JPH0762517B2 - Pipe joint between a branch pipe of a new branch pipe for gas distribution and an existing supply pipe - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pipe joint between a branch pipe of a new branch pipe in which gas flows and an existing supply pipe.

(Prior Art) In general, a buried supply pipe for city gas is formed by branching a main pipe into a branch pipe and branching a supplier (branch pipe) from the branch pipe to each consumer.

(Problems to be solved by the invention) By the way, in the work of replacing an old pipe that has deteriorated with a new pipe, excavate the buried part of the old pipe, install the new pipe next to the old pipe, and then bypass both pipes. Contact for construction. However, along with this work, it is necessary to connect the existing supply pipes that are piped to the customers from the old branch pipes and connect them to the branch pipes of the new branch pipes.

In this case, the contact work is done with the gas supply stopped. However, even after the contact work is completed, it is necessary for the customer who stopped the gas to perform an ignition test and a gas leak inspection. Therefore, in the case of this gas stop contact work, each customer is contacted in advance, but there are many cases where the customer is absent. For example, in the Tokyo area, about 40% is absent, and there is a problem that the construction cannot be performed.

In old residential areas and densely populated residential areas, it may not be clear to which consumer the existing buried supply pipe route is connected, or there may be a mixture of water pipes and buried pipes for other purposes. However, there is also a risk of accidental disconnection, and there is a problem that it takes time to proceed with the construction.

Therefore, if the customer is absent or there is a risk of accidental disconnection, the contact work will be performed without stopping the gas supply to the customer. In other words, in order to carry out connection work without stopping this gas supply, a simple temporary bypass is connected from the old branch pipe to the existing supply pipe to secure the gas supply to the customer, and then the branch pipe of the new branch pipe. And the existing supply pipe.

Explaining one example in detail, as shown in FIG. 12 (a), first, a new branch pipe b bypass-connected to the old branch pipe a is installed in parallel,
Gas is introduced into the new branch pipe b. Then, as shown in FIG. 12 (b), a temporary bypass d from the old branch pipe a to the existing supply pipe c is connected to a live pipe (a pipe that does not stop gas flow), and the temporary bypass d is connected to the existing supply pipe c. Secure gas inflow.
Then, the gas outflow at the branch portion e with the old branch pipe a and the existing supply pipe c is stopped. For example, as shown in FIG. 13, the plug h is removed from the communication passage between the clamp f and the branch joint g, and the rubber plug p is attached to allow the gas to flow from the old branch pipe a to the existing supply pipe c. Stop it. Subsequently, as shown in FIG. 12 (c), a gas bag i is inserted from the branch portion e into the existing supply pipe c to stop the backflow gas from the temporary bypass d. Then, the part of the existing supply pipe c that is closer to the gas back i position is cut m (FIG. (C)). Then, as shown in FIG. 12 (d), a branch part 1 consisting of a clamp and a branch joint is attached to the new branch pipe b.
The branch tube j is branched into a live tube via the. At the time of branching, the gas is stopped in the same manner as the branch part e of the old branch pipe a. Further, a mechanical elbow k having an elbow and a branch joint attached thereto is connected to the existing supply pipe c. After this connection, the gas bag i in the existing supply pipe c is taken out and the branch portion l
Also release the gas stop of. As a result, the branch pipe j from the new branch pipe b and the mechanical elbow k on the side of the existing supply pipe c are live-connected. Then, the temporary bypass d is removed, and the existing supply pipe c is changed from the old branch pipe a to the new branch pipe b.

However, such connection work requires excavation for the temporary bypass, and especially for the connection point with the existing supply pipe, it is necessary to connect the other end of the temporary bypass to the customer side, so As the area to be cut increases, the number of piping members required for temporary bypass also increases, and as a matter of course, the work load increases.

In addition, in addition to the above, there are many live pipe connection points in the case of using this temporary bypass, and it is necessary to sufficiently consider gas leaks and the like, which poses a problem of high work difficulty.

