JP3596073B2 - Pipe fittings for vacuum sewerage - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a pipe joint provided in a pipe for a vacuum type sewer and having an inspection port for introducing a test ball used for performing a vacuum test in the pipe.
[0002]
[Prior art]
Recently, with the spread of sewerage, sewer pipes have been installed even in lowlands, such as at zero meters above sea level, but there is no room to provide the required drainage gradient to the pipeline to the sewage treatment plant. In addition, when installing sewer pipes in an area where the density of living is lower than in urban areas, in order to provide the necessary drainage gradient, the burial depth of the sewer pipes will increase due to the length of the pipes, There is a problem that costs are enormous.
[0003]
Therefore, a vacuum type sewerage system that evacuates the sewage pipe and conveys sewage using the pressure difference has been developed and is gradually becoming popular. A vacuum pump system and an ejector system are known in this system.The former uses a water collecting tank as a sealed structure and generates a vacuum in a pipe by a vacuum pump, and the latter uses a water collecting tank. To open to the atmosphere, the wastewater in the water collection tank is circulated and ejected to the ejector by a wastewater circulation pump to generate a vacuum in the pipeline.
[0004]
In this system, for example, as shown in FIG. 6 (a vacuum pump system is illustrated here), sewage from each household 1 is dropped into a sewage unit 3 with a vacuum valve via a pipe 2. Rarely, it is sent to a vacuum station 5 via a vacuum sewer pipe 4, and further conveyed to a sewage treatment plant.
[0005]
In the sewage unit 3 with a vacuum valve, when the amount of sewage in the tank 3A exceeds a required amount, the controller 3B operates to open the vacuum valve 3C until a constant amount is discharged to the pipe 4. The pipeline 4 has a downward slope for appropriate drainage, but is provided with an upward slope in the middle to maintain a constant burial depth with respect to the ground surface.
[0006]
In the vacuum station 5, a vacuum pump 5C is connected to a sewage tank 5A that receives sewage from the pipe 4 via a pipe 5B, and exhausted to the atmosphere from an exhaust pipe 5E via a water sealing tank 5D. The sewage in the sewage tank 5A is transported to the sewage treatment plant by the pressure pump 5F.
[0007]
In such a vacuum sewer system, if there is a leak in the middle of the pipeline 4, air or water may enter from the outside during vacuum evacuation and hinder the conveyance of sewage. Need to be managed. Therefore, a pipe joint 6 having a three-pronged structure having an inspection port is arranged at an appropriate interval in the middle of the pipe line, and the inspection port is opened if necessary, and a test for a vacuum degree test is performed therefrom. A ball is introduced to locally block the line so that the degree of vacuum downstream can be checked.
[0008]
[Problems to be solved by the invention]
The problem here is that, in a general three-pronged pipe joint having a substantially T-shape, the inner diameter of each branch pipe is the same, and as shown in FIG. Even if the test ball introduction part 6C is obliquely connected to the pipe connection part 6A from the inspection port 6B, the connection opening 6D of the connection base of the test ball introduction part 6C is almost the same as the diameter of the inspection port 6B. Therefore, when a cylindrical test ball 7 having external dimensions close to this is loaded through the opened inspection port 6B, the test ball is pushed into the pipe connection portion 6A, expanded and contracted, The operation of pulling back is hindered at the connection points A and B before and after the connection opening 6D, and cannot be smoothly performed.
[0009]
[Object of the invention]
The present invention has been made based on the above circumstances, and provides a pipe joint for a vacuum type sewer with an improved structure so that a test ball can be easily loaded and removed from an inspection port during a vacuum test. What you are trying to do.
[0010]
[Means for Solving the Problems]
For this reason, in the present invention, as clarified in both the drawings and the embodiments, the test ball 17 is provided in the middle of the pipe 4 and the test ball 17 is inserted from the inspection port 16B to perform a vacuum degree test in the pipe 4. And a test ball introduction part 16C which is connected obliquely from an inspection port 16B to a pipe connection part 16A in a linear direction which connects the pipe lines 4 to each other, and the test ball introduction part The connection opening 16D of the connection base 16C-2 of the 16C has a tube connection portion such that the test ball 17 can be dropped into the tube connection portion 16A when the test ball 17 is loaded as compared with the upper portion 16C-1 of the test ball introduction portion 16C. It is characterized by having an internal shape enlarged in the front-rear direction of 16A. In addition, the inspection port 16B of the pipe joint is arranged so that it can be opened and closed from the ground via the manhole H (FIG. 6).
[0011]
[Action]
Therefore, the loading and unloading of the test ball 17 from the inspection port 16B can be performed smoothly, and the workability of the vacuum test can be improved.
[0012]
【Example】
Hereinafter, the present invention will be specifically described based on the illustrated embodiments. The pipe joint 16 of the embodiment shown in FIGS. 1 to 5 has a three-pronged structure, and is provided in the middle of the vacuum sewer pipe 4 as described above with reference to FIG. A test for the degree of vacuum in the pipeline 4 is performed by inserting a cylindrical test ball 17 made of rubber from 16B.
[0013]
