread portion 2 e is provided on the inner peripheral surface of one end portion in the axial direction of the nut 5. On the inner peripheral surface of the other end portion of the nut 5, an inner stepped portion 5b protruding in the inner diameter direction from the female screw portion 5a is integrally formed. When the nut 5 is tightened with respect to the joint body 2, the inner step part 5 b has a role of abutting against a side surface of an outer step part 7 c of the sleeve 7 described later and pulling the sleeve 7 toward the joint body 2. is there.

Inside the nut 5, a split ring 6 and a sleeve 7 made of metal parts are arranged. The split ring 6 is made of a material harder than the pipe P, and is provided with a radial elasticity by forming a slit 6a in a part of the ring-shaped part as shown in FIG. A claw portion 6b that bites into the outer peripheral surface of the pipe P is formed on the inner peripheral surface of the split ring 6, a cylindrical surface 6c is formed on the outer peripheral surface on one axial end side, and the cylindrical surface 6c on the outer peripheral surface on the other axial end side. A tapered surface 6d having a gradually increasing diameter is formed. That is, the maximum diameter portion of the tapered surface 6d and the cylindrical surface 6c are continuous. The claw portions 6b of the split ring 6 are not limited to one row, and may be formed in a plurality of rows. Further, it is not necessary to form the claw portion 6b continuously extending in the circumferential direction, and it may be an intermittent or distributed projection, as long as it can bite into the pipe P and can be locked.

The sleeve 7 has a tapered surface 7a corresponding to the tapered surface 6d of the split ring 6 on the inner peripheral surface on one end side in the axial direction, and a cylinder continuous with the smallest diameter portion of the tapered surface 7a on the inner peripheral surface on the other end side in the axial direction. A cylindrical part having a surface 7b. The inner diameter of the cylindrical surface 7b is smaller than the outer diameter of the cylindrical surface 6c of the split ring 6 in the free state. An outer stepped portion 7c having a diameter smaller than the inner diameter of the female threaded portion 5a of the nut 5 and capable of contacting the side surface of the inner stepped portion 5b is formed on the outer peripheral surface of the sleeve 7 in the axial direction. An inner flange portion (stopper portion) 7d that can abut against the end surface in the axial direction of the split ring 6 is formed on the inner periphery of the end portion so as to protrude in the inner diameter direction. The inner flange portion 7d prevents the split ring 6 from coming out of the sleeve 7 together with the pipe P when a strong tensile force acts on the pipe P with the nut 5 tightened.

Here, a method of connecting the pipe P using the main pipe joint 1 will be described.
First, the O-ring 3 and the presser ring 4 are inserted into the concave step 2 b of the joint body 2, and the split ring 6 and the sleeve 7 are fitted inside the nut 5. At this time, the taper surface 6d of the split ring 6 and the taper surface 7a of the sleeve 7 are merely in light contact. In this state, the pipe P is inserted into the nut 5 and the opening 2 a of the joint body 2.
Next, the female screw portion 5 a of the nut 5 is screwed into the male screw portion 2 e of the joint body 2. As the nut 5 is screwed and rotated, as shown on the left side of FIG. 2, the outer stepped portion 7 c of the sleeve 7 is drawn toward the joint body 2 by the side surface of the inner stepped portion 5 b of the nut 5, and the tapered surface 7 a of the sleeve 7 is pulled. However, the split ring 6 is deformed by a reduced diameter, and the claw portion 6b bites into the pipe P.

When the nut 5 is further tightened, the tapered surface 7 a of the sleeve 7 gets over the maximum diameter portion of the tapered surface 6 d of the split ring 6, and the cylindrical surface 7 b of the sleeve 7 comes into contact with the cylindrical surface 6 c of the split ring 6. At this time, the claw portion 6b of the split ring 6 is in a state where it is bitten into the pipe P to the maximum extent, and even if the nut 5 is further tightened, the amount of biting into the pipe P of the claw portion 6b does not change. That is, the locking force with respect to the pipe P does not change. On the other hand, the tightening torque of the nut 5 decreases after the taper surface 7a of the sleeve 7 gets over the maximum diameter portion of the taper surface 6d of the split ring 6. Since the end surface of the sleeve 7 abuts against the presser ring 4 and compresses the O-ring 3 from the side via the presser ring 4, the O-ring 3 is pressed against the outer periphery of the pipe P, and the sealing performance is improved. The subsequent tightening torque of the nut 5 is exclusively used for compression (sealing) of the O-ring 3.

