JP2018173286A - Insulation inspection jig and insulation inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a jig and method for performing an insulation inspection of a piping member having an insulation coating layer.SOLUTION: Provided are an insulation inspection jig of a piping member and an insulation inspection method. The insulation inspection jig consists of a material having elasticity and conductivity such as a conductive rubber, and includes piping member mounting parts 11 that can tightly adhere onto a front surface of an insulation coating layer 316 while applying pressurization force. The insulation inspection method includes a process for applying a voltage between a current-carrying part formed in the piping member and the insulation inspection jig so as to confirm electric continuity between the piping member and the insulation inspection jig.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an insulation inspection jig and an insulation inspection method using the same, which are applied to an insulation inspection of a piping member used for piping of gas or water. The piping member to which the present invention is applied includes, for example, an insulating universal joint that is assembled to a gas meter support device used for mounting a gas meter.

  Conventionally, when installing a gas meter in a detached house or an apartment house, for example, a gas meter unit (hereinafter referred to as a gas meter support device) as described in Patent Document 1 has been used. As shown in FIG. 6, the gas meter M (not shown) includes a gas supply pipe P <b> 1 (hereinafter referred to as a supply pipe) made of a steel pipe raised from the ground to the ground, and an indoor gas that draws the gas indoors. It installs via the gas meter support apparatus 10 between the pipes P2. In such a gas pipe, when any part of the indoor gas pipe P2 side with respect to the gas meter support device 10 is electrically connected to the reinforcing bar in the concrete of the building, the reinforcing bar in the concrete and the underground A large circuit in which a corrosion current flows is formed due to a potential difference with the supply pipe P1, and the underground supply pipe P1 may be corroded. Therefore, in the gas meter support device 10, as shown in FIGS. 6 and 7, a rotatable insulating universal joint 30 (corresponding to the piping member in the present invention) is provided at the end of the inlet pipe 20 to which the supply pipe P1 is connected. Thus, a structure that is electrically insulated from the supply pipe P1 is employed. In this way, by electrically insulating the gas meter support device 10 and the supply pipe P1, it is possible to prevent a corrosion current from flowing into the supply pipe P1, and to prevent the underground supply pipe P1 from corroding.

  Further, in Patent Document 1, a member having a function of being connected to the inlet pipe 20 rotatably and a member having a function of connecting the supply pipe P1 are provided independently so that the two members are electrically insulated from each other. It is composed of an insulating universal joint with a structure assembled in the following (hereinafter referred to as a “multi-member structure”) and a single member having both functions. ) Is described (hereinafter referred to as a single member structure). Here, the insulating universal joint 30 in FIGS. 6 and 7 is an insulating universal joint having a single member structure.

  By the way, an insulation test is performed in the process of manufacturing the gas meter support device in which such an insulating universal joint is assembled in order to confirm whether a desired insulation performance is obtained. The method of insulation inspection varies depending on the type of insulation universal joint.

  In the case of an insulating universal joint having a multi-member structure, a voltage is applied between both members assembled so as to insulate, and an electrical resistance is measured to confirm whether the insulation is made. Thus, before the inlet pipe and the insulating universal joint are assembled, the insulation inspection can be performed in a state where the insulating universal joint is alone. On the other hand, in the case of an insulating universal joint having a single member structure, since it is composed of a single member, the insulation inspection cannot be performed with the insulating universal joint alone. Therefore, after the insulative universal joint 30 and the inlet pipe 20 are assembled as shown in FIG. 7, a voltage is applied between the inlet pipe 20 and the insulating universal joint 30 to measure the electrical resistance value, whereby the inlet pipe 20 and the inlet pipe 20 are insulated. It is confirmed whether or not the joint 30 is electrically insulated. Thus, the risk of shipping a gas meter support device with poor insulation can be reduced by conducting an insulation test on the insulated universal joint.

JP 2014-182068 A

  However, as described above, the insulation universal joint 30 having the single member structure shown in FIGS. 6 and 7 can be inspected only after the insulation universal joint 30 and the inlet pipe 20 are assembled. The insulating universal joint 30 has a structure that cannot be easily disassembled once the insulating universal joint 30 and the inlet pipe 20 are assembled. Therefore, when an insulation failure is found in the insulation inspection, not only the insulating universal joint 30 but also the good inlet pipe 20 must be disposed of together, which is not economical. In addition, in this insulation inspection method, if a gap is generated between the insulating universal joint 30 and the inlet pipe 20 when the insulation inspection is performed, the insulating coating of the insulating universal joint 30 has a defect such as a scratch. However, it is conceivable that the insulating universal joint and the inlet pipe are not conducted and are judged as non-defective products.

