JPH05272666A - Double pipe and joint part thereof - Google Patents

Abstract

PURPOSE:To prevent the reduction of the inside diameter of a pipe passage over a certain degree even if the component and contained article in a fluid adhere on the inner wall of the pipe passage, by inserting a flexible pipe having the outer peripheral length shorter than the inner peripheral length into the tubular hole on a hard pipe and allowing the fluid to flow in the tubular hole of the flexible pipe. CONSTITUTION:A double pipe 1 is constituted of a hard pipe 3 on the outside and a flexible pipe 4 on the inside, and in the tubular hole of the hard pipe 3, the flexible pipe 4 having the outer peripheral length shorter than the inner peripheral length of the tubular hole is inserted. The flexible pipe 4 is made of the material having the small rigidity such as rubber, resin, and cloth. Since a gap 5 is formed between the hard pipe 3 and the flexible pipe 4 in the ordinary case, the air in the gap 5 is compressed when the flexible pipe 5 is expanded, and the excessive expansion of the flexible pipe 4 is prevented. When the flexible pipe 4 is broken, fluid continuously flows in the flexible pipe 4 in the state where the broken part of the flexible pipe 4 is attached on the inner wall surface of the hard pipe 3 by the pressure of the fluid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piping structure capable of preventing a diameter reduction of a pipe hole due to adhesion of fluid components and inclusions to an inner wall surface of the pipe and a joint portion thereof.

[0002]

2. Description of the Related Art In piping, while the fluid is being sent into the pipe, the components and contents of the fluid gradually adhere to the inner wall surface of the pipe. Finally, it is closed. Moreover, as the inner diameter of the flow path is reduced, the flow rate is reduced, the operating efficiency of the equipment associated with the pipeline is reduced, and the diameter reduction finally causes blockage and stops the function of the equipment.

For this reason, when the inner diameter of the flow path of the pipe is reduced to a certain extent, the deposits on the inner wall surface of the pipe are usually
It is removed by a method of cleaning with chemicals, a method of cleaning by spraying high pressure water on the inner wall surface of the pipe, a method of scraping off a lump composed of an elastic body inside the pipe by forcibly inserting it with high pressure air. It

When removing deposits in a pipe by such a method, normally, during the removal work, the flow of the fluid is stopped over the entire range of the pipeline for removing deposits, and the inside of the pipeline is further stopped. The fluid remaining in the chamber must be eliminated. If the flow of the fluid in the pipeline is stopped, the equipment related to the pipeline is normally suspended, and there is a problem that the economic loss due to the suspension of the equipment is large.

Further, the amount of fluid remaining in the pipeline increases as the pipeline length increases, and the work of removing the fluid is dangerous if the fluid is a chemical, a fluid containing dangerous substances, or the like. ,
Disposal of the removed fluid was very troublesome. Particularly, in chemical plants, sulfuric acid and lime are often used for neutralization, reaction, extraction, etc. of chemical substances, and sulfuric acid and lime are contained in the fluid in the pipes of chemical plants where sulfuric acid and lime are used. Often mixed and included.

In such a case, sulfuric acid and lime in the fluid react with each other to produce gypsum (CaSO ₄ ), the gypsum adheres to the inner wall surface of the pipe line, and the adhered substance is laminated to form the pipe line. Finally it is closed. For this reason, in the piping of the fluid containing gypsum or the fluid generated while the gypsum is being sent, the work of removing the gypsum adhering to the inner wall surface of the pipe is regularly performed, and the frequency thereof is high.

[0007] The gypsum adhering to the inner wall of the pipe is a chemically stable substance and is strong, so that the gypsum was chemically washed, washed by spraying high-pressure water, or made of an elastic body in the pipe. Since the bullet cannot be removed by washing by forcefully inserting it, the pipe of the pipe line is disconnected at its flange joint portion over the entire area, and is dropped to the ground, and then the outer surface of the pipe is struck with a hammer etc. It is cleaned by mechanical means such as applying shock or vibration with deformation to the pipe. The work of lowering the erected pipe to the ground is a large and troublesome work, and the work of hitting the lowered pipe with a hammer is a heavy-duty work. Further, since the direction of the flange of the pipe from which the gypsum has been removed is changed by the deformation of the pipe due to smashing, there is a problem that the work of installing the pipe as it is is extremely complicated.