When the nut 5 is tightened to the tightening limit position, as shown on the right side of FIG. 1, the end surface of the nut 5 comes into pressure contact with the outer flange portion 2 f of the joint body 2, and due to the pressure contact force between the nut 5 and the outer flange portion 2 f. It functions as a lock nut that suppresses loosening of the nut 5. It is desirable that a slight axial gap δ exists between the joint body 2 and the sleeve 7 at the tightening limit position. When rotational torque acts on the other end side of the pipe P, the split ring 6, sleeve 7, nut 5, and joint body 2 may rotate integrally with the pipe P, and loosening may occur. This is because the relative rotation between the joint body 2 and the sleeve 7 is allowed by the gap δ, so that the occurrence of looseness can be prevented.

In the state where the nut 5 is tightened to the tightening limit position, if a strong tensile force F (see FIG. 1) acts on the pipe P, the split ring 6 bites into the pipe P. Try to move in the F direction. Since the split ring 6 and the sleeve 7 are merely in contact with each other at the cylindrical surfaces 6 c and 7 b, there is a possibility that the split ring 6 comes off from the sleeve 7 in the axial direction. However, since the stopper portion 7d protruding in the inner diameter direction of the sleeve 7 restricts the axial movement of the split ring 6, it is possible to prevent the split ring 6 from coming off, and thus to prevent the pipe P from coming off.

FIG. 3 shows the relationship between the screwing rotation angle of the nut 5, the tightening torque of the nut 5, and the locking force of the pipe P.
In a region where the screwing rotation angle of the nut 5 is small, the taper surface 7a of the sleeve 7 comes into contact with the taper surface 6d of the split ring 6, so that the tightening torque and the locking force increase in proportion to the increase in the rotation angle. However, when the predetermined rotation angle is exceeded, the cylindrical surface 7b of the sleeve 7 comes into contact with the cylindrical surface 6c of the split ring 6, so that the tightening torque is reduced and stabilized at a value lower than the maximum torque by a certain value. On the other hand, since the locking force is proportional to the amount of biting of the claw portion 6b of the split ring 6, the maximum locking force can be maintained.

As described above, when the nut 5 is tightened, the nut 5 and the sleeve 7 are only in contact with the inner step portion 5b and the outer step portion 7c in the axial direction, and the tapered surfaces are not in friction welding. After the tightening torque is reduced and the sleeve 7 rides on the cylindrical surface 6a of the split ring 6, the tightening torque can be further reduced.
When the nut 5 is completely tightened, the sleeve 7 and the split ring 6 are in pressure contact with each other only in the radial direction, so that no axial force is applied to the nut 5 and it is difficult for loosening to occur. Further, even if the nut 5 is somewhat loosened due to vibration or external force, the outer periphery of the split ring 6 is held by the sleeve 7 and does not loosen, so there is no problem that the pipe P comes out of the joint body 2.

Further, when the O-ring 3 disposed on the inner periphery of the joint body 2 is replaced, if the nut 5 is loosened, the split ring 6 does not loosen with respect to the pipe P, so the position of the split ring 6 with respect to the pipe P does not shift. . Therefore, when the nut 5 is tightened again, it is not necessary to manage the insertion depth of the pipe P again, and the mounting is simple.
When rotational torque is applied to one end side of the pipe P, such as when the pipe P is cut, twisting torque is also applied to the other end side of the pipe P. However, since rotation is allowed between the split ring 6 and the sleeve 7 or between the sleeve 7 and the nut 5, the joint body 2 and the pipe P do not rotate integrally, and the torsional torque of the pipe P is reduced by the joint 1. It is possible to solve the problem that the joint portion of another pipe is loosened by being transmitted to the other pipe connected via.
Further, when the nut 5 is tightened, the taper surface 6d of the split ring 6 and the taper surface 7a of the sleeve 7 do not slide in the rotational direction, but only slide in the axial direction. Even if there is no difference in hardness from the split ring 6 or a similar material, no loud noise (sliding noise) is generated.

