JP2008255625A - Drain pipe system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce construction cost of the whole drain pipe system by simplifying an offset structure. <P>SOLUTION: This drain pipe system is constituted so that an inner diameter of a horizontal pipe 1 is formed larger than an inner diameter of both vertical pipes 45 and 46 on the upstream side and the downstream side, to a degree capable of securing a ventilation core in the horizontal pipe 1, and an inner diameter of an upstream side connecting pipe 20 becomes equal to the inner diameter of the horizontal pipe 1 in a connecting position with the upstream side of the horizontal pipe 1 by diametrically expanding from a state of being equal to the inner diameter of the upstream side vertical pipe 45, and an inner diameter of a downstream side connecting pipe 25 becomes equal to the inner diameter of the downstream side vertical pipe 46 in a connecting position with the downstream side vertical pipe 46 by diametrically contracting from a state of being equal to the inner diameter of the horizontal pipe 1. Thus, the ventilation core in the horizontal pipe 1 can be secured only by expanding the inner diameter of the horizontal pipe 1 and using an elbow of a special shape for the connecting pipe, and since there is no need to arrange a bypass passage, material cost of a bypass ventilation pipe itself can be reduced, and since a penetrating structure of a slab S is not required when arranging the bypass ventilation pipe, labor and cost of construction are not required by that extent, and design of skeleton strength is also facilitated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a drainage pipe system for a multi-story building, and more particularly to an improvement in the structure of the offset portion.

  In a multi-storey building such as an ordinary apartment house, as shown in FIG. 6, sanitary ware 41 and the like on each floor are connected to a vertical pipe 40 arranged vertically through a lateral branch pipe 42. The horizontal branch pipe 42 is provided with a trap 43 for preventing the backflow of drainage in the drain pipe. In the figure, 44 is a drainage collective joint.

  However, when the size of the dwelling unit or the room layout is different between the upper floor side or the lower floor side of the floor in the middle of the multi-story building, the standpipe 40 cannot be arranged in a straight line. As schematically shown in Fig. 7, on the intermediate floor (for example, the 14th floor in the figure) whose space, room layout, etc. are different, there is a vertical pipe (hereinafter referred to as the upstream side vertical pipe 45) coming down there, The downstream side vertical pipe 46 and the former upstream side vertical pipe 45 are divided into vertical pipes (hereinafter referred to as downstream side vertical pipes 46) that reach the subsequent floors, and the downstream side vertical pipes 46 are horizontally displaced. Are connected via a horizontal pipe 50 arranged horizontally. At that time, the upstream side vertical pipe 45 and the horizontal pipe 50, and the horizontal pipe 50 and the downstream side vertical pipe 46 are connected by the upstream side connecting pipe 47 and the downstream side connecting pipe 48, respectively. Such an offset structure has the following problems.

  That is, in such an offset structure, the offset portion from the upstream connection pipe 47 through the horizontal pipe 50 to the downstream connection pipe 48 is partially filled with water, and the horizontal space on the upper floor of the floor having the offset structure is filled. When a large amount of drainage flows from the branch pipe, the air in the upstream side pipe 45 immediately above the offset portion is compressed, and the trap 43 such as a sanitary instrument connected therebetween may be destroyed.

Therefore, in order to prevent the trap 43 from being destroyed due to the compression of the air in the upstream side stand pipe 45, for example, in the drain pipe system disclosed in Patent Document 1 below, FIG. As shown in FIG. 4, the bypass is configured to connect the drainage collecting joint 44 between the upstream side vertical pipe 45 and the horizontal pipe 50 and the drainage collecting joint 44 between the downstream side vertical pipe 46 and the horizontal pipe 50. A configuration in which a vent pipe 49 is provided is disclosed.
JP 2002-220862 A, paragraph 0004

  However, such a configuration is applied to the basic drainage pipe system composed of the upstream and downstream compatible pipes 45 and 46, the horizontal pipe 50 and the upstream and downstream connecting pipes 47 and 48 connecting them. Since the bypass vent pipe 49 is separately provided, an extra material cost is required for the bypass vent pipe 49 itself, and a part of the bypass vent pipe 49 penetrates the slab S in order to form the bypass passage. Since the structure (in FIG. 7, the floor slab S on the 15th floor is also penetrated), it takes time and effort to install it, and the construction cost increases accordingly, There is a problem. See Patent Document 1 above, paragraph 0004.

