JP3007516B2 - Supply pipe blockage method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a method of closing a pipe from a city gas main pipe to a gas meter of a customer, that is, a supply pipe (service pipe).

[0002]

2. Description of the Related Art When supplying city gas to consumers,
A method is generally adopted in which a take-out section (service team) is provided in a main pipe buried under the basement of a road, and a supply pipe is piped from the take-out section to a customer's premises.

[0003] Such a supply pipe is used as long as a customer uses gas. For example, when a house is demolished and this site is used for another purpose, gas supply becomes unnecessary. In such a case, the supply pipe is closed for safety. At present, there are the following two blocking methods.

A. Original arrangement method (Fig. 3) This method excavates the take-out point 21 of the supply pipe 20,
After removing the supply pipe 20, the service team 23 of the main pipe 22
Is a method of closing the branch portion 24 with a plug.

B. Resin filling method (FIG. 4) In this method, the length of the supply pipe 30 is measured to determine the entire internal volume, and the resin P corresponding to the internal volume is supplied to the compression cylinder 3.
1. The main pipe 33 is connected from the supply pipe 30 using the resin tank 32.
This is a method of filling and solidifying and closing up to the service tee 34.

[0006]

However, the above conventional example has the following disadvantages.

A. In the case of the former rearranging method, excavation of roads increases costs, and traffic stops and noises are generated during construction.

B. In the case of the resin filling method, the inner volume of the supply pipe is calculated by the length of the pipe × the standard cross-sectional area of the pipe.
6. Since the sleeve 37 and the like often exist, an error may occur between the calculated internal volume and the actual internal volume. Therefore, when the amount of resin is large, the resin P flows into the main pipe 33 to block the inside of the main pipe 33 or to become a resistance 38 in the main pipe 33. On the other hand, if the amount of resin is small, sufficient blocking will not be performed. Further, when the entirety of the supply pipe 30 is filled with the resin P, the amount of the resin P used increases, and the cost is increased. If the supply pipe is deteriorated, cracks or breakage occur due to the filling pressure, and the construction method becomes difficult. It may not be possible to adopt it

An object of the present invention is to solve the above-mentioned problems a and b in a method of closing a supply pipe.

[0010]

A method of closing a supply pipe according to the present invention is as follows.

A. Providing a highly elastic leading and trailing pig with a diameter slightly larger than the inner diameter of the supply pipe to be closed symmetrically, and a lubricant having a viscosity that does not drip under its own weight, b. Using sound waves, determine the length from the inlet of the supply pipe to the location of the service tee in advance, calculate the internal volume from this length and the inner diameter of the supply pipe, and then subtract the volume of the lubricant from this internal volume, and set the safety factor. A meter containing a quantity of water determined by multiplying by water and a pump for pumping the water into a supply pipe, c. Then, first insert the leading pig into the supply pipe, then fill the lubricant, then insert the rear pig to hold the lubricant between the leading pig and the rear pig, d. Pumping the leading pig, lubricating material and the rear pig into the supply pipe by applying water pressure using the pump from behind the rear pig, e. The decrease in the water amount and the change in the water pressure are monitored. Block the supply tube by leaving the lubrication material and the rear pig intact in the supply tube, f. A method for closing a supply pipe, characterized in that:

[0012]

[Function] Insert the top pig, lubricant, and rear pig from the tip of the on-site supply pipe in order, and connect the hose extended from the measuring instrument via the pump to the supply pipe to complete the preparation for work. Thereafter, when the pump is driven to apply water pressure to the rear pig, the water pressure pushes the rear pig, whereby the lubricant and the leading pig are pressed and fed into the supply pipe.

The rear pig receives the water pressure, the lubricating material assists the rear pig in sliding, the front pig stops the gas, and in the vertical part, moves in the supply pipe while preventing the fall by gravity. To reach. At this time, the driving of the pump is stopped because the water pressure rises rapidly and the amount of water in the measuring instrument becomes small or disappears. In this way, the supply pipe is closed by leaving the leading pig, the lubricant, and the rear pig as they are in the supply pipe. As a result, gas does not flow from the main pipe side to the supply pipe side, and conversely, air and water do not flow into the main pipe side from the supply pipe side. As the lubricant, a resin that has fluidity and solidifies after a certain period of time may be used in addition to a normal lubricant.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a closing method according to the present invention will be described with reference to FIG.

In this figure, 1 is a main pipe, 2 is a supply pipe to be closed, 3 is a service tee attached to a branch of the main pipe and the supply pipe 2, 4 is a riser pipe, and 5 is a riser pipe 4.
6 is a manual pump, 7 is a hose connecting the insert 5 and the pump 6, 8 is a measuring instrument containing water,
9 is a primary pressure gauge, 10 is a secondary pressure gauge, and 11 is a governor.

