JP2009138921A - Pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe joint for preventing the leakage of liquid from a pipe and the degradation of its sealing performance without lowering the fastening force of joint bolts even when a great amount of heat operates on the pipe joint. <P>SOLUTION: The pipe joint comprises a heat insulating material (a first heat insulating material A) having a heat insulating means α mounted in a region between fastening rings g, h and packing rings m, n to encircle the plurality of joint bolts k, a coating layer (a second heat insulating material B) arranged on the outer peripheral face of the heat insulating material A and having water shielding performance and heat insulating performance, and a plate-like fixing member C arranged on the outer periphery of the coating layer B for thrusting the coating layer (the second heat insulating material B) to the side of the heat insulating material A. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement of a pipe joint for connecting two pipes (connected pipes), and relates to a pipe joint having improved fire resistance.

When connecting two pipes, the generally required performance is:
(1) Sealing performance so that the fluid flowing inside the connected pipe does not leak from the joint.
(2) The distance between the pipe ends facing each other of the connected pipe can be varied, that is, slidable in the axial direction of the connected pipe,
(3) In some cases, the flexibility that the angle formed by the two connected pipes at the connection point can be somewhat varied,
There are three.

As a pipe joint having such performance, the applicant inserts a heat insulating means (α) in a region between the fastening ring (g, h) and the packing ring (m, n) which is a seal member. A pipe joint was proposed in which the packing ring (m, n) does not deteriorate even when exposed to a flame (see Patent Document 1).
FIG. 16 shows a side surface including a partial cross section of the pipe joint.
According to the related art (Patent Document 1), the heat insulation means (α) reduces heat conduction to the packing ring (m, n), the packing ring (m, n) has heat resistance, and is 800 ° C. No deterioration even after 30 minutes

However, according to the inventor's experiment, if the amount of heat of the flame acting on the pipe joint is enormous, the pipe coupling bolt (k) is plasticized by heat even if the packing ring (m, n) does not deteriorate. It turns out that it deforms (stretches).
As a result of the plastic deformation of the coupling bolt for pipe joint (k), the tensile force acting on the bolt (k) is reduced, and the tightening force acting on the packing ring (m, n) is reduced. It was found that a leak occurred and the sealing performance could not be maintained.
JP2006-112576

  The present invention has been proposed in view of the above-described problems of the prior art, and even if a large amount of heat acts on the pipe joint, the tightening force of the coupling bolt does not decrease due to the amount of heat, and leakage of liquid in the tube occurs. The purpose of the present invention is to provide a pipe joint that can prevent a decrease in sealing performance.

  In the pipe joint of the present invention, the socket pipe (d) loosely fitted to the (2) connected pipes (b, c) arranged in series with an interval L is the connected pipe (b, c). Clamping rings (g, h) arranged across the opposite pipe ends (e, f) and loosely fitted to each of the connected pipes (b, c) are arranged on both sides of the socket pipe (d), The fastening rings (g, h) are coupled by a plurality of coupling bolts (k), and the inner surfaces (tapered surfaces j, i) of both ends of the socket tube (d) and the outer peripheral surfaces of the connected tubes (b, c) ( packing ring (m, n) is sandwiched between bf and cf: pipe surface), and the packing ring (m, n) is connected to the outer periphery of the pipe to be connected (b, c) by the fastening ring (g, h). The pipes (b, c) are pressed against the surfaces (bf, cf) and are sealed so as to be slidable in the axial direction (X direction). Packing ring (m, ) Is interposed between the heat insulating material (first heat insulating material A) surrounding the plurality of coupling bolts (k) and the outer peripheral surface of the heat insulating material (A). A covering layer (second heat insulating material B) made of a material having a water shielding property and heat insulating property disposed on the outer periphery of the covering layer (B) and the covering layer (B) as a heat insulating material (A ) Side plate-shaped fixing member (metal outer ring C), and the heat insulating material (A) is divided into the same number of sections as the number of coupling bolts (k) in the circumferential direction, A groove (Au) for receiving the coupling bolt (k) is formed in each of the sections (claim 1).

  In the present invention, the plate-shaped fixing member (metal outer ring C) has a hinge portion (Ch), and the radius of curvature can be changed by changing the bending angle of the hinge portion (Ch). The plate-shaped fixing member (metal outer ring C) is provided with a fixing portion (Cb) at an end in the circumferential direction, and the plate-shaped fixing member (made of metal It has a function of pressing and fixing the covering layer (second heat insulating material B) to the heat insulating material (A) side by joining the fixing portions (Cb) at both ends in the circumferential direction of the outer ring C). (Claim 2).