On the other hand, in the pipe for sending purified water, as a method for preventing the adhered substance itself from adhering to the inner wall of the pipe, a pipe having zinc plated, copper plated or resin lining is laid on the inner wall of the pipe. A method, a method of laying a copper pipe or a resin pipe in the pipeline, and a method of ionizing the purified water in the pipeline are adopted.

In the method of laying a pipe plated with zinc plating or copper plating on the inner wall surface of the pipe, the plating is peeled off within a few years due to the erosion effect of the fluid, so that the effect of preventing adhesion of deposits by plating is limited. is there. The method of laying a copper pipe in the pipeline has the effect of preventing the buildup of deposits on purified water, but the copper pipe itself is expensive and is applicable to fluids containing components that cause a chemical reaction with copper. There was a problem that it could not be done and its application was limited. Furthermore, the method of ion-treating the purified water in the pipeline is also effective in preventing the buildup of deposits, but its use is limited to purified water, and there is a problem that it lacks versatility.

[0010] Even in the flow pipe for purified water, which is composed of water, which is a chemically stable substance, and has a very small amount of impurities, the above-mentioned problem occurs. Therefore, in the flow pipe for factory waste liquid, sewage, etc., It goes without saying that further careful maintenance is necessary. From the above,
The advent of a pipeline having a structure free of deposits was eagerly awaited.

[0011]

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, the present invention has an inner diameter of the pipeline to a certain extent or less even if a component or inclusion of a fluid flowing in the pipeline adheres to the inner wall of the pipeline. It is an object of the present invention to provide a pipe and its joint that do not reduce the diameter.

[0012]

According to the present invention, (1) a flexible tube having an outer peripheral length shorter than an inner peripheral length of the tubular hole is inserted into the tubular hole of the rigid tube, and the tubular hole of the flexible tube is provided. A double pipe for transporting fluid, characterized in that a fluid is passed through, and (2) two sets of a pipe having a flange at the end and a tapered inner surface having a reduced inner peripheral surface from the vicinity of the flange to the central portion side. A hard tube is tandemly arranged so that each of the flanges faces each other, and a flexible tube having an outer peripheral length shorter than an inner peripheral length of the tube hole is provided in a tube hole of each of the hard tubes from the end surface of the flange to the hole of the hard tube. The outer diameter of the flange is slightly larger than the inner diameter of the end face of the collar, and both ends have an outer diameter smaller than the inner diameter of the hard pipe. A short tube having a tapered outer surface whose outer diameter is reduced by inserting it into the mouth of the flexible tube in the tube hole of each of the hard tubes, and inserting it into the tapered surface of the hard tube through the mouth of the flexible tube. Short Between the head of the bolt and the nut by screwing a nut with a head into each of the plurality of opposing holes provided in each of the collars, by fitting the upper surface to each other. A joint for connecting adjacent double pipes for fluid transport, characterized in that the collars are connected to each other by sandwiching each of the collars, and (3) a collar having a plurality of holes at appropriate positions along the outer periphery at the end. A hard tube having a tapered inner surface whose inner peripheral surface shrinks from the vicinity of the flange toward the central portion, and a flexible tube having an outer peripheral length shorter than the inner peripheral length of the tube hole in a tube hole of the hard tube. It is inserted in a state where it slightly protrudes from the end face of the flange to the outside of the hole of the hard pipe, and a flange is provided on one end, and an outer diameter larger than the inner diameter of the end face of the hard pipe is provided near the flange and the other end is provided. And a short tube with a flange having an outer diameter smaller than the inner diameter of the hard tube and having a tapered outer surface whose outer diameter decreases from the vicinity of the flange toward the other end. A double pipe for fluid transport, characterized in that the double pipe for fluid transportation is inserted into the mouth of the flexible pipe in the pipe hole, and the taper surface of the short pipe is fitted to the taper surface of the hard pipe through the mouth of the flexible pipe. Fittings are the gist

[0013]

