JPH07280152A - Pipe separation preventing hardware for union nut joint - Google Patents

Abstract

PURPOSE:To enhance the separation resistant force of a joint pipe by providing a hook which projects in the direction of an inner diameter on the other end side of an arm which is fixedly connected to a lock ring on one side thereof and loosely fitting the hook into the recessed part of a split ring. CONSTITUTION:One in which a lock ring 6 is fixedly connected to a pair of arms 7, 7, is prepared, and after the upper and lower parts of a split ring 2 are displaced in the front and back direction and installed between the arms 7, 7, it is set to upright attitude. Next, after the hook 13 of the arm 7 is fitted into the recessed part 17 of the split ring 2, a union nut 9 is inserted into the space formed of the lock ring 6, the arm 7 and the split ring 2 from the free space 11 of the arm 7. Under this condition. the male screw part of a joint main body 8 is screwed into the female screw part of the union nut 9, and then the end of a joint tube 3 is inserted from the split ring 2 side, and after the end of the joint tube 3 is positioned in the joint min body 8, the union nut 9 is fastened and further the bolt 4 and the nut 5 of the split ring 2 are fastened to complete the operation of jointing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention inserts an end portion of a joint pipe, in which a screw is not engraved, into a receiving portion of a pipe or a joint body,
The present invention relates to a pipe disengagement prevention fitting for a pipe joint in which a rubber packing is interposed and a union nut is used for fastening.

[0002]

2. Description of the Related Art In addition to its simple and inexpensive point, the pipe endless threaded joint has a stretchable and flexible joint, and as a result, a protective function that absorbs vibration, elongation, strain, etc. of the pipe well. Since it has a diameter of 13 to 50 mm, it has a relatively small diameter and a normal pressure of at most 5 Kg / cm ^2.
It has been used favorably for joining methods of low-pressure pipes to a certain degree.

However, in the conventional pipe joint, the holding force of the rubber packing with respect to the joint pipe is determined according to the tightening force of the union nut at the time of joining work, so that it is necessary to strongly tighten it with a large pipe wrench or the like in a place where pressure is applied. there were.
In addition, if rust-preventing oil, oil during screw cutting, etc. adheres to the pipe, the force to hold the joint pipe is extremely reduced and it is extremely difficult to reliably prevent the joint pipe from coming off. Met.

Therefore, conventionally, a pipe detachment preventing metal fitting has been developed to prevent the joint pipe and the pipe joint main body from deviating when the joint pipe and the pipe joint main body can be flexibly expanded and contracted, and is attached to the pipe joint portion. However, the conventional pipe disengagement prevention metal fittings cannot fully exhibit stretchability and flexibility, and there is a conflicting problem that if one function is secured, the other function is sacrificed. In addition, when trying to secure expansion and contraction flexibility, the length of the entire joint becomes long, and the drawback that it cannot be used in a narrow area and the number of bolt fastening operations increase,
There were drawbacks such as very troublesome work.

Furthermore, in the conventional pipe detachment prevention fitting,
Since it is necessary to assemble each part as a set so that it will not be lost, it is necessary to perform temporary assembly at the factory shipment stage, disassemble it at the site, and then assemble it again, which is a troublesome work.

The present applicant has already applied for the technique of Japanese Patent Application No. 5-210821 as a solution to the drawbacks of the conventional pipe detachment preventing metal fittings. This prior application technology is shown in FIG.
And as shown in FIG. As shown in the figure, the pipe detachment prevention metal fitting 1 of this prior application has a split ring 2 as a retaining ring, which is cut out in the middle of the circumference, and a split pipe 2 for joining the split ring 2.
It is composed of a bolt 4 and a nut 5 which are fastened to the outer peripheral surface, a circular locking ring 6, and two arms 7, 7 which connect the split ring 2 and the locking ring 6.

As is apparent from FIG. 10, the split ring 2 has a C-shape with a cutout on the circumference thereof and is externally mounted on the joint pipe 3. On the other hand, the circular locking ring 6
The insertion hole 10 has a size larger than the outer diameter of the joint body 8 and smaller than the outer diameter of the union nut 9.

The split ring 2 and the locking ring 6 are connected by two arms 7 and 7, and the other space between the split ring 2 and the locking ring 6 is inserted with a tool or the like. It is a free space 11 where you can play. Further, an uneven portion for preventing slippage is formed on the inner peripheral surface of the split ring 2. The inner diameter between the arms 7 and 7 is set to be larger than the maximum outer diameter of the tool mounting portion of the union nut 9.