(Object of the invention) The present invention has been made in view of the above situation, and the connection between the branch pipe of the new branch pipe and the existing supply pipe while ensuring the flow of gas can be performed without requiring a temporary bypass. , A new gas distribution branch that not only can be performed easily and with good workability, but can reliably prevent gas leakage during and after connection work at the site to improve safety. It is an object of the present invention to provide a pipe joint between the branch pipe and the existing supply pipe.

(Structure of the Invention) In order to achieve the above object, a pipe joint between a branch pipe of a new branch pipe through which gas flows according to the present invention and an existing supply pipe has an inner peripheral surface which is formed on a lower surface and which corresponds to the upper half peripheral surface shape of the existing supply pipe. And a branch pipe portion that communicates with the inner peripheral surface of the recess is projected upward in the center, and both ends of the inner peripheral surface of the recess are protruded outward. An upper mold body provided with a mounting flange, and an inner peripheral surface corresponding to the lower half peripheral surface shape of the existing supply pipe are recessed on the upper surface, and a plug for perforation closing is formed at a position corresponding to the branch pipe portion of the upper mold body. A lower die main body provided with a fastening flange projecting outwardly on both upper end edges of the recessed inner peripheral surface so as to face the fastening flange of the upper die body. Fasten and connect the fastening flanges on both sides of the mold body and lower mold body at multiple points in the axial direction. A plurality of fastening bolts, a bottomed cylindrical closure cap that closes one end opening of a tube holding space formed inside both main bodies by assembling the upper mold body and the lower mold body, and one end side of the upper cap The other end of the branch pipe of the mold body can be connected to the branch pipe of the new branch pipe through a tightening seal mechanism, and an elbow with an air purge plug screwed into it and the upper mold body and lower mold A flange flange projecting in the direction perpendicular to the axis at one end of the main body in the axial direction, and a flange flange facing the flange flange and projecting outward at the opening end side of the closure cap are connected by tightening respectively. And a plurality of fastening bolts, which are fitted in the seal grooves circumferentially provided at both axial end portions of the inner peripheral surfaces of the upper mold body and the lower mold body, to perform the outer peripheral surface sealing action of the existing supply pipe. The ring-shaped sealing material and the upper die body and A sealing material interposed between the facing surfaces of both fastening flanges of the lower mold body along the axis to seal the joint surface between the two mold bodies, and the closing cap, the upper mold body and the lower mold body. A ring-shaped seal member is provided which is interposed in a seal accommodating portion provided around the surface portion and performs a sealing action between the both and an existing supply pipe.

(Operation of the Invention) According to the present invention having the above-described configuration, the branch pipe portion of the upper mold body is formed by sandwiching the upper mold body and the lower mold body with the existing supply pipe and connecting the two bodies. Connect the branch pipe of the new branch pipe to the elbow.

In this state, the air purge plug of the elbow is removed and the gas is circulated to purge the air in the branch pipe of the new branch pipe and the elbow to the outside, and after the air purge, the plug is screwed.

Next, the plug for piercing and closing the lower die body is removed, and piercing is performed by a piercing tool so as to penetrate the existing supply pipe inside. In this state, inflow gas from both the new and old branch pipes is being supplied to the consumer side.

Then, through the above-mentioned perforation, a gas bag or the like is inserted into the existing supply pipe on the old branch pipe side to block the gas flow with the old branch pipe side. In this state, gas is also stopped at the branch of the old branch pipe.

Next, the old branch pipe side of the existing supply pipe is cut, and the closing caps are tightened and coupled to the axial one ends of the upper and lower mold bodies, so that the pipe holding spaces formed in the upper mold and the lower mold bodies are closed. Close the opening at one end.

Finally, after a blocking tool such as a gas bag in the existing supply pipe is extracted through the hole and the plug hole, the hole closing plug is screwed.

By working in this way,
The connection work from the existing supply pipe to the branch pipe of the new branch pipe accompanying the replacement work of the old branch pipe can be performed with good workability while ensuring gas distribution.