  Moreover, it is preferable that the same number of divisions as the number of the connecting bolts (k) constituting the heat insulating material (A) have the same shape (Claim 3).

  The plate-like fixing member (C) has axial ends (X direction) at both ends in the axial direction (β: 50 mm) or more axially outward from both ends in the axial direction (X direction) of the coupling bolt (k) ( It is preferable to be configured to extend in the left-right direction of FIG. 13 and the left side of FIG. 14 (Claim 4).

  In the pipe joint of the present invention, the socket pipe (d) loosely fitted to the connected pipe (b, c) is disposed across the opposing pipe ends (e, f) of the connected pipe (b, c). Clamping rings (g, h) loosely fitted in each of the connected pipes (b, c) are arranged on both sides of the socket pipe (d), and the clamping rings (g, h) A packing ring (m, n) is connected between the inner surface (j, i) of both ends of the socket tube (d) and the outer peripheral surface (bf, cf) of the connected tube (b, c). And the packing ring (m, n) is brought into pressure contact with the outer peripheral surface (bf, cf) of the connected pipe (b, c) by the tightening ring (g, h), and the connected pipe (b, c) ) Is slidably sealed in the axial direction (X), and a heat insulating means (α) is provided in a region between the fastening ring (g, h) and the packing ring (m, n). Interspersed and said A coating layer (B) made of a material having water-proof and heat-insulating properties disposed on the outer peripheral surface of the ring (g, h), and the coating layer (B) disposed on the outer peripheral portion of the coating layer (B) And a plate-like fixing member (metal outer ring C) that presses the bolt toward the fastening ring (g, h), and both ends of the fixing member (C) in the axial direction (X direction) are connected to the coupling bolt ( k) extends outward in the axial direction by a predetermined distance (β: 50 mm, for example) from both ends in the axial direction (X direction).

  Here, the axial direction (X direction) length of the heat insulating material (B) is such that both ends of the heat insulating material (B) in the axial direction (X direction) are axially outward (both ends of the connecting bolt (k). It is preferably extended so as to protrude in the left-right direction in FIG. 13 and to the left in FIG. 14 (Claim 6).

According to the pipe joint of the present invention having the above-described configuration, the heat insulating material (A) surrounding the plurality of coupling bolts (k), and the water shielding and heat insulating properties arranged on the outer peripheral surface of the heat insulating material (A). A covering layer (second heat insulating material B) made of a material having a plate-like fixing disposed on the outer periphery of the covering layer (B) and pressing the covering layer (B) toward the heat insulating material (A) Since it has a member (metal outer ring C), even if a great amount of heat acts on the pipe joint, the heat insulating material (A), the coating layer (second heat insulating material B), and a plate-like fixing member Due to the (metal outer ring C), the amount of heat transferred to the fastening bolt (k) is extremely reduced.
Therefore, even if a large amount of heat acts on the pipe joint, the coupling bolt (k) does not reach the plastic region, and the coupling bolt (k) is stretched by the tensile force acting on the coupling bolt (k) by fastening with the nut. Since the tensile force acting on the coupling bolt (k), that is, the tightening force acting on the packing ring (m, n) is maintained without lowering, the occurrence of leakage of liquid in the tube is prevented. , The sealing performance of the pipe joint can be maintained.

Here, the place where the bolt head and the nut of the tightening bolt (k) are meshed with each other is the heat insulating material (A), the covering layer (second heat insulating material B), and the plate-shaped fixing member (metal outer ring C). Is not covered and exposed, so when adjusting the tightening force (tightening, etc.) of the tightening bolt (k) and checking for leaks of internal fluid during pipe fitting maintenance ( It is not necessary to remove A), the covering layer (second heat insulating material B), and the plate-shaped fixing member (metal outer ring).
Therefore, even if the fire resistance and heat resistance are improved, the original function as a pipe joint is not impaired, and maintenance is facilitated.

  Furthermore, according to the present invention, it is possible to improve the fire resistance and heat resistance of an existing pipe joint without requiring a complicated and expensive device.

  Then, both end portions in the axial direction of the plate-like fixing member (C) extend outward in the axial direction by a predetermined distance (β: 50 mm, for example) from both end portions of the coupling bolt (k), respectively. According to the fourth aspect of the present invention, the axially opposite ends of the metal outer ring (C) extending outward in the axial direction cause the flame that wraps inward in the radial direction to be connected to the coupling bolt (k) and the fastening ring. Reaching (g, h) is inhibited. Alternatively, even if the flame that wraps around inward in the radial direction reaches the connecting bolt (k) and the fastening ring (g, h), the temperature decreases (down from about 150 ° C. to 200 ° C.).