In the pipe disengagement prevention fitting 1 according to the prior application constructed as described above, the joint pipe 3 and the joint body 8 are sealed by the annular packing 12, and the annular packing 12 is formed.
It is possible to mutually bend centering around. When the joint pipe 3 moves so as to deviate to the left in FIG. 9 with respect to the joint body 8, the locking ring 6 comes into contact with the tip surface of the union nut 9 to prevent the joint pipe 8 from coming off.

The locking ring 6 is a single ring as a whole, and even if there is a movement to deviate in a state where the joint pipe 3 and the joint body 8 are bent, the locking ring 6 Will never get past Union Nut 9,
It is possible to prevent the joining pipe 3 from reliably deviating.

Further, it is possible to preliminarily mount the pipe disengagement prevention metal fitting 1, the union nut 9 and the annular packing 12 on the joint pipe 3 to perform the connection work with the joint body 8, and the connection work at the site. Is extremely easy.

[0012]

However, in the technique previously filed by the applicant of the present invention, when the joining pipe 3 is a hard pipe such as a hard vinyl chloride pipe or a steel pipe, there is a problem. However, when the joining pipe 3 is a soft pipe such as a soft polyethylene pipe, there are the following problems.

That is, when the joint pipe 3 is a soft pipe having a diameter of 60 mm, as shown in FIGS. 11 and 12, the inner peripheral surface of the split ring 2 has a diameter of 61 mm before fastening.
Is set so as to coincide with the center of the locking ring 6.

However, in the case of a soft tube, it is necessary to reduce the diameter by 6% or more in order to exert a predetermined separation preventing force. When the bolts 4 and the nuts 5 are tightened in order to exert such a separation preventing force, as shown in FIGS. 13 and 14, the soft joining pipe 3 has a diameter of 56.3 mm.
Then, the center of the split ring 2 and the center of the locking ring 6 are misaligned. The cause of misalignment is
When the arc formed by the split ring 2 is divided into an upper half circle and a lower half circle with the connecting portion of the arms 7 and 7 as a boundary, it becomes short only in the upper half circle of FIG. It is due to the fact that it does not change at half circumference.

To further explain this in detail, in FIG. 12 which is the state before fastening, the points on the circumference formed by the split ring 2 whose diameter is set to 61 mm are a, b,
c and d, and the attachment parts of the arms 7 and 7 of the locking ring 6 are A and B. When the bolt 4 and the nut 5 of the split ring 2 are tightened from this state, the split ring 2 bites into the welded pipe 3 because the joint pipe 3 is a soft pipe.
The diameter is reduced until the diameter becomes 56.3 mm. At this reduced diameter, the lengths of the arcs connecting a ₁ , c, b ₁ of the split ring 2 are unchanged because the arms 7, 7 are connected and fixed, but the remaining a ₁ , d, b ₁ The length of the arc connecting the two is shortened by narrowing the front of the cutout portion of the split ring 2.

Therefore, the split ring 2 of the arms 7, 7
As shown in FIG. 14, the center O ₁ moves downward from the center O of the locking ring 6 by 4.74 mm and is eccentric. Further, since both ends of the arms 7 and 7 are connected and fixed to the locking ring 6 and the split ring 2, respectively, the arms 7 and 7 can be twisted by the amount of the eccentricity, and as shown in FIG. Union nut 9
Comes into contact with the outer peripheral surface of the. Moreover, the joint pipe 3 is
As shown in FIG. 13, it was connected to the joint body 8 in a flexible posture.

Therefore, if this is used as it is, the arms 7, 7 will be further subjected to the stress due to the water pressure from the twisted state, and the arms 7, 7 will be broken at the test water pressure of about 35 Kgf / cm ^2. There is a drawback that an accident occurs and the joint pipe 3 easily deviates. Also the joint pipe 3
Since it is connected to the joint body 8 in a flexible posture, there is a drawback in that it cannot be further flexed and expanded or contracted in one direction in the use state.

[0018]

SUMMARY OF THE INVENTION The present invention is a further improvement of the technique previously filed by the applicant in view of the above-mentioned problems of the prior art, and the mounting work is extremely simple and even if it is a soft pipe. An object of the present invention is to provide a pipe disconnection prevention fitting that is not eccentrically connected.

