JPH0143199B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention connects conduit sections on the upstream and downstream sides of a construction site in a gas transport conduit for medium-pressure gas or the like using a bypass pipe, and A conduit portion downstream of the upstream communication portion of the bypass pipe with respect to the conduit and a conduit portion upstream of the downstream communication portion are respectively inserted into the conduit using a no-blow device and a tool, and are inflated. The upstream and downstream bags are used to shut off the gas, and then conduit work is carried out at the construction site, and after the conduit work is completed, the transport gas in the conduit upstream of the upstream bag is transferred to the conduit section between the two bags where the work has been completed. The present invention relates to an uninterrupted flow type non-blowout shutoff construction method for air purging the conduit section where the construction is completed by introducing the present invention into a construction method.

[Conventional technology]

Conventionally, as disclosed in Japanese Patent Publication No. 56-8234, for example, an insertion guide tube for a bag is connected to a conduit downstream of the upstream connection point of the bypass tube and upstream of the downstream connection point, and these insertion guides are connected to the conduit. A tube inserted the upstream and downstream bags into the conduit.

In addition, to perform air purge, connect the insertion pipe of the upstream bag to the bypass pipe through a communication pipe, and transport gas from the bypass pipe to the downstream conduit from the upstream bag through the communication pipe and the insertion guide pipe. On the other hand, the air on the upstream side of the downstream bag was discharged to the outside as the transport gas was introduced, using the insertion guide pipe of the downstream bag.

[Problem to be solved by the invention]

However, in addition to connecting the bypass tube to the conduit, it is necessary to connect two insertion guide tubes to the conduit, and it requires a lot of effort due to the need to use blowless equipment at four locations, drilling the conduit with tools, and connecting the conduit. It takes a lot of effort and time, and it also takes a lot of effort and time to connect the bypass tube and the insertion guide tube with a connecting tube, and it also takes a lot of effort and time to remove the bypass tube, the two insertion guide tubes, and the connecting tube. However, it also required a lot of labor and time, and had the drawback that it required a lot of labor and construction time as a whole.

An object of the present invention is to enable a predetermined construction work to be carried out without using two insertion guide pipes and a connecting pipe, thereby significantly saving labor and shortening the construction time.

[Means to solve the problem]

The characteristic means of the present invention is to insert the upstream bag into the conduit from the upstream proximal end of the bypass pipe, and insert the downstream bag into the conduit from the downstream proximal end of the bypass pipe, and complete the construction. To perform air purge of the conduit section, first install a hose through the upstream bag, connect one end of the hose to one end of the communication channel with a valve attached to the upstream base end tube section, and then Open the end on the downstream side of the upstream bag, let the upstream proximal tube portion communicate with the upstream side of the upstream bag and the other end of the communication channel, open the valve of the communication channel, and open the upstream bag. A transport gas for air purge is delivered from the upstream side to the downstream side of the bag through the upstream side proximal end pipe portion, the connecting channel, and the hose. Connecting one end of the hose to a dispersion channel with a valve attached to the pipe portion,
The other end of the hose is opened on the upstream side of the downstream bag, and the valve of the diffusion flow path is opened to supply air purge transport gas to the downstream side of the upstream bag. The air on the upstream side of the bag is discharged to the outside through the hose and the diffusion flow path,
Its effects are as follows.

[Effect]

That is, as illustrated in FIG. Pipe part 5a
into the gas transport conduit 1, the upstream bag 3 is positioned downstream of the upstream proximal tube portion 5a, and the gas transport conduit 1 is blocked by the upstream bag 3,
In addition, the downstream bag 4 is inserted into the gas transport conduit 1 from the downstream proximal tube portion 5b of the bypass tube 5,
The downstream bag 4 is located upstream of the downstream proximal tube portion 5b, the gas transport conduit 1 is blocked by the downstream bag 4, and the conduit work at the construction site 2 is carried out in this state, and then the construction is completed. Air purging of conduit section 1A is carried out as follows.

(a) A communication channel 14 in which the hose 18 passing through the upstream bag 3 is communicated with the upstream proximal tube portion 5a.
and communicates with the gas transport conduit 1 on the upstream side of the upstream bag 3, and connects the upstream proximal end tube portion 5a to the gas transport conduit 1 on the upstream side of the upstream bag 3, valve 15
a, 16a is opened, and the transport gas from the upstream side of the upstream bag 3 is made to flow in the order of the upstream proximal end portion 5a → the communication channel 14 → the hose 18, and is sent to the construction completion conduit portion 1A for air purging. Enter.

On the other hand, (b) a dispersion channel 21 in which the hose 19 passing through the downstream bag 4 is communicated with the downstream proximal tube portion 5b;
At the same time, the downstream bag 4 is connected to the gas transport conduit 1 on the upstream side, and the valve 15b is opened, and the air on the upstream side of the downstream bag 4 is transferred to the hose as the transport gas for air purge is introduced. 19 to a diffusion channel 21 and discharged to the outside.

