JPS6041275B2 - Structure of insulation pipe joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrically insulated pipe joint, and more particularly, to a so-called boltless electrically insulated pipe joint that does not require any bolts or nuts for connecting pipes.

In recent years, there has been a desire not only to improve the leakage prevention of the fluid flowing inside the pipes at the joints of fluid transport pipes such as city gas, water supply, and oil pipelines, but also to ensure that the pipes are completely cathodic-protected. Therefore, it is increasingly desirable to provide electrical insulation.

Therefore, for example, in the past, a flange was provided at the end of the pipe,
Turquoise greenery is performed using gaskets made of electrically insulating materials and electrically insulating bolts and nuts.
Joints with such a structure have weaknesses such as being difficult to handle and requiring maintenance, which is particularly problematic in underground pipes, and it has been difficult to provide complete electrical insulation and corrosion protection. Recently, so-called boltless electrically insulating joints that do not use flanges, bolts, nuts, etc. have been found, but these are weak against external forces in the direction of the tube axis or at right angles, and have various problems. The present invention is a bolt with a
This is an electrically insulated pipe that has a pipe joint structure that provides electrical insulation without using any nuts, and that can adapt to all external forces such as compressive force and tensile force in all directions of the pipe axis, and bending moment of the pipe. It provides a joint.

Hereinafter, the present invention will be described in detail based on the accompanying drawings.

Both FIG. 1 and FIG. 2 are illustrations of an embodiment of an electrically insulated pipe joint according to the present invention. First, in FIG. 1, 1 and 2 are lines that are connected to each other. In either one of the tubes 1 and 2, that is, in FIG. 1, a sheath tube 3 is provided so as to be joined to the connection side twill portion of the tube 1 and protrude from the connection side twill portion in the direction of the tube. A space is provided between the inner circumferential surface of this sheath tube 3 and the outer circumferential surface of the other tube 2. In this space, from the tube end, that is, the tube end 4 of tube 1, an insulating plate 5 interposed between the rising surfaces of both tubes 1 and 2, the outer periphery in contact with the inner surface of the sheath tube 3, and the outer periphery of the tube 2. a first insulating tube 6 having a content in contact with the outer surface; an elastic ring 7 having an outer circumference in contact with the inner surface of the sheath tube 3 and an inner circumference in contact with the outer surface of the tube 2; has an outer periphery that is spaced apart from the inner periphery of the outer periphery, an outer periphery in contact with the inner surface of the sheath tube 3, and an inner periphery in contact with the outer surface of the tube 2; A second insulating tube 9 is formed with an extending portion extending to and an extending portion covering the outer periphery of the tube 2 on the other end surface, and the second insulating tube 9 is in contact with the outer surface of the extending portion formed on the other end surface of the second insulating tube 9. A reinforcing ring 10 having an inner periphery and an outer periphery in contact with the inner surface of the sheath tube 3 is disposed, and this elastic ring 7 forms a bent portion 12 on the outer circumferential surface of the sheath tube 3 and a traverse portion 11 of the sheath tube 3 at the position portion, respectively. This is an electrically insulating pipe joint A having a configuration in which a pipe 13 is provided. Note that the insulating plate 5 is a laminated plate made of fiber-reinforced plastic or the like, and may be any material as long as it has electrical insulation properties and is made of a high-strength material. Further, the first insulating ring 6 and the second insulating ring 9 are obtained by adding laminated pipes made of fiber-reinforced plastic or the like into a desired shape as shown in FIG.

The elastic ring 7 is made of a sealing material, and is made of a rubber material such as natural rubber or synthetic rubber, which is an incompressible elastic material.Furthermore, the maxim 8 and the reinforcing ring 10 are It is made of a metal material such as steel, and the golden word 8 is fixed in advance to the outer peripheral surface of the pipe 2 by means such as welding.The bent part 12 is formed by drawing.
The bent portions 13 are each obtained by caulking. The electrically insulated pipe joint A having such a configuration has pipes 1 and 2.
Since it is possible to use a sheath pipe made of the same material as the pipes 1 and 2, the overall strength of the pipe joint is equal to or greater than that of the pipes 1 and 2. Further, the tensile force in the tube axis direction generated in the electrically insulated pipe joint A is caused by the bending part 13 formed at the flange 8 fixed to the pipe 2 via the second insulating ring 9 and the reinforcing face 10 and the traverse part 11 of the sheath pipe 3. The compressive force in the tube axis direction is received by the collar 8 and the insulating plate 5, and the bending moment is received by the first insulating ring 6 and the second insulating ring 9. It serves as the foundation for distributing and receiving the load, and also withstands bending moments.
A bending portion 12 provided on the sheath tube 3 provides cushioning properties. Furthermore, due to the bent portion 12, the elastic ring 7 at that position undergoes a volume change after assembly, and the stress corresponding to the amount of volume change eliminates the gap in the part where the elastic ring 7 is located, completely sealing it. Therefore, it exhibits an extremely excellent sealing function. In addition, for fluids where even the slightest leakage is not allowed, such as highly flammable gases or dangerous medium/high pressure gases, it is important to use a sealing function that has an even safer sealing function while still having an electrical insulation function. is required in the industrial market,
Moreover, there is a demand for electrically insulated pipe joints with a structure that can sufficiently withstand all kinds of external forces.