In FIG. 2, A is a leading pig and B is a trailing pig. In this embodiment, the leading pig A is made of natural rubber, the trailing pig B is made of silicon, and is larger than the minimum inner diameter of the supply pipe 2. It is a sphere with a diameter and both have high elasticity.
The use condition is that C is a lubricating material, and the lubricating material C has a viscosity that does not drip at a minimum.

Next, a working example will be described.

A. First, the distance from the riser pipe 4 of the supply pipe 2 to the service tee 3 is determined using sound waves, the internal volume is calculated from this distance and the diameter of the supply pipe 2, and the lubricant C to be used is further calculated from the internal volume. An amount of water obtained by subtracting the volume and multiplying by the safety factor is prepared in the measuring device 8.

B. Next, the leading pig A is inserted into the riser pipe 4 with the insertion tool 5 removed, and then the lubricating material C is filled in. Then, the rear pig B is inserted to insert the lubricating material between the leading pig and the rear pig. , And the insertion tool 4 is attached, and the hose 7 is connected to the insertion tool 4.

C. Next, the pump 6 is driven to move the rear pig B
The front pig A, the lubricant C, and the rear pig B are fed into the supply pipe 2 by applying a water pressure from the rear.

D. Next, the change in the water pressure was measured using a secondary pressure gauge 1.
While monitoring at 0 and monitoring the decrease in water volume, the water pressure showed a certain value or more, and at the same time, when the water volume was almost exhausted, the leading pig A reached the front end side of the supply pipe 2 and reached the place of Service Q3. Then, the drive of the pump 6 is stopped.

E. In this way, the leading end of the supply pipe 2 is closed by leaving the leading pig A, the lubricant C, and the rear pig B at the leading end of the supply pipe 2 as they are. This situation is shown in FIG.

F. Next, the insertion tool 5 is removed from the riser pipe 4, and the riser pipe 4 is removed if necessary, or a part of the supply pipe 2 is crushed to complete the operation.

[0024]

As described above, according to the present invention, the leading pig, the lubricating material, and the rear pig are fed into the supply pipe by hydraulic pressure, and this is stopped at the tip of the supply pipe and left to close the supply pipe. Has the following effects.

A. There is no need to excavate the road. Therefore,
The problem of traffic stoppages and noise during construction is eliminated, and construction costs can be greatly reduced because there is no excavation cost.

B. The use of the lubricating material allows the rear pig to be fed smoothly regardless of the conditions inside the pipe.

C. Since the entire pipe is not filled with resin, this cost can be reduced.

D. Even in the case of a deteriorated supply pipe, the pig moves smoothly due to the lubricant, so that a large internal pressure is not applied. Thus, there is no crack or breakage in the tube.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a closing method of the present invention.

FIG. 2 is an explanatory diagram of a closed state.

FIG. 3 is an explanatory view of an original arrangement method.

FIG. 4 is an explanatory view of a resin filling method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main pipe 2 Supply pipe 3 Service tee 4 Rise pipe 5 Insert 6 Pump 7 Hose 8 Measuring instrument 9 Primary pressure gauge 10 Secondary pressure gauge 11 Governor A First pig B Rear pig C Lubricant

Claims (1)

(57) [Claims] 1. A method comprising: a. Providing a highly elastic leading and trailing pig with a diameter slightly larger than the inner diameter of the supply pipe to be closed symmetrically, and a lubricant having a viscosity that does not drip under its own weight, b. Using the sound wave, determine the length from the inlet of the supply pipe to the service tee in advance, calculate the internal volume from this length and the inner diameter of the supply pipe, and then subtract the volume of the lubricant from this internal volume, and set the safety factor. A meter containing a quantity of water determined by multiplying by water and a pump for pumping the water into a supply pipe, c. Then, first insert the leading pig into the supply pipe, then fill the lubricant, then insert the rear pig to hold the lubricant between the leading pig and the rear pig, d. Pumping the leading pig, lubricating material and the rear pig into the supply pipe by applying water pressure using the pump from behind the rear pig, e. The decrease in the water amount and the change in the water pressure are monitored, and when the water amount is almost exhausted and the water pressure shows a certain value or more, it is determined that the leading pig is the tip of the supply pipe and has reached the place of the service team and the pump Block the supply pipe by stopping the driving of the supply pipe and leaving the leading pig, the lubricant, and the rear pig in the supply pipe as they are. F. A method for closing a supply pipe, characterized in that: