JPH09299500A - Water supplying pipeline apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a flexible pipe from being expanded and damaged and improve workability of a pipeline by covering a thin flexible metal pipe with a protective sleeve being formed cylindrically by braiding an arom. polyamide fiber. SOLUTION: A water supplying pipeline apparatus is constituted by using a thin flexible metal pipe and a protective sleeve covering this outer periphery as essential conditions. The protective sleeve is formed by braiding cylindrically an arom. polyamide fiber. As the arom. polyamide fiber, e.g. an assembly of para-type or meta-type filaments or an assembly of threads spun from para-type or meta-type staple fibers is used. It is pref. that highly heat-resistant and highly flame-resistant para-type fiber which does not melt and burn by contact with electric welding bar and electric welding spark is used. In addition, it is pref. that the thickness of the arom. polyamide fiber is made to be 100-2,000 denier and more pref. that it is about 400-1,500 denier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water supply piping device which is preferably used as an unwinding pipe for a fire extinguishing sprinkler.

[0002]

2. Description of the Related Art As a water supply piping device used as an unwinding pipe for a fire extinguishing sprinkler, for example, a flexible pipe is prevented from expanding on the outer circumference of a thin metal flexible pipe due to internal fluid pressure during actual use. In addition, there is known a structure in which various blades (protective sleeves) are covered for the purpose of protecting the flexible pipe from external damage during the piping work (construction). For example, Japanese Utility Model Publication No. 58-46835 discloses a structure in which the outer periphery of a thin-walled stainless steel bellows tube is covered with a metal blade formed by braiding a mild steel wire or a stainless steel wire in a tubular shape.

However, in the water supply piping device having the above-described structure, if a stray current flows in a state where the poorly insulated conductor is in contact with the metal blade, electric corrosion occurs in the flexible pipe inside and a hole is formed. There is a problem that it opens and a problem that the workability of the piping work is deteriorated because the metal blade is stiff and inferior in flexibility when performing bent piping. Therefore, as means for solving such a problem, for example, JP-A-6-159571 and JP-A-6-265066 have been proposed.

Japanese Unexamined Patent Publication (Kokai) No. 6-159571 discloses a structure in which the outer periphery of a thin-walled flexible metal tube is covered with a braid formed by bundling glass fibers into a tubular shape and braiding it into a tubular shape. Japanese Patent Laid-Open No. 6-265066 discloses a structure in which the outer periphery of a thin-walled flexible metal tube is covered with a braid formed by braiding polyethylene terephthalate fiber into a tubular shape. According to these publications, glass fiber and polyethylene terephthalate fiber are excellent in electrical insulation, and therefore, they can easily solve the problem of electrical corrosion of thin-walled metal flexible pipes and are also excellent in flexibility. It is said that it is possible to perform bent piping on the inside and to improve workability.

[0005]

However, first, in the case where the blade is made of glass fiber, the glass fiber itself is inferior in abrasion resistance, and the hygroscopicity is high, so that the tensile strength is lowered. If excessive internal fluid pressure is applied during actual use, or if there is a strong contact with other piping equipment during piping work, the blade may be damaged in some cases. When the blade is damaged, the fluff of the glass fiber may be scattered in the air, and the worker may inhale it to impair the health.

To solve such a problem, for example, by impregnating glass fiber with resin paint or rubber paint,
A method to improve the strength of the fiber and prevent the scattering of fluff is considered as a countermeasure, but in this case, since the stretchability of the glass fiber is impeded, it becomes difficult to coat the thin-walled metal flexible tube. .

On the other hand, in the case where the blade made of polyethylene terephthalate fiber is coated, the electric welding rod may accidentally come into contact during the piping work, or the electric welding spark may fall for a long time. There is a risk that the blade will partially melt and the thin metal flexible tube will be punctured accordingly. If a hole is made in the thin metal flexible tube, sufficient airtightness cannot be obtained in the airtightness test performed after several tens to several hundreds of sprinkler heads are installed, and it cannot be used as it is. I will end up. Therefore, it is necessary to investigate a portion having a hole, which requires a great deal of labor.
Further, as an airtightness test, a water pressure test is usually performed, but at this time, if a hole is formed in the thin-walled metal flexible pipe, water leaks and floods the inside of the ceiling, etc. Would require a great deal of effort.

