JP2005264977A - Piping method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To certainly block a through hole while preventing screwing releasing operation of a plug member screwed with a female screw portion after blocking a cutting end portion of an existing pipe, to certainly install a gas bag by using the through hole when a newly-established pipe is connected on the blocked cutting end portion side, and to certainly block the through hole after connecting the newly-established pipe. <P>SOLUTION: The female screw portion 2 is formed on an inner peripheral surface of a gas bag installing through hole 1, and the plug member 6 is screwed with the female screw portion. In order to prevent the screwing releasing operation of the plug member screwed with the female screw portion after blocking the cutting end portion of the existing pipe A, a covering member 7 for covering the plug member is removably welded and fixed to the existing pipe separated from the plug member. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  In the present invention, in order to cut the existing pipe for gas supply and close the cut end portion, a gas bag mounting through hole is formed in the existing pipe, and the gas bag is mounted in the pipe through the through hole. After blocking the inflow of gas to the planned cutting location of the existing pipe and closing the cut end, the gas bag is removed from the pipe and screwed into the female thread provided around the through hole. When plugging the through-hole with a plug member and connecting a new pipe to the closed cut end side, the screw end of the plug member is released and the cut end is removed with a gas bag attached to the pipe through the through-hole. After blocking the inflow of gas to the side and connecting the new pipe, the gas bag is removed from the pipe, and the plug member is screwed into the female thread and fixed by welding. The present invention relates to a plumbing method for closing a pipe.

The above-mentioned piping method is equipped with a gas bag that is formed so that a gas bag that cuts off the inflow of gas to the planned cutting position can be installed in the pipe when the existing pipe for gas supply is cut and its cut end is closed. A gas bag for blocking the inflow of gas to the cut end side can be installed in the pipe by using the through hole for connecting the newly installed pipe to the closed cut end side. There is an advantage that the number of through holes for mounting can be reduced.
In the conventional piping method, a plug member is provided on the inner peripheral side of a cylindrical adapter provided with a male screw portion that is screwed into a female screw portion formed on the inner peripheral surface of a gas bag mounting through hole (hereinafter simply referred to as a through hole). In the screwed state, the cylindrical adapter and the plug member are welded and fixed, or a cover member covering the plug member screwed to the cylindrical adapter is welded and fixed to the cylindrical adapter. After making a plug unit that can prevent the screw release operation of the screwed plug member in advance and using this plug unit to close the cut end of the existing pipe, the cylindrical adapter In the state where the male screw part is screwed to the female screw part formed on the inner peripheral surface of the through hole, and the cylindrical adapter is welded and fixed to the existing pipe, and the screw release operation of the plug member is prevented. Make sure to close the pipe and connect the new pipe to the cut end. When the plug member is unscrewed, the welded part between the cylindrical adapter and the plug member, or the cover member welded to the cylindrical adapter, is removed with a grinder. After screwing in the cylindrical adapter is released, the gas bag attached to the tube through the through hole blocks the flow of gas into the cut end, and after the new pipe is connected, the plug member is screwed into the cylindrical adapter. At the same time, the plug member is welded and fixed to the cylindrical adapter to close the through hole (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-213285

According to the above prior art, the cylindrical adapter and the plug member are welded and fixed so that the screw member can be prevented from being unscrewed by closing the cut end of the existing pipe and then screwed into the cylindrical adapter. Or the cover member that covers the plug member screwed into the cylindrical adapter is welded and fixed to the cylindrical adapter, so that the cylindrical adapter or the plug member is heated to a high temperature by welding heat during the welding. There is a problem that distortion is likely to occur in the threaded portion of the tubular adapter and the threaded portion of the tubular adapter and the plug member, and the plug member is screwed after closing the cut end of the existing pipe. Since the cylindrical adapter is welded and fixed to the existing pipe to close the through hole, the cylindrical adapter and the plug member are also heated to high temperatures by welding heat during the welding, so that the cylindrical adapter and the plug member are screwed together. There is a problem that distortion tends to occur.
For this reason, even if it is attempted to close the through hole with the plug member after closing the cut end portion of the existing pipe, the male screw portion is connected to the inner peripheral surface of the through hole due to distortion generated in the male screw portion of the cylindrical adapter. There is a possibility that the through-hole cannot be closed because it cannot be screwed into the female screw portion formed in the above.
In addition, even when the male threaded portion of the cylindrical adapter is screwed into the female threaded portion formed on the inner peripheral surface of the through hole to close the through hole, the new pipe is connected to the closed cut end side. Even if the welded part between the cylindrical adapter and the plug member or the cover member welded to the cylindrical adapter was removed to attach the gas bag to the gas bag, it occurred at the screwed portion between the cylindrical adapter and the plug member. Due to the distortion, there is a possibility that the screw bag cannot be released from the tubular adapter and the gas bag cannot be mounted.
Furthermore, even if the screwing of the plug member to the cylindrical adapter can be released, even after trying to screw the plug member into the cylindrical adapter again after connecting the new pipe, the screw cannot be screwed well and the through hole is There is a possibility that it cannot be blocked.
The present invention has been made in view of the above circumstances, and after closing the cut end portion of the existing pipe, the through-hole is reliably secured in a state in which the screw release operation of the plug member screwed into the female screw portion is blocked. When connecting the new pipe to the closed cutting end side, the gas bag can be securely attached using the through hole, and after connecting the new pipe, the through hole The purpose is to allow closure.

