JP5469655B2 - Leakage detection device and leakage detection method for underground water pipe - Google Patents

Description

  The present invention relates to a water leak detection device and a water leak detection method for underground water pipes that can easily detect a water leak point of a water pipe buried in the ground, and in particular, to detect a small amount of water leak in a water pipe. The present invention relates to a leak detection device and a leak detection method for underground underground water pipes.

  Generally, water pipes buried in the ground (hereinafter also referred to as piping) are prone to leakage due to secular changes, automobile vibrations, earthquakes, etc., but the underground pipes are long and It is not easy to accurately detect the water leakage position of a branched water pipe, and in the prior art, various water leakage position detection techniques as described in the following patent documents have been proposed.

  In the following Patent Document 1, a detection pipe that circulates water in a water pipe in a detection section is separately provided, and water in which a rare gas is dissolved is circulated through the detection pipe to detect a location where the rare gas leaks. The technology which detects a water leak location by this is described, and patent document 2 arrange | positions a pressure detector in the both ends and intermediate position of the water pipe of a detection area, and detects by each pressure detector at the time of propagating a pressure wave A technique for detecting a water leakage location using a difference in pressure propagation speed is described. In Patent Document 3, two vibration sensors installed along a pipe are arranged, and fluid transport pressures of two or more different levels are arranged. The magnitude of the sound signal measured originally is compared in the frequency domain, and the frequency component signal extracted using the characteristic that more leaked sound is included in the frequency band where the change in the magnitude of the signal is relatively large is 2 Depending on the time difference to reach each vibration sensor Technique for detecting the water portion is described.

JP-A-5-340837 JP 2000-131179 A JP 2005-134300 A

  Although the technique described in the above-mentioned patent document can detect a relatively large water leakage position, it is difficult to detect a small amount of water leakage position, and various types of large-scale devices are used for piping to be detected. There was a problem that the leak position had to be detected.

  An object of the present invention is to solve the above-described problems due to the prior art, and to provide a leak detection device and a leak detection method for a buried underground water pipe that can detect a small amount of water leakage in a water pipe with a simple configuration. Is to provide.

In order to achieve the above object, the present invention is an underground buried water pipe that is connected through a plurality of connecting pipes and detects a leakage position of a water pipe that supplies pressurized water to a predetermined faucet. A water leakage detection device,
An open / close valve between the pair of existing pipes arranged in a gap on one end side of a pair of existing pipes cut at a predetermined interval from the water pipe at the measurement position, with the other end side of the existing pipes sealed in water. And detecting a temporal change in water pressure from the pair of existing pipes with the on / off valve as a boundary. It is characterized by.

The present invention is also a leak detection device for underground water pipes that are connected through a plurality of connecting pipes and detect a leak position of a water pipe that supplies pressurized water to a predetermined faucet. And
A pair of single screw pipes connected to a gap on one end side of a pair of existing pipes cut at a predetermined interval from a water pipe at a measurement position, and the pair of single screw pipes connected to one end side of the pair of existing pipes A pair of joints that are connecting tools, a pair of T-shaped different diameter T-tubes, one of which is screwed to one end of the pair of one-threaded tubes, and the other of the pair of different-diameter T-shaped tubes A pair of screw pipes, one end of which is screwed and screwed at both ends, and the other end of the pair of screw pipes, for opening and closing the connection between the pair of screw pipes An opening / closing valve portion, and a pair of pressure detection portions connected to the pair of different diameter T-tubes and displaying the water pressure of the pair of different diameter T-tubes, and the opening / closing valve portion between the pair of existing tubes And detecting a temporal change in water pressure from a pair of existing pipes with the opening / closing valve section as a boundary. To.

  In addition, the present invention has a third feature that a drainage on-off valve is further provided.