[Function] Since the fluid flowing in the pipe always has some pulsation on the inner wall surface of the pipe through which the fluid flows, a force to spread the inner wall of the pipe in the radial direction acts in accordance with the change in pressure due to the pulsation of the fluid. .. Therefore, in the flexible tube that constitutes the double tube of the present invention, since the rigidity of the tube wall is small, the expanding and contracting force causes the flexible tube to expand and contract in the radial direction. It occurs every time. For this reason, when the attached material on the inner wall of the pipe reaches a certain thickness, it is peeled off due to the repeated motion of the expansion and contraction action of the inner wall of the flexible tube, and the detached attached matter is pushed away by the fluid flowing in the flexible tube. Be done.

When the amount of expansion and contraction in the circumferential direction of the flexible tube due to the pulsation of the fluid is small, the adhered matter adheres to the inner wall of the flexible tube without peeling off, but in such a case,
By appropriately stopping and starting the flow of the fluid, forced pulsation is generated in the fluid, and the grown deposit can be automatically removed from the inner wall of the pipe.

[0015] Normally, the equipment related to the pipeline is stopped and started during the maintenance, so that the above-mentioned forced pulsation occurs every time the maintenance is performed.
If the pulsation during operation is insufficient to remove the adhered matter, stop and start the appropriate number of operations repeatedly during inspection and maintenance to remove the grown adhered matter by the fluid. It will be washed away.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A double pipe 1 of the present invention, as shown in FIGS. 1 and 2, has a hard tube 3 on the outer side and a flexible tube 4 on the inner side. It is configured by inserting a flexible tube 4 having an outer peripheral length shorter than the inner peripheral length of the tube hole. The flexible tube 4 is one that expands and deforms in the radial direction by the pressure of the fluid flowing in the tube, or one that does not have rigidity that can keep the tube cross-sectional shape circular, and rubber,
It is made of a material having low rigidity such as resin or cloth.

FIG. 1 is a diagram showing a state in which the flexible tube 4 which expands and deforms in the radial direction by the pressure of the former fluid is used, and the fluid pressure of the flexible tube 4 shown by a solid line in the figure becomes large. The flexible tube 4 shown in phantom lines shows the state of expansion and contact with the inner wall of the hard tube 3 before the fluid pressure increases. Figure 2
FIG. 4 is a diagram showing a state in which the latter flexible tube 4 having no rigidity capable of keeping the cross-sectional shape of the tube in a circular shape is used. The flexible tube 4 indicated by the phantom line shows the state before the fluid pressure is increased.

The outer hard tube 3 has rigidity enough to withstand the expansion force in the outer diameter direction of the flexible tube 4 inserted therein, and is made of a metal tube, a resin tube, a concrete tube, or the like. ing.

Double pipe 1 having a sectional shape shown in FIG.
Since the outer surface of the flexible tube 4 contacts the inner surface of the hard tube 3, if the outer diameter of the flexible tube 4 is an appropriate size, the flexible tube 4 is prevented from expanding excessively. .. Therefore, by setting the outer diameter of the flexible tube 4 to an appropriate size, the life of the flexible tube 4 can be extended.

Double pipe 1 having a sectional shape shown in FIG.
Is caused by the inner diameter of the hard tube being larger than the outer diameter of the flexible tube when the flexible tube is expanded. When 4 expands, the air in the gap is compressed and the pressure of the compressed air prevents it from expanding too much. Therefore,
By setting the inner diameter of the hard tube 3 to an appropriate size, the life of the flexible tube can be extended.

If the flexible pipe 4 constituting the double pipe 1 of the present invention is broken by the deterioration of the material or the presence of the defect of the material while the fluid is being sent through the double pipe 1, the damage is caused. The fluid continues to flow in the flexible tube while the portion is in contact with the outer surface, that is, the inner wall surface of the hard tube by the pressure of the fluid. Further, by making the hard tube have a sealed structure, the fluid can continue to flow in the flexible tube without leaking to the outside of the hard tube, as before the breakage.