  SUMMARY OF THE INVENTION An object of the present invention is to enable an offset structure in a drainage pipe system of a multi-story building to be realized with less labor and less cost than conventional.

  In order to achieve the above object, the invention according to claim 1 is directed to a drainage pipe system in which a standing pipe of a drainage pipe system of a multi-story building is offset piped via a horizontal pipe between drainage collecting joints on upper and lower floors. Thus, a configuration is adopted in which the cross-sectional area of the horizontal pipe is larger than the cross-sectional areas of the upstream and downstream vertical pipes of the offset portion so that the ventilation core in the horizontal pipe can be secured.

  Since it did in this way, a ventilation core is ensured in the horizontal tube of an offset part.

  Next, in the invention according to claim 2, in the invention according to claim 1, a straight pipe in which an upstream connecting pipe that connects the upstream standing pipe and the horizontal pipe of the offset portion is connected to the upstream standing pipe. And a bent pipe connected to the horizontal pipe, and flowing water from the upstream side pipe on the inner wall surface of the straight pipe portion on the curvature center side of the bent portion. A configuration is adopted in which a protrusion is provided so as to be guided to the inner wall surface on the side opposite to the center of curvature of the portion.

  By doing so, the protrusion prevents the drainage flowing down along the inner wall of the straight pipe portion from colliding with the bent portion, and continues to flow down from the inner wall surface of the straight pipe portion along the inner wall surface of the bent portion. become.

  Further, the invention according to claim 3 is the invention according to claim 1 or 2, wherein the downflow water from the horizontal pipe is formed on the side wall inner surface of the downstream connection pipe connecting the downstream vertical pipe and the horizontal pipe of the offset portion. In this case, a configuration is adopted in which a guide surface is provided so as to flow into the downstream side vertical pipe in the form of a swirling flow along the inner periphery of the vertical pipe.

  By doing so, in the downstream side vertical pipe, the falling water flows down the inner surface of the vertical pipe along its inner periphery.

  Furthermore, in the invention according to claim 4, in the invention according to claim 3, a configuration in which a cleaning port is provided in the downstream connection pipe is adopted.

  By doing so, cleaning in this place where the solid matter in the drainage is most likely to accumulate becomes easy.

  According to the present invention, since the ventilation core in the horizontal pipe is secured by the above-described configuration, the bypass ventilation pipe in the conventional offset portion can be eliminated, the material cost of the bypass ventilation pipe itself can be reduced, and the bypass Since the structure for penetrating the slab S when the vent pipe is provided is not required, the labor and cost for the construction are not required, and the design of the frame strength is facilitated. Therefore, as a whole, it is possible to construct a drain pipe system that is easy to design and construct and has a low construction cost.

  Further, according to the invention of claim 2, the action of the projection in the bent pipe which is the upstream connecting pipe, that is, the drainage flowing down along the inner wall of the straight pipe portion continues to flow along the inner wall surface of the bent portion. By preventing the phenomenon that the drainage collides with the bent portion, the ventilation core in the upstream connection pipe is secured, which is the purpose of the present invention, securing the ventilation core in the horizontal pipe, This has the effect of further stabilizing the state. Moreover, the generation of noise due to the collision of drainage in the upstream connecting pipe is also prevented.

  Furthermore, according to the invention of claim 3, the action of the guide surface shape of the side wall inner surface of the downstream connection pipe, that is, the inflow drainage from the horizontal pipe is swung along the inner circumference of the vertical pipe with respect to the downstream vertical pipe. The effect of inflowing in the form of a flow also adds the effect of securing the vent core of the downstream side vertical pipe, so the drainage pipe system as a whole can strongly suppress abnormal air pressure fluctuations in the pipe, prevent trap destruction, This has the effect of providing an effective means for preventing noise.

  According to the fourth aspect of the present invention, in the downstream side connecting pipe where deposits are most likely to accumulate, the inside of the pipe can be easily cleaned through the cleaning port when checking the drainage system. There is an effect that the occurrence can be prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. About the same element as the past, the same code | symbol is attached | subjected and description is abbreviate | omitted. FIG. 1 is a partial schematic view of a drain pipe system having an offset structure of the present invention. In addition, the following pipes are basically all circular in cross-sectional shape.