Furthermore, the present invention is a water leak detection method for detecting a water leak position of a water pipe connected through a plurality of connection pipes and supplying pressurized water to a predetermined faucet by a water leak detection device,
The water leakage detection device is disposed in a gap on one end side of a pair of existing pipes cut at a predetermined interval from a water pipe at a measurement position, and the other end side of the existing pipes is sealed in a water-use manner. It is provided with a pair of water pressure gauges that shuts off existing pipes with an on-off valve and detects water pressure from the pair of existing pipes that have been shut off,
A first step of dividing the plurality of connection pipes for each approximate value of a value obtained by dividing the number of connection pipes of the water pipe by a predetermined value, and a boundary position of the plurality of connection pipes divided by the first step as a measurement position A second step that is set as a third step, a third step that excavates a water pipe at the measurement position set in the second step and cuts it to a predetermined length, and the leak test between a pair of existing pipes that are cut in the third step A fourth step in which a device is inserted and arranged to shut off the pair of existing pipes by an on-off valve provided in the water leakage inspection device; and from both ends of the pair of existing pipes after an arbitrary time has passed since the fourth step. A fourth feature is that a fifth step is performed to determine whether or not water leakage has occurred in a water pipe line whose pressure has decreased with respect to the measurement position.

Further, the present invention is a water leak detection method for detecting a water leak position of a water pipe connected through a plurality of connection pipes and supplying pressurized water to a predetermined faucet by a water leak detection device,
The water leakage detection device includes a pair of single screw pipes connected to a gap on one end side of a pair of existing pipes obtained by cutting a water pipe at a measurement position at a predetermined interval, and the pair of single screw pipes. A pair of joints which are connecting tools for connecting to one end of the tube, a pair of T-shaped different diameter T-tubes, one of which is screwed to one end of the pair of single screw tubes, and the pair of diameters The other end of the T-shaped tube is screwed at one end and a pair of screw tubes with screws engraved at both ends, and the other end of the pair of screw tubes is disposed between the pair of screw tubes. An on-off valve part for opening and closing a connection, and a pair of pressure detection parts connected to the pair of different-diameter T-shaped pipes and displaying the water pressure of the pair of different-diameter T-shaped pipes,
A first step of dividing the plurality of connection pipes for each approximate value of a value obtained by dividing the number of connection pipes of the water pipe by a predetermined value, and a boundary position of the plurality of connection pipes divided by the first step as a measurement position The second step to be set as, the third step to excavate the water pipe at the measurement position set in the second step and cut it to a predetermined length, and the interval between the pair of existing pipes cut by the third step A fourth step of inserting and connecting the water leakage detection device to the fifth step, a fifth step of supplying the water to the water pipe, and closing the on-off valve portion with the water filled in the water pipe by the fifth step. The difference in pressure between the pair of pressure detectors after an arbitrary time has elapsed since the sixth step and the sixth step were closed, and water leakage occurred in the water pipe line where the pressure was reduced relative to the measurement position. And performing the seventh step of judging the leakage side detection 5 is a feature of the.

  Further, the present invention provides the leakage detection method according to the third or fourth feature, wherein the determination of the individual position by the leakage detection device at the measurement position set by the second step is performed on the upstream side where the water pressure is applied. The sixth feature is that the process is performed from the downstream side toward the downstream side.

  The leak detection device for underground water pipes according to the present invention can detect the direction of the water pipe on the side where water leakage occurs by measuring temporal changes on both sides of the existing pipe at the measurement position. The water leakage detection method according to the above method is to set the boundary position where a plurality of connection pipes are divided for each approximate value of a value obtained by dividing the number of connection pipes provided in a water pipe by a predetermined value as a measurement position. It is possible to efficiently detect water leakage from a connecting pipe that is likely to occur, and a relatively small amount of water leakage can be detected by setting the measurement time to a relatively long time.

The figure for demonstrating the structure of the leak detection apparatus of the underground buried water pipe by one Embodiment of this invention. The figure for demonstrating piping of the water pipe used as the object of this invention. The figure for demonstrating the piping of a water pipe used as the object of this invention, and a measurement position. The figure for demonstrating the water leak detection method by one Embodiment of this invention.