The means adopted by the present invention to solve the above-mentioned problems is to insert a threadless joint pipe into a pipe or a joint body having a receiving portion having an external thread engraved on the outer peripheral surface thereof, and to form an annular rubber packing. In a pipe joint having a structure in which a union nut is screwed and tightened to the receiving portion by inserting and inserting, a halfway on the circumference is cut out, and the union nut is externally fitted and attached to the joint pipe on the rear end side of the union nut. With a split ring tightened with a bolt, etc., and an insertion hole that is larger than the outer diameter of the pipe or fitting body and smaller than the outer diameter of the union nut. A ring-shaped locking ring that is mounted loosely on one side, and an arm that connects the split ring and the locking ring at two opposing positions. The arm is integrally connected on the locking ring side. , The split ring side is A union nut, characterized in that the hook provided on either one of the tip and the outer peripheral surface of the split ring and the recess formed between the flanges provided on the other end are connected in a loose state by engagement. This is a fitting for preventing the pipe from coming off the joint.

[0020]

According to the present invention, in the pipe detachment preventing metal fitting previously filed by the applicant, the connecting structure of the split ring and the arm is improved, and the split ring and the arm are in a loose state. It is designed to be connected.

That is, a hook projecting in the inner diameter direction is provided at the tip of the arm on the split ring side, and a concave portion is formed between the projecting flanges on the outer peripheral surface of the split ring. Then, the hooks of the arms are fitted in the recesses of the split ring in a loosely fitted state to connect them. That is, the arm and the split ring are connected separately. The hook and the recess are the same even if the hook is provided on the outer peripheral surface side of the split ring and the recess is provided on the inner peripheral surface side of the arm tip.

As a result, even if the joining pipe is a soft pipe such as a soft polyethylene pipe, when the split ring is tightened, there is no restraint on the outer peripheral surface of the split ring. Therefore, the diameter is reduced on average, and the center position does not shift.

Therefore, even a soft joint pipe can be connected to the joint body in a linear posture, and
Since each member of the joint maintains a substantially concentric shape, it is possible to perform the connection in a state in which sufficient flexibility and elasticity are imparted, as in the case of the connection of the hard pipe. In addition, since no unreasonable force is applied to the arm at the time of connection, there is no breakage of the arm or deviation of the joint pipe even when large water pressure is applied.
It is an excellent pipe joint.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the embodiments shown in the drawings. The same reference numerals as in the conventional case are the same members. 1 to 3 relate to an embodiment of the present invention. FIG. 1 is a partial vertical cross-sectional view of a pipe joint showing a state after assembly, and FIG. 2 shows a pipe detachment preventing metal fitting 18 showing a state before tightening. A front view and FIG. 3 are front views showing a state after the tightening.

As shown in the figure, the pipe detachment prevention fitting 18 of this embodiment has a split ring 2 as a retaining ring, which is notched in the middle of the circumference, and the split ring 2 on the outer peripheral surface of the joining pipe 3. It is composed of a bolt 4 and a nut 5 that are fastened upward, a circular locking ring 6, and two arms 7 and 7 that connect the split ring 2 and the locking ring 6.

As is apparent from FIGS. 2 and 3, the split ring 2 has a C-shape with a cutout on the circumference thereof and is externally fitted and mounted on the joint pipe 3. On the other hand, the circular locking ring 6
Has an insertion hole 10 having a size larger than the outer diameter of the joint body 8 and smaller than the outer diameter of the union nut 9. The split ring 2 and the locking ring 6 are connected to each other by two upper and lower arms 7, 7, and the other space between the split ring 2 and the locking ring 6 should be inserted with a tool or the like. It is a free space 11 where you can play. Further, an uneven portion for preventing slippage is formed on the inner peripheral surface of the split ring 2. The inner diameter between the arms 7 and 7 is set to be larger than the maximum outer diameter of the tool mounting portion of the union nut 9.

Thus, the arms 7, 7 in this embodiment are
The connection with the split ring 2 is performed in a loose state, and the connection with the locking ring 6 is integrally connected and fixed. That is, hooks 13 and 13 projecting in the inner diameter direction are formed at the ends of the arms 7 and 7 on the split ring 2 side, and the outer peripheral surface of the split ring 2 corresponds to the flanges 14 and 1.
5,16 are formed and these flanges 14,15,1
A recess 17 is formed between the six members.