As a result, the coupling bolt (k) and the fastening ring (g, h) are prevented from being directly exposed to the flame, or high heat is prevented from acting on the coupling bolt (k). The extension due to the thermal expansion of (k) is suppressed.
Further, since the connecting bolt (k) and the fastening ring (g, h) are not directly exposed to the flame or the temperature of the flame is lowered, the connecting bolt (k) and the fastening ring (g, h). The temperature rise in is suppressed, and adverse effects due to high heat transmitted to the packing ring (m, n) can be prevented. And since the temperature rise of a fastening ring (g, h) decreases, the leakage of the fluid from a packing ring (m, n) is prevented.

  In addition to this, the axial length of the heat insulating material (B) is extended so that both end portions in the axial direction of the heat insulating material (B) are axially outward from the both end portions of the coupling bolt (k) (see FIG. If it is configured so as to protrude in the left-right direction in FIG. 13 and to the left in FIG. 14 (Claim 6), the flame that wraps around inward in the radial direction is further increased by the coupling bolt (k) and the fastening ring (g H) is difficult to reach.

  Further, according to the invention of claim 5, since the heat insulating material (A) can be omitted, in addition to the above-described effects, the number of components can be reduced, and the number of assembly steps can be reduced. Various costs can be reduced.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
In the illustrated embodiment, the same members are denoted by the same reference numerals, and redundant description is omitted.

In FIG. 1 and FIG. 2, the expansion / contraction flexible pipe joint denoted by reference numeral 100 as a whole can slide two connected pipes b and c arranged in series with an interval L in the direction of arrow X ( It can be expanded and contracted), and as shown by an arrow M, it is connected so that it can be bent (having flexibility).
A socket pipe d is loosely fitted radially outward of the connected pipes b and c, and the socket pipe d is disposed across the pipe ends e and f of the connected pipes b and c facing each other. .
Fastening rings g and h are loosely fitted to the outer sides of the connected pipes b and c in the radial direction. The fastening rings g and h are arranged near both ends of the socket pipe d. The two connecting bolts k are connected to each other.

Tapered surfaces j, i are formed on the inner surfaces of both ends of the socket tube d, and a rubber packing as a seal member is provided between the tapered surfaces j, i and the outer peripheral surfaces bf, cf of the connected tubes b, c. Rings m and n are arranged.
When a plurality of bolts k are tightened and the fastening rings g and h are brought close to each other, the rubber packing rings m and n are pressed and pressed against the outer peripheral surfaces bf and cf of the connected pipes b and c. The The rubber-made packing rings m and n are pressed against the outer peripheral surfaces bf and cf of the connected pipes b and c, so that the connected pipes b and c are slidable in the axial direction X. Is done.

In FIG. 2, symbol S is a bolt provided for restricting the movement of the socket tube d.
Refer to FIG. 3 for details of the structure of the region where the fastening rings g, h and the packing rings m, n are arranged on the outer peripheral surfaces (tube surfaces) bf, cf of the connected tubes b, c. It will be described later.

  In the expansion / contraction flexible pipe joint 100 according to the illustrated embodiment, since the socket pipe d and the fastening rings g and h are loosely fitted to the connected pipes b and c, the socket pipe d and the fastening rings g and h, A gap W1 exists between them, and a gap W2 exists between the fastening rings g, h and the connected pipes b, c. Therefore, the connected pipes b and c connected by the expansion / contraction flexible pipe joint 100 are bent in the directions of the arrows M and M with the part where the packing rings m and n are pressed against the pipe surfaces bf and cf as fulcrums. A song is possible. That is, it has flexibility.

  In the expansion / contraction flexible pipe joint 100, the packing rings m and n are pressed against the outer peripheral surfaces bf and cf of the connected pipes b and c by fastening rings g and h, and the connected pipes b and c are axially connected. X is sealed in a slidable state. Therefore, the connected pipes b and c can change the interval L between the pipe ends e and f. That is, the interval L can be shortened until the tube ends e and f abut. On the other hand, if the tube ends e and f are within the range until they reach the vicinity immediately below the packing rings m and n, the interval L can be lengthened while maintaining the sealed state.

Next, referring to FIG. 3, how the fastening rings g and h and the packing rings m and n are arranged on the outer peripheral surfaces (tube surfaces) bf and cf of the connected pipes b and c, explain.
Here, the structure composed of the fastening rings g and h and the packing rings m and n exists in the vicinity of the left and right ends of the socket tube d in FIG. 2, but FIG. 3 shows the structure on the left side of FIG. Only the broken circle O) is shown.

