JPS58109794A - Method of cutting and turning conduit for supplying gas - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas supply conduit cutting method for cutting and removing an existing gas supply conduit buried in the ground during sewer construction work.

Conventionally, as shown in Fig. 1, as this type of construction method, elbow a, which does not have a plug hole for removing the bag and is used only for simply connecting pipes, has been adopted. As shown in FIGS. 2 to 6, first, bags are placed in symmetrical positions facing the excavated hole C of the gas supply conduit at an appropriate distance from the edge of the excavated hole C of the gas supply conduit. Holes d and d are bored, and branch pipe saddles e and e are attached to face the bag holes d and d.

Next, insert gas bags f and f into bag holes d and d, respectively, and branch pipe saddle e.

By removing and inserting the plug i in the gas bag f and filling the balloon in the gas bag f with air, the gas in the gas supply conduit (N,
Keep it in an isolated state.

Next, in this state, the supply conduit 1 is cut and removed at the position shown by the broken line in FIG. 3 inside the bag holes d and d, and the cut end of the supply conduit 1 is removed as shown in FIG. Attach the elbow a and connect the U-shaped cutting pipe g as shown in Fig. 5, and then
Openable pulp (not shown) connected to the gas bag f
The air in the gas bag f is removed by opening the gas bag f, and the gas bag f is pulled out from the bag holes d and d from which the plug stoppers 1 have been removed. After extracting the gas bag f, the plugs i are again inserted into the branch saddles e and e to seal them, but the plugs on one discharge side (on the right side of Figure 5) must be cut and turned in advance. The air in the pipe g is extracted from the bag hole d on the discharge side by gas supply, and when this is finished, the bag hole d on the discharge side is tightly plugged and the gas supply is started by re-opening the conduit. A series of gas supply conduit cutting operations have been completed.

The conventional construction method for cutting gas supply pipes is as explained above, but in such conventional construction method,
Because it is necessary to install two gas bag saddles outside the cut part of the conduit, the excavation range of drilling hole C becomes wider due to the extra space taken by installing the branch pipe saddles.
Also, the use of two saddles increases costs. Fourth, there were drawbacks such as a reduction in work efficiency due to an increase in the excavation range and an increase in the labor involved in installing branch pipe saddles.

In this type of gas supply pipe cutting method, the present invention aims to minimize the area of ground excavation as much as possible, and reduce the equipment and labor used for cutting work, thereby reducing costs and improving work efficiency. In order to achieve this purpose, a gas bag is inserted through a bag hole drilled opposite to the inner surface of the excavated hole of the gas supply conduit, and by filling the gas bag with air, the inside of the conduit is increased. The gas flow is cut off, the conduit is cut and removed, an elbow having a plug hole for removing the bag is attached to the cut end of the conduit, and after the gas bag is extracted, the plug hole for removing the bag is tightly plugged. This is what I did.

Hereinafter, the seventh method for cutting a gas supply conduit according to the present invention will be described.
A detailed explanation will be given with reference to the drawings shown in FIGS. 12 to 12.

In Fig. 7, 1 is an existing gas supply conduit buried in the ground 2, and a rectangular excavation hole 3 is opened in the ground 2 to expose the area where the gas supply conduit 1 will be cut. be done.

Bag holes 4, 4 are drilled in the gas supply conduit 1 at symmetrical positions facing the inner surface of the excavated hole 3 of the conduit 1, spaced apart from the edge of the excavated hole 3 by an appropriate pressure. Set up Next, the gas bags 5 are inserted into the lug holes 4.4 toward both sides of the conduit 1.
The gas bag 5 is made up of a balloon having a size large enough to close the inside of the gas supply conduit 1 at one end, and the gas bag 5 is formed by connecting a thin rubber tube 5a. Then, by introducing air from one end of the rubber tube 5a until the gas bag 5 is filled,
As shown in FIG. 8, the flow of gas within the gas supply conduit 1 is maintained in a state where it is blocked by the gas bag 5.

