JP3651815B2 - Gas meter connection riser tube - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas meter connecting riser pipe for connecting a underground underground plastic pipe to a ground gas meter.
[0002]
[Prior art]
Conventionally, the underground plastic pipe and the ground gas meter are connected by connecting a metal pipe to the underground plastic pipe and setting up the metal pipe on the ground to connect to the ground gas meter.
As a metal pipe for this purpose, there is a pipe joint connecting a plastic pipe and a metal bellows pipe disclosed in Japanese Utility Model Laid-Open No. 6-20987, which was devised by the present applicant. This fitting has a metal bellows tube and a plastic tube attached to the inner surface of the end of the joint, and a metal stiffener is inserted over the inner surfaces of both of the attached tubes, and the diameter of the metal stiffener is expanded from the inner peripheral side. The bellows tube and the plastic tube are compressed and connected to the inner peripheral surface of the joint.
[0003]
[Problems to be solved by the invention]
When connecting from the ground to a gas meter on the ground, the metal pipe has a problem of corrosion caused by being buried in the ground, such as macrocell corrosion generated between soil and concrete.
For this reason, various anticorrosion measures such as providing a resin film on the surface of the metal tube or providing an insulating joint have to be taken, and due to this problem, it has been necessary to periodically conduct security inspections.
[0004]
In the above-mentioned pipe joint designed by the present applicant, the plastic pipe and the metal bellows pipe are compressed and fixed together on the inner peripheral surface of the joint, but the metal bellows pipe is thinner and wavy than the plastic pipe. The compressive strengths differed greatly, and both the pipes could not be uniformly compressed and fixed unless the diameter of the stiffener was increased separately for the plastic pipe part and the bellows pipe part. In addition, it was difficult to confirm whether both pipes were securely fixed and connected because both pipes were fixed with one stiffener. Further, since the wavy shape of the bellows tube becomes a straight tube shape and is compressed, there is a problem in that the compression performance of the bellows tube is impaired due to the inherent flexibility performance of the bellows tube.
The present invention eliminates the above problems, eliminates the problem of corrosion, maintains the original flexible performance of the bellows tube, connects the metal bellows tube and the plastic tube, and converts the underground plastic tube to the ground gas meter. A riser pipe for connecting a gas meter that can be easily connected is provided.
[0005]
[Means for Solving the Problems]
The gist of the present invention is that, on one end side, a seal inner surface that seals by attaching a packing to the groove of the connection portion of the bellows tube, and an inner surface of the seal that locks by attaching a retainer to the groove of the connection portion of the bellows tube The bellows tube is inserted and connected from the large-diameter side of the other end with a large-diameter locking inner surface, and a plastic tube is inserted into the other end side with an annular concave and convex groove on the inner surface. A metal joint in which the diameter of a metal stiffener attached to the inner surface of the pipe is expanded and a plastic pipe is connected and fixed;
It consists of a metal bellows connected to one end of the joint and a plastic pipe connected to the other end of the joint. The end of the plastic pipe is connected to the underground plastic pipe, and the end of the bellows pipe is the ground It is connected to the supply gas meter installed in the gas meter connection riser pipe.
[0006]
A gas meter connection riser characterized in that a protective tube is connected to the other end of the joint to cover the outer surface of the connected plastic tube, and the end of the protective tube is buried in the ground together with the plastic tube. It is a tube.
The gas meter connecting riser pipe is characterized in that the end of the protective pipe connected to the other end of the joint is sealed to the outer peripheral surface of the plastic pipe, and the seal connecting section is buried in the ground. is there.
[0007]
The gas meter connecting riser pipe is characterized in that a rubber containing thermal expansion graphite is mounted together with a packing in a concave groove of a connection part of the bellows pipe connected to one end side of the metal joint.
Further, the protective tube covering the outer surface of the plastic tube may be a protective tube made of vinyl chloride, metal or cement, which is resistant to ultraviolet rays.
[0008]
[Action]
The present invention has the above-described configuration, and the plastic pipe portion is connected to the underground plastic and is raised from the ground to the ground and piped. Accordingly, since the metal pipe portion connected to the gas meter is piped without contacting the soil in the ground, various corrosion problems due to the metal pipe contacting the soil do not occur. In addition, the plastic pipe that is set up on the ground is covered with a protective pipe and is protected and cut off from the external environment, so there is no problem such as ultraviolet deterioration of the plastic pipe.