The pipe joint 16 has a test ball introduction part 16C obliquely communicating from the inspection port 16B to a straight pipe connection part 16A connecting the pipelines 4, 4, and a lower part of the test ball introduction part 16C. The connection opening 16D of the connection base 16C-2 has a pipe connection portion 16A such that the test ball 17 can be dropped into the tube connection portion 16A when the test ball 17 is loaded as compared with the upper portion 16C-1 of the test ball introduction portion 16C. Has an internal shape enlarged in the front-rear direction. That is, the upper inner wall surface of the connection base 16C-2 of the test ball introduction portion 16C in the inclined direction is enlarged and inclined in the upwardly expanding direction, and the inner wall surface of the lower portion of the inclined direction and the inner wall surface of the continuous tube connection portion 16A are formed. The corners are cut off.
[0014]
In such a shape of the pipe joint, as shown in FIG. 3, the test ball 17 (solid line) is inserted from the opened inspection port 16B, and can be easily dropped (imaginary line) into the pipe connection portion 16A. . Then, as shown in FIG. 4, the test ball 17 is advanced slightly along the pipe line direction, and air pressure is applied to the test ball 17 from the outside to expand the test ball 17, whereby one side of the pipe joint 16A is closed. Then, the pipeline 4 is shut off. Thus, for example, a vacuum degree test can be realized on the downstream side of the closed portion.
[0015]
After the test, the test ball 17 may be retracted, the rear end of the test ball 17 may be pulled up, and removed from the inspection port 16B. A blind cover 18 is usually hermetically attached to the inspection port 16B. In the drawing, reference numeral 19 denotes packing for maintaining airtightness.
[0016]
As one specific example of such a pipe joint, as shown in FIG. 5, the main pipe part (the pipe joint part 16A) and the branch pipe part (the test ball introduction part 16C) have the same diameter, and the nominal diameter is 75 mm. Before the improvement, the inner diameter of the connection opening (a) portion of the branch pipe portion is 77 mmφ and the length of the (b) portion is 110 mm before the improvement. The outer diameter of the test ball 17 is 70 mmφ and the length is 150 mm. Inserting the test ball 17 from the inspection port 16B into the closed portion is due to the size and shape factors of the above (a) and (b) parts. (The test ball is made of rubber, but cannot be forced). On the other hand, in the improved type according to the present invention, the part (a) has a dimension of 77 mmφ at the branch upper part (upper part 16C-1), but 90 mmφ at the connection part with the main pipe part (pipe joint part 16A). , (B) is 150 mm in length, and it has been confirmed that the test ball 17 can be easily inserted from the inspection port 16B into the closed portion. In addition, in the specific example of FIG. 5, the center line of the branch pipe portion (test ball introducing portion 16C) is branched at approximately 45 degrees with respect to the center line of the main pipe portion (pipe joint portion 16A). 16C-2), the upper inner wall surface is inclined at an angle of approximately 35 degrees with respect to the center line of the main pipe portion (the pipe joint portion 16A), and the inclination angle of the inner wall surface is approximately 40 degrees to approximately 30 degrees. It is good to set in the range. The angle between the inner wall surface of the lower portion of the connection base portion 16C-2 of the test ball introduction portion 16C in the inclined direction and the center line of the main pipe portion (the pipe joint portion 16A) of the cut surface of the continuous inner wall surface of the pipe connection portion 16A. Is approximately 70 degrees.
[0017]
【The invention's effect】
The present invention, as described in detail above, is provided in the middle of a pipe, and inserts a test ball from an inspection port to perform a vacuum degree test in the pipe. In the joint, a test ball introduction portion is provided to communicate obliquely from the inspection port with respect to a pipe connection portion connecting the pipelines, and a connection opening of a connection base of the test ball introduction portion is connected to the pipe when the test ball is loaded. The inside shape is enlarged in the front-rear direction of the pipe connection part so that the test ball can be dropped into the part, so that the test ball can be smoothly loaded and unloaded from the inspection port and the workability of the vacuum test can be improved. .
[Brief description of the drawings]
FIG. 1 is an overall vertical side view showing an embodiment of the present invention.
FIG. 2 is an end view similarly showing a part of the cross section.
FIG. 3 is a vertical sectional side view showing a state of loading a test ball in the pipe joint of the present invention.
FIG. 4 is a vertical sectional side view showing a final state of loading a test ball.
FIG. 5 is an overall vertical sectional side view showing a specific example of the present invention.
FIG. 6 is a side view schematically showing a vacuum type sewer system according to the present invention.
FIG. 7 is a longitudinal sectional side view showing a structure of a pipe joint before improvement.
[Explanation of symbols]
1 Home 2 Pipe 3 Sewage unit with vacuum valve 4 Pipe 5 Vacuum station 6 Pipe fitting (before improvement)
7 Test ball 16 Fitting 16A Pipe connection 16B Inspection port 16C Test ball insertion 16D Connection opening 17 Test ball 18 Blind lid 19 Packing

Claims (1)

A straight-line pipe connection that connects pipes in a pipe joint for vacuum sewerage, which is installed in the middle of a pipe and is used to test the degree of vacuum in the pipe by inserting a test ball from the inspection port. A test ball introduction part is provided at the base of the test ball introduction part. The connection opening of the connection base of the test ball introduction part is compared with the upper part of the test ball introduction part. A pipe joint for a vacuum type sewer characterized by having an inner shape enlarged in the front-rear direction of a pipe connection portion into which a test ball can be dropped.

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