The flange 14 is a circumferential one formed on the end surface of the split ring 2 near the union nut 9, and the flanges 15 and 16 are continuous with the annular flange 14 in a direction parallel to the axial center line. It has been provided to. The hooks 13, 13 of the arms 7, 7 are fitted in the recesses 17 of the split ring 2 in a loose fit. The split ring 2, the arms 7 and 7, and the union nut 9 are set to have a dimensional relationship of E> F + G + H as shown in FIG. This will be described later. The outer diameter of the flange 14 of the split ring 2 is set to be smaller than the inner diameter of the arms 7, 7. Further, the inner diameters of the hooks 13 and 13 are set to be smaller than the outer diameter of the bottom surface of the recess 17.

Next, the manner of use of the pipe detachment prevention fitting 18 thus constructed will be described with reference to FIGS. 4 to 7.
First, as shown in FIGS. 4 (a) and 4 (b), a lock ring 6 and arms 7, 7 are connected and fixed, and a split ring 2 is placed on the top and bottom of the split ring 2 in the front-back direction. Slide it and attach it between the arms 7, and fix it in an upright posture. The figure (a) and the figure (b) of this figure show this state. Then, as shown in FIGS. 5A and 5B, the hooks 13, 13 of the arms 7, 7 are fitted into the recesses 17, 17 of the split ring 2.

After that, as shown in FIGS. 6 (a) and 6 (b), the arms 7, 7 are inserted into the space formed by the locking ring 6, the arms 7, 7, and the split ring 2. 7 free spaces 1
Insert the union nut 9 from 1. The packing 12 is fitted and attached to the inner peripheral surface of the union nut 9 in advance. Then, in this state, the male screw engraved on the outer peripheral surface of the joint body 8 is screwed onto the female screw on the inner peripheral surface of the union nut 11. The screwing may be performed by inserting a tool such as a spanner into the free space 11 of the arms 7, 7.

When shipped from the factory, the split ring 2, the locking ring 6 and the arms 7 and 7, the packing 12 and the union nut 9 and the joint body 8 are assembled into one set as described above. You can go in. After being assembled in the set state, each of these parts will not fall apart.

This is because the assembling dimensional relationship of the respective parts is set to E> F + G + H as described above.
Even when the locking ring 6 is in contact with the end surface of the union nut 9 and the end surface of the split ring 2 is in contact with the rear end surface of the union nut 9, the hooks 13, 13 are fitted and retained in the recesses 17, 17. , Split ring 2 has hooks 13 and 13
This is because it does not deviate from. Therefore, each part is not lost between the factory shipment and the construction site, and it is not necessary to procure each part at the site.

Finally, at the construction site, as shown in FIG.
And, as shown in (b), the pipe end of the joint pipe 3 is inserted from the split ring 2 side, the pipe end of the joint pipe 3 passes through the union nut 9 and the packing 12 attached thereto, and the joint body 8
Located inside the. After that, the union nut 9 may be tightened with a tool, and in this state, the bolt 4 and the nut 5 of the split ring 2 may be tightened to fix the split ring 2 to a predetermined position on the outer peripheral surface of the joint pipe 3.

In this case, in this embodiment, since the arms 7 and 7 and the split ring 2 are separately and independently connected, the joint pipe 3 is a soft pipe such as a soft polyethylene pipe. However, as the split ring 2 is tightened, the split ring 2 does not have any restraint on the outer peripheral surface thereof, so that the split ring 2 has an average diameter reduction from the entire circumference, and the center thereof is the locking ring 6. Don't cheat with the center of.

Therefore, even a soft joint pipe 3 can be connected to the joint body 8 in a linear posture, and each member of the joint maintains a substantially concentric shape. Similar to the case of connection, it is possible to connect in a state where sufficient flexibility and stretchability are imparted. Also when connecting,
Since an unreasonable force is not applied to the arms 7 and 7, even when a large water pressure is applied, there is no breakage of the arms 7 and 7 or deviation of the joining pipe, and an excellent pipe joint is obtained.