Hereinafter, a leak detection device and a leak detection method for underground underground water pipes according to an embodiment of the present invention will be described in detail with reference to the drawings.
[Description of water pipes]
First, as shown in FIG. 2, for example, the water pipes to be detected by the water leakage detection device according to the present embodiment are a plurality of fire hydrants 401 arranged in a plurality of buildings 91 to 95 built adjacent to each other in a predetermined site. ˜413 for supplying fire extinguishing water stored in the water tank 101 by pressure from the pump 102, and the fire hydrants 404 and 405 arranged adjacent to the side wall of the building 91 and the side wall of the building 92. Fire hydrants 401 to 403 disposed adjacent to each other, fire hydrants 411 and 413 disposed adjacent to the side wall of the building 93, fire hydrants 409, fire hydrant 410, fire hydrant 412 disposed adjacent to the side wall of the building 94, and the building It is piped to supply fire-fighting water to the fire hydrants 406 to 408 disposed adjacent to the 95 side walls.

  The water distribution pipe according to the present embodiment has a straight first piping line L1 that supplies water for fire extinguishing from the pump 102 to the fire hydrant 401, the fire hydrant 402, and the fire hydrant 404, as shown in FIG. Branching from the middle of the first piping line L1 and branching from the middle of the second piping line L2 and the straight second piping line L2 for supplying fire-fighting water to the fire hydrant 403, the fire hydrant 405, and the fire hydrant 407 The fire hydrant 406, the fire hydrant 409, and the fire hydrant 412 are connected to the straight third pipe line L3 for supplying fire water to the fire hydrant 412 and the end of the third pipe line L3, and the fire hydrant 408, fire hydrant 410, fire hydrant 411, It is comprised from the linear 4th piping line L4 which supplies the water for fire extinguishing to the fire hydrant 413.

  The first pipe line L1 branches to a fire hydrant 401 via a T-shaped branch pipe T1 and a short-circuit pipe SL, branches to a fire hydrant 402 via a branch pipe T2 and a short-circuit pipe SL, and passes through a branch pipe T3. It branches to the said 2nd piping L2, and the edge part is connected to the fire hydrant 404. The second pipe line L2 has one end connected to the branch pipe T3 of the first pipe line L1, branches to the fire hydrant 403 via the branch pipe T4 and the short-circuit pipe SL, and passes through the branch pipe T5 and the short-circuit pipe SL. Branches to a fire hydrant 405, connects to the third pipe L3 via a cross-shaped branch pipe T6, branches to a fire hydrant 407 via a branch pipe T7 and a short-circuit pipe SL, and a fourth pipe via a branch pipe T8. The other end is connected to the path L4.

The third pipe line L3 has a central portion connected to the cross-shaped branch pipe T6 of the second pipe line L2, one end connected to the fire hydrant 406, and branches to the fire hydrant 409 via the branch pipe T9 and the short-circuit pipe SL. The other end is connected to the fire hydrant 412 via the L-shaped tube T10 and the short-circuit tube SL. The fourth pipe line L4 is connected to the branch pipe T8 of the second pipe line L2, branched at one end to the fire hydrant 408 via the L-shaped pipe T11 and the short-circuit pipe SL, and via the branch pipe T12 and the short-circuit pipe SL. Branching to the fire hydrant 410, branching to the fire hydrant 411 via the branch pipe T13 and the short-circuit pipe SL, and the other end connected to the fire hydrant 413 via the L-shaped pipe T14 and the short-circuit pipe SL.
In this specification, the T-shaped and cross-shaped branch pipes and L-shaped pipes that are highly likely to cause water leakage are collectively referred to as connection pipes, and the short-circuit pipe SL is also included in the connection pipes. However, in this embodiment, in order to facilitate understanding, the short-circuit tube SL will be described assuming that there is no water leakage.