In FIG. 3, the region sandwiched between the fastening ring h, the packing ring n and the socket tube d, more specifically, the right side surface hi of the fastening ring h, the lower side surface hti of the rib ht of the fastening ring h, In a region surrounded by the left side no of the packing ring n and the outer periphery df of the socket ring d, a heat insulating material α made of a heat resistant material is interposed.
The heat insulating material α is entirely formed in an annular shape, and a rib portion αt is formed on the peripheral edge thereof. The radially inner edge (lower edge in FIG. 3) αe of the heat insulating material α is in contact with the outer peripheral surface (tube surface) cf of the connected tube c.
In FIG. 3, the symbol ho indicates the left side surface of the fastening ring h.

The heat insulating material α can be applied as long as it is a material having both heat insulating properties and flexibility that does not cause inconvenience, and can be formed using a known heat insulating material. And it is possible to use asbestos and the gasket material developed as an asbestos substitute.
As the heat insulating material α, for example, a gasket material having a trade name “NON-ASS JOINT SHEET” (product of Nippon Valqua Industries, Ltd .: “NON-ASS” is a registered trademark of Nippon Valqua Industries, Ltd.) can be used.

Here, the thickness dimension of the heat-resistant material α (the X-direction dimension in the portion other than the rib portion αt in FIG. 3) can be arbitrarily determined, and can be in the range of 5 mm to 10 mm, for example.
However, if the thickness dimension of the heat-resistant material α is too small, there is a possibility that sufficient heat insulating performance may not be exhibited. On the other hand, if the dimension in the thickness direction of the heat insulating material α is too large, when the fastening bolt k is tightened to shorten the distance between the tightening rings g and h, the tightening force is equal to the thickness of the heat insulating material α. Since it is absorbed, the sealing performance by the packing rings m and n may be deteriorated.

In other words, the thickness dimension of the heat-resistant material α can be freely set as long as it is within a range that does not adversely affect the sealability and within a range that can exhibit the required heat resistance.
In the experiment conducted by the applicant, the effect was effective when the thickness dimension of the heat-resistant material α was about 3 mm, but the effect was poor at 1 mm.

By interposing the heat insulating material α, the heat (heat transfer) transmitted through the side surface hi of the metal fastening ring h and / or the side surface hti of the rib ht is blocked by the heat insulating material α. Heat (heat transfer) does not act on the packing ring n. Therefore, the packing ring n is prevented from being softened due to heat transfer from the metal fastening ring h.
Further, even if high-temperature air indicated by the arrow TF attempts to enter the packing ring n side through a gap (space W2) between the fastening ring h and the outer peripheral surface (tube surface) cf of the connected pipe c, the heat-resistant material Since the radial edge portion α (lower edge portion in FIG. 3) αe is in contact with the outer peripheral surface (tube surface) cf of the connected pipe c, the high-temperature air TF is also shut off, and the packing ring n is thermally damaged. Is prevented from being given.

Although not shown, it is preferable to use fluorine rubber (FPM rubber) that is not easily softened even at high temperatures as a material for the packing rings m and n (only the packing ring n is shown in FIG. 3). Since the fluoro rubber (FPM rubber) is not easily softened even when exposed to high temperatures, there is no possibility that the packing material softens and flows. Other materials having a high softening point are preferred.
However, even if the packing rings m and n are made of an inexpensive acrylonitrile-butadiene rubber (NBR) to form the heat insulating material α, heat resistance is ensured. By using NBR, it is possible to reduce the manufacturing cost of the pipe joint.
In addition, although fluororubber is hardened | cured by high temperature, such hardening does not raise a technical problem in particular.

  The structure of the heat insulating material is not limited to the structure of the heat insulating material α shown in FIGS. The heat insulating material α1 shown in FIG. 4 may be used, or the heat insulating material β shown in FIG. 5 may be used. Furthermore, as shown in FIGS. 4 and 6, it is possible to use a combination of heat insulating materials having different structures.

  Returning to FIG. 1 and FIG. 2, a region between the cylindrical space having the radius of the outermost periphery of the tightening rings g and h and the outer periphery df of the socket tube d is sandwiched between the tightening rings g and h. A first heat insulating material A is interposed in the region.

As shown in FIG. 1, the first heat insulating material A is divided into the same number as the number of bolts k (eight in the illustrated example) in the circumferential direction. Each block (individual sections divided in the circumferential direction) of the heat insulating material A is connected in a ring shape.
A groove Au extending in the radial direction is formed on the inner peripheral surface of each block of the heat insulating material A, and the coupling bolt k is accommodated in the groove Au. The bolt k is configured to be shielded from high heat.
One block of the heat insulating material A is formed with a convex portion Aa and a concave portion Ab on the end surface in the circumferential direction, and the adjacent blocks engage with each other by the concave and convex portions Ab and Aa, thereby causing a radial shift. It is connected while restraining.