FIGS. 3 and 4 show the manner of connecting the double pipes according to the present invention. FIG. 3 shows a state in which the pipes are connected by using a flange joint, and FIG. 4 shows a state in which a screw joint is used. The respective pipes are shown to be connected to each other, and any one of them may be appropriately applied in consideration of the usage environment and conditions.

FIG. 5 is a view showing a longitudinal section of a joint portion of adjacent double pipes of the present invention. Reference numeral 7 in the drawing denotes a collar provided at the end of each of the hard pipes 3 facing each other. A tubular connecting pipe having a tapered inner peripheral surface 9 whose inner peripheral surface contracts from the end surface 8 toward the center of the pipe, and a tapered outer peripheral surface 11 whose outer peripheral surface contracts toward both ends from the center. The outer diameter of the center of the connecting pipe is larger than the inner diameter of the collar end face 8, and the outer diameter of the end face of the connecting pipe 10 is the collar end face 8.
Smaller than the inner diameter of.

In the joint portion 2 of the double pipe 1 of the present invention, the tapered outer surfaces 11 on both sides of the connecting pipe 10 are connected to the ends of the holes of the flexible pipe 4 which are inserted into the adjacent hard pipes 3. The end portions 15 of the adjacent flexible tubes 4 are tapered to the taper inner peripheral surface 9 by fitting and fastening the facing flanges 7 with bolts 13 and nuts 14 through bolt holes provided in the flanges 7. The flexible tube 4 is pressed and sandwiched by the outer peripheral surface 11 to keep the flexible tube 4 sealed and the airtightness of the gap 5 between the flexible tube 4 and the hard tube 3.

Double pipe 1 of the present invention in which a hard pipe has a sealed structure 1
In the case where the flexible tube 4 is damaged, as shown in FIG.
By opening small holes 6 in the lower part of each hard tube 3 between the collars 7 and finding the fluid that leaks through the small holes 6 and leaks, the double pipe 1 at the damaged position of the flexible tube 4 can be found. .. In this case, the upper side of the small hole 6 is pressed below the bottom surface of the hard tube 3 and further by the bottom surface of the flexible tube 4 to be closed, so that even if the flexible tube 4 is damaged, A large amount of fluid does not spout.

Therefore, in the double pipe 1 of the present invention in which the hard pipe 3 has a sealed structure, even if the flexible pipe 4 is damaged, expansion and contraction around the damaged portion of the flexible pipe 4 is eliminated, and the fluid inside the pipe is Flows as usual, and it takes a long time to reduce the diameter of the area around the damaged part due to adhered matter, so the flexible tube may be replaced at an appropriate time.

FIG. 6 is a side view of the double pipe 1 and the joint portion 1 of the present invention.
6 is a vertical cross-sectional view showing another example of 6, in which 17 is a cylindrical connecting pipe 17 having a tapered outer peripheral surface 11 whose outer peripheral surface shrinks from one end to the other end. The outer diameter of one end is larger than the inner diameter of the flange end surface 8 of the hard pipe 3, and the outer diameter of the other end of the connecting pipe 17 is smaller than the inner diameter of the hard pipe 3.

The joint portion 16 of the adjacent double pipe is the connecting pipe 1
7 are opposed to each other with the packing 19 interposed therebetween, the tapered outer peripheral surface 11 of the connecting pipe 17 is fitted into the end portion of the pipe hole of the flexible pipe 4 inserted into the hard pipe 3, and the facing flange 7 is attached to the flange 7. The end portion 15 of the flexible tube 4 is pressed and sandwiched between the tapered inner peripheral surface 9 and the tapered outer peripheral surface 11 by tightening the bolt 13 and the nut 14 through the bolt holes provided in the flexible tube 4, and the flexible tube 4 is sealed. Further, the airtightness of the gap 5 between the flexible tube 4 and the hard tube 3 is maintained.