Therefore, it is not necessary to perform conventional anti-corrosion treatment such as providing an insulated joint or coating a metal tube with a resin, and it is possible to easily perform piping with a gas meter in combination with a flexible metal bellows tube. .
[0009]
In addition, the metal bellows tube is connected to the inner surface of the joint without damaging the flexible shape of the metal bellows tube while maintaining the corrugated shape of the bellows tube. In addition, it can be connected easily without extra parts and work such as expanding the diameter of the stiffener or tightening with a wrench with another cap nut. Furthermore, since the plastic pipe portion is connected to the inner surface of the joint by expanding the diameter of only the plastic pipe portion, it is possible to perform secure connection and fixing according to the diameter and thickness of the plastic pipe.
Furthermore, since the outer surface of the plastic tube is protected by a protective tube, and the joint between the joint and the bellows tube is fitted with a rubber containing thermally expanded graphite, it has fire resistance.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a state in which a gas meter connecting riser pipe 10 of this embodiment is piped. The riser pipe 10 has a plastic pipe 30 connected to the lower part of the joint 20 and a metal bellows pipe 40 connected to the upper part of the joint 20. The lower plastic pipe 30 is connected to the underground plastic pipe 5 and the plastic joint 6 and is started up on the ground. The portion of the plastic tube 30 that stands on the ground is covered with another protective tube or the like so that the outer surface is not exposed.
The upper metal bellows tube 40 is connected to the gas meter 8 via a gas meter unit 7 fixed to a building or the like. The outlet side of the gas meter 8 is piped into the building by a metal flexible tube 9 and supplied to each supply gas appliance in the building.
[0011]
FIG. 2 is a half sectional view of the gas meter connecting riser pipe 10 showing an embodiment of the present invention. In the figure, a metal bellows tube 40 connected to the upper side of the joint 20 is covered with a resin film 41 made of vinyl chloride on the outer surface, and O-rings 42 and 42 and thermal expansion are provided in the concave groove on the connection side end with the joint 20. A graphite-containing rubber 44 is attached, and a metal half retainer 45 that is engaged with the groove at the end is attached, and is connected to the inner surface of the upper end of the metal joint 20. In this connection, the bellows tube 40 is inserted into the joint inner surface with the O-ring, the retainer 45, etc. attached from the lower large diameter side of the joint 20, and the packing 42 is compressed to the seal inner surface 21 of the joint 20 and the retainer 45 is engaged. Locked to and connected to the stop surface 22. The locking inner surface 22 does not come out even if the retainer 45 rotates slightly larger than the seal inner surface 21. Accordingly, the bellows tube 40 is sealed by the O-ring 42 and locked by the retainer 45 and connected to the joint 20. Further, since the rubber 44 with thermally expanded graphite is attached, the sealing performance between the joint 20 and the bellows tube 40 is achieved even in the event of a fire.
The length of the bellows tube 40 from the joint portion is about 1 M, and the upper end is connected to a gas meter fixed to a building or the like.
[0012]
The joint 20 is provided with a seal inner surface 21 through which the resin film 41 of the bellows tube is inserted on the upper inner surface and a locking inner surface 22 larger in diameter than the seal inner surface 21, and a water-tight packing 23 is attached to the end to seal the resin film 41 and the seal 20. And connected to the bellows tube 40.
An annular concave / convex groove 24 for compressing a plastic tube, a seal portion 26 fitted with a seal packing 25, a female screw 27, and a watertight packing 28 are provided on the inner surface of the lower side. A plastic tube 30 fitted with a metal stiffener 31 is inserted into this portion, and a rubber bulge expanding tool (not shown) is inserted from the end side of the plastic tube 30 to expand the stiffener 31. It compresses and fixes to the annular uneven groove 24 of an inner surface. At this time, the seal packing 25 is also compressed and sealed. The length of the plastic pipe 30 from the joint 20 is about 300 mm, and the lower end is connected to the underground plastic pipe 5 and is set up on the ground.
