JP2011112124A - Method for removing branch pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for removing a branch pipe connected to an original pipe via a service T-joint while cutting a rising portion of the service T-joint to almost eliminating a portion protruded from the original pipe and externally fitting a cap joint to the base of the cut rising pipe portion to secure a required fusion area during thermal fusion. <P>SOLUTION: After a hole saw 13 built in the rising pipe portion is pushed into the base of the rising pipe portion and temporarily plugged therein, the rising pipe portion 3 is scraped up to its base 3a to remove a spigot 6 together with the branch pipe 1 and the rising pipe portion 3 is cut at the level of the lower end of an opening 6a of the spigot 6 formed in the rising pipe portion 3. The fusion area of the cap joint is expanded by an equivalent of a thickness t of the spigot 6 to secure the fusion strength of the cap joint during thermal fusion. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for removing a branch pipe branched from a main pipe in resin pipe piping equipment.

  Taking gas pipes as an example, resin pipes such as polyethylene pipes, which are rich in corrosion resistance and earthquake resistance, have recently been frequently used as gas pipes, and electrofusion joints are usually used to connect resin pipes. ing. One of them is the electric fusion service Qi joint used to branch the branch pipe from the main pipe.

  When a building is removed, the building plumbing is usually removed from the main pipe and removed. When the branch pipe is connected to the main pipe via a service tee joint, the branch pipe is usually connected to the spigot of the service tee joint attached to the main pipe by a socket joint, and removal of the branch pipe is conventional. The spigot or branch pipe on one side of the socket joint was squeezed off and cut, and the cut end was covered with a cap joint and fused, but the service-tee joint protruded from the main pipe. It was easy to get in and was in the way. A method for removing a branch pipe to solve this problem is disclosed in Patent Document 1 below. This method will be described with reference to FIG. 1. When the branch pipe 1 is removed, a cap attached to the tip of the rising pipe portion 3 of the service tee joint 2 is first removed, and then a hole saw (shown in the figure) stored above the rising pipe portion. Is not screwed in with a tool, and is pushed into a tapping hole formed in the main tube 15 and sealed.

  Next, the base of the rising pipe portion 3 a immediately below the spigot is cut, and the rising pipe portion 3 and the spigot 6 are removed together with the branch pipe 1. The cutting position of the riser 3 is above the hole saw that does not interfere with the hole saw pushed into the tapping hole.

  After cutting the riser pipe part, a no-blow bag (not shown) is attached to the root 3a of the riser pipe part 3, and then the hand is put into the no-blow bag, and the hole saw is turned in a loosening direction using a tool and removed. Thereafter, the temporary stopper is pushed into the tapping hole from which the hole saw has been removed, and is attached and sealed, and then the no blow bag is removed. After removing the no-blow bag, the main plug 8 attached to the tool 7 is press-fitted into the rising pipe root 3a from above the temporary plug 9 as shown in FIG. 2, and is heat-sealed by frictional heat to close the tapping hole. Instead of heat-sealing this plug by frictional heat, as shown in FIG. 3, an insertion-type cap joint 10 is provided in which a heating wire is embedded in the insertion portion 10a, and is inserted into the root portion 3a of the riser and is electrically fused. A thing is also known (patent document 2). In addition, there is also known a structure in which a seal plug is provided in the rising pipe portion instead of the hole saw.

JP 2002-295724 A JP 2006-258256 A

  According to the method shown in the figure, since the rising pipe portion under the spigot is cut, the protruding portion from the main pipe can be almost eliminated as compared with the conventional method described above, but the root portion of the rising pipe portion remaining after cutting is short. For this reason, the fusion area with the plug is also reduced, and there is a problem that sufficient fusion strength cannot be obtained.

  An object of the present invention is to provide an improved method of the above-described conventional method, and to provide a method for removing a branch pipe that can secure a wider fusion area of the main plug.