By the way, since all of the above work is performed on-site, it is difficult to uniformly tighten the fastening bolts for connecting the upper mold body and the lower mold body, and the tightening is uneven, Or, there may be a case where the main tightening is forgotten only by the temporary tightening, and as a result, the sealing material intervening along the axis between the facing surfaces of the fastening flanges of the two mold bodies and performing the joint surface sealing action extends over its entire length. May not be securely tightened, or the annular sealing material that acts as a seal on the outer peripheral surface of the existing supply pipe intervening at both ends in the axial direction of the concave inner peripheral surfaces of the above two mold bodies may be unevenly tightened. do it,
Gas leakage may occur not only during work but also after work. Even in such a case, according to the present invention, the flanges at one end in the axial direction of the upper mold body and the lower mold body are made to face each other by connecting the connecting flanges of the tubular cap having the bottom to the plurality of flanges. Since they are configured to be tightened and connected by fastening bolts, it is possible to securely and evenly tighten the joint surface seal material and both annular seal materials with the tightening connection of both flanges. , If the fastening bolts that connect the upper mold body and the lower mold body are loosened, such as by forgetting to fully tighten the fastening bolts, the fastening connection between the flange flange and the closure cap connecting flange will be difficult. Since it cannot be performed, it is possible to detect looseness of the bolt for connecting the upper mold body and the lower mold body at that time, and to perform tightening without looseness. Therefore, by firmly connecting the upper mold body and the lower mold body, it is safe against earthquakes and ground subsidence, and
By enhancing the sealing effect of each of the above-mentioned sealing materials, a safe connection state without gas leakage can be obtained.

(Effect of the invention) Therefore, the pipe joint of the branch pipe of the new gas-flowing branch pipe of the present invention and the existing supply pipe, the existing supply pipe from the branch pipe of the old branch pipe with the replacement of the old branch pipe and the new branch pipe. The work to change the connection to the branch pipe of the new branch pipe can be done without stopping the gas supply on the customer side and preventing gas leakage, and it can be accomplished without the need for a conventional temporary bypass. Due to the large area excavation and the piping members required for temporary bypass and the work load associated with them, the branch pipes of the new branch pipes and the existing supply pipes can be connected with a prescribed workability with good workability. Can be implemented economically.

Moreover, according to the present invention, since all the work is performed on-site, the fastening of the plurality of fastening bolts that connect the upper die body and the lower die body may be uneven, or only the temporary fastening may be performed. Considering that loosening is likely to occur due to forgetting tightening, etc., as described above, with the flange flange at one end in the axial direction of the upper mold body and the lower mold body and the connecting flange of the bottomed cylindrical closure cap. By adopting a configuration in which each of them is tightened and connected by a plurality of fastening bolts, by this, the joint surface sealing material and both annular sealing materials are securely and evenly tightened, and the sealing effect of each sealing material is enhanced,
A remarkable effect that it is possible to obtain a safe connection state without gas leakage and to strengthen the connection between the upper mold body and the lower mold body to make it a safe structure against earthquakes and ground subsidence. Is played.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

In the pipe joint of this embodiment, an inner peripheral surface 3 corresponding to the shape of the upper half peripheral surface of the existing supply pipe 51 is concavely formed on the lower surface, and a branch pipe portion 4 communicating with the inner peripheral surface is provided at the center so as to project upward. The mold main body 1 and the lower mold main body 2 in which an inner peripheral surface 5 matching the shape of the lower half peripheral surface of the existing supply pipe 51 is recessed on the upper surface, and a perforation closing plug 6 is screwed on the central lower surface, and these upper and lower parts. In the combined state of the mold bodies 1 and 2, a closed cap 9 having a cylindrical shape with a bottom for closing one end side of the tube holding space 8 formed by the inner peripheral surfaces 3 and 5 and the upper mold body 1
Pipe path L-shaped elbow in which one end side is connected to the branch pipe portion 4 of the above through a tightening seal mechanism 10 and the other end side can be connected to the branch pipe 13 of the new branch pipe 12 through the tightening seal mechanism 11. It is composed of 14 and.