Further, the joint pipe 3 and the joint body 8 are sealed by an annular packing 12 and can be flexed with respect to each other around the annular packing 12. Further, when the joint pipe 3 makes a movement to deviate to the left in the same figure with respect to the joint body 8 as shown in FIG. 8, the locking ring 6 comes into contact with the tip end surface of the union nut 9 and comes off. It will be stopped. The locking ring 6 is a single ring as a whole,
Even if the joining pipe 3 and the joint main body 8 undergo a movement in an attempt to deviate in a state in which the joining pipe 3 is bent, the locking ring 6 never rides over the union nut 9, so that the joining pipe 3 can be securely held. It is possible to prevent deviations.

Moreover, when a force in the deviating direction acts on the joint pipe 3, as shown in FIG. 8, the flange 1 of the split ring 2 is
4 and the hooks 13 and 13 of the arms 7 and 7,
The pulling force to the left in the figure acts on the locking ring 6 to deform it. However, at the portion where the locking ring 6 contacts the end surface of the union nut 9, a force to the right in the figure acts, and the stresses in the opposite directions cause the hooks 13 and 13 of the arms 7 and 7. A force in the diameter reducing direction acts on. That is, when a force in the deviating direction acts on the joining pipe 3, a force in the diameter reducing direction acts on the hooks 13, 13 of the arms 7, 7, and the hooks 13, 13 are structured so as not to come off.

By the way, the present invention is not limited to the above-mentioned embodiment, and for example, the hooks 13 and 13 and the recesses 17 and 17 may have a reversed mounting positional relationship. That is, the hooks 13 and 13 are formed on the outer peripheral surface side of the split ring 2 so as to project radially outward, and the flanges 14, 15 and 16 are formed on the inner peripheral surface side of the tips of the arms 7 and 7 so as to project radially inward. To form the recesses 17, 17 and hooks 13, 13 and the recess 1
You may make it engage with 7, 17 in a loose state.

[0039]

As described above, according to the present invention,
On the other end of the arm, one end of which is connected and fixed to the locking ring, a hook protruding in the inner diameter direction is provided, and a recess is provided between the protruding flanges on the outer peripheral surface of the split ring, so that the hook of the arm can be secured. Since the arm and the split ring are separated and independently connected by fitting in the recess of the split ring in a loose state, the split ring can be used even if the joint pipe is a soft pipe such as soft polyethylene pipe. As the split ring is tightened, there is no restraint on the outer peripheral surface of the split ring, so the diameter of the split ring decreases on average from the entire circumference, and the center positions of the locking ring and split ring deviate from each other. There is no.

Therefore, even a soft joint pipe can be connected to the joint body in a linear posture, and since each member of the joint maintains a substantially concentric shape, the connection of the hard pipe can be prevented. As in the case, it is possible to connect in a state where sufficient flexibility and elasticity are imparted. Also when connecting,
Since an unreasonable force is not applied to the arm, even if a large water pressure is applied, there is no breakage of the arm or deviation of the joint pipe, and it is an excellent pipe joint.

Further, when a force in the deviating direction acts on the joint pipe, a force in the diameter reducing direction acts on the hook of the arm, so that the hook does not come off from the split ring, and the deviating resistance force of the joint pipe is prevented. Can be improved.

In addition to this, it goes without saying that the present invention is an improvement of the technique previously filed by the present applicant and has the effects of this prior application technique. That is, the portion other than the two arms between the split ring and the locking ring is a free space, and the union nut can be fastened with a tool such as a spanner or a pipe wrench. Therefore, it is possible to attach the pipe separation prevention fitting, the union nut and the annular packing to the joint pipe in advance to make a set, and just insert the joint pipe and fasten it without disassembling it. It is possible to perform connection work with the joint body with, and connection work on site is extremely easy.

Further, the pipe disengagement prevention metal fitting of the present invention is not of a half-divided shape as a whole, and even if a large drawing force is applied, the locking ring at the tip never expands in diameter, and the pulling resistance is also high. Improved and excellent in reliability as a pipe joint. Since there is no need to worry about expanding the diameter in this way, the locking ring and two arms can be made thinner, and smaller bolts and nuts can be used, resulting in cheaper and more reliable release. It is possible to provide preventive metal fittings.

Further, as the union nut, a conventional general-purpose product can be used, and the contractor only needs to newly purchase the disengagement preventive fitting, and the detachment preventive fitting of the present invention can be applied to the existing pipe joint. Is also possible.