[Explanation of leak detection device]
The leakage detection device 1 for underground underground water pipes according to the present embodiment is constituted by the plurality of pipes described above, and between existing pipes that are cut at intervals from water pipes connected to a fire hydrant by a plurality of branch pipes. As shown in FIG. 1, a single screw tube 20A, which is installed in a gap between the existing tube 10A and the existing tube 10B cut at a predetermined interval and has a screw engraved on one side, as shown in FIG. The single screw tube 20B, the joint 21A and the joint 21B which are connecting tools for connecting the single screw tube 20A and the single screw tube 20B to the existing tube 10A and the existing tube 10B, and the single screw tube 20A and the single screw tube 20B. One end of the T-shaped different diameter T-shaped tube 23A and the different diameter T-shaped tube 23B, and one end of the other end of the different diameter T-shaped tube 23A and the different diameter T-shaped tube 23B. And Both screw tubes 22A and both screw tubes 22B with screws engraved at both ends, and the other screw tube 22A and the other screw tube 22B are arranged at the other end and connected between both screw tubes 22A and both screw tubes 22B ( An opening / closing valve portion 26 and an operation handle 26A for opening and closing a water flow path), and a flange 25A for connecting the other end of the screw pipe 22A and the screw pipe 22B with the opening / closing valve portion 26 in between. Meters 28A and 28B connected to the flange 25B, the different diameter T-shaped tube 23A and the different diameter T-shaped tube 23B, and indicating the water pressure of each of the different diameter T-shaped tube 23A and the different diameter T-shaped tube 23B, and the meter 28A And 28B are configured to include a pressure detection unit 24A and a pressure detection unit 24B including gauge cocks 27A and 27B that are closed when removed.

  The joint 21A and the joint 21B are composed of a sleeve made of an elastic material such as synthetic rubber and covering the outer periphery of the pipe, and an annular casing that fastens the sleeve to the outer periphery of the pipe. The joint 21A is configured to hermetically connect the existing pipe 10A and the single screw pipe 20A, and the joint 21B is configured to hermetically connect the existing pipe 10B and the single screw pipe 20B. Is adjustable by using the joint 21A and the joint 21B, so that the leakage detector according to the present embodiment is inserted into the cut distance between the existing pipe 10A and the existing pipe 10B in an assembled state. It fulfills the function of absorbing the dimensional margin. In addition, the horizontal dimension of the state in which the water leakage detection device according to the present embodiment is assembled is 934 mm, and the cut interval between the existing tube 10A and the existing tube 10B facilitates the installation work of the water leakage detection device. It is preferably about 954 mm with a margin of 10 mm on the left and right. In addition, the gauge cocks 27A and 27B are closed when the water leak detector is attached to the existing pipe and water is passed for a long period of time, because the needles of the meters 28A and 28B may be fixed or the accuracy may be lost. The opening / closing cock for removing the meters 28A and 28B.

  The operation method at the measurement position using the water leakage detection device 1 configured as described above includes the first step of excavating a water pipe embedded in the measurement position and cutting, for example, 954 mm with the pump 102 stopped, and this cutting. The second step of inserting and connecting the water leakage detection device 1 into the cut interval between the existing pipe 10A and the existing pipe 10B on both sides of the water pipe and the water for fire extinguishing stored in the water tank 101 by driving the pump 102 A third step for supplying water pipes and pipes in the water leakage detection device, and a fourth step for stopping the pump 102 in the state where the water pipes in the water pipes and the water leakage detection device 1 are filled with water by the third step. The step, the fourth step of closing the valve of the on-off valve portion 26 of the water leakage detection device 1, and the pressure detection portion 24A and the pressure detection portion 24B when the valve of the on-off valve portion 26 is closed by the fourth step are equal. The meter 28A and By comparing the pressure of the pressure detectors 24A and 24B after a predetermined time has elapsed from the fifth step with reference to 28B, and performing the sixth step of checking the difference between the two pressures, It is possible to know that water leakage has occurred in the pipe line where the pressure has dropped due to the pressure difference between the upstream side (pump 102 side) and the downstream side at the measurement position. If it is relatively large, about 5 minutes, generally about 30 minutes, even if the amount of water leakage is extremely small, it can be known by observing the pressure change for about several hours. The leak position can be narrowed down by repeating the above-described leak side detection determination from the upstream side at a plurality of measurement positions.