Examples of the heat insulating material A include “Fiber Max” (trade name) 14R board manufactured by ITM Co., Ltd., and “Fine Flex” (trade name) molded product T / # 5420 manufactured by NICHIAS Corporation.
The material of the heat insulating material A is required to have a heat insulating property such that the shaft portion of the bolt k is not damaged by being exposed to a high temperature.

A sheet-like second heat insulating material B is wound around the outer periphery of the heat insulating material A so as to cover the outer periphery of the heat insulating material A.
A thin plate-shaped fixing member C (metal outer ring C) is disposed on the outer periphery of the second heat insulating material B. By tightening with the metal outer ring C, the end in the width direction of the heat insulating material B can be pressure-bonded to the outer peripheral surface of the tightening rings g and h to prevent water from entering.

The second heat insulating material B is also required to have heat insulating properties, but the main purpose of the second heat insulating material B is to exhibit waterproofness or water shielding. Here, since the heat insulating material B is a sheet shape and is wound around the outer periphery of the heat insulating material A, the purpose of waterproofing or water shielding can be achieved.
In addition, the sheet-like heat insulating material B is pressed against the outer peripheral surface of the fastening rings g and h by the metal outer ring C, so that the waterproof property and the water shielding property are further improved.

  2 and 3, a folded portion (flange) Cf is formed at the end in the width direction of the metal outer ring C, and the left and right end faces of the heat insulating material B are formed by the folded portion (flange) Cf. It is configured to be covered. With this configuration, the waterproof property is further enhanced.

  As the material of the second heat insulating material B, a ceramic fiber cloth with a rubber trigger wire is preferable. For example, “Valkertex gasket N314” (trade name) manufactured by Nippon Valqua Industries, Ltd. can be used. However, the material of the heat insulating material B is not limited to this.

The metal outer ring C is preferably made of stainless steel in consideration of rust prevention.
In FIG. 1, a metal outer ring C is formed by forming two stainless steel plates into a semicircular cross section, forming a hinge Ch at one end of each stainless steel plate, and engaging a fixing bolt k2 at the other end. The bracket Cb is attached by welding.
Two stainless steel plates are connected by a hinge Ch, and each stainless steel plate is configured to be rotatable about the hinge Ch.

In the bracket Cb, the metal outer ring C is fixed so as to crimp the second heat insulating material B by tightening with the fixing bolt k2. Here, when tightening with the fixing bolt k2, a bending moment acts in a direction in which the stainless steel plate is separated from the second heat insulating material B. In order to cope with such a bending moment, a plurality of reinforcing ribs Cr are welded across the bracket Cb and the stainless steel plate.
Note that the bracket Cb and the rib Cr may be collectively referred to as a “fixed portion”.

  In FIG. 1, the metal outer ring C is composed of two stainless steel plates, and the two stainless steel plates are connected by a hinge Ch. However, the thickness of the steel plate is larger than the arc radius of the stainless steel plate. Is sufficiently thin, the metal outer ring C is made of one stainless steel plate, and the hinge does not have to be provided. In the illustrated example, the thickness of the stainless steel plate is 1.2 to 1.6 mm.

Further, instead of welding the bracket Cb to the end portion of the stainless steel plate, the other end of the stainless steel plate can be bent at a right angle, and the reinforcing rib Cr can be welded to the side forming the right angle.
Further, instead of the reinforcing rib Cr, a bead may be formed by press forming a stainless steel plate.
Further, the fixing portion can be configured by a so-called “binding mechanism”. As the binding mechanism, for example, a well-known mechanism employed in ski equipment can be applied as it is.

In FIG. 1, for example, a stainless steel thin plate D is disposed on the outer peripheral surface of the heat insulating material B and in a region including both end portions Be of the metal outer ring C.
The stainless steel thin plate D covers a gap (see reference numeral δ in FIG. 12) generated at the end of the metal outer ring C and prevents the heat insulating material B from being directly exposed to a high temperature.

Next, a method for assembling the pipe joint according to the illustrated embodiment will be described based on FIGS.
First, in the process shown in FIG. 7, the fastening rings h and g, the heat insulating material α, and the packing rings n and m are set in the vicinity of the pipe end portion of each of the connected pipes c and b, and the connected pipe c , B are inserted into both ends of the socket tube d.
Then, the coupling bolt k is inserted into the fastening rings h and g and fastened.
FIG. 7 shows a state in which the fastening rings h and g are omitted. In FIG. 8, it is for illustrating the state which surrounds the volt | bolt k with the heat insulating material A. In FIG.

