JP2007051754A - Crosslinked polyethylene two-layered pipe for detecting water leakage and crosslinked polyethylene two-layered pipe for city water used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily and certainly confirm whether there is a possibility that water leaks from a crosslinked polyethylene two-layered pipe for city water by penetration of a metal fixture. <P>SOLUTION: The crosslinked polyethylene two-layered pipe for detecting water leakage is provided with: the crosslinked polyethylene two-layered pipe 1 for city water comprising an outer layer 3 made of non-crosslinked polyethylene and an inner layer 2 made of crosslinked polyethylene; and an electrically conductive cap 4 installed in the end of the crosslinked polyethylene two-layered pipe 1 for city water. The outer layer 3 has electrical conductivity or semi-electrical conductivity made of non-crosslinked polyethylene containing an electrically conductive material. The electrically conductive cap 4 is installed in the crosslinked polyethylene two-layered pipe 1 for city water in the electrically insulating state to the outer layer 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cross-linked polyethylene double-layer pipe for water supply arranged under the floor of an apartment, and in particular, a metal fixture such as a nail or a wood screw for fixing a floor board or the like is provided in the cross-linked polyethylene double-layer pipe. The present invention relates to a cross-linked polyethylene double-layer tube for water leakage detection for detecting a case where there is a possibility of water leakage. The present invention also relates to a cross-linked polyethylene double-layer pipe for water supply used in the cross-linked polyethylene double-layer pipe for detecting water leakage.

  Conventionally, water pipes placed under the floor of condominiums were made of metal, so metal fixtures such as nails and wood screws for fixing floor boards etc. penetrated the water pipe and could leak water. There was never.

  By the way, in recent years, cross-linked polyethylene pipes for water supply have been placed under the floor of apartments due to the ease of handling, light weight, low price, and metal water pipes due to metal rust. Such a cross-linked polyethylene pipe for water supply may have a possibility of water leakage due to penetration of a metal fixture such as a nail or a wood screw for fixing a floor board or the like.

  However, after construction of the floorboard, etc., the cross-linked polyethylene pipe for water supply is covered with the floorboard, etc., so it is apparent whether there is a possibility of water leakage due to penetration of metal fasteners such as nails and wood screws. Cannot be judged at all.

  And if it becomes clear that the water leaks after the apartments are completed and delivered to the purchaser, it is necessary not only to repair the room where the water leaked, but also to compensate for the damage of the lower room due to the water leak. It may lead to damage of 10 million yen.

  An object of the present invention is to advantageously solve the above-mentioned problems, and a cross-linked polyethylene double-layer tube for water leakage detection according to the present invention comprises an outer layer made of non-cross-linked polyethylene and an inner layer made of cross-linked polyethylene. A cross-linked polyethylene double-layer pipe for water leakage detection comprising a cross-linked polyethylene double-layer pipe for water supply, and a conductive cap attached to an end of the cross-linked polyethylene double-layer pipe for water supply, wherein the outer layer is conductive A conductive or semi-conductive material made of non-crosslinked polyethylene containing a material, wherein the conductive cap is mounted on the cross-linked polyethylene double-layer pipe for water supply in an electrically insulated state with respect to the outer layer. To do.

  Further, a cross-linked polyethylene double-layer pipe for water supply of the present invention is used for the above-mentioned cross-linked polyethylene double-layer pipe for detecting water leakage, and has a conductive or semiconductive outer layer made of non-cross-linked polyethylene containing a conductive material. And an inner layer made of crosslinked polyethylene.