[0013]
Reference numeral 50 denotes a protective tube connected to the female thread 27 of the joint 20. In this embodiment, an outer surface resin-coated steel tube is used. The outer surface of the portion of the plastic tube 30 that is raised on the ground is covered with ultraviolet rays. It is protected so that heat is not transmitted to the plastic tube 30 due to damage due to external force, fire, or the like. In place of the steel pipe, a vinyl chloride pipe, a cement pipe, an asbestos pipe or the like may be used.
One end of the protective tube 50 is sealed with the watertight packing 28 of the joint, and the other end is screwed with a resin cap nut 51 to compress the packings 52 and 53 and seal the outer surface of the plastic tube 30. The seal portion by the cap nut 51 is buried in the ground.
Therefore, according to the present embodiment, even if the gas in the plastic pipe 30 leaks due to some influence at the connection part of the plastic pipe 30 to the joint 20 or the ground rising part of the pipe 30, the protection pipe 50 is not discharged. Do not leak. Further, the electrical insulation between the underground buried portion and the joint 20 and the metal bellows tube 40 is sealed from the external environment by a resin cap nut 51 at the end even if the protective tube 50 is an outer surface resin-coated steel tube. So insulation is achieved.
[0014]
【The invention's effect】
As described above, the present invention eliminates various corrosion problems caused by the metal pipes coming into contact with the soil, and the plastic pipes set up on the ground are protected from the external environment so that there are no problems such as ultraviolet degradation. . Accordingly, it is not necessary to perform an anticorrosion treatment such as providing an insulating joint or coating a metal pipe with a resin, and piping with a gas meter can be easily carried out together with a flexible metal bellows pipe.
In addition, since the metal bellows tube is connected to the inner surface of the joint while maintaining the corrugated shape of the bellows tube, the flexibility of the metal bellows tube is not impaired, and the connection with the plastic tube depends on the diameter and thickness of the tube Secure connection fixation can be performed.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a state in which a riser pipe for connecting a gas meter according to one embodiment of the present invention is piped.
FIG. 2 is a half sectional view showing a riser pipe for connecting a gas meter according to an embodiment of the present invention.
[Explanation of symbols]
5 buried plastic pipe 7 gas meter connection unit 8 gas meter 9 metal flexible pipe 10 gas meter connection riser pipe 20 joint 21 joint seal inner surface 22 joint locking inner surface 24 joint annular uneven groove 25 seal packing 26 joint seal portion 27 joint Female screw 28 Watertight packing 30 Plastic pipe 31 Metal stiffener 40 Metal bellows pipe 41 Plastic film of bellows pipe 42 O-ring 44 Rubber with thermally expanded graphite 45 Retainer 50 Protective pipe 51 Cap nut 52, 53 Packing

Claims (4)

On one end side, a seal inner surface that seals by attaching a packing to the groove of the connection portion of the bellows tube, and an inner surface of the seal that has a larger diameter than the inner surface of the seal that attaches and locks the retainer to the groove of the connection portion of the bellows tube The bellows tube is inserted and connected from the large-diameter side of the other end, and the other end side has an annular concave and convex groove on the inner surface, and is inserted into the inner surface of the plastic tube. A metal joint with a diameter of a metal stiffener and a plastic pipe connected and fixed;
It consists of a metal bellows connected to one end of the joint and a plastic pipe connected to the other end of the joint. The end of the plastic pipe is connected to the underground plastic pipe, and the end of the bellows pipe is the ground A riser pipe for connecting a gas meter, which is connected to a supply gas meter installed in Covering the outer surface of the plastic tube with the connection by connecting the protective tube to the other end of the joint, the gas meter of claim 1, wherein an end portion of the protective tube, characterized in that it is buried in the ground with a plastic tube Riser tube for connection. End of the protective tube connected to the other end of the joint, the connecting outer circumferential surface and the seal of the plastic tube, the seal connecting portion according to claim 1 or 2 wherein, characterized in that it is buried in the ground Riser tube for connecting a gas meter. Gas meter connection riser tubes of claims 1 to 3, wherein the thermal expansion graphite-containing rubber with the packing to the connecting portion groove of the bellows tube fitted to be connected to one end of the metal fitting.

Images