JP3385393B2 - Water leak detection type flexible pipe joint - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water leak detection type flexible pipe joint, and more particularly, to cracks and the like from the pipe peripheral wall of the flexible pipe joint. The present invention relates to a flexible pipe joint which can be detected early and reliably. 2. Description of the Related Art Conventionally, in a water pipe such as a drain pipe, a relatively short length is used for a bent portion or a rising portion on the ground or in the ground, or a connection portion to various devices or equipment. A flange joint type flexible pipe joint is used. Such a flexible pipe joint has a pipe peripheral wall and flanges integrally provided at both ends thereof, which are made of an elastic flexible material such as synthetic rubber or plastic material. . The flange portion is sandwiched between a flange on the connected pipe side and a companion flange provided separately therefrom to be flange-coupled. Generally, a reinforcing layer such as a tire cord or a spiral metal wire is buried in a flexible pipe joint at a pipe peripheral wall portion for reinforcement, and a pipe peripheral wall portion is provided to enhance flexibility of the flexible pipe joint. Are formed in a bellows shape. However, a flexible pipe joint made of a flexible material such as synthetic rubber as described above is liable to cause deterioration such as corrosion or cracks in the peripheral wall of the pipe over a long period of use, and the fluid flowing inside is a corrosive liquid. In hot water or hot water, the tendency is remarkable. Such corrosion and cracking of the peripheral wall of the pipe gradually progresses, eventually leading to water leakage. However, if left unattended, the surrounding equipment and facilities may be seriously damaged. [0003] In order to solve such a problem in the flexible pipe joint, various water leak detection methods or devices have been conventionally proposed. As a method for detecting water leakage when a conductive liquid such as water flows inside, two conductors are run along the surface of the peripheral wall of the flexible pipe joint, and the ends of the conductors are connected to an alarm device. In addition, there has been proposed a device that operates an alarm device by conduction between conductive wires due to water leakage. [0004] However, in the above method,
There is a problem that detection cannot be performed until water leakage reaches the surface of the pipe peripheral wall portion, and there is no time allowance for repair or replacement of the flexible pipe joint. In addition, since the bare conductor runs along the surface of the peripheral wall of the flexible pipe joint, the conductor itself is susceptible to corrosion and damage, and there is a problem that reliability is low. Therefore, in order to solve such a problem, the present applicant buried a conductive layer such as a tube inside the pipe peripheral wall portion of the flexible pipe joint, and extended the end portion into the flange portion as a companion flange. A water leak detection type flexible pipe joint exposed to the contact surface of the above was proposed earlier. (Japanese Patent Application No. 6-052828) The water leak detection type flexible pipe joint proposed above is used when deterioration such as cracks progresses from the inside to the position of the conductor buried along the pipe peripheral wall. The conductor and the internal liquid are electrically connected to each other by using the liquid slightly oozing through the crack as a medium. Therefore, a lead wire is connected to a metal pipe which is a pipe to be connected to a flexible pipe joint, and conduction between the lead pipe and a companion flange which is in contact with an exposed portion of the conductor is detected by an appropriate detection device. Thus, the progress of deterioration such as cracks can be detected at an early stage. In addition, since the conductor is embedded in the peripheral wall of the tube, there is an effect that the problem of corrosion and damage of the conductor itself does not occur. However, even with such a water leak detection type flexible pipe joint, crack detection requires the progress of cracks from the inside to the position of the conductor buried along the pipe peripheral wall. If a crack or the like can be detected at the very beginning when a crack or the like has occurred, the time margin before water leakage can be extended, thereby facilitating the planning of repair and replacement. Therefore, an object of the present invention is to improve the water leak detection type flexible pipe joint previously proposed, and to be able to detect cracks and the like earlier and more reliably. That is, a flexible pipe joint for detecting water leakage according to the present invention has flanges at both ends of a pipe peripheral wall (2).
(3) are provided integrally, and the front end surface (3a) and rear end surface (3b) of the flange portion (3) in the axial direction are respectively provided on the flange on the connected pipe (4) side and the companion flange (9). Pressed and flanged to connect to a conduit through which conductive liquid flows
In flexible pipe joint (1) being a flange at both ends from the tube peripheral wall (2) applied to (3), in the thickness of the tube
A fibrous inner reinforcing layer (19a) is buried on the inner side of the pipe from the core.
And a fibrous outer reinforcing layer (19b) near the outer surface of the tube.
Is buried and along the rising part of the flange (3).