  As shown in FIG. 1, in this drain pipe system, a vertical pipe 40 descending vertically from the uppermost floor is connected to an upstream side vertical pipe by a horizontal pipe 1 on an intermediate floor (14th floor in the figure) where an offset portion is formed. 45 and the downstream vertical pipe 46, the lower end of the upstream vertical pipe 45 is located upstream of the horizontal pipe 1 via the upstream connection pipe 20, and the upper end of the downstream vertical pipe 46 is downstream connection pipe 25. What is connected to the downstream side of the horizontal pipe 1 via the is the basic structure. This basic structure is the same as that of the drainage pipe system shown in FIG.

  The drain pipe system of the present invention differs from the conventional one shown in FIG. 7 in that the bypass vent pipe 49 in FIG. 7 is eliminated, and as an alternative configuration, the inner diameter of the horizontal pipe 1 of the offset portion is upstream and downstream. That is, the inner diameter of the compatible tubes 45 and 46 on the side is larger.

  Accordingly, the upstream side connecting pipe 20 that connects the upstream side vertical pipe 45 and the upstream side of the horizontal pipe 1 also has an inner diameter equal to that of the upstream side vertical pipe 45 at the connection position with the upstream side vertical pipe 45. The diameter is increased toward the downstream, and is equal to the inner diameter of the horizontal tube 1 at the connection position with the horizontal tube 1.

  On the other hand, the downstream side connecting pipe 25 connecting the downstream side of the horizontal pipe 1 and the downstream side vertical pipe 46 has an inner diameter equal to that of the horizontal pipe 1 at the connection position with the horizontal pipe 1 and thereafter shrinks downstream. The diameter is gradually increased and is equal to the inner diameter of the downstream side standpipe 46 at the connection position with the downstream side standpipe 46. The above is the basic configuration of the drainage pipe system of the present invention. With this configuration, the ventilation core in the horizontal pipe 1 is secured. Hereinafter, details of the embodiment of the present invention will be described.

(First embodiment)
In the first embodiment, the inner diameter of the horizontal pipe 1 is larger than the inner diameters of the upstream and downstream compatible pipes 45 and 46, and the upstream connecting pipe 20 is a straight pipe portion 21 as shown in FIG. And a large bend elbow joint composed of the bend portion 22 and the bend portion 22. 2A is a plan view thereof, and FIG. 2B is a front view including a partial cross section. The inner diameter of the upper end of the straight pipe portion 21 is equal to the inner diameter dimension of the upstream side stand pipe 45 indicated by a two-dot chain line in the figure. On the other hand, the inner diameter at the right end of the bent portion 22 in the drawing is equal to the inner diameter of the horizontal tube 1 indicated by a two-dot chain line in the drawing.

  Further, as shown in FIG. 3, the downstream connection pipe 25 is one in which the joint of FIG. 2 is turned upside down. The inner diameter at the left end of the bent portion 26 in the figure is equal to the inner diameter dimension of the horizontal tube 1 indicated by a two-dot chain line in the figure. On the other hand, the inner diameter dimension of the lower end of the straight pipe portion 27 is equal to the inner diameter dimension of the downstream side standpipe 46 indicated by a two-dot chain line in the figure.

(Second Embodiment)
In the second embodiment, a joint having a special shape is used as both the upstream and downstream connecting pipes. FIG. 4 shows the upstream connecting pipe 30 of the second embodiment, and FIG. 5 shows the downstream connecting pipe 35 of the second embodiment. Other configurations are the same as those of the first embodiment.

  First, as shown in FIG. 4, the appearance of the upstream side connecting pipe 30 is the same as that shown in FIG. 2 of the first embodiment, but has an internal structure. That is, the drainage that has flowed down from the upstream side pipe 45 to the side 31a that is connected to the inner wall 32a on the side near the center of curvature of the bent part 32 of the inner wall of the straight pipe part 31 that is connected to the lower end of the upstream side pipe 45. The guide plate 33 is provided for guiding the inner wall 32b away from the center of curvature of the bent portion 32 as a swirling flow.

  In this way, the drainage flowing down from the upstream side pipe 45 to the upstream side connection pipe 30 causes the guide plate 33 to cause the swirling flow on the inner wall surface of the straight pipe portion 31 to the bottom surface of the bent portion 32. Without falling, it continues to be a swirling flow and flows down along the inner periphery of the bent portion 32.