The invention according to claim 1 is a method of removing a branch pipe connected to a main pipe through a service Q joint, and after removing a cap attached to the tip of the rise pipe section of the service Q joint, Screw the hole saw or seal plug stored above and go over the spigot and push and seal it into the tapping hole drilled at the root or main pipe of the rising pipe, and after pushing the hole saw or seal plug, Characterized in that it comprises a step of cutting from the root, and a step of heat-sealing the plug to the riser tube root after the cutting step, preferably electric fusion,
The invention according to claim 2 is characterized in that, in the invention according to claim 1, after the step of cutting the spigot, there is a step of cutting the rising pipe part from the lower end of the opening of the spigot or just above it.

  The invention according to claim 3 is the invention according to claim 2, wherein the spigot cutting in the spigot cutting step is performed by scraping the rising pipe portion with an annular cutter inserted from the tip of the rising pipe portion. It is characterized by.

  The invention according to claim 4 is characterized in that, in the invention according to claim 1, after the step of cutting the spigot, the opening of the cut spigot is closed with a stopper.

  According to the invention according to claim 1, since the spigot is cut from the root, the amount of protrusion can be reduced compared to the conventional method of cutting the spigot or the branch pipe on one side of the socket joint, and the spigot is fused to the rising pipe portion. Compared with the above-described conventional method, the present plug has an effect that the fusion area can be increased and the fusion strength can be increased.

  According to the invention according to claim 2, since it is cut from the root of the riser pipe portion, the amount of protrusion from the main pipe can be reduced, and the problem of getting in the way can be solved, compared to the conventional method shown in the figure, At least the thickness of the tubular spigot has an effect that the fusion area can be increased and the fusion strength can be increased accordingly.

  According to the invention of claim 3, since the spigot is cut and the outer peripheral surface of the rising pipe portion is scraped to become a circumferential surface free from dirt, the cap is put on the base of the rising pipe portion and fused. can do.

  According to the invention according to claim 4, it is possible to secure a sufficient fusion area as much as necessary by the plug that closes the opening, and prevents the molten resin from being blocked by the plug and leaking from the spigot opening at the time of fusion. Can do.

The partial cross-sectional front view which connected the branch pipe to the main pipe through the service Q joint. The partial cross-section front view when this plug is attached. The front view of an insertion type cap coupling. Sectional drawing of the service tee joint which connects a branch pipe to a main pipe. Sectional drawing which shows the state which pushed the hole saw in the standup pipe part base. Sectional drawing when a riser part is scraped by a scrape. Sectional drawing of the service Qi joint before and after cutting. The partial cross section front view which attached the cap coupling.

  Embodiments of the present invention will be described below with reference to the drawings. In the figure, the same reference numerals are given to the same structural parts as those shown in FIGS.

  FIG. 4 shows an electric fusion service tee joint 2 for connecting the branch pipe 1 to the main pipe 5. The saddle section 11 is electrically fused to the main pipe 5, and the rising pipe section rising from the saddle section 11. 3 and a spigot 6 projecting laterally from the rising pipe portion 3 and connected to the branch pipe 1 via an electric fusion socket joint 12. In the figure, reference numeral 13 denotes a hole saw pulled up in the rising pipe portion 3 above the spigot. FIG. 4 shows a state where a cap (not shown) attached to the leading end of the rising pipe portion is removed.

  In removing the branch pipe 1, first, in the service tee joint 2 shown in FIG. 4 with the cap removed, the hole saw 13 is screwed and pushed into the riser pipe root 3a using a tool (not shown) such as a special hexagon wrench fly. And temporarily plug (Fig. 5). After temporary plugging, the spigot 6 is cut while scraping the outer periphery of the rising pipe portion from the tip of the rising pipe portion by a scraper 15 that is an annular cutter. The scraping of the riser pipe section 3 is performed up to the riser pipe root 3a (FIG. 6).

  After the scraping, the scraper 15 is extracted from the rising pipe section 3, and then the rising pipe section 3 is cut from the dotted line position at the lower end of the opening 6a of the spigot 6 (FIG. 7). After cutting, the electric fusion cap joint 16 as the main plug is fitted from the outside to the scraped riser pipe root portion 3a, and is electrically fused (FIG. 8).