Also embedded flange portion reinforcing layer of the fibrous (19c) is I, along the pipe peripheral wall (2), the tube inner surface side of the inner
On the inner surface side of the pipe further than the side reinforcing layer (19a), the inner circumferential surface of the pipe
Not to be exposed over its entire length, and
Stand up outside the flange reinforcement layer (19c) and
<br/> conductor layer a U-turn so as to bypass the flange portion reinforcing layer (19c) (20) are embedded, ends the <br/> flange portion of the electrically conductor layer (20) (3 ) Only at the contact surface with the companion flange (9)
Is exposed to, and the phase flange (9), the dew on the pipe inner surface
Water leak detection means is provided between the exposed conductor . In the flexible pipe joint of the present invention,
As in the case of Japanese Patent Application No. 6-052828 previously proposed by the present applicant, when deterioration such as a crack progresses from the inside to the position of the conductor layer buried along the peripheral wall of the tube, the crack is slightly passed through the crack. The conductive layer and the internal liquid are electrically connected to each other using the oozing liquid as a medium. However, in the water leakage detection type flexible pipe joint according to the present invention, since the conductor layer is buried inside the pipe from the reinforcing layer along the pipe peripheral wall, the occurrence of cracks or the like in the pipe peripheral wall can be detected earlier and more reliably. it can. Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing a state in which an example of a water leakage detection type flexible pipe joint of the present invention is used in a piping system, and FIG. 2 is a perspective view showing the flexible pipe joint portion. FIG. 3 is a partially enlarged sectional view of FIG. In these figures, a flexible pipe joint 1 has a pipe peripheral wall portion 2 formed in a bellows shape, and flange portions 3 integrally provided at both ends thereof, which are made of synthetic rubber or the like. It is made from an electrically insulating and flexible material by molding or the like. The tube peripheral wall 2 may be formed in a straight cylindrical shape instead of in a bellows shape. Reference numeral 4 denotes a metal connection pipe, and reference numeral 5 denotes a flange thereof. An electrically insulating lining layer 6 such as rubber is formed on the inner peripheral surface of the connected pipe 4. An annular insulating plate 7 such as a rubber plate, which is electrically insulating, is disposed on the distal end surface of the flange 5, and a metallic annular conductive plate 8 is arranged on the surface of the insulating plate 7. The distal end surface 3 of the flange portion 3 of the flexible pipe joint 1
a is in contact with the conductive plate 8, and the rear end face 3b is in contact with a conductive companion flange 9 made of metal or the like. Then, an electrically insulating insulating bolt 11 is inserted into a bolt hole provided in the flange 5, the insulating plate 7 and the conductive plate 8, and a bolt hole 10 provided corresponding to the companion flange 9. It is clamped, pressed and fastened. An insulating spacer 14 having an electrically insulating, externally threaded shaft portion and an enlarged head is screwed into a plurality of small bolt holes 13 having internal threads provided at appropriate positions on the companion flange 9. Thereby, the space between the conductive plate 8 and the companion flange 9 is maintained in parallel at a predetermined interval. FIG. 4 is a partially enlarged sectional view showing a state in which the flange 5, the insulating plate 7, the conductive plate 8 and the companion flange 9 are fastened by the insulating bolt 11 and the nut 12. In FIG. 1 and FIG. 2, a lead is provided between a terminal 15 attached to a screw hole provided on the outer peripheral surface of the companion flange 9 and a terminal attached to a screw hole similarly provided on the outer periphery of the conductive plate 8. Power supply 1 such as line 16 and storage battery
An alarm 18, for example a buzzer, a lamp or a relay means, is connected via 7. The relay means is used for driving alarm means such as a buzzer provided on a remote control panel. By providing the alarms 18 and the like on both of the companion flanges 9 as described above, even if one of the alarm circuits or the like fails, the other can make up for it. However, depending on the case, one of them may be omitted. The insulating bolt 11 and the insulating spacer 14 may be made of a plastic material itself, or may be a metal material having an electrically insulating coating formed on the surface. A plurality of reinforcing layers 19, such as tire cords formed by weaving nylon or polyester fibers, are buried from the pipe peripheral wall 2 to the flanges at both ends thereof. Conductor layer 2 inside
0 is buried. As shown in FIG. 3, the reinforcing layer 19 includes an inner reinforcing layer 19a embedded along the radially inner side of the pipe peripheral wall portion 2 and an outer reinforcing layer 19b embedded parallel to the outer side in a radial direction at a predetermined interval. And a pair of flange reinforcing layers 19c circulating around both flanges 3