[Explanation of measurement position settings]
The setting of the measurement position in the pipe using the water leakage detection device 1 described above has a high probability that a water leakage point will occur in the connection pipe that branches the water. Therefore, the connection branching like the pipe shown in FIG. When the number of pipes is 14 such as branch pipes T1 to T14, for example, an approximate value of the value obtained by dividing the number of connected pipes 14 in the entire pipe by 3 (an integer obtained by rounding down or raising the decimal point of the division value) Thus, in this example, the entire piping is divided for each of the number of joints (3 and 4), and set for each of the divided piping. Specifically, the group (A) including the branch pipes T1 to T4 piped from the pump 12 to the measurement point A and the branch pipes T5, T6, T9, T10 piped from the measurement point A to the measurement point B. , A group including the branch pipes T7, T8, T11 piped from the measurement point B to the measurement point C, and a branch pipe piped from the measurement point C to the terminal fire hydrant 413 As in the group (d) including T12 to T14, the number of branch pipes is divided into 4 groups so that the number of branch pipes is 3 to 4, and the three positions of positions A to C that divide these groups are measured positions of the water leakage detector. Set as.

  Further, the measurement at the measurement position repeats the above-mentioned water leakage side detection determination from the upstream side at a plurality of measurement positions, but the water pipe is long, and a T-shaped or cross-shaped branch pipe or L-shaped pipe is used. When the number of connecting pipes is extremely large (for example, 100), the number of groups in the entire pipe is increased (the value that divides the number of connected pipes is further increased), or a large number of connecting pipes are divided into small groups (for example, 5 groups) It is also possible to determine a group that has leaked water and divide the determined small group into small groups to narrow down the small groups that have leaked water.

[Explanation of leak detection method]
In the water leakage detection method according to the present embodiment, first, a step of setting a plurality of measurement positions in all pipes of the water pipe according to the description of the method for setting the measurement position, and a measurement on the upstream side where the pump 102 is installed. In order from the position, as described in [Explanation of water leakage detection device], with the pump 102 stopped (sealed in terms of water), the water pipe embedded at the measurement point is excavated and cut, for example, by 954 mm And the step of inserting and connecting the water leakage detection device 1 into the cut interval between the cut existing pipe 10A and the existing pipe 10B, and the water for fire extinguishing stored in the water tank 101 by driving the pump 102 A step of stopping the pump 102 in a state where the water pipe is filled with fire-extinguishing water by this step, a step of closing the valve of the on-off valve portion 26, and an on-off valve portion by this step The process of confirming that the pressure detectors 24A and 24B are equal when the valve 26 is closed by the numerical values of the meters 28A and 28B, and the pressures of the pressure detectors 24A and 24B after a predetermined time elapses in the meters 28A and 28B. A leakage side detection determination is made to determine that water leakage has occurred in the pipe where the pressure on the upstream side and the downstream side with respect to the measurement position including the step of referring to and comparing and confirming the difference between both pressures has decreased.

  For example, the upstream side connected to the pump 102 at the measurement position A shown in FIG. 4 is compared with the downstream pressure downstream from the upstream side, and the downstream pressure from the measurement point A is compared with the upstream side. When the water pressure is lowered, the next water leakage side detection determination at the next measurement position B is performed because water leakage has occurred on the downstream side, and the pressure on the upstream side at this measurement position B is lower than that on the downstream side. , It is possible to detect the occurrence of water leakage in the branch pipes T7, T8 or T11 included in the group (c), and the branch pipes T7, T8 and T11 are excavated to visually check the underground piping state. By confirming, it is possible to detect the location of water leakage.

  In addition, when it is measured in the water leakage side detection determination at the measurement point A that the pressure on the upstream side is lower than that on the downstream side, any of the branch pipes T1 to T4 included in the group (A) When it is measured that the upstream side pressure is lower than the downstream side in the leakage side detection determination at the measurement point B, the group ( B) It can be detected that water leakage has occurred in any of the branch pipes T5, T6, T9, and T10 included in the branch pipe, and water leakage is caused by excavating the branch pipes (connection pipes) in these groups. If there is no leakage in the branch pipe (connection pipe), it is possible to dig a water pipe of the corresponding group. Leak test It can be narrowed down water leakage position using the device 1.

