JP2016095004A - Protective cover for pipeline - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protective cover for a pipeline capable of preventing temperature rise and freezing of service water, and protecting a pipeline from external force.SOLUTION: A protective cover for a pipeline is mounted to a pipeline 2, laid in a state of being exposed on the ground and transporting liquid, so as to cover the outer periphery of the pipeline 2. The protective cover for a pipeline includes: an inner layer 3 that faces to the pipeline 2, and comprises a mixture containing a first resin having heat resistance and weather resistance and particles of a first substance having high heat insulation property; and an outer layer 4 that is laminated on one surface facing to the outside of the inner layer 3, and comprises a mixture containing a second resin having heat resistance and weather resistance and particles of a second substance having high light shade property.SELECTED DRAWING: Figure 1

Description

  The present invention is for a pipe that can be suitably implemented to protect a pipe such as a temporary water pipe installed in a state exposed to the ground by replacement work of a water pipe buried in the ground from heat and the like. Regarding protective cover.

  In the replacement work to replace a water pipe buried in the ground with a new water pipe, a temporary water pipe on the ground is used to prevent interruption of the supply of tap water to customers during the construction. A temporary pipe is laid and tap water is supplied to each house by the temporary pipe during the required period.

  As temporary piping, polyethylene pipe is often used, and it is laid on concrete structures and ground such as asphalt pavement, concrete pavement, gutters, etc., so the temperature of tap water rises due to solar radiation, burning due to cigarette butts, stones and passers-by In order to prevent damage such as damage due to contact and freezing of tap water due to a decrease in temperature in winter, a protective sheet made of, for example, soft polyvinyl chloride is wound around the temporary piping to protect the temporary piping (for example, patent documents) 1).

  In the above-described prior art, since the protective sheet is merely wound around the temporary piping, sufficient effects are not obtained in terms of heat insulation, heat resistance, and impact resistance. If the temperature rises in summer, the water temperature rises accordingly, which is not preferable for tap water customers. In addition, if a cigarette butt or the like that is not extinguished is thrown away and directly contacts the protective sheet, the protective sheet is burned out by heat, thereby reducing the heat insulation. Furthermore, when an external force acts on the protective sheet due to contact of a flying object such as a stone that the passing vehicle has bounced off or a falling object, the protective sheet is damaged and the temporary piping is also damaged. If the temporary piping is damaged, water cannot be supplied to the downstream area, and the water may be cut off.

  An object of the present invention is to provide a piping protective cover that can suppress the temperature rise of tap water, prevent freezing of tap water when the temperature falls, and protect piping such as temporary piping from external force Is to provide.

The present invention is a protective cover for piping that is installed on a pipe that is laid on the ground and transports a fluid so as to cover the outer periphery of the pipe, and has heat resistance and weather resistance facing the pipe. An inner layer made of a mixture containing a first resin having the above and particles of a first material having high heat insulation properties;
The protective cover for piping includes a second resin layered on one surface facing the outside of the inner layer, and an outer layer made of a mixture containing a second resin having heat resistance and weather resistance and particles of a second substance having high light shielding properties.

  According to the present invention, the first resin and the second resin are low density polyethylene, the first substance is mica, and the second substance is titanium oxide.

  According to the present invention, the inner layer is composed of a mixture containing the first resin having heat resistance and weather resistance and the particles of the first substance having high heat insulation, and the surface facing the outside of the inner layer has heat resistance. And an outer layer composed of a mixture containing a second resin having weather resistance and particles of a second substance having a high light-shielding property, so that heat due to solar radiation is not easily transferred from the outer layer to the inner layer, realizing high heat insulation. Thus, it is possible to suppress the temperature rise of the fluid such as water flowing in the pipe by suppressing the temperature rise of the pipe to which the heat insulating cover is attached and suppressing the temperature rise of the pipe.

  In addition, since the first resin and the second resin have heat resistance, they are not easily burned by heat due to contact with a non-extinguishing butt, etc., and a reliable protection state is maintained for the piping. can do. In addition, since the first resin and the second resin are made of a weather-resistant resin, there is little deterioration due to a decrease in temperature, the temperature of the pipe is prevented from being lowered due to heat insulation, and freezing of fluid such as water flowing in the pipe is prevented. can do.