  In the cross-linked polyethylene double-layer pipe for water leakage detection according to the present invention, the cross-linked polyethylene double-layer pipe for water leak constituting the cross-linked polyethylene double-layer pipe for water leak detection is electrically conductive or made of non-cross-linked polyethylene containing a conductive material. Since the semiconductive outer layer is electrically insulated from the metal or other conductive cap attached to the end of the cross-linked polyethylene double-layer pipe for water supply, it is usually between the outer layer and the conductive cap. Is not electrically conductive. On the other hand, if a metal fastener such as a nail or a wood screw penetrates the water-soluble cross-linked polyethylene double-layer pipe and water enters the water-soluble cross-linked polyethylene double-layer pipe, Metal fixture that contacts the water inside the polyethylene double-layer pipe and the outer layer of the cross-linked polyethylene double-layer pipe for water supply, and penetrates to the inside of the inner layer of the cross-linked polyethylene double-layer pipe for water supply and contacts the water inside Thus, the conductive or semiconductive outer layer and the conductive base are electrically connected.

  Therefore, according to the cross-linked polyethylene double-layer pipe for water leakage detection of the present invention, the cross-linked polyethylene double-layer pipe for water supply that constitutes the cross-linked polyethylene double-layer pipe for water leak detection after the construction of the floor board or the like is filled with water. Just check the electrical continuity between the conductive cap at the end of the two-layer pipe and the outer layer of the cross-linked polyethylene double-layer pipe with a continuity tester. If there is a possibility of water leakage through the fixing fixture, it can conduct electricity (including so-called semi-conductivity), so it can be easily and reliably confirmed whether there is any water leakage. It is possible to prevent a large amount of damage from occurring.

  In the cross-linked polyethylene double-layer pipe for water leakage detection according to the present invention, the conductive cap is inserted into the inner layer at the end of the cross-linked polyethylene double-layer pipe for water supply, and the cross-linked polyethylene double-layer pipe for water supply It is preferable that an insulator such as an insulating washer is interposed between the outer layer and the outer layer of the end. In this way, the conductive base is attached to the end of the cross-linked polyethylene double-layer pipe for water supply with a simple configuration and electrically insulated from the outer layer at the end of the cross-linked polyethylene double-layer pipe for water supply It can be.

On the other hand, in the cross-linked polyethylene double-layer pipe for water supply of the present invention, the volume resistivity of the outer layer is preferably 10 ⁸ Ωcm or less. If the volume resistivity of the outer layer is 10 ⁸ Ωcm or less, it becomes a semi-conductive state due to water leakage as described above, and more preferably 10 ⁶ Ωcm or less, it becomes a conductive state. It can be easily detected with a relatively simple detector such as a tester.

  In the cross-linked polyethylene double-layer pipe for water supply of the present invention, the outer layer may contain conductive carbon black, or the outer layer may contain metallic fine particles or fine powder. Furthermore, the outer layer may contain fine powder of carbon fiber or metal fiber, or the outer layer may contain a nonmetallic inorganic conductive filler. The outer layer of non-crosslinked polyethylene containing these conductive materials can easily be made conductive or semiconductive.

  Furthermore, in the crosslinked polyethylene double-layer pipe for water supply of the present invention, the inner layer may be formed of, for example, water-crosslinked polyethylene that is crosslinked by contact with moisture.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 (a) and 1 (b) are a longitudinal sectional view and a transverse sectional view showing an embodiment of a cross-linked polyethylene double-layer tube for water leakage detection according to the present invention. Reference numeral 1 in the drawing denotes the embodiment. As an example of a cross-linked polyethylene double-layer pipe for water supply of the present invention that constitutes a cross-linked polyethylene double-layer pipe for water leakage detection, a cross-linked polyethylene double-layer pipe for water supply placed under the floor of an apartment, etc. The inner layer of the polyethylene double-layer pipe 1, 3 is the outer layer of the cross-linked polyethylene double-layer pipe 1 for water supply, and 4 is the cross-link for water leakage detection of the above embodiment, attached to one end of the cross-linked polyethylene double-layer pipe 1 for water supply A base made of a copper alloy as a conductive base constituting the polyethylene double-layer tube is shown.