  The first characteristic configuration of the present invention is that a gas bag mounting through-hole is formed in the existing pipe in order to cut the existing pipe for gas supply and close the cut end portion, and the pipe is mounted in the pipe through the through-hole. An internal thread provided around the through-hole after removing the gas bag from the pipe after blocking the inflow of gas to the planned cutting position of the existing pipe with the gas bag and closing the cut end. When the through hole is closed with a plug member that is screwed to the plug, and a new pipe is connected to the closed cutting end, the screw that is screwed to the plug member is released, and the gas fitted into the pipe through the through hole After the gas flow to the cut end side is blocked by the bag and the new pipe is connected, the gas bag is removed from the pipe, and the plug member is screwed into the female screw portion and fixed by welding. A piping method for closing the through-hole, and The cover member covering the plug member is separated from the plug member so that the screw member can be prevented from being unscrewed by screwing the plug member and closing the cut end. In this point, it is fixed to the existing pipe by welding.

[Action and effect]
Since the plug member is screwed into the female screw portion provided around the through hole, the through hole can be reliably closed even after the cut end portion of the existing pipe is closed.
In addition, the covering member covering the plug member is blocked by the plug member or the female screw portion so that the screw member can be prevented from being unscrewed by closing the cut end portion and then screwing into the female screw portion to close the through hole. In order not to be heated to high temperature by welding heat, it is welded and fixed to the existing pipe so as to be removed from the plug member, so that the screwed portion between the female screw portion and the plug member is hardly distorted.
Therefore, after the cut end of the existing pipe is closed, the through hole can be reliably closed in a state where the screw release operation of the plug member screwed into the female screw portion is blocked, and the closed cut end When connecting the new pipe to the side, all or part of the cover member is removed and the screwing of the female screw part of the plug member is released, so that the gas bag can be securely attached using the through hole. Even after the pipe is connected, the through hole can be reliably closed by screwing the stopper member into the female thread portion and fixing it by welding.

  According to a second characteristic configuration of the present invention, the other end side of the cylindrical body having a flange portion at one end side is hermetically welded and fixed to the existing pipe, and the outer peripheral portion of the plug member screwed into the female thread portion is spaced apart. The cover member is formed by sealing the inside with a cover plate that is surrounded by a space and is bolted to the flange portion.

[Action and effect]
The other end of the cylinder having a flange portion at one end is hermetically welded and fixed to an existing pipe, and the outer peripheral portion of the plug member screwed into the female screw portion is surrounded with a gap, and bolted to the flange portion. Since the inside of the lid is sealed with a cover plate to form the cover member, even if gas in the pipe leaks from the screwed part between the female thread and the plug member, the leaked gas stays inside the cover member. Thus, it is possible to easily remove the lid plate by removing the bolts from the flange portion of the lid plate so that continuous leakage of gas can be prevented and the screwing of the plug member to the female thread portion can be released.
In addition, the cap plate can be removed by removing the bolt fixing to the flange part so that the screwing to the female thread part of the plug member can be released without using a grinder or a torch for fusing with the occurrence of sparks. Work can be performed safely.

  As shown in FIGS. 1 to 3, the existing gas supply pipe A through which combustible gas such as city gas flows is cut by a no-blow construction method in which the gas in the pipe is not jetted outside, and the cut end An embodiment of the pipe construction method according to the present invention in which the new pipe B is connected to the cut end 4 side by the no-blow method when it is necessary to connect the new pipe B at a later date with the section 4 closed. To do.

  As shown in FIG. 1 (a), the no-blow construction shutter device is fixed to the existing pipe A and attached to the shutter device. As shown in FIG. The side wall of the existing pipe A is formed with a circular through hole 1 in a plan view for mounting the gas bag so that the gas in the pipe does not blow out to the outside, and the female screw part 2 is formed on the inner peripheral surface of the through hole 1. 1 and the two gas bags 3 mounted in the pipe through the through-holes 1 are used to block the inflow of gas to the planned cutting point X of the existing pipe A, and as shown in FIG. While cutting A, a cap 5 is welded to the cut end 4 to close the cut end 4.