FIG. 4 shows a second embodiment of the split ring. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
The split ring 6 ′ has a pair of tapered surfaces 6 d and 6 d on the outer peripheral surface at both ends in the axial direction, and a cylindrical surface 6 c on the outer peripheral surface in the central portion in the axial direction. Since this split ring 6 'can lock the pipe P regardless of the orientation, there is an advantage that erroneous assembly can be prevented.

The present invention is not limited to the above embodiment, and can be modified without departing from the spirit of the present invention.
In the above embodiment, the seal ring and the presser ring are arranged in the concave step portion on the inner periphery of the joint body, and the seal ring is compressed in the axial direction via the presser ring by the sleeve, but the presser ring is omitted. In the same manner as in FIG. 5, a seal ring may be disposed in the inner peripheral groove of the joint body.
In the above embodiment, the seal ring (O-ring) is arranged on the inner peripheral part of the joint body. However, as in Patent Document 1, a cylinder part that fits from the joint body to the inner periphery of the pipe is provided, and the outer periphery of the cylinder part is provided. A seal ring may be disposed on the surface. Although an O-ring is used as a seal member that seals between the joint body and the pipe P, other known seal members such as a gasket having a lip may be used.
In the above embodiment, an example in which the joint body has a socket shape having a connection port opened in two directions has been shown, but a connection port opened only in one direction or a connection port in three directions or four directions is provided. May be good. In short, the shape of the joint body can be freely selected as long as it has at least one opening.
The present invention can be used not only for connection of metal pipes such as copper pipes but also for connection of resin pipes such as crosslinked polyethylene pipes. Furthermore, the pipe joint of the present invention can be used not only for connection of liquid piping but also for connection of gas piping.

It is a half section front view of the 1st example of the pipe joint concerning the present invention. It is an exploded view of the pipe joint shown in FIG. It is a figure which shows the relationship between the rotation angle of a nut, fastening torque, and pipe | tube latching force. It is a half section front view of the 2nd example of a split ring. It is sectional drawing of the conventional pipe joint.

Explanation of symbols

P Pipe 1 Pipe joint 2 Joint body 2a Opening 2b Concave step 2e Male thread 2f Stopper (outer flange)
3 O-ring (seal ring)
4 Presser ring 5 Nut 5b Inner step 6 Split ring 6b Claw 6c Cylindrical surface 6d Tapered surface 7 Sleeve 7a Tapered surface 7b Cylindrical surface 7c Outer step 7d Stopper (inner flange)

Claims (4)

A joint body having an opening for receiving a pipe and having an external thread on the outer periphery;
A nut having an internal thread portion screwed into the male screw portion on the inner surface on one axial end side, and an inner stepped portion projecting on the inner diameter side from the female screw portion on the inner surface on the other axial end side;
The inner peripheral surface has a claw that bites into the outer peripheral surface of the tube, the outer peripheral surface on one end side in the axial direction has a cylindrical surface, and the outer peripheral surface on the other end side in the axial direction has a taper that gradually increases in diameter toward the cylindrical surface. A split ring having a surface and having radial elasticity;
The inner peripheral surface on one end side in the axial direction has a tapered surface corresponding to the tapered surface of the split ring, and the inner peripheral surface on the other end side in the axial direction has a cylindrical surface continuous with the smallest diameter portion of the tapered surface. And a cylindrical sleeve having an outer stepped portion that contacts the inner stepped portion of the nut,
The nut is screwed onto the joint body, and the outer stepped portion of the sleeve is pulled toward the joint body side by the inner stepped portion of the nut. A pipe joint characterized in that it is radially deformed and the cylindrical surface of the sleeve rides on the cylindrical surface of the split ring. On the outer periphery of the joint body, there is provided a stopper portion that comes into contact with one axial end portion of the nut in a state where the nut is screwed until the cylindrical surface of the sleeve rides on the cylindrical surface of the split ring. The pipe joint according to claim 1, wherein the pipe joint is characterized. On the inner periphery of the opening of the joint body, a concave step is formed that opens to the other end in the axial direction.
A seal ring for sealing the outer periphery of the tube and a presser ring that can come into contact with one axial end portion of the sleeve are disposed in the concave step portion,
The pipe joint according to claim 1 or 2, wherein the sleeve is capable of compressing the seal ring in the axial direction through the presser ring. The pipe joint according to any one of claims 1 to 3, wherein a stopper portion is provided on the inner peripheral surface of the sleeve on the other end side in the axial direction so as to protrude in the axial direction of the split ring.

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