JPH0743058B2 - Hot water supply / water supply piping - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to hot water supply or water supply piping constructed by a sheath pipe header method.

<Prior Art> Conventionally, when hot water or water is supplied to various places in a building, a trunk pipe is laid, and a pipe in which branch pipes are branched and connected to the above-mentioned places is used in the middle of the trunk pipe. However, in such a piping structure, if water is simultaneously passed through a large number of branch pipes, the discharge amount becomes smaller toward the branch pipe on the far end side of the main pipe, and uniform hot water supply or water supply becomes difficult and the main pipe length increases. There is a problem in the case of a hotel, a building, or a high-rise group house where there is a large number of branch pipes on the way.

For this reason, hot water supply or water supply pipes in hotels, buildings, etc. are provided with hot water supply / water supply headers 4'on the near end side of hot water supply or water supply, as shown in FIG.
, A so-called header construction method for extending a plurality of branch pipes 3 '... has been developed. For its construction, a pipe sheath pipe 3' ... The hot water supply pipes or the water supply pipes 3 ′, ... The so-called sheath pipe method is used because of its advantages such as ease of pipe renewal work.

As described above, in the so-called sheath pipe header construction method in which the header piping system and the sheath pipe construction method are combined, a pipe structure in which the hot water supply pipe and the water supply pipe are passed inside the sheath pipe is provided.

<Problems to be Solved> However, the hot water supply / water supply pipe constructed by the sheath pipe header method has the following problems.

(1) The inner tube is loosely housed in the sheath tube, the inner tube easily vibrates, the water hammer phenomenon is intense, and the collision noise is intense. If much of the vibration energy of the water hammer source can be absorbed as strain energy of the pipe material, the water hammer phenomenon can be alleviated and the collision noise can be reduced, but in the above hot water supply / water supply pipes, the sheath pipe is distorted and deformed in the pipe axis direction. Although it is a flexible tube that is easy to do,
It is difficult to transfer vibration energy to the sheath tube, and the water hammer phenomenon is intense.

(2) Water easily accumulates in the sheath pipe due to dew condensation on the surface of the inner pipe, and in the case of the hot water supply pipe, the heat loss increases remarkably. An air layer exists between the inner pipe and the sheath pipe, but it is difficult to use this air layer as an effective heat insulating layer due to the accumulated water in the sheath pipe.

The object of the present invention is to provide a hot water supply / water supply system that can reduce the above water hammer phenomenon in a hot water supply / water supply pipe to be constructed by the sheath pipe header method and effectively use the air layer of the inner pipe and the sheath pipe as a heat insulating layer. To provide a tube.

<Means for Solving the Problem> The hot water supply / water supply pipe according to the present invention has a hot water supply pipe or a water supply pipe as described above in a corrugated flexible plastic sheath pipe having three or more recesses continuous on the outer surface in the pipe axial direction. The configuration is characterized in that the inner tip of the recess is supported substantially concentrically in the sheath tube.

<Operation> With this configuration, vibration energy can be well transmitted to the flexible sheath tube with a wave, and a large strain can be generated in the sheath tube due to the flexibility of the sheath tube. Because of this, the water hammer phenomenon can be buffered and the occurrence of collision noise can be reduced. Furthermore, since the inner pipe can be positioned at the center of the sheath pipe, the contact of the inner pipe with the accumulated water can be avoided and the hot water supply pipe can be satisfactorily insulated with the air layer when the condensed water is in the sheath pipe.

The hot water supply / water supply pipe according to the present invention is used in the sheath pipe header construction method, and it is necessary to have good pipe permeability. In the present invention, however, since the recess that is continuous in the axial direction of the pipe is used as the means for supporting the inner pipe, the contact pressure between the inner tip of the recess and the inner pipe can be lowered, and good ductility is achieved. Can be guaranteed.

<Description of Embodiments> Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1A is an explanatory view showing an embodiment of the present invention, FIG. 1B is a bb sectional view in FIG. 1A, and FIG. 1C is a cc sectional view in FIG. 1B.