  According to the present invention, the first resin and the second resin are low-density polyethylene, the first substance is mica, and the second substance is titanium oxide, so that it is opaque and has high hiding power against sunlight. It is possible to realize a protective cover for piping having excellent robustness against sunlight and heat.

It is sectional drawing which shows the protective cover 1 for piping of one Embodiment of this invention. It is a top view which shows typically the temperature measurement equipment M1 used by the 1st temperature measurement test by this inventor. It is a graph which shows the measurement temperature obtained by the temperature measurement equipment M1, FIG. 3 (1) shows the measurement temperature of the 1st day, and FIG. 3 (2) shows the measurement temperature of the 2nd day. It is a top view which shows typically the temperature measurement equipment M2 used by the 2nd temperature measurement test by this inventor. It is sectional drawing of piping installation position vicinity seen from cut surface line AA of FIG. It is sectional drawing of piping installation position vicinity seen from the cut surface line BB of FIG. It is sectional drawing of piping installation position vicinity seen from the cut surface line CC of FIG. Is a graph showing the measured temperature at the measuring point P _A temperature measurement equipment M2, 6 (1) shows the measured temperature of the first day, 6 (2) shows the temperature measured by the second day. It is a graph showing the measured temperature at the measuring point P _B of the temperature measurement facility M2, 7 (1) shows the measured temperature of the first day 7 (2) shows the temperature measured by the second day. Is a graph showing the measured temperature at the measuring point P _C in the temperature measurement facility M2, 8 (1) represents the measured temperature of the first day, 8 (2) indicates the measured temperature of the second day. It is sectional drawing which shows the protective cover 1a for piping of other embodiment of this invention. It is a figure for demonstrating the manufacturing method of the protective cover 1a for piping. It is sectional drawing which shows the protective cover 1b for piping of other embodiment of this invention.

FIG. 1 is a cross-sectional view showing a piping protective cover 1 according to an embodiment of the present invention. The piping protective cover 1 (hereinafter sometimes abbreviated as “protective cover”) of the present embodiment covers the outer periphery of the pipe 2 on the pipe 2 that is laid on the road surface and the side groove in a state of being exposed to the ground. To be fitted. The protective cover 1 includes an inner layer 3 facing the pipe 2 and an outer layer 4 laminated on one surface facing the outside of the inner layer 3.

  Pipe 2 is a temporary pipe installed on the ground when a water pipe buried in the ground is replaced with a new water pipe, and is constant until the old underground water pipe is replaced with a new pipe. Used to transport water pipes instead of old water pipes for a period of time.

  The inner layer 3 is made of a first mixture containing a first resin having heat resistance and weather resistance and particles of a first material having high heat insulation. As the first resin having heat resistance and weather resistance, low density polyethylene having a density of 0.910 to 0.925 is used. In addition, as the first material particles having high heat insulating properties, mica (also referred to as mica) particles are used. The first mixture of the first resin and the particles of the first substance has a blending ratio of 2 parts by weight or more and 20 parts by weight or less of mica powder with respect to 100 parts by weight of the low density polyethylene. It can be obtained by dispersing and mixing the mica powder as a substance.

  The outer layer 4 consists of the 2nd mixture containing the 2nd resin which has heat resistance and a weather resistance, and the particle | grains of the 2nd substance with high light-shielding property. As the second resin having heat resistance and weather resistance, low density polyethylene similar to the first resin is used. In addition, titanium oxide powder is used as the second material particles having high light shielding properties. The second mixture of the second resin and the particles of the second substance is a blending ratio of 2 parts by weight or more and 20 parts by weight or less of titanium oxide powder as the second substance with respect to 100 parts by weight of the low density polyethylene. It can be obtained by dispersing and mixing titanium oxide powder in low density polyethylene.

