JP3426622B2 - Live tube cutting and closing method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cutting a gas pipe by interrupting a gas flow without stopping gas supply. 2. Description of the Related Art As shown in FIG. 1, for example, when an underground gas pipe 2 is to be shortened and an outdoor gas meter 3 needs to be repositioned for an extension of a house 1, the road surface 4 must be moved one by one. Excavating and closing the main plug 5 of the main pipe takes time and troubles the neighborhood, so it is often desired to cut the gas pipe without stopping the gas. In such a case, conventionally, FIG.
As shown in (1), the gas pipe 2 is cut, the outflow of gas is temporarily stopped with a rubber stopper, then a transparent bag is attached, and the rubber stopper is removed.
After connecting the elbow 6 and the valve tee (main plug) 7, the transparent bag was removed, and the standing pipe 9 was connected via the screw mechanism elbow 8, and then the valve tee 7 was opened. . [0003] However, in the above-described standing pipe repositioning work, there is a risk that the gas will be blown out at the time of cutting the gas pipe, so that it may be ignited by the sparks of the saw. Has to be performed in a transparent bag, which is troublesome and dangerous. An object of the present invention is to solve these problems and to provide a method of cutting and closing a live tube which is easy and safe. [0004] The method for cutting and closing a live tube according to the present invention comprises, as shown in FIGS. 3 to 5, a joint body 11 which is fastened and fixed to an outer periphery of a gas pipe 2 by a fitting 10. A piston 13 that moves from one side of the internal space to the other side due to a small explosion of the gas generating agent 12 embedded in the inner wall surface is provided inside, and a part of the gas pipe 2 is cut and drilled at the tip of the piston 13. A live pipe branching joint A provided with a cutting blade 14 is fastened and fixed to the upstream side of a cut portion of the gas pipe 2, and a sealing material injection gun 16 is attached to a branch pipe connection port 15 of the joint A, and a piston 13 is mounted. Is operated to pierce the gas pipe 2 and then inject the sealing material B to cut off the gas pipe 2 by blocking the gas flow with the sealing material B. According to the method of the present invention, when the gas pipe 2 is pierced by the cutting blade 14, the branch pipe connection port 15 of the live pipe branch joint A is closed by the sealing material injection gun 16. In addition, gas does not leak outside from the joint A,
Since the injected paste-like sealing material B enters the gas pipe 2 through the joint A and completely blocks the gas flow,
The cutting operation of the gas pipe 2 can be performed with confidence. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An active pipe branching joint A used in the method of the present invention comprises:
As shown in FIG. 6, the joint body 11 is a commercially available (trade name: magic joint), and is composed of a joint body 11 and a mounting bracket 10 each having a lower surface and an upper surface formed in a semi-cylindrical shape. Are fastened to the outer peripheral surface of the gas pipe 1 by bolts 17. As shown in FIG. 3, inside the joint body 11, a cutting blade 14 is formed at a distal end portion, and a piston 13 having a small diameter portion at a body portion is slidably mounted. A gas generating agent 12 is embedded in the inner surface of one side wall of the joint body 11, and when an impact force is applied to the gas generating agent 12 from the outside by a hammer 18 and a push pin 19, FIGS. )
As shown in (c), a small explosion of the gas generating agent 12 causes the piston 13 to momentarily move from one side of the internal space to the other side, and at that time, the cutting blade 14 cuts a part of the gas pipe 2. hand,
A through hole 20 is opened in the pipe wall, so that the section 21 of the pipe wall is held between the distal end face of the piston 3 and the other side wall face, and passes through the small-diameter portion of the piston 13. hand,
As shown by an arrow in FIG. 4C, a gas path from the through hole 21 to the branch pipe connection port 15 is formed. In FIG. 6, reference numeral 22 denotes a refractory packing, and reference numeral 23 denotes an O-ring for keeping the through hole 20 airtight. In the present embodiment, first, the active pipe branching joint A is fastened and fixed to the upstream side of the cut portion of the gas pipe 1 with the branch pipe connection port 15 facing upward. At this time, the gas pipe 2
If there is a synthetic resin coating, the coating is peeled in advance. Next, a bushing 25 having a sealing gun fitting hole 24 at the center is fitted to the branch pipe connection port 15, and the sealing material injection gun 16 is fitted to the fitting hole 24. Next, the piston 13 is operated by the push pin 18 to open the through hole 20 in the side wall of the gas pipe 2, and then the sealing material injection gun 16 is immediately fired. The sealing material B is filled into the gas pipe 2 until the gas pipe 2 enters the gas pipe 2 and closes the gas pipe 2. The sealing material fitting hole 24 is formed by a screw hole.