  The present invention has been made in view of the above-mentioned problems, and an insulation inspection jig and an insulation inspection method capable of performing insulation inspection independently and reliably for a piping member having an insulating coating layer. The purpose is to provide.

  In order to achieve the above object, the present invention is an insulation inspection jig used for insulation inspection of a piping member having an insulating coating layer, made of a material having elasticity and conductivity, and formed on the piping member The gist of the invention is to have a piping member mounting portion that can be in close contact with the surface of the insulating coating layer while applying a pressing force.

  The present invention also relates to an insulation inspection method for a piping member having an insulating coating layer, the step of preparing the insulation inspection jig, the step of mounting the piping member on the insulation inspection jig, and the piping member. The present invention includes a step of applying a voltage between the formed energization part and the insulation inspection jig and confirming conduction between the piping member and the insulation inspection jig.

  By adopting the above-described configuration, it is possible to perform an insulation test with a single piping member that could not be performed before. Furthermore, since the insulation inspection jig adheres firmly to the surface of the insulation coating layer while applying a pressing force to the insulation coating layer of the piping member due to its elasticity, the insulation inspection can be reliably performed.

  According to the insulation inspection jig and the insulation inspection method according to the present invention, before assembling a piping member constituted by a single member with a device such as a gas meter support device, a single and reliable insulation inspection is performed. It can be carried out. Along with this, it is possible to eliminate unnecessary disposal of non-defective products that occurred during the production of the device, and it is possible to produce the device economically.

It is sectional drawing which shows an insulation universal joint. It is an expanded sectional view which shows the state by which the inlet pipe and the insulated universal joint were assembled. It is a top view of an insulation inspection jig concerning the present invention. It is AA sectional drawing of the insulation test jig | tool which concerns on this invention. It is a schematic diagram which shows the mode of the insulation test | inspection of the piping member which concerns on this invention. It is a perspective view which shows the whole gas meter support apparatus. It is sectional drawing which shows the state by which the inlet pipe and the insulated universal joint were assembled.

  Hereinafter, the details of the insulation inspection jig and the insulation inspection method according to the present invention will be described with reference to the drawings. Here, an insulating universal joint will be described as an example of a piping member, and an inlet pipe of a gas meter support device will be illustrated as an example of an apparatus in which the piping member is assembled. However, the insulation inspection jig and the insulation inspection method according to the present invention are applied. The items to be inspected are not limited to these.

  First, the structure of the insulating universal joint to be inspected for the insulation inspection and the assembled state of the inlet pipe and the insulating universal joint will be described, and then the insulation inspection jig and the insulation inspection method will be described. FIG. 1 is a sectional view showing an insulating universal joint, and FIG. 2 is an enlarged sectional view showing a state in which the insulating universal joint is assembled with an inlet pipe.

A. Structure of Insulating Universal Joint The insulating universal joint 30 is a metal member such as a ductile, for example. As shown in FIGS. 6 and 7, the insulating universal joint 30 is a hollow piping member that is assembled at the end of the inlet pipe 20 that constitutes the gas meter support device 10.

  As shown in FIG. 1, the insulating universal joint 30 has a member fitting portion 31 that is fitted to a device fitting portion 21 formed at the end portion of the inlet pipe 20 at the end portion. In the member fitting portion 31, a first step portion 311, a second step portion 312, a first annular groove 313, a second annular groove 314, and a third annular groove 315 are formed in order from the end portion. ing. On the other hand, a supply pipe connection portion 32 connected to the supply pipe P1 is formed on the supply pipe P1 side. The supply pipe connection portion 32 is formed with a tapered portion 321 that gradually narrows toward the back side and a female screw portion 322 that is screwed into the supply pipe.