Fibers that are carbonized only by contact with an electric welding rod or electric welding sparks and do not melt by heat include, for example, glass fiber, carbon fiber, cotton yarn, novoloid fiber and the like. However, glass fiber is not preferable because it has the drawbacks described above.
Further, carbon fibers have poor electrical insulation properties, and cotton yarns may cause flames when electric welding sparks stay on the surface. In the case of novoloid fibers, currently only short fibers can be produced, and since this is a spun shape, it has low tensile strength, and like glass fibers, problems such as blade breakage and fluff scattering occur. . Even in the case of novoloid fibers, it is possible to improve the strength of the fibers and prevent the scattering of fluff by impregnating them with resin paint or rubber paint. As a result, the work of coating a thin-walled flexible metal pipe becomes difficult.

The present invention has been made on the basis of such a point, and an object of the present invention is to reliably prevent expansion of a thin-walled metal flexible pipe and damage from the outside, and at the same time, to perform piping work. It is to provide a water supply piping device capable of improving workability.

[0010]

In order to achieve the above object, a water supply pipe apparatus according to the present invention comprises a thin metal flexible pipe, a protective sleeve coated on the outer periphery of the flexible pipe, and the flexible pipe to the outside. In the water supply piping device including a connecting means for connecting to the device, the protective sleeve is characterized by being formed by braiding aromatic polyamide fibers in a tubular shape.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The constituent material, shape, size and the like of the thin-walled flexible metal pipe used in the present invention are appropriately selected depending on the intended use of the water supply piping device obtained by the present invention. It is not particularly limited. For example, when the water supply piping device of the present invention is used as unwinding piping for a fire extinguishing sprinkler, it is conceivable to use, for example, a stainless bellows tube having a thickness of about 0.3 mm to 0.6 mm.

In the present invention, it is essential that the outer circumference of the thin-walled flexible metal tube be covered with a protective sleeve made of aromatic polyamide fiber. As the aromatic polyamide fiber, for example, an assembly of para-based or meta-based long fibers, or an assembly of fibers spun para-based or meta-based short fibers, in the present invention,
For example, it is preferable to use highly heat-resistant and highly flame-resistant para-based fibers that are unlikely to melt or burn due to contact with an electric welding rod or electric welding sparks. Generally, there is a limiting oxygen index for evaluating flame resistance, but the aromatic polyamide fiber used in the present invention has a limiting oxygen index of 25% or more. As fibers having a limiting oxygen index of 25% or more, there are, for example, flame-retarded polyester fibers in addition to aromatic polyamide fibers. However, these fibers are difficult to fire but are exposed to high temperatures. It is not preferable because it has a drawback that it melts. Among the para-type aromatic polyester fibers, long fibers are preferable because they are superior in tensile strength and have less yarn breakage and fuzz during braiding.

The thickness of the aromatic polyamide fiber is 1
00 denier or more and 2000 denier or less, preferably
A material having a density of 400 to 1500 denier is used. If the density is less than 100 denier, the number of converging fibers (the number of aligned fibers) must be increased in order to obtain a desired shielding rate. In this case, however, the fibers are sagged when braided, resulting in poor appearance. This may cause breakage, yarn breakage or fluff. Further, when it exceeds 2000 denier, the thickness of the protective sleeve obtained becomes too thick, which makes it difficult to coat a thin metal flexible tube and increases the cost.

One or more of the above aromatic polyamide fibers are aligned or twisted and used to form a protective sleeve by braiding in a tubular shape by a conventionally known stringing method. At this time, it is preferable that the braid be formed so that the shielding ratio is 70% or more and 95% or less. Shielding rate is 70
If it is less than%, a gap is generated in the braid of the protective sleeve, which is not preferable because there is a concern that electric welding sparks may adversely affect the thin flexible metal pipe. On the other hand, the shielding rate is 9
When it exceeds 5%, the degree of freedom of the protective sleeve is impaired and the elasticity is reduced, so that the work of coating the thin-walled metal flexible pipe becomes difficult. The shielding rate in the present invention is calculated by the following equation (I).

[0015]

In the present invention, when a thin metal flexible tube is coated with a protective sleeve, a silicone varnish, a silicone resin or the like diluted to an appropriate viscosity and concentration is used to prevent fraying of both ends of the protective sleeve. The fibers may be bonded to each other by applying or immersing them on the end of the protective sleeve.

The thin-walled metal flexible tube covered with the protective sleeve is connected to an external device by a predetermined connecting means and is put to practical use. The connecting means is appropriately selected depending on the intended use, and is not particularly limited. For example, when the water supply piping device of the present invention is used as unwinding piping for a fire extinguishing sprinkler, for example, a cap nut or the like may be used to connect it to the sprinkler head mounting pipe.