  As shown in FIGS. 1 (a) and 1 (b), the cross-linked polyethylene double-layer pipe for water leakage detection of this example was attached to the cross-linked polyethylene double-layer pipe 1 for water supply of the above example and at least one end thereof. The inner layer 2 of the water-based cross-linked polyethylene double-layer pipe 1 is, for example, water cross-linked by bringing it into contact with moisture using polyethylene having an active silane group in the molecule. It consists of cross-linked polyethylene such as polyethylene, and as such polyethylene, for example, trade name “LINKRON” manufactured by Mitsubishi Chemical Corporation and trade name “ELMEX” manufactured by Mitsui Chemicals, Inc. can be used.

Moreover, the outer layer 2 of the crosslinked polyethylene double-layer pipe 1 for water supply here is a conductive or semiconductive one made of non-crosslinked polyethylene containing a conductive material, and the non-crosslinked polyethylene has a high volume resistivity. The conductive material is contained at a ratio of 10 ⁸ cm or less, more preferably 10 ⁶ Ωcm or less. Examples of such a conductive material include conductive carbon black such as “Ketjen Black” manufactured by Lion Corporation and “# 5500” manufactured by Tokai Carbon Co., Ltd., or manufactured by Fukuda Metal Foil Powder Co., Ltd. Metal fine particles or fine powders such as spherical powder and granular powder of Ni, Fe, Cu, etc., or carbon fiber or metal fiber fine powder such as carbon fiber manufactured by Osaka Gas Chemical Co., Ltd., or manufactured by Otsuka Chemical Co., Ltd. Non-metallic inorganic conductive fillers such as “Dentol WK” can be used alone or in appropriate mixture.

  In the cross-linked polyethylene double-layer pipe for water leakage detection of this embodiment, an insulating washer 6 made of, for example, bakelite or the like is placed in the inner layer 2 at the end of the cross-linked polyethylene double-layer pipe 1 for water supply of the above-described embodiment that has been inserted through the metal ring 5 in advance. Is inserted into the base 4 and the metal ring 5 is shifted on the outer layer 2 so as to be positioned on the base 4, so that the metal ring 5 is brought into close contact with the outer layer 2 at the end of the cross-linked polyethylene double-layer pipe 1 for water supply. At the same time, the end of the cross-linked polyethylene double-layer pipe 1 for water supply is tightened with the metal ring 5 to prevent the pipe 2 from coming off, and the lead wire 7 is connected to the metal ring 5.

  In the cross-linked polyethylene double-layer pipe for water leakage detection of this embodiment, the outer layer 3 of the cross-linked polyethylene double-layer pipe 1 for water supply is electrically insulated from the base 4 by the insulating washer 6, so that the outer layer is usually used. 3 and the base 4 are not electrically connected. On the other hand, as shown in FIG. 1 (a), a metallic fastener 8 such as a nail or a wood screw penetrates the water-crosslinked polyethylene double-layer pipe 1, and When water W is contained in the inner layer 2, the water W inside the cross-linked polyethylene double-layer pipe 1 for water supply and the outer layer 3 of the cross-linked polyethylene double-layer pipe 1 for water supply and the cross-linked polyethylene double layer for water supply The outer layer 3 and the base 4 are electrically connected (or semi-conductive) through a metal fixture 8 that penetrates to the inside of the inner layer 2 of the tube 1 and contacts the water W inside the tube. Become.

  Therefore, according to the cross-linked polyethylene double-layer pipe for water leakage detection of this embodiment and the cross-linked polyethylene double-layer pipe 1 of this embodiment used therein, the construction of the floorboard and the like is performed in the cross-linked polyethylene double-layer pipe 1 for water supply. Fills the water W and leads the electrical continuity between the base 4 at the end of the cross-linked polyethylene double-layer pipe 1 for water supply and the metal ring 5 in close contact with the outer layer 3 of the cross-linked polyethylene double-layer pipe 1 for water supply Just by examining with a continuity tester 9 or the like through the wire 7, if there is a possibility of water leakage if a metal fixture 8 such as a nail or a wood screw penetrates the cross-linked polyethylene double-layer pipe 1 for water supply (conduction ( Or semi-conducting), it is possible to easily and surely check whether there is a possibility of water leakage, and it is possible to prevent the occurrence of great damage due to water leakage from the cross-linked polyethylene double-layer pipe 1 for water supply.

  Moreover, according to the cross-linked polyethylene double-layer pipe for water leakage detection of this embodiment, the base 4 is inserted into the inner layer at the end of the cross-linked polyethylene double-layer pipe 1 for water supply, and the cross-linked polyethylene double-layer pipe 1 for water supply Since the insulating washer 6 is interposed between the outer layer and the outer layer at the end of the pipe, the base 4 is attached to the end of the cross-linked polyethylene double-layer pipe 1 for water supply with a simple configuration and the cross-linked polyethylene double-layer pipe for water supply It can be made into an electrical insulation state with the outer layer of 1 edge part.

  Although the present invention has been described based on the illustrated examples, the present invention is not limited to the above-described examples, and can be appropriately changed within the scope of the claims. For example, the conductive base is formed of plastic. In addition, the surface may be covered with a metal film to provide conductivity, and the electrical insulation between the conductive base and the outer layer at the end of the cross-linked polyethylene bilayer pipe for water supply is determined at the end. It may be obtained by removing the outer layer near the edge in an annular shape.

  Thus, according to the cross-linked polyethylene double-layer pipe for water leakage detection according to the present invention, it is possible to easily and surely confirm the possibility of water leakage, and the occurrence of a great deal of damage due to water leak from the cross-linked polyethylene double-layer pipe for water supply is obviated. Can be prevented.

(A), (b) is a longitudinal sectional view and a cross section showing one embodiment of a cross-linked polyethylene double-layer pipe for water leakage detection according to the present invention and one embodiment of a cross-linked polyethylene double-layer pipe for water supply of the present invention used therein. FIG.

Explanation of symbols

1 Cross-linked polyethylene double-layer pipe for water supply 2 Inner layer 3 Outer layer 4 Base 5 Metal ring 6 Insulating washer 7 Lead wire 8 Metallic fixture 9 Continuity tester W Water

Claims (8)

A crosslinked polyethylene double-layer pipe for water supply comprising an outer layer made of non-crosslinked polyethylene and an inner layer made of crosslinked polyethylene;
A conductive base attached to an end of the cross-linked polyethylene double-layer pipe for water supply;
A cross-linked polyethylene double-layer tube for water leakage detection comprising:
The outer layer is a conductive or semi-conductive one made of non-crosslinked polyethylene containing a conductive material,
A cross-linked polyethylene double-layer tube for water leakage detection, wherein the conductive base is attached to the cross-linked polyethylene double-layer tube for water supply in an electrically insulated state with respect to the outer layer.   The conductive base is inserted into the inner layer at the end of the water-crosslinked polyethylene double-layer tube, and an insulator is interposed between the outer layer at the end of the cross-linked polyethylene double-layer tube for water supply. The cross-linked polyethylene double-layer tube for water leakage detection according to claim 1, wherein A cross-linked polyethylene double-layer pipe for water supply used in the cross-linked polyethylene double-layer pipe for water leakage detection according to claim 1 or 2,
A conductive or semiconductive outer layer made of non-crosslinked polyethylene containing a conductive material;
A cross-linked polyethylene double-layer pipe for water supply, comprising an inner layer made of cross-linked polyethylene. The cross-linked polyethylene double-layer pipe for water supply according to claim 3, wherein the volume resistivity of the outer layer is 10 ⁸ Ωcm or less.   The cross-linked polyethylene bilayer pipe for water supply according to claim 3 or 4, wherein the outer layer contains conductive carbon black.   The cross-linked polyethylene double-layer pipe for water supply according to claim 3 or 4, wherein the outer layer contains metal-based fine particles or fine powder.   The cross-linked polyethylene bilayer pipe for water supply according to claim 3 or 4, wherein the outer layer contains fine powder of carbon fiber or metal fiber.   The cross-linked polyethylene double-layer pipe for water supply according to claim 3 or 4, wherein the outer layer contains a non-metallic inorganic conductive filler.

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