  The insulating universal joint 30 is provided with anticorrosion coating except for a part of the tapered portion 321. The non-coating portion 323 in the taper portion 321 functions as an energization portion that energizes the insulated universal joint in an insulation test described later. The non-coating portion 323 is formed so that the paint does not adhere by masking when painting. The non-coating portion 323 is formed at a position where it is easy to energize when performing an insulation test. Further, the inner surface and the outer surface of the member fitting portion 31 are provided with an insulating coating layer 316 over the entire surface. The insulating coating layer 316 is formed of, for example, an epoxy-based paint.

B. Assemble structure of insulated universal joint and inlet pipe As shown in FIG. 2, a member fitting portion 31 of the insulated universal joint 30 is assembled to the equipment fitting portion 21 of the inlet pipe 20. At this time, the first step portion 311 of the member fitting portion 31 has a spacer 34, the second step portion 312 has a fire-resistant O-ring 35, the first annular groove 313 has a sealing O-ring 33, and a second step portion 311. A snap ring 36 is attached to the annular groove 314, and a watertight O-ring 37 is attached to the third annular groove 315. The insulating universal joint 30 is assembled so as to be rotatable with respect to the device fitting portion 21 by the snap ring 36 straddling the device-side annular groove 211 and the second annular groove 314.

  Member large diameter portion 317 (a portion other than the first step portion 311, the second step portion 312, the first annular groove 313, the second annular groove 314, and the third annular groove 315 in the member fitting portion 31) The outer diameter of the state covered with the insulating coating layer 316 is substantially the same as the inner diameter of the device fitting portion 21. Therefore, the insulating coating layer 316 in the member large diameter portion 317 is in contact with the inner surface of the device fitting portion 21. In other words, the insulating universal joint 30 is electrically insulated from the inlet pipe 20 by providing the insulating coating layer 316 between the member large diameter portion 317 and the inlet pipe 20. Thus, in the insulating universal joint 30, it is particularly important that the outer surface of the member large diameter portion 317 is reliably covered with the insulating coating layer 316.

C. Insulation Inspection Jig FIG. 3 is a plan view of an insulation inspection jig according to the present invention. FIG. 4 is an AA cross-sectional view of the insulation inspection jig. In FIG. 4, the left side shows a state where an insulating universal joint is not mounted, and the right side shows a state where an insulating universal joint is mounted.

  The insulation inspection jig 1 is used for insulation inspection of the insulating universal joint 30 having the insulating coating layer 316, and is formed with a piping member attachment portion 11 to which the insulation universal joint 30 is attached. In FIG. 3, although two piping member mounting portions 11 are formed in the insulation inspection jig 1, one or three or more locations may be provided as necessary. The insulation inspection jig 1 is made of a material having elasticity and conductivity. As the material having elasticity and conductivity, for example, conductive rubber in which conductive carbon black or metal powder is blended with various rubber raw materials such as natural rubber and synthetic rubber can be used.

  The piping member mounting portion 11 is formed such that the member fitting portion 31 covered with the insulating coating layer 316 is fitted and the insulating universal joint 30 can be mounted. The piping member mounting portion 11 is formed with a large diameter portion 111 and a small diameter portion 112 so that the inner diameter gradually decreases in order from the side on which the insulating universal joint 30 is mounted (upper side in FIG. 4). The large diameter portion 111 can fit the member large diameter portion 317 of the insulating universal joint 30, and the small diameter portion 112 can fit the first step portion 311 and the second step portion 312. The inner diameter of the large-diameter portion 111 is slightly smaller than the outer diameter of the member large-diameter portion 317 that is covered with the insulating coating layer 316. The dimensional difference is provided so that at least the radial dimension is equal to or greater than the thickness of the insulating coating layer 316. As a result, when the insulating universal joint 30 is mounted, the piping member mounting portion 11 applies a pressing force to the surface of the insulating coating layer 316 of the opposing member large diameter portion 317 when the inner surface of the large diameter portion 111 is mounted. Close contact is possible. Furthermore, when the insulating coating layer 316 has defects such as scratches and peeling, and the metal portion is exposed at a part of the member large diameter portion 317, the inner surface of the large diameter portion 111 is elastic along the defect. By deforming, the metal portion exposed in the member large diameter portion 317 is surely contacted. As a result, since the insulating universal joint 30 and the insulation inspection jig 1 are electrically connected, an insulation failure due to a defect in the insulation coating layer 316 can be reliably detected in the insulation inspection.