The water supply piping device of the present invention thus obtained can surely prevent expansion of the thin-walled metal flexible pipe and damage from the outside, and also improve workability of the piping work. Becomes

[0019]

EXAMPLES The following examples show examples in which the water supply piping system of the present invention is applied to unwinding piping for fire extinguishing sprinklers. In this embodiment, a stainless steel bellows tube having an outer diameter of 26 mm and a wall thickness of 0.6 mm is used as the thin-walled metal flexible tube, and after covering it with a protective sleeve having the configuration described below, one end of the water supply tube is It was connected to the branch joint and the other end to a sprinkler head mounting pipe having a sprinkler head by using a conventionally known connecting means such as a cap nut.

Example 1 One para-aromatic polyamide long fiber (thickness 1500 denier, limiting oxygen index 25%, specific gravity 1.39) was used, and a braiding density of 15 stitches / 25 mm was used with a 96-strand braiding machine. Was braided into a cylinder to produce a protective sleeve having a shielding rate of 90%.

Example 2 Para-aromatic polyamide long fibers (thickness 100 denier,
A protective sleeve with a limiting oxygen index of 25% and a specific gravity of 1.39) is used. Was produced.

Example 3, Example 4, Comparative Example 1, Comparative Example 2 In Example 3, Example 4, Example 4, Comparative Example 1 and Comparative Example 2, the braiding specifications (shielding ratio) of the protective sleeve in Example 1 described above were used. It is an example of the changed one. That is, Example 3 has a braid density of 2
A protective sleeve having a shielding rate of 95% was prepared by changing to 0/25 mm. In Example 4, the braid density was changed to 10 stitches / 25 mm to produce a protective sleeve having a shielding rate of 70%. In Comparative Example 1, the braid density was changed to 8 stitches / 25 mm and the shielding rate was 65%.
% Protective sleeve was made. Comparative Example 2 has a braid density of 2
A protective sleeve having a shielding rate of 100% was prepared by changing to 5 meshes / 25 mm.

The following comparative examples are examples in which the constituent material of the protective sleeve is changed. The shielding rate was set to 90% as in Examples 1 and 2 above.

Comparative Example 3 A single polyester fiber (thickness 1800 denier, limiting oxygen index 22%, specific gravity 1.38) was used and braided in a tubular shape with a braiding density of 96 stitches at a braid density of 17 stitches / 25 mm. Then, a protective sleeve having a shielding rate of 90% was produced.

COMPARATIVE EXAMPLE 4 A twelve polyester braiding machine was used in which 12 flame-retarded polyester fibers (thickness 150 denier, limiting oxygen index 26%, specific gravity 1.38) were aligned. Braid density 1
A protective sleeve having a shielding rate of 90% was produced by braiding in a cylindrical shape with 7 meshes / 25 mm.

Comparative Example 5 One novoloid fiber (thickness 2000 denier, limiting oxygen index 30%, specific gravity 1.27) was used, and was braided in a tubular shape with a braiding density of 96 stitches at a braid density of 15 stitches / 25 mm. Then, a protective sleeve having a shielding rate of 90% was produced.

Comparative Example 6 Alkali-free glass fiber (540TEX count, specific gravity 2.8
4) Using one strand, braid density 15 with 96-strand
A protective sleeve having a shielding rate of 90% was produced by braiding in a cylindrical shape with eyes / 25 mm.

Here, the characteristics of the protective sleeve were evaluated using the 10 kinds of water supply piping devices thus manufactured as samples. The evaluation items were flame resistance, spatter resistance, abrasion strength, hydraulic strength and workability, and the following tests were carried out. The results are shown in Table 1.

Flame Resistance First, absorbent cotton was laid on a horizontal desk, and a gas burner having an inner diameter of 3/8 inch adjusted to have an outer flame of 5 inches and an inner flame of 1.5 inches was placed thereon. Next, above the gas burner,
The sample was held horizontally so that the tip of the internal flame of the gas burner was in contact with the protective sleeve surface. After the gas burner was ignited for 10 seconds, the flame was removed, and the ignition and burning time of the protective sleeve at this time was measured by a stopwatch, and the time until self-extinguishing was defined as the burning time. In addition, it was visually observed whether the absorbent cotton burned due to the dripping phenomenon during the period from ignition to self-extinguishing. Further, after the test was completed, it was visually observed whether a hole was formed on the surface of the protective sleeve due to melting or shrinkage of the fiber.