In short, since the upstream and downstream bags are inserted into the conduit using bypass pipes, the insertion guide pipes for the two bags required in the prior art described above can be omitted, and along with this, the pipes at two locations can be omitted. Connection work, pipe drilling work, and pipe removal work can be eliminated.

In addition, by using a pre-prepared hose, a connecting flow path with a valve, and the upstream proximal end of the bypass pipe, the air purge that was required in the conventional technology described above can be achieved with the simple operation of simply opening the valve. By omitting the communication pipe, the transport gas for air purge can be sent to the upstream side and the downstream side of the upstream side bag, and this also makes it possible to eliminate some of the pipe connection work and pipe removal work.

〔Effect of the invention〕

As a result, we developed an uninterrupted, no-blowout method for shutting off gas transport pipes, which is even better in terms of labor savings and shortening the construction period, by making it possible to shut off the pipes using two bags and to perform air purging using the transport gas in a short time and with less effort. I was able to establish it.

〔Example〕

Next, an example will be shown with reference to FIG.

The upstream and downstream conduit sections of the construction site 2 in the gas transport conduit 1 are connected using a bypass pipe 5, and the bypass pipe 5 for the conduit 1 is connected to each other.
A conduit portion downstream from the upstream connecting part of the
The sections of the conduit upstream from the downstream communication section are each shut off using pressure bags 3 and 4 which are inserted into the conduit 1 using non-splashing equipment and tools and are inflated.

The work procedure up to the illustrated state is as follows.

Conduit 1 on the upstream and downstream sides of construction site 2
Set the non-jet tool bodies 6a and 6b on the main bodies 6a and 6b, set the non-jet drilling machine (not shown) on the bodies 6a and 6b, and release the attached shutters 7a and 7b [gate valve, sluice valve] on the main bodies 6a and 6b, respectively. etc.], the hole saw of the drilling machine is lowered and rotated to drill a hole in the conduit 1, the hole saw is pulled up, shutters 7a and 7b are closed, and the drilling machine is removed from the main bodies 6a and 6b.

A bypass pipe 5 is connected to the main bodies 6a and 6b, and the upstream bag 3 is stored in a contracted state in the upstream proximal end pipe portion 5a of the bypass pipe 5, and the downstream bag 3 is stored in the downstream proximal end pipe portion 5b of the bypass pipe 5. The side bag 4 is stored in a contracted state.

Open the shutters 7a and 7b, selectively operate the valves 8 and 8' installed in the bypass pipe, and purge the air in the bypass pipe 5 through the diffusion holes 9 and 9'.
After completing the transportation gas replacement, open both valves 8 and 8'.
Bypass pipe 5 allows gas to be transported.

The upstream bag 3 is inserted into the conduit 1 from the upstream proximal tube section 5a, the downstream bag 4 is inserted into the conduit 1 from the downstream proximal tube section 5b, and the valve 1 is inserted.
0a and 10b are opened, fluid (usually air) from an unillustrated pressure source is forced into the bags 3 and 4 using the hoses 12b and 12c, and the bags 3 and 4 are expanded to block the flow inside the conduit 1. , valve 10a,1
Close 0b.

At this time, the bag 3 is moved by the upstream guide 12a.
The bag 4 is guided by the downstream guide 12b to the downstream side of the upstream proximal tube portion 5a, and the bag 4 is guided to the upstream side of the downstream proximal tube portion 5b.

Thereafter, the pressure inside the bypass pipe 5 is measured using the pressure gauge 13 of the bypass pipe 5 to confirm that gas transport is being carried out, and while the valve 16a is closed and the valve 15a is opened, the pressure inside the bypass pipe 5 is measured. The pressure change in the pipe No. 2 is measured with the pressure gauge 22, and the shutoff performance of Bag No. 3 is checked.

For safety, an auxiliary pressure bag may be inserted into the conduit 1 and inflated. In this case, the auxiliary pressure bag is inserted near the downstream side of the upstream bag 3 and near the upstream side of the downstream bag 4. use

Conduit work is carried out at the construction site in the above-mentioned state, and after the conduit work is completed, air purge is performed on the completed conduit section 1A.Next, the air purge will be explained.

(b) For air purge, install upstream bag 3 in advance.
One end of the hose 18 is connected to one end of a communication channel 14 with valves 15a and 16a attached to the upstream proximal tube portion 5a, and the other end of the hose 18 is connected to the upstream side bag 3. is opened on the downstream side, and the upstream proximal end tube portion 5a is communicated with the upstream side of the upstream side bag 3 and the other end of the communication channel 14, and furthermore, a hose 19 is provided in the downstream side bag 4 in a penetrating state, Downstream proximal tube portion 5b
One end of the hose 19 is connected to a dispersion flow path 21 with a valve 15b attached thereto, and the other end of the hose 19 is opened on the upstream side of the downstream bag 4.