  Therefore, the ventilation core is firmly secured in the upstream connection pipe 30, and the securing of the ventilation core is made stable for the lateral pipe 1 on the downstream side.

  On the other hand, the downstream side connecting pipe 35 shown in FIG. 5 has a shaft in the vertical direction of the drawing as shown in FIG. The resulting shape is used as the substrate 36.

  The lower end of the cylinder of the base body 36 has a flange shape 37, and the downstream side standpipe 46 indicated by a two-dot chain line is connected to the flange shape 37. Further, as shown in FIG. 5B, a branch pipe 38 whose axis is eccentric from the axis 36a of the base body 36 protrudes in the horizontal direction from the open part of the left side surface of the base body 36 as shown in FIG. Is made.

  The downstream end of the horizontal pipe 1 indicated by a two-dot chain line is connected to the left side (upstream side) of the branch pipe 38 in the drawing. In the present invention, the inner diameter of the horizontal pipe 1 is larger than the inner diameters of the upstream and downstream compatible pipes 45 and 46. Therefore, the inner diameter of the branch pipe 38 to which the horizontal pipe 1 is connected is also the horizontal pipe 1. The outer circumference of the tube is fittable and is larger than the inner diameter of the downstream side standpipe 46.

  As shown in FIG. 5 (c), the inner surfaces 39 a of both side walls 39 of the branch pipe 38 of the downstream connection pipe 35 allow the inflow and drainage from the horizontal pipe 1 to stand up against the downstream side stand pipe 46. Both side walls 39 facing each other so as to swirl along the cylindrical inner surface of the base body 36 immediately before the drainage flows into the downstream vertical pipe 46 in order to flow in the form of a swirling flow swirling along the inner circumference of the pipe. , 39 form a pair of guide surfaces.

  By doing in this way, the waste water flowing into the downstream connecting pipe 35 from the horizontal pipe 1 is swung along the inner periphery of the base 36 as shown in FIG. 5C in the base 36 of the downstream connecting pipe 35. The flow then flows into the downstream vertical pipe 46 in the form of a swirling flow. Therefore, the ventilation core is firmly secured in these pipes, and the trap is not easily broken.

  The upper surface of the base body 36 of the downstream connection pipe 35 is provided with an opening for cleaning, and a lid 36b is provided there.

Moreover, in each said embodiment, although the cross-sectional shape of the horizontal tube 1 was made into the perfect circle, it is good also as an egg-shaped thing which made the taper side down. In the egg shape, drainage swirling from the upstream connecting pipe and flowing into the horizontal pipe collide with each other, and the swirling energy of the drainage disappears. This is because the air core in the horizontal tube is not easily blocked. Next, a comparative experiment for showing the effect of the present invention will be described.
[Experimental results of examples and comparative examples]

Example 1
In Example 1, the configuration of the first embodiment was applied, and the large bend elbow joint 20 shown in FIG. 2 was used as the upstream connecting pipe. The straight pipe portion 21 connected to the lower end of the upstream side pipe 45 has an inner diameter of 100 mm at the connection position (upper end in the figure) with the upstream side vertical pipe 45 and the bent portion 22 connected to the upstream side of the horizontal pipe 1. A connecting part (right end in the figure) having an inner diameter of 125 mm was used.

  Further, as the downstream connection pipe 25, the large pipe elbow joint shown in FIG. 3 of the first embodiment is also used, and the horizontal pipe 1 of the bent section 26 connected to the downstream end of the horizontal pipe 1 is used. The inner diameter of the connecting position (left end in the figure) is 125 mm, the inner diameter of the connecting position (lower end in the figure) of the straight pipe portion 27 connected to the upper end of the downstream side standing pipe 46 and the downstream side standing pipe 46 is 100 mm. The thing of was used.

(Example 2)
In Example 2, the configuration of the first embodiment was applied, and the large bending elbow joint 20 shown in FIG. The straight pipe portion 21 connected to the lower end of the upstream side pipe 45 has an inner diameter of 100 mm at the connection position (upper end in the figure) with the upstream side vertical pipe 45 and the bent portion 22 connected to the upstream side of the horizontal pipe 1. The connecting part (the right end in the figure) had an inner diameter of 150 mm.