  After the cut end 4 is closed, the gas bag 3 is removed from the tube so that the gas in the tube does not spout outside, and the plug member screwed into the female screw portion 2 as shown in FIG. The steel cover member 7 that covers the plug member 6 can be removed from the plug member 6 and removed to the existing pipe A so that the through hole 1 can be blocked by 6 and the screw release operation of the plug member 6 can be prevented. Fix by welding.

  As shown in FIGS. 2 and 3, the cover member 7 has the same end as the through hole 1 on the other end side of the cylindrical body 8 having an inner diameter of about twice the diameter of the through hole 1. The core member is hermetically welded and fixed to the existing pipe A, the outer peripheral portion of the plug member 6 screwed into the female screw portion 2 is surrounded with a gap, and the cover plate 9 is bolted to the flange portion 8a with the gasket 10 interposed therebetween. And the inside can be sealed.

  When the new pipe B is connected to the cut end 4 side of the existing pipe A closed by the cap 5, a no-blow bag or the like is used so that the gas in the pipe does not blow out to the outside. The bolts 8a are removed, the cover plate 9 is removed, the screwing of the plug member 6 to the female screw portion 2 is released, and two pieces mounted in the pipe through the through hole 1 as shown in FIG. The gas bag 3 cuts off the inflow of gas to the cut end 4 side, and the new pipe B is connected as shown in FIG.

  After the new pipe B is connected, the gas bag 3 is removed outside the pipe using a no-blow bag or the like so that the gas in the pipe does not spout to the outside, and the plug is closed as shown in FIG. The member 6 is screwed into the female thread portion 2 and fixed to the existing pipe A by welding to close the through hole 1, and the cylindrical body 8 is cut and removed with a grinder or the like.

[Other Embodiments]
1. In the pipe construction method according to the present invention, when a covering member is constituted by a cylinder body that is welded and fixed to an existing pipe and a cover plate that closes an end portion of the cylinder body, the through hole is closed by a plug member after closing the cut end portion. It may be possible to weld and fix only the cylinder to the existing pipe before, and after fixing the cylinder to the existing pipe by welding, if a female thread is formed on the inner peripheral surface of the through hole for attaching the gas bag, the welding heat Therefore, it is possible to prevent the internal thread portion from being distorted.
2. The pipe construction method according to the present invention is such that when a covering member is constituted by a cylindrical body that is welded and fixed to an existing pipe and a cover plate that closes an end of the cylindrical body, the cylindrical body is welded and fixed to the existing pipe, and then the cylinder A lid plate may be fixed to the body by welding.
3. In the piping method according to the present invention, after closing the cut end portion of the existing pipe, the plug member is screwed into the female thread portion formed on the inner peripheral surface of the through hole to close the through hole, and then the plug member A covering member formed in a cap shape so as to cover the plug member may be welded and fixed to the existing pipe so as to prevent the screw release operation.

Illustration of piping method Cross section of the main part Partial cutaway plan view of the main part

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas bag mounting through-hole 2 Female thread part 3 Gas bag 4 Cutting end part 6 Plug member 7 Cover member 8 Cylindrical body 8a Flange part 9 Cover plate A Existing pipe B New pipe

Claims (2)

In order to cut the existing pipe for gas supply and close the cut end portion thereof, a gas bag mounting through hole is formed in the existing pipe, and the existing pipe is cut by the gas bag mounted in the pipe through the through hole. Shut off the gas flow to the planned location,
After closing the cut end, the gas bag is removed outside the tube, and the through hole is closed with a plug member screwed into the female screw portion provided around the through hole,
When connecting a new pipe to the closed cutting end side, the screw member is released and the gas bag attached to the pipe through the through hole is used to block the gas flow to the cutting end side. And
After connecting the new pipe, the gas bag is removed outside the pipe, and the plug member is screwed into the female thread portion and welded and fixed to close the through hole,
A covering member that covers the plug member, so as to prevent the screw release operation of the plug member screwed into the female screw portion after the plug member is screwed into the female screw portion and the cut end portion is closed, A piping method that is welded and fixed to the existing pipe away from the plug member.   The other end side of the cylinder having a flange portion at one end side is hermetically welded and fixed to the existing pipe, and the outer peripheral portion of the plug member screwed into the female screw portion is surrounded with a space therebetween, and the flange portion is bolted The piping method according to claim 1, wherein the cover member is configured by sealing the inside with a fixed lid plate.

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