FIG. 7 is a vertical cross-sectional view showing a connecting portion between the double pipe 1 of the present invention and an ordinary pipe with a flange.
The outer surface 18 of the connection pipe 17 of No. 6 is brought into contact with the flange surface of the normal hard tube 20 with the flange 21 via the packing 22,
Attach the flange 7 and the flange 21 facing each other to the bolt 13 and the nut 14.
The end portion of the flexible tube 4 is pressed and sandwiched between the tapered inner peripheral surface 9 and the tapered outer peripheral surface 11, and the flexible tube 4 is sealed and the gap 5 between the flexible tube 4 and the hard tube 3 is secured. It is airtight. With the above-described configuration, in the conventional pipeline, the pipeline section in which the diameter reduction phenomenon is likely to occur can be easily changed to the double pipe of the present invention.

(First Embodiment) FIG. 8 shows an embodiment of a double pipe 1 and a joint portion 2 thereof according to the present invention. Hard pipes 26a and 26b constituting the double pipe are flexible in their barrels. The flanged half tube 23 that surrounds the tube 4 has bolts 24 and nuts 25.
Concluded by Half split short tube with flange 23
As shown in FIG. 8, the length B is larger than the distance A from the flange end surface 8 forming the adjacent hard tube 26a to the end surface 27 of the existing connecting pipe 10 protruding from the end surface 8.

With the above structure, the bolts 13 and 24 fastening the joint portion 2 and the flanged half-split tube 23 are removed, and then the flanged half-split tube 23 is removed. By pulling the pipe 26a toward the hard pipe 26b side, between the end face 27 of the existing connection pipe 10 and the brim end face 8 constituting the hard pipe 26a, a gap having a width that allows the hard pipe 26a to be pulled out in the radial direction thereof is obtained. You can

Therefore, the flexible pipe 4 is provided near the brim side of the hard pipe 26a, that is, near the hard pipe 26a side of the end portion 27 of the existing connection pipe 10 and near the brim side of the hard pipe 26b.
The hard tubes 26a and 26b can be removed by cutting at a position near the hard tube 26b side (not shown) of the 0 end portion 27.

The removed double pipe part is the removed hard pipe 2
6a, 26b and the flanged half-split tube 23 are joined together to form the flexible tube 4 slightly longer than the length of the rigid tube 26a,
26b, the tapered outer peripheral surfaces of the existing connecting pipes 10 that are provided so as to face each other are inserted into the respective end holes of the flexible pipe 4, and the flanged half-split pipe 23 is inserted. It can be restored by fastening between the hard pipes 26a and 26b, and then fastening each collar 7 near each existing connection pipe with a bolt and a nut.

A gap is formed between the end surface hole of the flange 7 and the flexible tube 4 at the fitting portion of the existing connecting pipe 10, and the end 15 of the flexible tube 4 is tapered to the inner peripheral surface 9 and the outer peripheral surface of the taper. When it is not possible to press and clamp with 11, it can be pressed and clamped by appropriately changing the thickness of the packing 28 of the flanged half-divided short tube portion 23.

(Second Embodiment) FIG. 10 shows an embodiment of the double pipe 39 of the present invention and the joint portion 16 thereof. The hard pipe 29 constituting the double pipe 39 of the present invention is provided at the end thereof. It has a ring-shaped projection 30, and the end portion of the double pipe 39 is fitted into a short pipe 31 with a collar that constitutes the joint portion 16 of the present invention. The bridging short tube 31 has a brim 7 at one end of a short tube made of a hard tube, has a screw 32 on the outer peripheral surface at the other end, and has a tubular end on the one end from the brim end surface 8 A tapered inner peripheral surface 9 whose inner peripheral surface is contracted is provided on the screw 32 side, and a tapered inner wall 33 whose diameter is reduced to the tube hole on the other side end side is provided.

Reference numeral 34 denotes a cap nut, and the cap nut 34
Has a hole for inserting the hard tube 29 in the center of the inner wall 35 of the screw 36, and a ring-shaped projection 37 of an appropriate length having an outer diameter smaller than the inner diameter of the collared short tube 31 on the inner wall 35.
Have. The packing 38 is formed in a ring shape between the inner peripheral surface of the tube hole near the screw 32 side of the flanged short tube 31 and the outer peripheral surface of the hard tube 29 forming the double pipe 39.