  Further, as the downstream connecting pipe, the large pipe elbow joint 25 shown in FIG. 3 of the first embodiment is also used, and the horizontal pipe 1 of the bent section 26 connected to the downstream end of the horizontal pipe 1 is used. The inner diameter of the connecting position (left end in the figure) is 150 mm, and the inner diameter of the connecting position (lower end in the figure) of the straight pipe portion 27 connected to the upper end of the downstream standing pipe 46 is 100 mm. Used

(Example 3)
In Example 3, the connection pipes between the upstream pipes 45 and 46 and the horizontal pipe 1 on the upstream side and the downstream side, respectively, have the shapes shown in FIGS. 4 and 5 of the second embodiment.

  And the internal diameter of the connection part with the upstream standing pipe 45 of the upstream connection pipe 30 was 80 mm, and the internal diameter of the connection part with the horizontal pipe 1 was 100 mm.

  On the other hand, the inner diameter of the connection portion between the downstream connection pipe 35 and the horizontal tube 1 was 100 mm, and the inner diameter of the connection portion with the downstream side stand pipe 46 was 80 mm.

(Comparative Example 1)
Comparative Example 1 is for comparison with Examples 1 and 2. As in the present invention, the inner diameter of the horizontal tube 1 of the offset portion is larger than the inner diameters of the compatible tubes 45 and 46 on the upstream side and the downstream side. 7 is a drainage pipe system without the vent pipe 49 in the configuration shown in FIG. 7, and the upstream and downstream compatible pipes 45 and 46 and the horizontal pipe 50, and the upstream and downstream sides connecting them. This is a drainage pipe system in which the inner diameters of both the connecting pipes 47 and 48 are constant. Both the upstream and downstream connecting pipes 47 and 48 were large bent elbow joints having a constant inner diameter over the entire length. In Comparative Example 1, the common inner diameter dimension was 100 mm.

(Comparative Example 2)
Comparative Example 2 is for comparison with Example 3, and in this case also, as in the present invention, the inner diameter of the horizontal pipe 1 of the offset portion is the inner diameter of the compatible pipes 45 and 46 on the upstream side and the downstream side. 7 is a drainage pipe system configured as shown in FIG. 7, in which the upstream and downstream compatible pipes 45 and 46 and the horizontal pipe 50 and both the upstream and downstream connections for connecting them are connected. This is a drain pipe system in which the inner diameters of all the pipes 47 and 48 are constant. Further, both the upstream and downstream connecting pipes 47 and 48 are large bent elbow joints having a constant inner diameter over the entire length. In Comparative Example 2, the common inner diameter was set to 80 mm.

  The above is the experimental drainage pipe system for comparing the example and the comparative example. The comparison items are the maximum generated positive pressure in the pipe within the drainage joint 44 in the slab S on the 15th floor and the 14th floor. The maximum generated negative pressure in the pipe in the drainage collective joint 44 in the slab S was taken.

  In FIG. 1 and FIG. 7 in the background art section, only the main parts of these drainage pipe systems that are relevant to the present invention are depicted, but these drainage pipe systems are also in Table 1 shown later. As described above, the experiment tower was designed assuming a multi-story building in which the top floor is the 17th floor and the bottom floor is the first floor. Table 1 also shows the drainage load flow rates on the 17th, 16th and 15th floors of this experimental drainage pipe system. Table 1 shows the numerical values and experimental results of each element related to the comparative experiment under the above configuration.

Table 1 shows, in the left column, Example 1, Example 2, Example 3, Comparative Example 1, and Comparative Example 2, in order from the left to the right, the inner diameter of the upstream side pipe 45 and the upstream connection. The inner diameters of both ends of the pipes 20 and 25, the inner diameter of the horizontal pipe 1, the inner diameters of both ends of the downstream connecting pipes 30 and 35, the inner diameter of the downstream vertical pipe 46, the drainage load flow rate on the 17th, 16th and 15th floors, as described above Each numerical value of the maximum generated positive pressure in the pipe and the maximum generated negative pressure in the pipe at the position is shown.

  As is clear from Table 1, in the case of Example 1 of the present invention, the maximum generated positive pressure in the pipe is 382 Pa, which is lower than the judgment standard of 400 Pa, and is significantly lower than the 582 Pa of Comparative Example 1, approximately 65%. The maximum generated negative pressure in the pipe is -366 Pa, which is lower than -400 Pa of the criterion, and is much lower than -506 Pa of Comparative Example 1, and is reduced to about 72%.