As described above, the leak detection device and the leak detection method for underground water pipes can detect the direction of the water pipe on the side where the water leak occurs by measuring temporal changes on both sides of the existing pipe at the measurement position. Furthermore, it is possible to cause water leakage by setting a boundary position where a plurality of connection pipes are divided for each approximate value of a value obtained by dividing a plurality of connection pipes provided in a water pipe by a predetermined value as a measurement position. Therefore, it is possible to efficiently detect water leakage from a connecting pipe having high performance, and it is possible to detect a very small amount of water leakage by setting the measurement time to a relatively long time.
<Other embodiments>

  Further, for example, a configuration in which the water leakage detection device 1 is further provided with a drain on-off valve (not shown) may be employed. If comprised in this way, in the water leak detection operation | work, it can prevent that the water with which the water pipe was filled overflows on the spot, and worsens a scaffold. That is, when the installed water leakage detection device 1 is removed, the water filled in the water pipe inevitably overflows. However, if a drain on-off valve is provided separately, the drain on-off valve The water filled in the water pipe can be treated before removing the device. For example, a drainage hose may be connected to communicate with the drainage on-off valve, or a pump may be connected to positively discharge water in the water pipe.

  In addition, the single screw pipes 20A and 20B of the water leakage detection device 1 are provided with various single screw pipes having different diameters on the side to be connected to the existing pipes while keeping the diameters on the screw sides. It is also possible to replace the existing pipes with different diameters widely.

  Moreover, if the diameter of the pipe | tube which comprises the water leak detection apparatus 1 is comprised so that it may become more than the diameter of the existing pipe | tube, when detection work takes time (for example, when it is necessary to install over several days) ), The original purpose of the existing pipe is not greatly impaired by opening the on-off valve.

  In the above-described embodiment, an example has been described in which the water leakage position of a water pipe that supplies fire-fighting water to a fire hydrant provided in a building is detected as water in the fire-fighting equipment, but the present invention is limited to fire-fighting equipment. Instead, it is possible to detect the leakage position of a water pipe that supplies drinking tap water. Further, in the above-described embodiment, the example in which the individual position determination is performed from the upstream side where the water pressure at the measurement position set in the water pipe is large has been described, but the leak detection device in which one end of the cut existing pipe is connected is sandwiched. However, if the other ends of the existing pipes on both sides are sealed in terms of water, the order of performing the water leakage side detection determination is not limited to this embodiment, but the situation of the buried pipes in the field (age, It is desirable to set the order of performing the water leakage side detection determination according to the possibility of water leakage depending on the pavement situation, the situation where the vehicle is close to the road, etc. Also, in the buried gas pipe, the leak detection position may be narrowed down in the same manner as in the above embodiment by installing the water leakage detection device with the gas in the gas pipe being removed and filling the gas pipe with harmless gas. it can.

401-413 fire hydrant,
10A and 10B Existing pipe,
20A and 20B single screw tube,
21A and 21B joints,
22A and 22B both screw pipes,
23A and 23B T-tubes,
24A and 24B pressure detector,
25A and 25B flanges,
26 On-off valve part,
27A and 27B gauge cocks,
28A and 28B meters,
26A operation handle,
91-95 building,
101 aquarium,
102 pump,
T1-T14 T-shaped branch pipe,
AC measurement position

Claims (6)