  According to this method, compared to the conventional method of cutting the spigot or the branch pipe on one side of the socket joint, the amount of protrusion from the main pipe is small, so that it does not get in the way, and the rising pipe section 3 just below the spigot. Compared with cutting, the length l of the rising pipe root 3a after cutting is increased by at least the thickness t of the spigot 6, and the fusion area is increased correspondingly, and the adhesive strength by the cap joint 16 is increased. The scraper 15 can scrape the rising pipe portion 3 and can cut the spigot 6. The spigot 6 can be cut off. The hole saw 13 is temporarily plugged in, and a no blow bag is attached as in the conventional method, and the hole saw 13 is removed. The work to remove the branch pipe is easy, the workability is improved, and the work time can be shortened. Since the cap is not inserted into the riser pipe root 3 a by the cap joint 16, the hole saw 13 can be held at any position of the riser pipe root under the opening of the spigot 6. Have.

  In the above-described embodiment, after the rising pipe portion 3 is scraped, the rising pipe portion 3 is cut from the lower end of the opening of the spigot 6, and then covered with the cap joint 16 to be electrically fused. It may be performed above the lower end of the opening of the spigot 6, or the rising pipe portion 3 may not be cut at all. The seal by the main plug may be externally fitted to the riser pipe portion 3 by using a cap joint 16 longer than the cap joint 16 shown in FIG. 8 and may be electrofused. It may be inserted into the tube portion 3 and electrofused. In any case, after the spigot 6 is removed, a plug is attached to the opening 6a so that the molten resin does not leak from the opening 6a formed in the riser 3 and the plug is closed. It is desirable to install this plug.

  In the present embodiment, the hole saw 13 is also fastened to the rising pipe root 3a, but may be pushed into the tapping hole 5a of the main pipe 5. In this case, the length up to the hole saw can be sufficiently secured at the riser pipe root 3a, and the main plug can be fitted and attached.

  In the above-described embodiment, the hole saw 13 is fastened to the riser pipe root 3a as described above. However, the hole saw 13 is attached to the riser pipe root 3a using a tool in the state where the no blow bag is attached to the riser pipe root 3a as described above. Then, the temporary plug may be pushed into the riser tube root 3a to be attached and sealed.

  The main pipe can be drilled by using a dedicated tool without using the hole saw 13. In this case, after drilling, the dedicated tool is removed from the rising pipe portion 3, and a seal plug is attached in the rising pipe portion 3. At the time of cutting the rising pipe portion, a seal plug is pushed into the root of the rising pipe portion or the tapping hole 5a of the main pipe 5 in place of the above-described hole saw 13 and temporarily plugged. After the temporary stopper, as described above, the spigot 6 is cut while scraping the outer periphery of the rising pipe portion, and then the electric fusion cap joint 16 is electrically fused.

1 ・ ・ Branch tube 2 ・ ・ Service tee joint 3 ・ ・ Rise pipe section 3a ・ ・ Rise pipe section root 5 ・ ・ Main pipe 6 ・ ・ Spigot 8 ・ ・ Main plug 9 ・ ・ Temporary plug 10 ・ ・ Insertion type cap Fitting 11 ·· Saddle 12 · · Socket fitting 13 · Hole saw 15 · Scraper 16 · · Cap fitting

Claims (4)

  A method for removing a branch pipe connected to a main pipe via a service tee joint, and after removing a cap attached to the tip of the rise pipe section of the service tee joint, a hole saw or a seal plug stored in the upper part of the rise pipe section A step of pushing and sealing the tapping hole formed in the base of the riser pipe or the main pipe, the step of cutting the spigot from the root after the step of pushing the hole saw or the seal plug, and the cutting A method of removing a branch pipe, comprising the step of fusing the plug to the root of the rising pipe after the process.   2. The branch pipe removing method according to claim 1, further comprising a step of cutting the rising pipe portion from the lower end of the opening of the spigot or immediately above the spigot after the cutting step of the spigot.   3. The method for removing a branch pipe according to claim 2, wherein the spigot is cut in the spigot cutting step by scraping the rising pipe portion with an annular cutter inserted from the tip of the rising pipe portion.   The method for removing a branch pipe according to claim 1, wherein after the spigot cutting step, the opening of the cut spigot is closed with a stopper.