As shown in FIG. 2, fastening flanges 15 and 15 are provided outwardly at both lower edges of the inner peripheral surface 3 of the upper mold body 1 to project outward, and the inner peripheral surface 5 of the lower mold body 1 is secured. A fastening flange 16 is provided on both upper end edges of the same so as to project outward, and both flanges are fastened and engaged by a fastening bolt 17 ...

Also, the fastening flanges 15, 1 of the upper mold body 1 and the lower mold body 2
(6) At the mutually facing portions, one engaging flange 15 is provided with an engaging concave portion 18 and the other engaging flange 16 is provided with an engaging convex portion 19 so that both mold bodies 1 and 2 are positioned relative to each other. Has become.

Furthermore, the inner peripheral surfaces of the upper mold body 1 and the lower mold body 2 that face each other
Seal grooves 20 and 21 are provided around 3 and 5, respectively, and umbrella-shaped band grooves 22 and 23 are provided outside the seal grooves 20 and 21, respectively. An annular seal member 24 having a notched portion is interposed so as to perform an outer peripheral surface sealing action of the existing supply pipe 51, and a ball band 25 is interposed between the band grooves 22 and 23 so that the shaft of the existing supply pipe 51 is inserted. It blocks the movement in the direction. The ball band 25 is a ring-shaped band with a part cut away.
Hard balls 27 are embedded in the periphery of 26 at appropriate angular intervals.

Further, one of the joint surfaces of the upper die body 1 and the lower die body 2, that is, the joint surface of the lower die body 2 in this embodiment, is provided with a concave groove 28 for connecting the annular seal members 24 arranged at the both ends. Then, the joint surface sealing material 29 is fitted to this so that the joint surface sealing action of both the main bodies 1 and 2 is performed.

Further, at one end of the upper mold body 1 and the lower mold body 2, flange flanges 30 and 31 are provided so as to project in a direction perpendicular to the axis.

As shown in FIG. 3, the hole closing plug 6 of the lower mold body 2 is screwed into the screw hole 32 along the axis of the branch pipe portion 4 of the upper mold body 1 as shown in FIG. There is.

The closing cap 9 has upper and lower mold bodies 1 and 2 at its open end.
A connecting flange 33 is provided which can be connected to the flange flanges 30 and 31 of FIG. Further, a taper portion 34 is provided around the inner circumference of the opening of the closure cap 9 so as to gradually reduce its diameter toward the inner part. In this taper portion 34,
A ring-shaped closing sealing material 100 and a ring-shaped pressing body 35 are arranged from the inner part toward the opening. And
In the state where the closing cap 9 is connected to the flange flanges 30 and 31 of the upper and lower mold bodies 1, the closing seal member 100 is pressed by the pressing body 35 and is compressed, so that the outer peripheral surface of the existing supply pipe 51 is sealed. Has become.

As shown in FIG. 1, the tightening seal mechanisms 10 and 11 of the elbow 14 have male threads 3 provided on the outer circumferences of both ends of the L-shaped tube body 36.
7,37 and a push ring 3 with an internal thread 38 for screwing
9, 39 and the annular seal member 4 mounted on the inner peripheral surfaces of both ends of the pipe main body 36 in the tapered portions 40, 40 that gradually decrease in diameter toward the inside of the pipe.
1, 41 and the ball bands 43, 43 attached to the taper portion 42 that gradually reduces in diameter from the center of the inner circumference of the push wheels 39, 39 toward the inner part.
And annular pressing bodies 44, 44 interposed between the annular sealing material 41 and the ball band 43.

Then, the tightening and sealing mechanism 10, 11 attaches the push ring 39 to the pipe main body 36.
The annular pusher 44 is screwed into
41 is pressed and compressed, the outer peripheral surface of the branch pipe portion 4 of the upper mold body 1 or the branch pipe 13 of the new branch pipe 12 connected by this compression is performed, and the annular push body 44 also pushes the ball band 43. The branch pipe portion 4 and the branch pipe 13 connected together are prevented from coming off.

Further, the elbow 14 is provided with a screw hole 45 along one axis and communicating with the inside, and an air purging plug 46 is screwed into the screw hole 45.