Spatter resistance At a position 30 cm above the sample held horizontally, the galvanized steel pipe and the welding rod for iron are brought into contact with each other to generate welding sparks,
This was allowed to fall on the sample for 30 seconds. Then, it was visually confirmed whether or not a hole was formed on the surface of the thin metal flexible tube.

Abrasion Strength First, the tape abrasion strength was measured according to JIS C 3406. At this time, the type of tape used was 150 AA. Next, the blade wear strength was measured according to the blade reciprocation method (load 510 g) of the wear resistance test of JASO D608.

Water pressure strength A predetermined water pressure (internal fluid pressure) is applied inside the thin metal flexible pipe.
Was added to conduct a water pressure test, and the pressure when the protective sleeve was damaged by the expansion of the thin-walled flexible metal tube was measured.

Workability The workability of coating the protective sleeve on the thin-walled metal flexible tube was evaluated, and if the coating work was difficult, it was determined to be "poor". Further, it was visually observed whether the fluff of the fibers forming the protective sleeve was scattered during the covering operation.

[0034]

[Table 1]

According to the results shown in Table 1, first, regarding flame resistance, Comparative Example 1 provided with a protective sleeve made of polyester fiber and Comparative Example 2 provided with a protective sleeve made of flame-retarded polyester fiber In both cases, a hole was formed in the surface of the protective sleeve, and the thin metal flexible tube inside was exposed, whereas no abnormality was observed in any of the examples.

Regarding the spatter resistance, no abnormality was observed in any of the examples, but although the aromatic polyamide fiber was used, the shielding rate was at the lower limit of the preferred range (70). In Comparative Example 1 in which the ratio was less than 100%, a gap was formed in the braid, which caused a partial hole in the surface of the thin metal flexible tube. Further, in both Comparative Example 1 having a protective sleeve made of polyester fiber and Comparative Example 2 having a protective sleeve made of flame-retarded polyester fiber, holes were formed on the surface of the protective sleeve due to welding sparks. There was also a hole in the surface of the thin metal flexible tube.

Regarding the abrasion strength and the hydraulic strength, the strength of the present embodiment is significantly higher than that of Comparative Example 5 having a protective sleeve made of novoloid fiber and Comparative Example 6 having a protective sleeve made of glass fiber. showed that.
Among the present examples, Example 1, Example 3 and Example 4 in which one aromatic polyamide fiber is used for braiding,
The strength is superior to that of Example 2, which is braided by using a plurality of aromatic polyamide fibers aligned.

Regarding workability, both Comparative Example 5 provided with a protective sleeve made of novoloid fiber and Comparative Example 6 provided with a protective sleeve made of glass fiber had a problem in safety and hygiene due to scattering of fluff. However, no scattering of fluff was observed in the example. In Comparative Example 2 in which the shielding rate of the protective sleeve exceeds the upper limit value (95% or less) of the preferred range of the present invention, some difficulty was observed in the covering work.

As described above, all of the examples according to the present invention have excellent flame resistance, spatter resistance, abrasion strength, hydraulic strength, and workability, and are used for expanding thin-walled metal flexible pipes and externally. It was proved that the damage can be surely prevented and the workability of the piping work can be improved. Also, when forming the protective sleeve,
It was proved that braiding one aromatic polyamide fiber is more preferable in terms of abrasion strength and hydraulic strength than braiding a plurality of aromatic polyamide fibers in parallel. Further, it was proved that the shielding rate during braiding is preferably 70% or more and 95% or less in terms of spatter resistance and workability.

[0040]

As described in detail above, according to the present invention, by using an aromatic polyamide fiber as a constituent material of a protective sleeve for covering a thin-walled metal flexible pipe, it is possible to expand the thin-walled metal flexible pipe. It has become possible to provide a water supply piping device capable of reliably preventing damage from the outside and improving the workability of piping work. Therefore, it can be suitably used, for example, as an unwinding pipe for a fire extinguishing sprinkler.

Claims (3)

[Claims] 1. A water supply piping device comprising a thin-walled metal flexible pipe, a protective sleeve coated on the outer circumference of the flexible pipe, and a connecting means for connecting the flexible pipe to an external device. The water supply piping device, wherein the sleeve is formed by braiding aromatic polyamide fibers in a tubular shape. 2. The water supply piping device according to claim 1, wherein the protective sleeve is formed by braiding an aromatic polyamide fiber having a thickness of 100 denier or more and 2000 denier or less in a tubular shape. 3. The water supply piping device according to claim 1, wherein the protection sleeve has a shielding rate of 70% or more and 95% or less.