A leak detection device for underground underground water pipes connected via a plurality of connection pipes to detect a water leak position of a water pipe that supplies pressurized water to a predetermined faucet,
An open / close valve between the pair of existing pipes arranged in a gap on one end side of a pair of existing pipes cut at a predetermined interval from the water pipe at the measurement position, with the other end side of the existing pipes sealed in water. And a pair of water pressure gauges for detecting the water pressure from the pair of existing pipes that have been shut off, and detecting temporal changes in water pressure from the pair of existing pipes with the on-off valve as a boundary. Leak detection device. A leak detection device for underground underground water pipes connected via a plurality of connection pipes to detect a water leak position of a water pipe that supplies pressurized water to a predetermined faucet,
A pair of single screw pipes connected to a gap on one end side of a pair of existing pipes cut at a predetermined interval from a water pipe at a measurement position, and the pair of single screw pipes connected to one end side of the pair of existing pipes A pair of joints that are connecting tools, a pair of T-shaped different diameter T-tubes, one of which is screwed to one end of the pair of one-threaded tubes, and the other of the pair of different-diameter T-shaped tubes A pair of screw pipes, one end of which is screwed and screwed at both ends, and the other end of the pair of screw pipes, for opening and closing the connection between the pair of screw pipes An opening / closing valve portion, and a pair of pressure detection portions connected to the pair of different diameter T-tubes and displaying the water pressure of the pair of different diameter T-tubes, and the opening / closing valve portion between the pair of existing tubes And detecting a temporal water pressure change from a pair of existing pipes with the opening / closing valve section as a boundary. Leak detection apparatus of the middle buried water pipes.   Furthermore, the water leak detection apparatus of Claim 1 or 2 provided with the on-off valve for drainage. A water leakage detection method for detecting a water leakage position of a water pipe connected through a plurality of connection pipes and supplying pressurized water to a predetermined faucet by a water leakage detection device,
The water leakage detection device is disposed in a gap on one end side of a pair of existing pipes cut at a predetermined interval from a water pipe at a measurement position, and the other end side of the existing pipes is sealed in a water-use manner. It is provided with a pair of water pressure gauges that shuts off existing pipes with an on-off valve and detects water pressure from the pair of existing pipes that have been shut off,
A first step of dividing the plurality of connection pipes for each approximate value of a value obtained by dividing the number of connection pipes of the water pipe by a predetermined value, and a boundary position of the plurality of connection pipes divided by the first step as a measurement position A second step that is set as a third step, a third step that excavates a water pipe at the measurement position set in the second step and cuts it to a predetermined length, and the leak test between a pair of existing pipes that are cut in the third step A fourth step in which a device is inserted and arranged to shut off the pair of existing pipes by an on-off valve provided in the water leakage inspection device; and from both ends of the pair of existing pipes after an arbitrary time has passed since the fourth step. And a fifth step of performing a water leakage side detection determination that water leakage has occurred in a water pipe line having a reduced pressure with respect to the measurement position. A water leakage detection method for detecting a water leakage position of a water pipe connected through a plurality of connection pipes and supplying pressurized water to a predetermined faucet by a water leakage detection device,
The water leakage detection device includes a pair of single screw pipes connected to a gap on one end side of a pair of existing pipes obtained by cutting a water pipe at a measurement position at a predetermined interval, and the pair of single screw pipes. A pair of joints which are connecting tools for connecting to one end of the tube, a pair of T-shaped different diameter T-tubes, one of which is screwed to one end of the pair of single screw tubes, and the pair of diameters The other end of the T-shaped tube is screwed at one end and a pair of screw tubes with screws engraved at both ends, and the other end of the pair of screw tubes is disposed between the pair of screw tubes. An on-off valve part for opening and closing a connection, and a pair of pressure detection parts connected to the pair of different-diameter T-shaped pipes and displaying the water pressure of the pair of different-diameter T-shaped pipes,
A first step of dividing the plurality of connection pipes for each approximate value of a value obtained by dividing the number of connection pipes of the water pipe by a predetermined value, and a boundary position of the plurality of connection pipes divided by the first step as a measurement position The second step to be set as, the third step to excavate the water pipe at the measurement position set in the second step and cut it to a predetermined length, and the interval between the pair of existing pipes cut by the third step A fourth step of inserting and connecting the water leakage detection device to the fifth step, a fifth step of supplying the water to the water pipe, and closing the on-off valve portion with the water filled in the water pipe by the fifth step. The difference in pressure between the pair of pressure detectors after an arbitrary time has elapsed since the sixth step and the sixth step were closed, and water leakage occurred in the water pipe line where the pressure was reduced relative to the measurement position. And performing the seventh step of judging the leakage side detection Water leak detection method according to symptoms.   6. The determination of the individual position by the water leakage detection device at the measurement position set in the second step is performed from the upstream side to the downstream side where the water pressure is applied. Water leakage detection method.