To form a loop. On both surfaces of the reinforcing layer 19, an intermediate layer 21 made of, for example, rubber is provided for the purpose of enhancing the reinforcing effect. The conductor layer 20 buried inside the tube from the reinforcing layer 19 in the tube peripheral wall portion 2 is buried along the tip surface 3a side of the reinforcing layer 19 in the flange portion 3, and the end portion thereof is connected to the companion flange 9. Is exposed on the contact surface. That is, the conductor layer 20 is extended in a loop shape so as to orbit around the flange portion reinforcing layer 19c in the flange portion 3, and then extends in the rear end face 3b of the flange portion 3 and further horizontally from the tube peripheral wall portion. Extended to the surface of 2,
It is exposed at the contact surface between the side surface of the companion flange 9 and a part of the inner peripheral surface. Note that an annular ring 22 made of, for example, metal or a fiber aggregate is embedded in the flange portion 3 in order to further enhance the reinforcement if desired. FIG. 5 is a front view partially showing an example of the conductor layer 20, and FIG. 6 is a partially enlarged perspective view of a weft fiber 20a constituting the conductor layer 20. In these figures, a conductor layer 20 has a large number of conductive transverse fibers 20a such as, for example, carbon fibers or metal fibers, which are arranged at predetermined intervals in the horizontal direction, and at predetermined intervals in the vertical direction intersecting the horizontal fibers 20a. It is composed of a large number of longitudinal fibers 20b made of ordinary synthetic fibers such as nylon yarns arranged in a woven fabric. In addition, at least a part or all of the vertical fibers 20b may be conductive fibers to provide conductivity with the horizontal fibers 20a. The conductive weft fiber 20a may be formed by twisting a plurality of carbon fibers or metal fibers. However, as shown in FIG. It can also be configured by twisting with a reinforcing fiber 20d made of a synthetic fiber. The conductor layer 20 is not limited to the one woven in the form of a drip as shown in FIG. 5, but may be a woven fabric such as a plain weave or a non-woven fabric. The conductor layer 20 configured as described above is formed in a tubular shape, and is buried inside the tube from the reinforcing layer 19 along the tube peripheral wall portion 2 as shown in FIG. It is folded back and embedded in the flange portion 3. The tube peripheral wall portion 2 and the flange portion 3 in which the reinforcing layer 19 and the conductor layer 20 are embedded can be integrally formed by a method usually employed in this field, for example, insert molding. In order to flange-connect the above-mentioned flexible pipe joint 1 to the pipe 4 to be connected as shown in FIG.
c, and the insulating bolts 1 with the insulating plate 7 and the conductive plate 8 interposed between the flange 5 and the companion flange 9 of the pipe 4 to be connected.
1 and the nut 12. Thereby, the end of the conductive layer 20 exposed on the rear end face 3 b of the flange 3 is pressed against the companion flange 9. In addition, a flexible pipe joint 1
The flange portion 3 and the companion flange 9 may be bonded in advance by means such as bonding, and the insulating plate 7 and the conductive plate 8 may be fastened to the companion flange 9 by insulating bolts 11 and nuts 12. In the case where the insulating lining layer 6 is not provided on the inner peripheral surface of the connected pipe 4, that is, the inner peripheral surface of the metal pipe constituting the connected pipe 4 is electrically contacted with the liquid flowing therein. In this case, the insulating plate 7 and the conductive plate 8 are not used,
It is only necessary to connect one end of the lead wire 16 to the connected pipe 4. Next, the operation of the flexible pipe joint 1 will be described. FIG.
For example, when a crack is formed in the pipe peripheral wall portion 2 of the flexible pipe joint 1, the internal liquid reaches the conductor layer 20 through the gap of the crack, and the companion flange 9-the conductor layer 20-the internal liquid- Conductive plate 8-Lead wire 16-Power supply 17-Alarm 1
An electrical closed circuit is created by the 8-lead wire 16, which activates the alarm 18 and issues an alarm. At this time, the conductor layer 20 on the tube peripheral wall portion 2
Is buried along the inside of the pipe from the reinforcing layer 19, particularly the inner reinforcing layer 19a near the inner circumferential surface of the pipe peripheral wall portion 2, so that the distance from the inner circumferential surface of the pipe to the conductor layer 20 becomes a small distance, so that the initial cracks Can be reliably detected. Further, by connecting an electric insulation meter such as a mega or a resistance measuring device instead of the alarm device 18, even if a slight crack is generated, it can be detected by a decrease in the resistance value. Therefore, the flexible pipe joint 1 of the present invention can perform preventive maintenance. It should be noted that such an electric insulation meter or resistance measuring instrument and the alarm 18 can be switched by switching means such as a switch. Further, as in the above example, the conductor layer 20 is buried in the flange portion 3 along the tip surface 3a side from the reinforcing layer 19 buried in the flange portion 3, and the end portion is brought into contact with the companion flange 9 in the flange portion 3. Exposure to the surface makes it possible to detect at an early stage the occurrence of a crack on the tip end surface 3a side of the flange portion 