With such a configuration, the old branch pipe 60 and the new branch pipe 12 are connected via the bypasses 50, 50 as shown in FIG.

Then, as shown in FIG. 5, the existing supply pipe of the old branch pipe 60
A branch pipe (13) is branched from the new branch pipe (12) to the new branch pipe (12) near the branch portion (51 ') via a saddle branch pipe or the like.

Next, as shown in FIG. 6, the upper and lower mold bodies 1 and 2 are clamped to the supply pipe 51 near the old branch pipe 60, and the fastening flanges 15 and 16 of both mold bodies 1 and 2 are fastened to each other. The bolts 17 are connected by tightening, and the elbow 14 is attached to the branch pipe 4 of the upper mold body 1.
The branch pipe 13 of the new branch pipe 12 is connected via.

Then, in this state, the air purging plug 46 of the elbow 14 is removed, and the branch pipe 13 and the elbow 14 of the new branch pipe 12 are removed.
The plug 46 is screwed and attached to the screw hole 45 in a state where the air inside is exhausted and filled with gas.

Next, the plug 6 for closing the perforation of the lower mold body 2 is removed, and as shown in FIG. 7, the existing supply pipe 51 inside the screw hole 32 is perforated 52, 53 with a hole saw 70 as a perforation tool (see FIG. 1). And FIG. 3).

Then, as shown in FIG.
The no-blowing bag 62 is attached to the surrounding boss portion 61, and the hole saw 70 is removed in the no-blowing bag 62 and taken out of the bag.

In this state, the new branch pipe is installed on the existing supply pipe 51 facing the consumer side.
Gas is supplied from both the 12 and the old branch pipe 60.

The gas bag 71 is attached to the inside of the supply pipe 51 on the side of the old branch pipe 60 a little from the hole 53 through the no-blowing bag 62, the screw hole 32, and the hole 53 of the existing supply pipe 51.
Block 60 side. In this state, gas is also stopped at the branch portion 51 'of the old branch pipe 60.

Next, the old branch pipe 60 side of the existing supply pipe 51 is cut to
As shown in the figure, the connection flange 33 of the closure cap 9
Face the flange flanges 30 and 31 of the lower mold bodies 1 and 2, respectively,
The flanges 33 and 30, 31 are connected to each other via fastening bolts 90, and the cutting side is closed.

Then, the gas bag 71 in the existing supply pipe 51 is removed in the no-blowing bag 62, and the plug 6 is screwed and attached to the screw hole 32.

In this way, the steps of can be performed. Therefore, along with the replacement work of the new branch pipe 12 and the old branch pipe 60, the existing supply pipe 51 that is piped to the old branch pipe 60 is replaced with the branch pipe 13 of the new branch pipe 12.
It is possible to carry out the connection work to be exchanged and connected to the gas leak prevention state without stopping the gas.

In addition, in the above-mentioned one embodiment, the closing sealing material 100 and the pressing body 35.
Is the connecting flange 33 of the closing cap 9 and the upper and lower mold bodies 1,
The upper and lower mold bodies 1 and 1 are provided between the flange flanges 30 and 31 of the second mold.
Although the facing portion between 2 and the closing cap 9 is sealed, the present invention is not limited to this, and the upper and lower mold bodies 1 and 2 facing the connecting flange 33 of the closing cap 9 as shown in FIG.
The circumferential flanges 101 and 102 are formed on the flange flanges 30 and 31 of the
Insert the O-ring 103, which is a sealing material, into 1
30,31,33 are connected, and the upper and lower mold bodies 1 and 2 and the closing cap 9
It is also possible to reduce the number of parts by sealing the facing part with. In addition, as shown in FIG. 10, the ball band on the side of the closing cap 9 is eliminated and the structure is simplified as compared with the one of the above-mentioned embodiment, and one ball band is shown.
25 may prevent the existing supply pipe 31 from moving in the axial direction. Further, as shown in FIG. 11, the O-ring 1 is provided between the flange facing surfaces of the upper and lower mold bodies 1 and 2 and the closing cap 9.
It is sealed with 03, and the ball bands placed on the inner circumference of both ends of the upper and lower mold bodies 1 and 2 are removed. Instead of this, existing supply is provided to both ends of the upper and lower mold bodies 1 and 2. The protrusions 104 and 105 having an inner diameter smaller than the outer diameter of the pipe 51 are integrally formed, and the fastening bolts 17 that connect the upper and lower mold bodies 1 and 2 to the existing supply pipe 51 by fastening are installed. Supply pipe 51
The protrusions 104 and 105 are cut into the outer peripheral surface of the
It is also possible to reduce the number of parts by blocking the movement in the axial direction.