Furthermore, since the union nut need only be lightly tightened so as not to cause water leakage, a large pipe wrench is not required. Also, the bolts and nuts may be small, and since there is only one tightening point, the workability of construction can be greatly improved and the work efficiency can be dramatically improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a joint portion equipped with a pipe separation prevention fitting according to the present invention.

FIG. 2 is a front view showing the pipe separation prevention fitting according to the present invention before being fastened.

FIG. 3 is a front view showing a state at the time of fastening the pipe detachment preventing metal fitting according to the present invention.

4A and 4B are views showing an assembling process of the pipe detachment preventing metal fitting according to the present invention, wherein FIG. 4A is a plan view and FIG. 4B is a side view.

5A and 5B show an assembling process of the pipe detachment prevention metal fitting according to the present invention, FIG. 5A is a plan view and FIG. 5B is a side view.

6A and 6B are views showing an assembling process of the pipe detachment preventing metal fitting according to the present invention, wherein FIG. 6A is a plan view and FIG. 6B is a side view.

7A and 7B are views showing a state after assembly of the pipe detachment prevention metal fitting according to the present invention, in which FIG. 7A is a plan view of a joint portion, and FIG.
[Fig. 3] is a side view of a joint portion.

FIG. 8 is a plan view showing a state in which a tensile force is applied to the joint equipped with the pipe separation prevention fitting according to the present invention.

FIG. 9 is a vertical cross-sectional view of a joint portion to which a pipe separation prevention fitting according to the applicant's prior application is attached.

FIG. 10 is a front view showing a pipe separation prevention fitting according to the applicant's prior application.

FIG. 11 is a side view showing a state before fastening of a joint portion to which a pipe detachment preventing metal fitting according to the applicant's prior application is attached.

FIG. 12 is a front view showing a state before fastening of the pipe detachment preventing metal fitting according to the applicant's prior application.

FIG. 13 is a side view showing a state in which a joint portion equipped with a pipe separation prevention fitting according to the applicant's prior application is fastened.

FIG. 14 is a front view showing a state after fastening of the pipe separation prevention fitting according to the applicant's prior application.

FIG. 15 is a plan view showing a state in which an arm is deformed when the pipe separation prevention fitting according to the applicant's prior application is attached to a soft pipe and a bolt and a nut are fastened.

[Explanation of symbols]

2 ... Split ring 3 ... Joining pipe 4 ... Bolt 5 ... Nut 6 ... Locking ring 7 ... Hook 8 ... Joint body 9 ... Union nut 10 ... Insertion hole 12 ... Packing 13 ... Hook 14 ... Flange 15 ... Flange 16 ... Flange 17 … Recessed part 18… Pipe detachment prevention fitting

Claims (3)

[Claims] 1. A pipe having a socket having an external thread engraved on the outer peripheral surface thereof, or a joint body, into which a threadless joint pipe is inserted, and an annular rubber packing is inserted and inserted to insert the union nut into the socket. In a pipe joint with a structure that is screwed and tightened into a pipe, a split ring that is cut out in the middle of the circumference and is externally fitted to the joint pipe on the rear end side of the union nut and tightened with bolts, etc. A circular engagement member that has an insertion hole that is larger than the outer diameter of the joint body and smaller than the outer diameter dimension of the union nut, and that is mounted loosely on the pipe on the tip side of the union nut or on the outer peripheral surface side of the joint body. A stop ring and an arm that connects the split ring and the locking ring at two opposing positions, and the arm is integrally connected on the locking ring side,
On the split ring side, the hook provided on one of the arm tip and the split ring outer peripheral surface and the recess formed between the flanges provided on the other side are connected in a loosely connected state. Characteristic pipe detachment prevention fitting for union nut joints. 2. The split ring side of the arm is engaged by a hook formed in the distal end of the arm and projecting in an inner diameter direction and a recess formed between flanges projecting on the outer peripheral surface of the split ring. The pipe disengagement prevention fitting for a union nut joint according to claim 1, wherein the fittings are connected in a loose fit state. 3. A recess formed on the split ring side of the arm between a hook provided on the outer peripheral surface of the split ring and protruding in the outer diameter direction, and a flange provided on the inner peripheral surface of the arm tip in a protruding shape. The pipe disengagement prevention fitting for the union nut joint according to claim 1, wherein the fitting is connected in a loosely engaged state by engagement with.