In FIGS. 1A to 1C, reference numeral 1 is a flexible sheath tube made of plastic (for example, polyethylene) with a corrugation, and has a rectangular corrugated shape having ring-shaped rectangular peaks 11 and rectangular valleys 12 alternately. It is corrugated. 2, ... Recesses that are continuous in the tube axis direction, and 3 to 6 recesses are provided at equal circumferential intervals. The above corrugation is also applied to the pipe wall 21 that constitutes the recess 2. Reference numeral 3 denotes a hot water supply pipe, and a plastic inner pipe (polyethylene, cross-linked polyethylene, polybutene) as a water supply pipe, which is supported by the inner ends 22 of the recesses 2, ... In a position substantially concentric with the sheath pipe 1. .

The corrugated flexible sheath tube can be manufactured by forming a plastic strip having a square wave and a concave portion into a tubular shape, and joining the vertical joints by welding or the like. Also, a plastic tube is extruded in a shape having a circular recess,
It can be manufactured by subsequently extruding the outer peripheral portion using a corrugator to form irregularities in the circumferential direction, or by using a corrugator to expand the diameter by decompression to form the irregularities in the circumferential direction. Further, a rectangular wave may be corrugated by a corrugator following extrusion molding of a plastic tube, and the recess may be formed by a roll. At the time of forming the recess, the plastic tube is considerably solidified, and even if the tube wall is recessed by the roll, the expansion of the tube wall can be well prevented, and the square corrugation in the recess can be sufficiently maintained.

To construct the hot water supply / water supply pipe, a sheath pipe is arranged at the time of building a building, and a plastic inner pipe is passed through the sheath pipe at a later date.

In this case, in the curved route, the sheath tube is slightly flattened, so that the space between the inner tips of the recesses is narrowed, and during passage, the sheath is expanded by the inner tube so that the space between the inner tube and the inner tip of the recess is reduced. The contact pressure acts as the expansion reaction force. Also in the straight route, if the distance between the inner tips of the recesses and their centers is smaller than the inner pipe radius, the contact pressure acts. However, as shown by the dotted line in FIG. 2, the expansion of the mouth 23 of the recess 2 greatly contributes to the expansion of the diameter of the sheath or the like, and this expansion occurs with a relatively small tip pressing force P. The pressure can be kept small (for example, when the inner pipe support cannot be expanded, the sheath pipe wall must be stretched by circumferential tension, so that the contact pressure is significantly high), and good communication is achieved. Can maintain tubularity. Also, the recess 2
By making the shape of the shape as shown in FIG. 3, it is possible to further reduce the contact pressure at the time of pipe passage.

<Effects of the Invention> The hot water supply / water supply pipe according to the present invention is configured as described above, and it is possible to support the hot water supply / water supply pipe from the surroundings in the sheath pipe while maintaining the good ductility of the hot water supply / water supply pipe. Moreover, since its supporting position can be located in the center of the sheath tube, the vibration energy of the water hammer phenomenon is transmitted to the flexible sheath tube under the sheath tube header construction method, and the water hammer phenomenon is well absorbed by absorbing the strain energy. In addition, it is possible to guarantee an excellent heat insulating effect on the inner pipe by preventing contact between the accumulated water and the inner pipe due to dew condensation in the sheath pipe.

[Brief description of drawings]

1A is an explanatory view showing an embodiment of the present invention, FIG. 1B is a bb sectional view in FIG. 1A, FIG. 1C is a cc sectional view in FIG. 1B, and FIG. FIG. 3 is an explanatory view showing a contact pressure acting between a sheath pipe and an inner pipe in the present invention, FIG. 3 is a partial sectional view showing another embodiment of the present invention, and FIG. 4 is a known sheath pipe header. It is explanatory drawing which shows a construction method. 1 ... Sheath tube, 11 ... Wave peak, 12 ... Wave trough, 2 ...
Recess, 3 ... Hot water supply pipe or water supply pipe.

Claims (1)

[Claims] 1. A hot water supply pipe or a water supply pipe is supported by a corrugated flexible plastic sheath pipe having three or more recesses continuous on the outer surface in the pipe axial direction at substantially concentric positions inside the sheath pipe by the inner end of the recess. Hot water supply / water supply piping that is characterized by