JPS6317169B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to, for example, the work of cutting and removing old conduits and replacing them with new pipes to customers who are dealing with remaining pipes other than the replacement locations. In order to ensure that the gas supply can be carried out without interruption, a part of the gas transport pipe was cut and removed, and two pipes were installed at appropriate intervals in the remaining gas transport pipe.
Insert two stoppers, inflate both stoppers with a fluid pressure supply device so that they come into close contact with the inner wall surface of the pipe, and while supplying transport gas under pressure into the remaining gas transport conduit, the transport gas connects to both stoppers. Leakage through the gap between the gas transport pipes is prevented by elastic contact between the two stoppers and the inner wall surface of the pipe, and the quality of the blocking state by the two stoppers is checked by measuring the internal pressure of the conduit portion between the two stoppers. Regarding the method of determination.

[Conventional technology]

Conventionally, in the above-mentioned construction work, no special pressurizing means was used to pressurize the space between the two stoppers, and the pressure was initially set to slightly higher than atmospheric pressure by simply inflating both stoppers. If the pressure rise between both stoppers exceeds the set value, it is determined that there is a disconnection failure between the inner stopper and the gas transport conduit, and the pressure between both stoppers becomes approximately equal to atmospheric pressure. If it decreases like this,
It was determined that there was a disconnection failure between the outside stopper and the gas transport pipe.

[Problem that the invention seeks to solve]

However, construction work on gas transmission pipelines generally takes a considerable amount of time, and the temperature changes considerably from morning to noon and from noon to evening, and the part of the pipeline to be shut off is exposed and receives direct sunlight. Moreover, since the internal volume between the two stoppers is small, the internal pressure between the two stoppers fluctuates widely due to changes in temperature and solar radiation conditions.

Therefore, even if the pressure between both stoppers changes by more than the set value, it is practically impossible to accurately determine whether the problem is truly caused by a faulty shutoff or a temperature change. However, until now, such technical issues have not been recognized at all, and even if it were caused by temperature fluctuations, construction work would have to be halted and comprehensive safety inspections would be required, reducing work efficiency. There were flaws.

The purpose of the present invention is to solve the following problems:
The object of the present invention is to enable easy and accurate determination of the cutoff state of a stopper by measuring the pressure between both stoppers without being adversely affected by temperature changes.

[Problem that the invention seeks to solve]

The characteristic means of the present invention is that the pressure within the conduit portion between the two stoppers, which is brought into close contact with the inner wall surface of the pipe by expansion within the gas transport pipe remaining after cutting and removal, is supplied to the remaining gas transport pipe under pressure. The measurement pressure supply device is initially set to a pressure sufficiently higher than the pressure of the transport gas being used, the pressure change between the two stoppers is detected, and the shutoff state by the two stoppers is determined based on the detection of a pressure drop exceeding the set value. Its purpose is to detect defects, and its functions and effects are as follows.

[Effect]

In other words, if the pressure between both stoppers is initially set to be sufficiently higher than the pressure of the transport gas, for example, if the pressure of transport gas is approximately 200 mmH ₂ O, the pressure between both stoppers is initially set to approximately 1500 mmH ₂ O. If a failure occurs between the inner stopper and the gas transport conduit, the pressure between both stoppers will be close to 200mmH ₂ O, and if a failure occurs between the outer stopper and the gas transport conduit, the pressure between both stoppers will increase. On the other hand, fluctuations in temperature and solar radiation conditions result in a pressure drop of around 100 mmH ₂ O at most, so the pressure drop due to a faulty shutoff can easily and accurately compensate for the pressure drop due to temperature changes. It is also possible to easily and reliably determine which stopper on the inside is causing a failure in shutting off.

〔Effect of the invention〕

As a result, it is possible to easily and accurately check whether the stopper is in a closed state by measuring the pressure between both stoppers without being adversely affected by temperature changes, and the construction can be carried out safely and without unnecessary interruptions or inspections. I am now able to carry out tasks more efficiently.

〔Example〕

Next, an example will be described.

As shown in FIG. 1, to form the shutoff device, two stoppers A inserted into the gas transport conduit P at appropriate intervals are connected to each other by a swingable connecting device 1.
A wire 2 for pulling and moving both stoppers A within the conduit P is connected to the first stopper A. A sealing material 3 for tightly sealing the inside of the conduit P by expanding it by supplying fluid pressure (air or other gas may be used in addition to liquids such as water and oil) to each stopper A, and tightly contacting the inner wall surface of the conduit P; , a pressure measuring port 4 for measuring the pressure inside the conduit P is provided, a fluid pressure supply hose 5 is connected to the sealing material 3 of the first stopper A, and
Connect the measuring pressure supply hoses 6 to the pressure measuring ports 4, respectively,
Fluid pressure supply hoses 5, 5', 5'' are connected to the sealing material 3 of the second stopper A, and measurement pressure supply hoses 6, 6', 6'' are connected to the pressure measurement port 4, respectively.