Next, in this state, the gas bag 5 and the bag hole 4 are
The gas supply conduit 1 is cut and removed at the position shown by the broken line in FIG. Elbow 6 is the first
As shown in the θ diagram, a bag removal plug hole 7 is provided approximately on the extension of the gas supply conduit l connected to this elbow 6, and a plug 8 is screwed into this bag removal plug hole 7. has been done. Then, connect the U-shaped cutting pipe 9 to the elbow 6 as shown in FIG. ) by opening the gas bag 5 to remove the air from the gas bag 5 and remove the gas bag 5 from the bag removal plug hole 7.
Extract.

After extracting the gas bag 5, the bag removal plug hole 7 is sealed again with the stopper 8, but before doing so, the seal plug on one of the discharge sides (the right side in FIG. The air inside is drawn out from the plug hole 7 on the discharge side by gas supply, and when this is finished, the plug hole 7 on the discharge side is tightly plugged, and gas supply through the conduit l is started again, and a series of gas The cutting work of the supply conduit is completed.

As mentioned above, what should be noted in the method of cutting the gas supply conduit of the present invention is that the cut part of the gas supply conduit is located between the bag hole and the edge of the excavation hole. It is now possible to cut the conduit as close to the edge as possible, minimizing the area of the hole to be excavated into the ground, significantly improving work efficiency.
A plug hole 7 for removing the bag is provided in the bent elbow 6, so that there is no need to use a saddle for the gas bag, and the cost can be reduced and the work efficiency as a whole can be improved.

The method for cutting a gas supply conduit according to the present invention involves drilling a hole in the ground so that the conduit is exposed when cutting and cutting a gas supply conduit buried underground, and cutting the conduit as described in ijj. A pair of left and right bag holes are bored on the inner side of the hole (7. Insert a gas bag into both sides of the conduit through each bag hole, fill this gas bag with air, and release air to the gas bag. The flow of gas in the conduit is interrupted by the filling of the conduit, the conduit is cut and removed between the gas bag and the bag hole, and an elbow having a plug hole for removing the bag is attached to the cut end of the conduit. After removing the gas bag from the bag removal plug hole,
Since the plug hole for removing the bag is tightly plugged, the cutting part of the conduit is located between the bag hole and the edge of the excavation hole, and therefore, the cut part of the conduit is located as close as possible to the edge of the excavation hole. It is now possible to cut the conduit while the pipe is in the open position, and the area of excavation of the hole can be kept to a minimum, significantly improving work efficiency. In addition, there is no need to use a saddle for the gas bag, and a plug hole for removing the bag can be cut. The gas bag can be easily inserted and removed using just the provided elbow.
This method has excellent advantages such as being able to reduce costs and greatly rationalizing the cutting work as a whole.

[Brief explanation of drawings]

Figures 1 to 6 show the conventional method of cutting a gas supply conduit. Figure 1 is a partially vertical side view of an elbow, and Figures 2 to 6 are side views based on the conventional method. 7 to 12 show an embodiment of the method for cutting a gas supply conduit according to the present invention, and FIGS. The side view based on the construction method, Figure 1O, is a drawing equivalent to Figure 1. 1. Gas supply conduit, 2. Ground, 3. Excavation hole, 4. Bag hole, 5. Gas bag, 6
・Elbow, 7...Plug hole for bag removal, 8 ・
plug. Patent applicant: Seibu Gas Co., Ltd. Inmoto Steel Pipe Fittings Co., Ltd. Representative patent attorney: Takashi Suzue −

Claims (1)

[Claims] When cutting and turning a gas supply conduit buried in the ground, a hole is drilled in the ground so that the conduit is exposed, and a pair of left and right bag holes are drilled opposite the inner surface of the excavated hole of the conduit. A gas bag is inserted into the conduit side through each bag hole, and the gas bag is filled with air, and the gas flow in the conduit is interrupted by filling the gas bag with air. After cutting and removing the conduit between the gas bag and the bag hole, attaching an elbow having a bag removal plug hole to the cut end of the conduit, and extracting the gas bag from the bag removal plug hole of this elbow. A method for cutting a gas supply conduit, characterized in that the plug hole for removing the bag is sealed tightly.