The electrically insulating pipe joint A shown in FIG. 1 can meet the demands of the industrial market. And as shown in Figure 2,
With the configuration of the electrically insulated pipe joint B, even greater safety is ensured against medium- and high-pressure dangerous fluids. This electrically insulating pipe joint B has the same basic structure as the electrically insulating pipe joint A shown in Fig. 1, except for the first insulating ring 6' and the second insulating ring 9'. . That is, in Figure 2,
Grooves were formed on the inner and outer circumferential surfaces of each of the first insulating ring 6' and the second insulating ring 9' of the electrically insulating pipe joint B, and secondary packings 14 and 15 such as ○ rings were loosened in each groove. It is designed to improve safety even further. As described in detail above, the present invention provides complete electrical insulation between the pipes to be connected, withstands all external forces, and
Moreover, it is a pipe joint with advantages such as excellent sealing function.

Of course, it goes without saying that the pipe diameter of the joint portion is 4 mm smaller than that of a conventional flange type joint. Furthermore, in the present invention, if the pipes to be connected are made into short pipes in advance and connected by the means of the present invention to form a pipe joint configuration, it is possible to form a unit having short pipe ends at both ends. Since it is a joint, for example, by cutting an arbitrary part of the existing piping,
Instead, there is an advantage that the pipe joints of this unit can be easily attached by welding or the like. In addition, the present invention
For example, the means for providing the sheath pipe fixed to the green part of one of the pipes to be connected include welding means, etc.
It will be obvious that forging, machining, screwing means, etc. are also possible, and thus include modifications and means that can be easily discovered by those skilled in the art.

[Brief explanation of the drawing]

The drawings are all embodiment diagrams according to the present invention, and FIG.
FIG. 2 is a cross-sectional view of an electrically insulating pipe joint showing another embodiment. A, B...Electrical insulating pipe joint, 1, 2...Pipe, 3...Sheath pipe, 5...Insulating plate, 6, 6'
...First insulating ring, 7... Elastic ring, 8...
... Tsuba, 9, 9'... Second insulating ring, 10...
...Reinforcement ring, 12, 13...Bent part, 14
,15...Secondary packing. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1 In a pair of pipe ends to be connected, a sheath tube is provided at one tube edge, and the tube end is provided in a space formed by the inner circumferential surface of the sheath tube and the outer circumferential surface of the other tube. An insulating plate interposed between the tube end surfaces of both tubes, a first insulating ring having an outer circumference in contact with the inner surface of the sheath tube and an inner circumference in contact with the outer surface of the other tube, an outer circumference in contact with the inner surface of the sheath tube and the other tube; an elastic ring having an inner periphery in contact with the outer surface; a flange fixed to the outer periphery of the other tube and having an outer periphery spaced apart from the inner periphery of the sheath tube; an outer periphery in contact with the inner surface of the sheath tube and an inner periphery in contact with the outer surface of the other tube. A second insulating ring has an extension part formed on one end face that covers the outer periphery of the collar and an extension part that covers the outer periphery of the other pipe on the other end face, and an extension part formed on the other end face of the second insulating ring. An electrically insulated pipe joint comprising: a reinforcing ring having an inner periphery in contact with the outer surface and an outer periphery in contact with the inner surface of the sheath tube; and bent portions are provided on the sheath tube and the sheath tube edge in a portion where the elastic ring is located. 2. The electric insulating pipe joint according to claim 1, wherein a plurality of grooves are formed on the inner and outer circumferential surfaces of the first insulating ring and the second insulating ring, and packing is interposed in the plurality of grooves. .