In the step shown in FIG. 8, each block of the heat insulating material A is moved inward in the radial direction, and the bolt k is inserted into the groove Au. At the same time, adjacent blocks of the heat insulating material A are connected. When connecting the blocks of the heat insulating material A, the concave portion Ab and the convex portion Aa on the circumferential end surface are engaged. Accordingly, the heat insulating material A is mounted on the outer peripheral portion df of the socket tube d in a state where the bolt k is surrounded by the heat insulating material A.
FIG. 9 illustrates a state where the heat insulating material A is mounted without omitting the fastening rings h and g, and the mounted heat insulating material A is indicated by a dotted line.

In the process shown in FIG. 10, the sheet-like heat insulating material B is wound around the outer periphery of the heat insulating material A. Then, a stainless steel thin plate D is placed on the outer peripheral surface of the heat insulating material B in the region including both end portions Be in the sheet-shaped heat insulating material B that has been wound.
10 and 11, the tightening rings h and g are omitted as in FIGS. 7 and 8.
In the step shown in FIG. 11, the metal outer ring C is attached. In FIG. 11, the hinge Ch of the metal outer ring C is arranged at a position opposite to the position where the stainless steel thin plate D is placed (in FIG. 11, a position symmetrical with respect to the center of curvature of the heat insulating material B). And the metal outer ring C is crimped | bonded to the outer peripheral surface of the sheet-like heat insulating material B, making the bracket Cb of the metal outer ring C which opposes approach (moving to the arrow Y direction).

In the step shown in FIG. 12, the fixing bolt k2 is inserted into the opposing bracket Cb of the metal outer ring C and is tightened by the nut N. Thus, the assembly of the pipe joint 100 is completed.
Even if both ends of the metal outer ring C are tightened with an appropriate tightening torque, a gap δ is formed. However, since the stainless steel thin plate D covers the gap δ, it is possible to secure a state where the heat insulating materials B and A are shielded from the outside air.

According to the pipe joint 100 according to the illustrated first embodiment, the heat insulating material A that surrounds the plurality of connecting bolts k, and the heat insulating material that is disposed on the outer peripheral surface of the heat insulating material A and has a water shielding property and a heat insulating property. Since it has the metal outer ring C which is arrange | positioned at the outer peripheral part of the material B and the heat insulating material B, and presses the heat insulating material B to the heat insulating material A side, even if a great amount of heat acts on a pipe joint By the heat insulating material A, the heat insulating material B, and the metal outer ring C, the amount of heat transmitted to the fastening bolt k is extremely reduced.
Therefore, even if a large amount of heat acts on the pipe joint, the connecting bolt k does not reach the plastic region, and the connecting bolt k undergoes plastic deformation (plastic elongation) due to the tensile force acting when fastened with the nut. Is prevented.
Therefore, the tensile force acting on the coupling bolt k, that is, the tightening force acting on the packing rings m and n, does not decrease, the leakage of the fluid flowing in the connected pipes b and c is prevented, and the sealing performance of the pipe joint is maintained. I can do it.

Here, the portion where the bolt head and the nut of the tightening bolt k mesh with each other is not covered with the heat insulating material A, the heat insulating material B, and the metal outer ring C, and is exposed. It is not necessary to remove the heat insulating material A, the heat insulating material B, and the plate-shaped metal outer ring C when adjusting the tightening force (tightening, etc.) or checking for leakage of internal fluid during maintenance of the pipe joint.
Therefore, even if the fire resistance and heat resistance are improved, the original function as a pipe joint is not impaired, and maintenance is facilitated.

  Furthermore, according to the pipe joint 100, the fire resistance and heat resistance of the existing pipe joint can be improved without requiring a complicated apparatus or an expensive apparatus.

Next, a second embodiment will be described with reference to FIGS.
The pipe joint 100 according to the first embodiment shown in FIGS. 1 to 12 includes a metal outer ring C and a heat insulating material B whose axial direction (X direction) length is the outer circumference of the opposing fastening rings g and h, and This is the minimum length necessary to cover the heat insulating material A.
On the other hand, in the pipe joint 102 according to the second embodiment shown in FIGS. 13 and 14, the axial direction (X direction) length of the metal outer ring C is longer than that in the first embodiment. .

More specifically, as shown in FIGS. 13 and 14, both ends in the axial direction of the metal outer ring C are axially outward (see FIG. 13) by a predetermined amount β or more from both ends in the axial direction of the coupling bolt k. In FIG. 14, it extends in the left-right direction, and in FIG. Here, the predetermined amount β is a numerical value of, for example, 50 mm or more.
Further, in the second embodiment shown in FIGS. 13 and 14, the length in the axial direction (X direction) of the heat insulating material B is extended as compared with the first embodiment, and the axial direction is longer than both ends of the coupling bolt k. It protrudes outward (left and right in FIG. 13 and left in FIG. 14).