3 where a crack or the like is likely to occur. FIG. 7 is a partially enlarged sectional view showing another embodiment of the present invention. This example is different from the example shown in FIG. 1 (and FIG. 3) in that an annular groove 23 is formed in the rear end face 3b of the flange portion 3 of the flexible pipe joint 1, and the end of the conductive layer 20 is further formed. Except for being exposed along the groove 23, the other configuration is the same. (The center of the flange portion 3 is embedded with a ring formed by bundling reinforcing materials such as metal wires 24 for the same purpose as the ring 22 shown in FIG. 3). As the companion flange 9 (not shown) to be used, one having an annular projection adapted to the groove 23 is used. With such a configuration, the flange connection can be more reliably stabilized. The present invention has the above-described structure,
For example, when a crack progresses from the inside to the position of the conductor layer 20 buried along the pipe peripheral wall portion 2, the conductor layer 20 and the internal liquid are electrically connected to each other by using a medium slightly oozing through the crack as a medium. Conduct. Therefore, by detecting the conduction between the companion flange 9 contacting the exposed portion of the conductor layer 20 and the internal liquid with a suitable alarm 18, the progress of the crack can be detected at an early stage. At this time, since the conductor layer 20 in the tube peripheral wall 2 is embedded along the inside of the tube from the reinforcing layer 19, particularly the inner reinforcing layer 19a near the inner peripheral surface of the tube peripheral wall 2, the conductor layer 20 The distance to the layer 20 is a small distance, so that the initial stage of the crack can be reliably detected. In addition, by connecting an electric insulation meter or resistance measuring device such as a mega in place of the alarm device 18, even when a slight crack is generated, it can be reliably detected. Therefore, the flexible pipe joint 1 of the present invention can perform preventive maintenance. Further, since the conductor layer 20 is buried in the tube peripheral wall portion 2, there is no problem of corrosion or damage of the conductor layer 20 itself.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing a state in which an example of a water leakage detection type flexible pipe joint of the present invention is used in a piping system. FIG. 2 is a perspective view showing a flexible pipe joint part of FIG. 1; FIG. 3 is a partially enlarged sectional view of FIG. 1; FIG. 4 shows a flange 5, an insulating plate 7, and a conductive plate 8 in FIG.
FIG. 4 is a partially enlarged cross-sectional view showing a state in which the companion flange 9 is fastened with an insulating bolt 11 and a nut 12. FIG. 5 is a front view partially showing an example of a conductor layer 20 in FIG. 1; 6 is a weft fiber 2 constituting the conductor layer 20 in FIG.
FIG. 4 is a partially enlarged perspective view showing an example of Oa. FIG. 7 is a partially enlarged cross-sectional view showing another example of the water leakage detection type flexible pipe joint of the present invention. [Description of Signs] 1 Flexible pipe joint 2 Pipe peripheral wall 3 Flange 3a Front end 3b Rear end 3c Flange 4 Connected pipe 5 Flange 6 Insulating lining layer 7 Insulating plate 8 Conductive plate 9 Compatible flange 10 Bolt hole 11 Insulation Bolt 12 Nut 13 Small bolt hole 14 Insulating spacer 15 Terminal 16 Lead wire 17 Power supply 18 Alarm 19 Reinforcing layer 19a Inner reinforcing layer 19b Outer reinforcing layer 19c Flange reinforcing layer 20 Conductor layer 20a Horizontal fiber 20b Vertical fiber 20c Conductivity Fiber 20d Reinforcing fiber 21 Intermediate layer 22 Annular ring 23 Groove 24 Metal wire

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01M 3/16 F16L 55/00 G01M 3/04

Claims (1)

(57) [Claims] [Claim 1] Flanges (3) are integrally provided at both ends of a pipe peripheral wall (2), and axial end surfaces (3a) of the flanges (3) are provided. And the rear end face (3b) are pressed against the flange on the connected pipe (4) side and the flange on the companion flange (9), respectively, and are flanged and connected to a conduit through which the conductive liquid flows. <Br / In the flexible pipe joint (1), from the pipe peripheral wall (2) to the flanges (3) at both ends thereof, a fibrous inner side is provided on the inner side of the pipe from the center of the thickness of the pipe. Supplement
The strong layer (19a) is buried and the fiber
Outer reinforcing layer (19b) is embedded and its flange
Even along the rising part of (3), the fibrous flange
A strong layer (19c) is buried, and along the pipe peripheral wall (2), the inner supplementary surface on the inner surface side of the pipe is provided.
On the inner surface side of the pipe further than the strong layer (19a),
So that it is not exposed over its entire length, and
Stand up outside the reinforcement layer (19c) and
Conductor layer a U-turn so as to bypass Nji portion reinforcing layer (19c) (20) is embedded, the electrically conductor layer and the end portion is the flange portion (20) (3) mating flange in (9) Exposed only on the contact surface of the conductor, the companion flange (9) and the conductive exposed on the inner surface of the conduit.
A water leak detection type flexible pipe joint , wherein water leak detection means is provided between the body and the body .