(b) Open the valves 15a and 16a of the communication channel 14 and the valve 15b of the diffusion channel 21, and transport gas from the upstream side of the upstream side bag 3 to the downstream side of the upstream side proximal tube portion 5a, the communication channel 14, The air on the upstream side of the downstream bag 4 is discharged to the outside through the hose 19 and the diffusion channel 21 as the transport gas is introduced.

At this time, by adjusting the opening degrees of the valves 15a, 16a, and 15b, the introduced gas pressure can be adjusted to the pressure gauge 22 to the optimum value for reliable and quick air purge.
Adjust using.

Once the air purge is complete, the valves 10a, 1
0b is opened to deflate the bags 3 and 4, and the bags 3 and 4 are pulled up and stored in the upstream and downstream proximal tube portions 5a and 5b.

The shutters 7a and 7b are closed to block the perforation of the conduit 1, and the bypass pipe 5 is removed from the main bodies 6a and 6b. Finally, a non-jet plug mounting machine (not shown) is set in the main bodies 6a, 6b, the shutters 7a, 7b are opened, a closing plug is set in the perforation, and the shutters 7a, 7d are closed again.

Note that the main bodies 6a and 6b may be removed, but
It may be left in place for safety reasons.

[Another example]

Next, another embodiment will be described.

In the embodiments described above, the procedures may be reversed or multiple procedures may be performed simultaneously.

When using the auxiliary pressure-resistant bag described above, the hoses 18 and 19 can be used for a tightness test between the upstream bag 3 and the downstream bag 4 and the auxiliary pressure-resistant bag. In the event that there is overflow gas, the overflow gas is discharged to the outside through hoses 18, 19 and diffusion channels 21, 23.

The air purge communication channel 14 connected to the hose 18 may be directly connected to the proximal tube portion 5a as shown in FIG.

The bypass pipe 5 may have a flexible portion between the valves 8 and 8' to facilitate connection, may be made entirely of a high-strength pressure-resistant rubber hose, or may have a bellows joint in the middle.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of the invention, and FIG. 2 is a partially cutaway side view showing another embodiment of the invention. 1... Conduit, 1A... Construction completed conduit section, 2...
...Construction area, 3...Upstream bag, 4...Downstream bag, 5...Bypass pipe, 5a...Upstream proximal pipe portion, 5b...Downstream proximal pipe portion, 14...Connecting channel , 15a, 16b... valve, 15b...
Valve, 18, 19...hose, 21...dispersion channel.

Claims (1)

[Scope of Claims] 1. Conduit sections on the upstream side and downstream side of the construction site 2 in the gas transport conduit 1 are connected to each other using a bypass pipe 5, and from the upstream side communication part of the bypass pipe 5 with respect to the conduit 1 The downstream conduit portion and the conduit portion upstream from the downstream communication portion are each inserted into the conduit 1 using non-jet equipment and tools,
and the upstream and downstream bags 3 and 4 to be inflated.
After that, the conduit work is carried out at the construction point 2, and after the conduit work is completed, the transport gas in the conduit upstream of the upstream bag 3 is transferred to the part of the conduit between the two bags 3 and 4 where the work has been completed. 1A, the air purge of the conduit section 1A for which the work has been completed is carried out. At the same time, the downstream side bag 4 is inserted into the conduit 1 from the downstream proximal tube section 5b of the bypass tube 5, and the air purge of the construction completed conduit section 1A is carried out in advance. A hose 18 is provided in a penetrating state in the side bag 3, and one end of the hose 18 is connected to one end of a communication channel 14 with valves 15a and 16a attached to the upstream proximal tube portion 5a.
8 is opened on the downstream side of the upstream bag 3, and the upstream proximal tube portion 5a is communicated with the upstream side of the upstream bag 3 and the other end of the communication channel 14, The valves 15a and 16a of the communication channel 14 are opened to supply the air purge transport gas from the upstream side of the upstream bag 3 to the downstream side of the upstream proximal tube portion 5.
a, the connecting flow path 14 and the hose 18;
is provided in a penetrating state, one end of the hose 19 is connected to a dispersion channel 21 with a valve 15b attached to the downstream proximal tube portion 5b, and the other end of the hose 19 is connected to the upstream side of the downstream bag 4. The valve 15b of the diffusion flow path 21 is opened, and the air on the upstream side of the downstream bag 4 is transferred to the hose as the transport gas for air purge is fed to the downstream side of the upstream bag 3. 19 and a dispersion channel 21 to discharge the water to the outside.