  Similarly, in the case of Example 2, the maximum generated positive pressure in the pipe is 358 Pa, which is lower than the determination standard of 400 Pa, and is greatly lower than the 582 Pa of Comparative Example 1 and reduced to about 61%, and the maximum generated in the pipe is The negative pressure is −349 Pa, which is lower than the criterion of −400 Pa, and is significantly lower than −506 Pa of Comparative Example 1, and is reduced to about 69%.

  Also in the case of Example 3, the maximum generated positive pressure in the pipe is 342 Pa, which is lower than the judgment standard of 400 Pa, and is greatly lower than 611 Pa of Comparative Example 2, being reduced to about 56%, and the maximum generation in the pipe is The negative pressure is −345 Pa, which is lower than the criterion −400 Pa, and is significantly lower than −531 Pa of Comparative Example 2, and is reduced to about 65%.

  As is clear from the comparative experiment described above, according to the present invention, “the inner diameter of the horizontal pipe 1 is made larger than the inner diameters of the upstream and downstream side vertical pipes 45 and 46 to such an extent that a ventilation core in the horizontal pipe 1 can be secured”. With this configuration alone, the occurrence of abnormal air pressure in the offset portion is prevented without providing a “bypass ventilation path”, and a ventilation core is secured.

  Therefore, as in the case where a conventional “bypass ventilation passage” is provided, the material cost of the bypass ventilation pipe 49 itself is required, and in order to form the bypass passage, A structure that partially penetrates the slab S is also required, and it takes time and labor to install the structure, and the construction cost increases.

  The present invention can be applied to piping of an offset portion in a drainage pipe system of a multi-story building.

1 schematically shows a drain pipe system having an offset structure according to the present invention. The upstream connecting pipe of the first embodiment is shown in a plan view in (a) and in a front view including a partial cross section in (b). The downstream connection pipe of 1st Embodiment is shown with the front view. The upstream connection pipe of the second embodiment is shown in a plan view in (a) and in a front view including a partial cross section in (b). The downstream connecting pipe of the second embodiment is shown in a front view in (a), in a plan view in (b), and in (c), the VV cross section of (a) is shown. It shows its action. The conventional example of the drainage pipe system of the multi-storey building without an offset structure is shown. The conventional example of the drainage pipe system of the multi-storey building which has an offset structure is shown typically.

Explanation of symbols

1, 50 Horizontal pipe 20, 30 Upstream connecting pipe 21, 31 Straight pipe section of upstream connecting pipe 22, 32 Bending section of upstream connecting pipe 25, 35 Downstream connecting pipe 26 Bending section of downstream connecting pipe 27 Downstream Straight pipe portion of side connecting pipe 33 Guide plate 36 Substrate of downstream connecting pipe 37 Flange shape 38 Branch pipe 39 Side wall of branch pipe 39a Inner surface of side wall of branch pipe 43 Trap 44 Collecting pipe 45 Upstream side pipe 46 Downstream side pipe 46 47 Upstream connection pipe 48 Downstream connection pipe 49 Bypass vent pipe

Claims (4)

In the drainage pipe system in which the vertical pipe of the drainage pipe system of the multi-story building is offset through the horizontal pipe between the drainage collecting joints on the upper and lower floors,
The drain pipe system characterized in that the cross-sectional area of the horizontal pipe is larger than the cross-sectional areas of the upstream and downstream vertical pipes of the offset portion so that a ventilation core in the horizontal pipe can be secured. In the drain pipe system according to claim 1,
The upstream connecting pipe that connects the upstream vertical pipe and the horizontal pipe of the offset portion is a bent pipe that includes a straight pipe portion connected to the upstream vertical pipe and a bent portion connected to the horizontal pipe. A projection that guides the falling water from the upstream side vertical pipe to the inner wall surface opposite to the curvature center side of the bent portion on the inner wall surface of the straight pipe portion on the curvature center side of the bent portion. A drainage pipe system characterized by being provided. The drainage pipe system according to claim 1 or 2,
On the side wall inner surface of the downstream side connecting pipe connecting the downstream side vertical pipe and the horizontal pipe of the offset portion, the flowing water from the horizontal pipe forms a swirl flow along the inner circumference of the vertical pipe with respect to the downstream side vertical pipe. A drainage pipe system characterized in that a guide surface adapted to flow in is provided. The drainage pipe system according to claim 3,
A drainage pipe system, wherein the downstream connection pipe is provided with a cleaning port.