In the first embodiment of FIGS. 1 to 12, the flame directed from the axially outer side (left and right direction in FIG. 13 and left side in FIG. 14) toward the pipe joint 100 is the radial direction of the heat insulating material B and the metal outer ring C. There is a case where the connecting bolt k and the tightening rings g and h are directly exposed to the flame by wrapping inward.
If the connecting bolt k and the fastening rings g and h are directly exposed to the flame, the extension of the connecting bolt k due to thermal expansion becomes large. Then, when the temperature of the coupling bolt k and the fastening rings g and h rises significantly, and high temperature is transmitted to the packing rings m and n, such a high temperature causes adverse effects such as fluid leakage.

On the other hand, according to the pipe joint 102 of the second embodiment shown in FIGS. 13 and 14, both end portions in the axial direction of the metal outer ring C are respectively separated by a predetermined distance β from both end portions in the axial direction of the coupling bolt k. (For example, 50 mm) or more, extending axially outward (left-right direction in FIG. 13, leftward in FIG. 14), by both axial ends of the metal outer ring C extending outward in the axial direction, A flame that attempts to wrap inward in the radial direction is prevented from reaching the connecting bolt k and the fastening rings g and h. Alternatively, even if the flame that wraps inward in the radial direction reaches the connecting bolt k and the fastening rings g and h, the temperature decreases by 150 ° C. to 200 ° C.
As a result, the connecting bolt k and the fastening rings g and h are prevented from being directly exposed to the flame, or high heat is prevented from acting on the connecting bolt k. Is suppressed.

Further, since the connecting bolt k and the fastening rings g and h are not directly exposed to the flame or the temperature of the flame is lowered, the temperature rise in the connecting bolt k and the fastening rings g and h is suppressed, and the packing It is possible to prevent adverse effects due to high heat transmitted to the rings m and n. And since the temperature rise of the fastening rings g and h decreases, the leakage of the fluid from the packing rings m and n is prevented.
In addition to this, in the second embodiment of FIGS. 13 and 14, the heat insulating material B also has its axial length extended, and both end portions of the heat insulating material B in the axial direction are both ends of the coupling bolt k. 13 protrudes outward in the axial direction (left and right in FIG. 13 and left in FIG. 14), so that the flame that tries to wrap inward in the radial direction together with both ends of the metal outer ring C in the axial direction , So that it is difficult to reach the connecting bolt k and the fastening rings g and h.
Other configurations and operational effects in the second embodiment shown in FIGS. 13 and 14 are the same as those in the first embodiment shown in FIGS.

FIG. 15 shows a pipe joint 103 according to the third embodiment of the present invention.
The third embodiment in FIG. 15 has a configuration in which the heat insulating material A is omitted from the second embodiment in FIGS. 13 and 14.
As described in the second embodiment of FIGS. 13 and 14, both axial ends of the metal outer ring C are axially extended by a predetermined distance β (for example, 50 mm) from the axial ends of the connecting bolt k. It extends outward (left and right in FIG. 13 and left in FIG. 14), and both axial ends of the heat insulating material B are axially outward (left and right in FIG. 13) from both ends of the coupling bolt k. If it protrudes to the left in FIG. 14, the flame that has entered inward in the radial direction is prevented from reaching the connecting bolt k and the fastening rings g and h, or the temperature of the flame is lowered.

According to the inventor's research, as in the case of the second embodiment of FIGS. 13 and 14, the flame that wraps inward in the radial direction is inhibited from reaching the coupling bolt k and the fastening rings g and h. If the temperature of the flame is lowered, even if the heat insulating material A is omitted, the influence on the inside of the pipe joint is small.
The third embodiment in FIG. 15 is based on such knowledge.

According to the pipe joint 103 according to the third embodiment of FIG. 15, the heat insulating material A is omitted. Therefore, the number of components is reduced, and the step of incorporating the heat insulating material A is not necessary, thereby reducing the number of assembly steps. As a result, the manufacturing cost can be reduced.
Other configurations and operational effects in the third embodiment in FIG. 15 are the same as those in the second embodiment in FIGS. 13 and 14.

  It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.