By applying a sealing material to these screw holes and screwing a plastic nozzle of the sealing gun 16, a slight thread groove is formed on the peripheral surface of the nozzle, so that the nozzle can be inserted sufficiently firmly. There is no danger of the nozzle coming off or the gas leaking out when 13 is actuated. As the sealing material B, a JIS-A5758 architectural sealing material can be used. There is sufficient room if one commercially available cartridge is used for the 25A tube and two commercially available cartridges are used for the 32A tube. Also, there is almost no droop even in a vertical gas pipe. After the sealing material B has been filled, the upstream and downstream sides of the joint A are cut off, as shown in FIG. 5, and a mechanical joint (lining SGM socket) as shown in FIG.
, And the joint A is discarded.
At this time, the upstream cutting position C needs to be filled with a sealing material. Depending on the case, the plug may be closed downstream of the joint A, but if the joint A is left in the ground, a space is required and an anti-corrosion treatment is required. Since the old meter side is closed, the sealing material flows to the upstream side of the gas pipe 2 and hardly flows to the downstream side as shown in the figure. Further, when the branch pipe is started from the gas pipe 2, a separate live pipe branch joint A ′ is attached upstream of the joint A as shown in FIG.
The valve A 7, the elbow 8, the standing pipe 9 and the like are connected to the joint A '. In this embodiment, the branch pipe connection port 15 of the joint A is used.
Although the bushing 25 and the sealing material injection gun 16 are directly inserted into the nozzle, when the gas pipe 2 is inclined, or when the vertical hole is narrow and both the push pin 19 and the injection gun 16 are to be operated from above, If the injection gun 16 is attached to the connection port 15 via a swell bushing and the stake (elbow) is rotated, the insertion direction of the injection gun 16 can be freely changed. According to the method of the present invention, as described above, when cutting the gas pipe, the gas flow is completely shut off by the sealing material, so that there is an advantage that the operation can be performed with a sense of security. Therefore, since it is not necessary to excavate the road surface and close the main plug of the main pipe, there is an advantage that the number of working steps can be significantly reduced and there is no risk of inconvenience to the neighborhood. Since the joint A remains attached to the gas pipe 2, the component cost is slightly higher than that of the conventional method.
The benefits of being able to ensure safety and saving a lot of man-hours are much greater.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic piping arrangement diagram for explaining the background of the present invention. FIG. 2 is a schematic side view illustrating a conventional standing pipe position changing operation. FIG. 3 is a cross-sectional view showing an initial stage of the method of the present invention. FIGS. 4A, 4B, and 4C are cross-sectional views showing stages during the method of the present invention. FIG. 5 is a schematic side view showing the final stage of the method of the present invention. FIG. 6 is an exploded perspective view of a live pipe branch joint used in the method of the present invention. [Description of Signs] 10 Mounting bracket 11 Joint body 12 Gas generating agent 13 Piston 14 Cutting blade 15 Branch pipe connection port 16 Sealing material injection gun 20 Through hole 24 Sealing gun fitting insertion hole 25 Bushing A Live pipe branch joint B Sealing material C Cutting position

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Atsunori Komura 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi Inside Osaka Gas Co., Ltd. (56) References JP-A-2-142995 (JP, A) JP-A Hei 4-19495 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16L 41/06

Claims (1)

(57) [Claims 1] One side of the internal space due to a small explosion of the gas generating agent embedded in the inner wall surface inside the joint body which is fastened and fixed to the outer periphery of the gas pipe by the mounting bracket. A live pipe branching joint having a piston moving from the other side to the other side and having a cutting blade for cutting and drilling a part of the gas pipe at the tip of the piston is fastened and fixed to the upstream side of the cutting point of the gas pipe. hand,
Attach a sealing material injection gun to the branch pipe connection port of the joint, operate the piston, pierce the gas pipe, and then inject the sealing material to cut off the gas pipe by blocking the gas flow with the sealing material. A method for cutting and closing a live tube.