  The first mixture and the second mixture are extruded by an extrusion molding machine 5 shown in FIG. 10 to be described later, and two-color molding is performed, whereby the protective cover 1 is manufactured. In the protective cover 1 manufactured as described above, the inner layer 3 has a cross section perpendicular to the axis obtained by dividing the right cylindrical body at one place in the circumferential direction. The outer layer 4 is laminated on the outer surface of the inner layer 3 and has a peripheral wall portion 6 having a right-angle cross section obtained by dividing the right cylindrical body in the circumferential direction at one location in the circumferential direction, and ends on both sides of the circumferential wall portion 6 in the circumferential direction. It has a pair of ridge parts 9 and 10 which are connected to the parts 7 and 8 and protrude substantially in parallel radially outward from the center of the cross section perpendicular to the axis of the peripheral wall part 6. Each protrusion 9, 9 extends continuously along an axis L1 passing through the center of the cross section perpendicular to the axis of the peripheral wall 6.

  The outer diameter D1 of the protective cover 1 is set as shown in the following Table 1 according to the nominal diameter and type of the pipe 2. In Table 1, PE pipe is a polyethylene pipe, JLPVB is a galvanized steel pipe, and JLPVD is a coated steel pipe made of polyvinyl chloride.

  FIG. 2 is a plan view schematically showing the temperature measurement facility M1 used in the first temperature measurement test conducted by the present inventors, and FIG. 3 is a graph showing the measurement results obtained by the first temperature measurement facility M1. Yes, FIG. 3 (1) shows the measured temperature on the first day, and FIG. 3 (2) shows the measured temperature on the second day.

  The present inventor conducted a first temperature measurement test using a temperature measurement facility M1 shown in FIG. The temperature measuring equipment M1 has two wooden bases 11 and 12 mounted in parallel on a concrete floor of a concrete structure roof, and five nominal diameters as pipes on the bases 11 and 12, respectively. 50A polyethylene pipes P1 to P5 are placed parallel to each other at intervals, and among these polyethylene pipes P1 to P5, nothing is attached to the first polyethylene pipe P1, and the second polyethylene pipe P2 is shown in FIG. A protective cover 1 similar to that of the first embodiment is attached, the protective cover 1 is attached to the third polyethylene pipe P3, and the polyethylene pipe P3 in the protective cover 1 is made of a foamed polyethylene sheet having a thickness of about 10 mm. The material is wound, a heat insulating sheet on which aluminum is vapor-deposited is wound around the fourth polyethylene pipe P4, and a polyvinyl chloride pipe having the same diameter as the protective cover 1 is wound around the fifth polyethylene pipe P5. The attached, to fill water into the polyethylene pipe P1 to P5, and insert the digital thermometer that transmits measured temperature data at radio, sealing the both ends by the caps 13, 14. In addition, the air temperature and the concrete floor temperature were also measured with a digital thermometer.

  The measured values of the water temperature, air temperature, and concrete temperature in the polyethylene pipes P1 to P5 by the digital thermometer are as shown by the lines L11 to L17 in FIG. 3 (1) and the lines L21 to L27 in FIG. 3 (2). is there.

  As is clear from the temperature measurement results, it was confirmed that the heat insulating effect was obtained by the protective cover.

  FIG. 4 is a plan view schematically showing the temperature measurement equipment M2 used in the second temperature measurement test conducted by the present inventor, and FIG. 5A is a sectional view in the vicinity of the pipe installation position as seen from the cutting plane line AA. 5B is a cross-sectional view of the vicinity of the pipe installation position viewed from the cutting plane line BB, and FIG. 5C is a cross-sectional view of the vicinity of the pipe installation position viewed from the cutting plane line CC.

Piping L _C piping L _D and the pipe L _D is connected to the middle position leads to the supply mains tap water, one end of which is closed by a fire hydrant, at the other end the pipe L _A, L _B is connected. _A consumer who consumes tap water is connected to the pipes L _A and L _B. Pipe _{L A} is a polyethylene pipe of nominal diameter 25A, as shown in Figure 5A, it is laid directly soil 15. Pipe L _B is polyethylene tube nominal diameter 50A, as shown in Figure 5B, it is laid on the concrete structure 16. Pipe L _C is a polyethylene tube of nominal diameter 75A, as shown in Figure 5C, is laid into the concrete gutter 17. Pipe _{L D} is polyethylene tube nominal diameter 75A, is buried in the ground.

Figure 6 is a graph showing the measured temperature at the measuring point P _A temperature measurement equipment M2, 6 (1) shows the measured temperature of the first day, 6 (2) The second day of measurement temperature Indicates. FIG. 7 is a graph showing the measured temperature at the measurement point P _B of the temperature measuring equipment M2, FIG. 7 (1) shows the measured temperature on the first day, and FIG. 7 (2) shows the measured temperature on the second day. Indicates. Figure 8 is a graph showing the measured temperature at the measuring point P _C in the temperature measurement facility M2, 8 (1) represents the measured temperature of the first day, 8 (2) The second day of measurement temperature Indicates.

  In the temperature measurement facility M2 as described above, the temperature measurement points A1, B1, and C1 measured with the same digital thermometer as described above are the results of the lines L31 and L32 in FIG. 6 (1) and FIG. 6 (2). 7, lines L 51 and L 52 in FIG. 7 (1), lines L 61 and L 62 in FIG. 7 (2), lines L 71 and L 72 in FIG. 8 (1), and lines L 81 and L 82 in FIG. 8 (2). As shown.

  As is clear from the measurement results of the second temperature measurement test, it was confirmed that the heat insulating effect can be obtained regardless of the installation environment by attaching the protective cover 1 to the pipe 2.

  FIG. 9 is a cross-sectional view showing a piping protective cover 1a according to another embodiment of the present invention, and FIG. 10 is a view for explaining a method of manufacturing the piping protective cover 1a. In addition, this embodiment is similar to the protective cover for piping 1 of the above-described embodiment, and corresponding portions are denoted by the same reference numerals. The piping protection cover 1a of the present embodiment is a piping protection divided in the circumferential direction by cutting a molded product extruded in a cylindrical shape from the extrusion molding machine 5 by a cutter member 18 at one circumferential position. The cover 1a can be obtained.

  Thus, since the protective cover 1a for piping of this embodiment is divided | segmented into the circumferential direction, it can be easily attached to the piping 2 and can be easily removed from the piping 2.

  FIG. 11 is a cross-sectional view showing the piping protective cover 1b. Note that the same reference numerals are given to the portions corresponding to the above-described embodiment. The piping protection cover 1b of the present embodiment, like the piping protection cover 1a of the above-described embodiment, cuts one place in the circumferential direction by the cutter member 18, and then injects cooling water by the nozzle member 19, By cooling the outer surface side of the molded product after cutting, it is possible to shrink the inside and overlap the divided circumferential ends in the thickness direction.

  Thus, in this embodiment, since it is comprised so that the circumferential direction both ends of the protective cover 1b for piping may overlap in the thickness direction, the protective cover 1b for piping will remove | deviate from piping easily by the effect | action of an undesired external force. This can be prevented.

  The present invention is not limited to pipes that transport liquids such as tap water, but can also be used to insulate pipes that transport gas in plants and the like.

1, 1a, 1b Piping protective cover 2 Piping 3 Inner layer 4 Outer layer 5 Extruder 6 Peripheral wall portion 7 End portion 8 End portion 9 Protruding portion 10 Protruding portion 11 Base 12 Base 13 Cap 14 Cap 15 Soil 16 Concrete Structure 17 Side groove 18 Cutter member 19 Nozzle member

Claims (2)

A piping protective cover that is installed in a state of being exposed on the ground and transporting a fluid so as to cover the outer periphery of the piping,
An inner layer composed of a mixture containing a first resin having heat resistance and weather resistance facing the pipe, and particles of a first material having high heat insulation properties;
A protective cover for piping comprising a second resin layered on one surface facing the outside of the inner layer, and comprising an outer layer made of a mixture containing a second resin having heat resistance and weather resistance and particles of a second substance having a high light shielding property. The first resin and the second resin are low density polyethylene,
The first substance is mica;
The heat insulating cover for piping according to claim 1, wherein the second substance is titanium oxide.

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