The front view explaining the structure of 1st Embodiment of this invention. FIG. 3 is a partial cross-sectional side view corresponding to FIG. The principal part enlarged view of FIG. The figure which showed arrangement | positioning of the heat insulating material different from FIG. The figure which showed arrangement | positioning of the heat insulating material different from FIG. 3, FIG. The figure which showed arrangement | positioning of the heat insulating material which combined FIG. 3 and FIG. Process drawing which assembles the pipe joint which concerns on embodiment. The figure which shows the process of continuing in FIG. The figure which shows the state which completed the process of FIG. The figure which shows the process which continues in FIGS. The figure which shows the process which continues in FIGS. The figure which shows the process which continues in FIGS. The side view explaining the structure of 2nd Embodiment of this invention. The elements on larger scale of FIG. The fragmentary sectional side view explaining the structure of 3rd Embodiment of this invention. Sectional drawing of the pipe joint regarding a prior art.

Explanation of symbols

A ... 1st heat insulating material B ... 2nd heat insulating material C ... Metal outer ring D ... Thin plate b, c ... Connected pipe d ... Socket pipe g, h. ..Clamping ring k ... Binding bolt m, n ... Packing ring

Claims (6)

  The socket pipe (d) loosely fitted to the connected pipe (b, c) is disposed across the opposing pipe ends (e, f) of the connected pipe (b, c), and the connected pipe (b, c) ) Are fitted on both sides of the socket tube (d), and the fastening rings (g, h) are coupled by a plurality of coupling bolts (k) to form a socket. Packing rings (m, n) are sandwiched between the inner surfaces (j, i) at both ends of the pipe (d) and the outer peripheral surfaces (bf, cf) of the pipes (b, c) to be connected. , N) are brought into pressure contact with the outer peripheral surfaces (bf, cf) of the connected pipes (b, c) by the tightening rings (g, h), and the connected pipes (b, c) are slid in the axial direction (X). It is configured to be movably sealed, and a heat insulating means (α) is interposed in a region between the tightening ring (g, h) and the packing ring (m, n). Wrap the connecting bolt (k) A heat insulating material (A), a coating layer (B) made of a material having a water shielding property and a heat insulating property arranged on the outer peripheral surface of the heat insulating material (A), and an outer peripheral portion of the coating layer (B); It has a plate-shaped fixing member (metal outer ring C) that presses the coating layer (B) toward the heat insulating material (A), and the heat insulating material (A) is formed of the coupling bolt (k) in the circumferential direction. The pipe joint is divided into the same number of sections, and a groove (Au) for receiving the coupling bolt (k) is formed in each section.   The plate-like fixing member (C) has a hinge part (Ch), and has a function of changing the radius of curvature by changing the bending angle of the hinge part (Ch). Fixing portions (Cb) are provided at the circumferential ends of the plate-like fixing member (C), and fixing portions (Cb) at both ends in the circumferential direction of the plate-like fixing member (C). The pipe joint of Claim 1 which has a function which presses and fixes the said coating layer (B) to the heat insulating material (A) side by couple | bonding together.   The pipe joint according to claim 1 or 2, wherein the same number of sections as the number of coupling bolts (k) constituting the heat insulating material (A) have the same shape.   The plate-like fixing member (C) has axially opposite ends extending axially outward from the axially opposite ends of the coupling bolt (k) by a predetermined distance (β). Pipe fittings.   The socket pipe (d) loosely fitted to the connected pipe (b, c) is disposed across the opposing pipe ends (e, f) of the connected pipe (b, c), and the connected pipe (b, c) ) Are fitted on both sides of the socket tube (d), and the fastening rings (g, h) are coupled by a plurality of coupling bolts (k) to form a socket. Packing rings (m, n) are sandwiched between the inner surfaces (j, i) at both ends of the pipe (d) and the outer peripheral surfaces (bf, cf) of the pipes (b, c) to be connected. , N) are brought into pressure contact with the outer peripheral surfaces (bf, cf) of the connected pipes (b, c) by the tightening rings (g, h), and the connected pipes (b, c) are slid in the axial direction (X). It is configured to be movably sealed, and a heat insulating means (α) is interposed in a region between the fastening ring (g, h) and the packing ring (m, n). The outer peripheral surface of the ring (g, h) A coating layer (B) made of a material having a water-blocking property and a heat-insulating property, and a coating layer (B) arranged on the outer peripheral portion of the coating layer (B) and moving the coating layer (B) to the fastening ring (g, h) side A plate-shaped fixing member (C) to be pressed, and both ends of the fixing member (C) are axially outward at a predetermined distance (β) or more from both axial ends of the coupling bolt (k). A pipe joint characterized by extending to   The axial length of the heat insulating material (B) is extended so that both axial end portions of the heat insulating material protrude outward in the axial direction from both end portions of the coupling bolt (k). 5 pipe fittings.

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