With the above structure, the short pipe 31 with the flange is fastened to the adjacent flange 7 by the bolts 13 and the nuts 14, and then the cap nut 34 is screwed into the short pipe 31 with the flange 38, so that the packing 38 is formed. The protrusion 37 of the cap nut 34 pushes against the side surface of the ring-shaped protrusion 30 at the end of the hard pipe 29, expands in the radial direction, and the gap between the brim short pipe 31 and the hard pipe 29 forming the double pipe. Can be sealed. Therefore, the space between the flexible tube 4 and the hard tube 29 can be made airtight.

When the flexible pipe 4 is damaged and the double pipe 39 having the flexible pipe 4 is removed, the screw 36 of the cap nut 34 is removed from the short pipe 31 with the flange and the cap nut 34 of the double pipe 39 is removed. Also, since the flexible tube 4 is exposed by moving the flanged short tube 31 toward the center of the double pipe, it can be removed by cutting the exposed flexible tube 4 part.

(Third Embodiment) FIG. 11 shows a double tube 4 of the present invention.
No. 0 and its joint portion 16 are shown as other examples, and both ends of the double pipe 40 of the present invention are fitted into the collared short pipes 41 constituting the joint portion of the present invention. Reference numeral 41 denotes a short tube with a collar, and the short tube with a collar 41 has a collar 7 at one end of the short tube made of a hard tube, and an outer peripheral surface on the other end side radially from the center of the short tube. Through screw holes 42 with appropriate spacing
And a tapered inner peripheral surface 9 whose inner peripheral surface is reduced from the flange end surface 8 to the other end side in the tube hole at the one end.

With the above construction, after the short pipe 41 with a collar is fastened to the adjacent flange 7 by the bolt 13 and the nut 14, the short pipe with a collar is required by screwing a bolt 44 into the screw hole. It is possible to obtain a double piping structure having a length. When the flexible tube 4 is damaged and the flexible tube 4 is replaced,
The double pipe 40 is loosened by loosening the bolt 44, shifting the short pipes 41 with flanges at both ends of the hard pipe to the center of the double pipe 40, and cutting each exposed portion of the flexible pipe 4.
Can be removed.

In the removed double pipe 40 portion, the flexible pipe 4 having substantially the same length as the distance between the end faces of the existing connecting pipe 17 facing each other is inserted into a hard pipe having a short pipe 41 with a collar at both ends. , The taper surfaces of the existing connection pipes 17 facing each other are fitted into the end holes of the flexible pipes, and the flanges of the existing connection pipes are connected by pulling the bolts 13 and the nuts 14 together to connect the bolts 44. By tightening the
Can be restored by connecting to the short pipe with a collar at both ends.

In this embodiment, since the gap between the flexible tube 4 and the hard tube 43 is not sealed, when the flexible tube 4 is damaged, the fluid leaks from the end of the flanged short tube 41 on the bolt 44 side. However, it is useful as a simple pipe because it has a function of preventing the fluid components and inclusions from adhering and laminating, and has a simple structure.

[0043]

As described above, by using the double pipe of the present invention and the joint portion thereof in the pipe line, it becomes unnecessary to clean the pipe hole due to the diameter reduction and to install a new alternative pipe.
Further, even if the diameter is reduced, the degree of the diameter reduction is small, so the reduction in the flow rate is within the flow rate setting error range, and the reduction in the operating capacity and efficiency of the equipment due to the diameter reduction of the pipeline is hindered. It became a thing. Further, since the equipment failure due to the reduced diameter of the pipe is eliminated, the equipment can be operated stably. Therefore, the economical effect obtained by using the double pipe of the present invention and the joint portion thereof for the fluid transport pipe becomes extremely large.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along the line AA in FIG. 5, showing a cross-sectional shape of double pipes.

FIG. 2 is a cross-sectional view taken along the line BB of FIG. 7, showing a cross-sectional shape of the double pipe.

FIG. 3 shows a partial vertical sectional view of a double pipe having a flange joint.

FIG. 4 shows a partial longitudinal sectional view of a double pipe having a threaded joint.

FIG. 5 shows a vertical sectional view of a double pipe joint portion.

FIG. 6 shows a vertical sectional view of a double pipe joint portion.

FIG. 7 shows a vertical sectional view of a double pipe joint portion.