Construction using the above-mentioned blocking device will be explained below with reference to FIG. 2.

Cut and remove a part of the gas transport pipe P, insert two stoppers A into the remaining gas transport pipe P at intervals determined by the connector 1, and connect the wire 2 and four hoses 5 and 6 for blocking. Extending from the cup 7 to the outside of the pipe, the fluid pressure supply hose 5 is connected to the fluid pressure supply device 8,
In addition, the measurement pressure supply hose 6 is connected to the measurement pressure supply device 9.

The sealing material 3 of both stoppers A is expanded by the fluid pressure supply device 8 to bring it into close contact with the inner wall surface of the pipe, and while supplying transport gas under pressure to the gas transport conduit P remaining beyond the stopper A, the transport gas is supplied to both stoppers A. A and the gas transport conduit P to prevent leakage.

Next, the measuring gas from the measuring pressure supply device 9 is supplied to both stoppers A through the pressure measuring port 4 of the first stopper A.
Pressure is supplied to the conduit portion _P1 between the two stoppers A, and the pressure between the two stoppers A is measured at the pressure measuring port 4 of the second stopper A.
and hoses 6″, 6′, 6 and pressure tester (cage pipe)
The initial setting is sufficiently higher than the pressure of the transport gas measured by For example, when the pressure of the transport gas is about 200 mmH ₂ O, the pressure between both stoppers A is initially set to about 1500 mmH ₂ O.

Then, the pressure change between both stoppers A is detected using the pressure measuring port 4 of the first stopper A and the hose 6, and based on the detection of a pressure drop exceeding a set value, a malfunction in the shutoff state of both stoppers A is detected. Detect. In other words, if the pressure between both stoppers A approaches the pressure of the transport gas, it is determined that a shutoff failure has occurred in the inner (second) stopper A, and if the pressure between both stoppers A approaches atmospheric pressure, it is determined that the inner (second) stopper A has a shutoff failure. It is determined that there is a failure in shutting off at the stopper A in 1), and it is determined that the shutting condition is good otherwise.

[Another example]

Next, another example will be shown.

A device that automatically warns when a shutoff failure occurs may be used, for example, as shown in FIG. A comparator 12 is provided to determine whether the difference between the pressures measured by the measuring devices 10 and 11 is greater than a set value, and an alarm device is provided to detect a failure in shutting off based on a command from the comparator 12. Bye.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, FIG. 1 is a schematic diagram of the block diagram, FIG. 2 is an explanatory diagram of the construction state, and FIG. 3 is another embodiment of the device used in the present invention. FIG. 2 is a block diagram showing an example. 8...Fluid pressure supply device, 9...Measuring pressure supply device, A...Stopper, P...Gas transport conduit,
P ₁ ... Conduit part.

Claims (1)

[Claims] 1. Cut and remove a part of the gas transport pipe P, insert two stoppers A into the remaining gas transport pipe P at appropriate intervals, and connect both stoppers A to the fluid pressure supply device 8. to inflate it and bring it into close contact with the inner wall of the pipe,
While supplying transport gas under pressure into the remaining gas transport conduit P, the transport gas is supplied to both stoppers A.
leakage between the gas transport pipe P and the gas transport pipe P is prevented by elastic adhesion of both the stoppers A to the inner wall surface of the pipe, and by measuring the internal pressure of the pipe portion _P1 between the both stoppers A, A method for determining whether or not the shutoff state is good or not, the pressure in the conduit portion _P1 between the two stoppers A is set to be higher than the pressure of the transport gas being pressurized and supplied into the remaining gas transport pipe P. A gas that is initially set to a sufficiently high pressure by a measurement pressure supply device 9, detects a pressure change between the two stoppers A, and detects a defective shutoff state by the two stoppers A based on a detection of a pressure drop that is equal to or higher than a set value. A method for detecting conduit interruption defects during transportation conduit construction. 2 The pressure of the transport gas in the gas transport conduit P is approximately
In the case of 200 mmH ₂ O, the method for detecting a failure in shutting off during construction of a gas transport conduit according to claim 1, wherein the pressure between the two stoppers A is initially set to about 1500 mmH ₂ O.