D. Insulation Inspection Method An inspection method for an insulating universal joint using the insulation inspection jig 1 will be described. FIG. 5 is a schematic diagram showing a state of the insulation inspection.

  As shown in FIG. 5, the insulating universal joint 30 is mounted by pushing a member fitting portion 31 into the piping member mounting portion 11 of the insulation inspection jig 1. The insulating universal joint 30 is pushed in until the first step portion 311 and the second step portion 312 are fitted into the small-diameter portion 112 and the end surface of the second step portion contacts the bottom surface of the large-diameter portion 111. Since the piping member mounting portion 11 has the large diameter portion 111 formed smaller than the outer diameter of the member fitting portion 31 (particularly, the member large diameter portion 317), the insulating universal joint 30 is formed by the member large diameter portion 317. The large diameter part 11 is mounted while being expanded. At this time, since the insulation inspection jig 1 has elasticity, the inner surface of the piping member mounting portion 11 is in close contact with the surface of the insulating coating layer 316 covering the member large diameter portion 317 while applying a pressing force.

  Next, as shown in FIG. 5, for example, a probe of a resistance measuring instrument is brought into contact with the non-painted portion 323 provided in the tapered portion 321 of the insulating universal joint 30 and a part of the insulation inspection jig 1 to apply a voltage. By applying and measuring the electrical resistance value, continuity between the insulating universal joint 30 and the insulation inspection jig 1 is confirmed. At this time, when the outer surface of the member fitting portion 31 is entirely covered with the insulating coating layer 316 free from defects such as scratches and peeling, the space between the insulating universal joint 30 and the insulation inspection jig 1 is completely removed. Insulated and no current flows. As a result, the measured electrical resistance value is a large numerical value exceeding the acceptance criterion (for example, 200 MΩ), and it can be determined that the insulating universal joint 30 is a non-defective product. On the other hand, when there is a part where the metal part is exposed in a part of the member fitting part 31 due to a defect in the insulating coating layer 316, the part flows electrically with the insulation inspection jig 1, and a current flows. As a result, the measured electric resistance value is, for example, several MΩ. Thereby, it can confirm that the insulated universal joint 30 and the insulation test | inspection jig | tool 1 are electrically connected, and can determine that the insulated universal joint 30 is defective. As described above, according to this insulation inspection method, the insulation universal joint can be independently and accurately inspected.

  The insulation inspection jig and the insulation inspection method of the present invention are not limited to those described above, and it goes without saying that various modifications can be made without departing from the scope of the invention. For example, the present invention can also be applied to a piping member that has a portion requiring an insulation test on its inner surface. Moreover, in order to confirm electrical continuity, you may measure an electric current value instead of an electrical resistance value.

1: Insulation inspection jig 11: Piping member mounting part 111: Large diameter part 112: Small diameter part 10: Gas meter support device 20: Inlet pipe 21: Equipment fitting part 211: Equipment side annular groove 30: Insulating universal joint 31: Member fitting Joint portion 311: First step portion, 312: Second step portion, 313: First annular groove, 314: Second annular groove, 315: Third annular groove, 316: Insulating coating layer, 317: Member large diameter portion 32: supply pipe connection portion 321: taper portion, 322: female screw portion, 323: non-coating portion 33: sealing O ring 34: spacer 35: fireproof O ring 36: snap ring 37: water tight O ring

Claims (5)

An insulation inspection jig used for insulation inspection of a piping member having an insulation coating layer,
Made of elastic and conductive material,
An insulation inspection jig comprising a piping member mounting portion that can be in close contact with the surface of the insulating coating layer while applying a pressing force.   The insulation inspection jig according to claim 1, comprising an electrically conductive rubber. An insulation inspection method for a piping member having an insulation coating layer,
A step of preparing an insulation inspection jig having a piping member mounting portion that is made of a material having elasticity and conductivity and can be in close contact with the surface of the insulating coating layer while applying a pressing force;
Attaching the piping member to the insulation inspection jig;
Applying a voltage between the current-carrying part formed on the piping member and the insulation inspection jig to confirm electrical continuity between the piping member and the insulation inspection jig. Insulation inspection method characterized by.   The insulation inspection method according to claim 3, wherein the insulation inspection jig is made of conductive rubber. The insulation inspection method according to claim 3 or 4, wherein the energization part is a non-coating part formed on at least a part of the piping member when the piping member is painted.

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