FIG. 8 is a diagram showing a first embodiment of the double pipe and its joint of the present invention.

9 is a cross-sectional view taken along the line AA of FIG.

FIG. 10 is a view showing a second embodiment of the double pipe and its joint of the present invention.

FIG. 11 shows a third embodiment of the double pipe and its joint of the present invention.

[Explanation of symbols]

1,39,40 Double piping 2 Joint part 3,29,43 Hard tube 4 Flexible tube 5 Gap 6 Small hole 7 Collar 8 Collar end face 9 Tapered inner peripheral surface 10, 17 Connection pipe 11 Tapered outer peripheral surface 13, 24 , 44
Bolts 14,25 Nuts 15 Ends of flexible pipes 16 Joints 18 Outer side surfaces 19, 22, 28, 38 Packing 20 Steel pipes 21 Flange 23 Flange half split pipes 26a to 26c
Hard tube 27 End surface 30,37 Protrusion 31,41 Short tube with collar 32,36,42
Screw 33 Taper inner wall 34 Cap nut 35 Back wall

Continuation of front page (51) Int.Cl. ⁵ Identification number Reference number in the agency FI Technical indication location F16L 23/028 23/036 (72) Inventor Hiroyuki Masuda No. 1 Hibatacho, Tobata-ku, Kitakyushu, Fukuoka Japan Steel Works Co., Ltd. Yawata Works (72) Inventor Tokuyuki Kiba 1-1 Tobahata-cho, Tobata-ku, Kitakyushu, Kitakyushu, Fukuoka In-house Yahata Works (72), Nippon Steel Co., Ltd. Yoji Tamura Tobata, Kitakyushu, Fukuoka Prefecture No. 1-1 Tobata-cho, Shin-Nippon Steel Co., Ltd. Yawata Works

Claims (3)

[Claims] 1. A fluid transport characterized by inserting a flexible tube having an outer peripheral length shorter than the inner peripheral length of the hard tube into the tube hole of the hard tube, and passing a fluid through the tube hole of the flexible tube. For double piping. 2. Two sets of hard pipes each having a flange at the end and a tapered inner surface having an inner peripheral surface that shrinks from the vicinity of the flange toward the central portion are arranged in tandem with each of the flanges facing each other. Inserting a flexible tube having an outer peripheral length shorter than the inner peripheral length of each of the hard tubes into the tube hole of each of the hard tubes in a state of slightly protruding from the end surface of the collar to the outside of the hole of the hard tube,
The central portion has an outer diameter larger than the inner diameter of the end surface of the brim, and the both end portions have an outer diameter smaller than the inner diameter of the hard pipe, and also have tapered outer surfaces whose outer diameter decreases from the central portion toward the both end sides. Insert the short cylinder into the mouth of the flexible tube in the tube hole of each of the hard tubes, and fit the taper surface of the short cylinder into the tapered surface of the hard tube through the mouth of the flexible tube. A headed bolt is communicated with each of a plurality of opposing holes provided in the collar, and a nut is screwed into the bolt, and the collar is sandwiched between the head and the nut of the bolt for connection. A joint for connecting adjacent double pipes for fluid transportation, which is characterized in that 3. A hard pipe having a collar having a plurality of holes at appropriate positions along the outer periphery and a tapered inner surface whose inner peripheral surface is reduced from the vicinity of the collar toward the central portion at the end, Insert a flexible tube having an outer peripheral length shorter than the inner peripheral length of the tube into the tube hole of the hard tube in a state of slightly protruding from the end surface of the flange to the outside of the hole of the hard tube,
A flange is provided at one end, an outer diameter larger than the inner diameter of the end surface of the flange of the hard pipe is provided near the flange, and an outer diameter smaller than the inner diameter of the hard pipe is provided at the other end from the vicinity of the flange to the other end. A short tube with a collar having a tapered outer surface whose outer diameter is reduced is inserted into the mouth of the flexible tube existing in the tube hole of the hard tube, and the taper surface of the hard tube is inserted through the mouth of the flexible tube. A double pipe joint for fluid transportation, characterized by fitting the tapered surface of a short cylinder.