In the above-mentioned embodiment, the upper mold body 1 is shown above and the lower mold body 2 is shown below. Of course, however, the upper mold body 1 may be used below and the lower mold body 2 may be used above. Upper and lower mold body 1,
There is also a case where 2 is used sideways.

[Brief description of drawings]

1 to 9 show an embodiment of the present invention. FIG. 1 is a half sectional view, FIG. 2 is an exploded perspective view, FIG. 3 is a lateral sectional view of the present model, and FIGS. Is an explanatory diagram explaining the procedure,
10 is a partially cutaway sectional view showing another modification of the present invention, FIG. 11 is a partially cutaway sectional view showing yet another modification of the present invention, and FIG. 12 (a). , (B), (c),
(D) is an explanatory view showing an example in which the existing supply pipe in the related art is changed from the old branch pipe to the new branch pipe, and FIG. 13 is a sectional view showing an example of the pipe branch portion. 1 …… Upper mold body 2 …… Lower mold body 4 …… Branch pipe section 6 …… Punching plug for plugging 8 …… Supply pipe holding space 9 …… Closing cap 10,11 …… Tightening seal mechanism 12 …… New branch pipe 13 …… Branch pipe 14 …… Elbow 24 …… Annular seal material 25 …… Ball band 29 …… Bonding surface seal material 100 …… Blocking seal material 35 …… Pressing body 46 …… Gas purge plug 51 …… Existing supply pipe

Claims (1)

[Claims] 1. An inner peripheral surface corresponding to the upper half peripheral surface shape of an existing supply pipe is recessed on the lower surface, and a branch pipe portion communicating with the recessed inner peripheral surface is protruded upward in the center. Also, the upper mold body is provided with fastening flanges projecting outward on both lower edges of the recessed inner peripheral surface, and the inner peripheral surface matching the lower half peripheral surface shape of the existing supply pipe is recessed on the upper surface. In addition, the perforation closing plug is screwed into a position corresponding to the branch pipe portion of the upper mold body, and both upper end edges of the recessed inner peripheral surface are opposed to the fastening flange of the upper mold body. And a plurality of fastening bolts for fastening and connecting the both fastening flanges of the upper die body and the lower die body to each other at a plurality of positions in the axial direction. The tube holding space formed inside both of the upper and lower mold bodies by assembling them. With a bottomed tubular closure cap that closes the opening at one end, one end side can be connected to the branch pipe part of the upper mold body, and the other end side can be connected to the branch pipe of the new branch pipe through a tightening seal mechanism. An elbow to which an air purging plug is screwed, a flange flange projecting from the axial ends of the upper mold body and the lower mold body in a direction perpendicular to the axis line, and the flange cap facing the flange flanges. A plurality of fastening bolts for respectively tightening and connecting a connecting flange protruding outward on the opening end side, and circumferentially provided on both axial end portions of the inner peripheral surfaces of the upper mold body and the lower mold body. An annular seal member that fits in the seal groove and seals the outer peripheral surface of the existing supply pipe, and is interposed along the axis between the facing surfaces of the two side fastening flanges of the upper mold body and the lower mold body. Sealing process for the joint surface of both types of body And a ring which is interposed in a seal accommodating portion provided around the facing surfaces of the closing cap and the upper mold body and the lower mold body to perform a sealing action between them and on the outer peripheral surface of the existing supply pipe. A pipe joint between a branch pipe of a new branch pipe through which a gas flows and an existing supply pipe, characterized in that the pipe joint is provided.