JPS643898Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a high-pressure insulating gasket used when connecting a pair of pipe flanges in an insulating state for cathodic protection or the like in a piping system for high-pressure fluid.

Conventionally, as such a gasket, as shown in FIG. 7, a rubber gasket which elastically contracts when pressed by the pipe flanges 31, 31 is placed on both sides of an insulating spacer 32 interposed between a pair of pipe flanges 31, 31. However, in this case, for example, it is not possible to sufficiently increase the contact pressure between the sealing material 33 such as rubber and the seating surface of the pipe flanges 31, 31. There was an inconvenience that sufficient sealing performance could not be obtained. That is, since the spacer 32 has a groove in which the sealing material 33 is inserted and held, there is a risk that cracks may occur due to stress concentration in the groove portion due to tightening of the flanges 31, 31 or bending of the flanges 31, 31 due to external force, etc. Therefore, it is possible that leakage occurs through the interior of the spacer 32. Furthermore, even if the spacer 32 has the strength to apply a compressive force sufficient to compress the sealing material 33 and has the strength to withstand external forces such as bending, the spacer 32 does not have a groove for engaging the sealing material 33. Therefore, the height of the spacer 32 inevitably becomes high, and the spacer 32 receives a force pushing outward in the radial direction due to the internal pressure, causing slippage on the sealing surface of the sealing material 33 and the flange 31.
The sealing performance under high pressure is deteriorated, and from this point of view as well, there is a disadvantage that sufficient sealing performance cannot be obtained.

For this reason, the inventor of the present invention, as shown in FIG.
Ring-shaped sealing material 35 made of resin or the like and having insulation properties
In a cross-sectional view, a pair of pipe flanges 36,
36, each of the lateral end portions is formed into a wedge shape or a shape close to it so as to be pressed against the opposing inner surfaces of the engagement grooves 37, 37 formed in each of the grooves 36,
By tightening the bolt 38, the sealing material 35 is inserted into the groove 3.
7, 37 with sufficient pressure and in a sufficiently blended state, and even if the sealing material 35 is pressed radially outward by fluid pressure, it will not contact the inner surface of the groove. However, in this case, since only the sealing material 35 is provided, the bolts 38 may be over-tightened during assembly, causing the sealing material 35 to be damaged by the material. This has the disadvantage of causing cold flow and cracks, and there is also a risk that the flanges 36, 36 may come into contact with each other. or,
Even if the flanges 36 and 36 are not in contact with each other, foreign matter in the fluid can easily enter the gap formed between the two pipe flanges 36 inside the sealing material 35, and electrical insulation may be impaired due to the conductivity of the foreign matter. However, it was difficult to put it into practical use because it easily caused sealing failure due to external bending force applied to the tube.

The present invention was devised in view of the above-mentioned circumstances, and its purpose is to ensure that sufficient sealing performance and electrical insulation properties are exhibited in a highly reliable state over a long period of time; An object of the present invention is to provide a high-pressure insulating gasket that can be easily and reliably assembled into a desired state.

The characteristic configuration of the present invention is such that the insulating ring-shaped sealing material is pressed into contact with the opposing inner surfaces of the engagement grooves formed in each of the pair of pipe flanges in a cross-sectional view. An insulating ring-shaped spacer is formed so that it has a wedge-like shape or a shape close to it, and that regulates the distance between the pair of pipe flanges. The ring-shaped spacer is arranged to protrude inward from the inner surface of the pipe flange.

Next, the effects of the feature configuration of the present invention will be described.

(b) Both side end portions of the ring-shaped sealing material are shaped into a wedge shape or similar to it, and are brought into pressure contact with the opposing inner surfaces of the engagement groove of the pipe flange, so the sealing material can be applied with sufficient pressure against the pipe flange. , and can be brought into contact with the product in a well-blended state.
Even if the sealing material is pressed radially outward by fluid pressure, the contact state can be maintained in an appropriate state, and good sealing performance can be reliably maintained even against high fluid pressure.

(b) Since ring-shaped spacers are placed on both the outside and inside of the sealing material, cold flow and cracking of the sealing material due to tightening of bolts can be reliably avoided, making assembly between pipe flanges easier. The attachment work can be done easily and reliably in good condition. In addition, the strength against external bending force on the tube is sufficiently increased by the action of both spacers, and seal failures caused by the external bending force can be sufficiently prevented.

(c) Since the inner spacer protrudes inward from the inner surface of the pipe flange, foreign matter in the flow pressure may enter the gap between the pipe flanges or adhere to both pipe flanges in a continuous manner. Inconvenient situations can be reliably prevented, and electrical insulation defects caused by conduction of foreign objects can be reliably prevented.

As a result, good sealing performance can be reliably maintained even when the fluid is under high pressure or external bending force is applied to the pipe, and good electrical insulation is maintained even when the fluid contains conductive foreign matter. can be reliably maintained,
Moreover, it has become possible to provide a high-pressure insulating gasket that is easy to assemble and has even better overall performance and workability.

Next, embodiments of the present invention will be described based on the drawings.

As shown in FIGS. 1 and 2, a pair of various fluid transport pipe flanges 1, 1 are connected to an insulating sleeve 2.
The connection is made in an insulated state using a bolt 3, an insulating washer 4, a high-voltage insulating gasket 5, etc., which will be described later.

To configure the gasket 5, a ring-shaped sealing material 5A having an insulating property, such as polysulfur resin, is formed on each of the pair of pipe flanges 1, 1 on the upper and lower surfaces of both lateral ends when viewed in cross section. Both lateral end portions are formed in a wedge shape so as to be brought into pressure contact with the inner surfaces of the engagement grooves 6, 6, and a material such as Bakelite filled with fabric is used to regulate the distance between the pair of pipe flanges 1, 1. The insulating ring-shaped spacers 5B and 5C are positioned both on the outside and inside of the sealing material 5A, so that the state shown in FIG. 3A is achieved before the bolt 3 is tightened. As the bolt 3 is tightened until the spacer 5B, 5C regulates the distance between the positioned sealing material 5A as shown in FIG. It is designed so that it can be brought into contact after being sufficiently blended.

In addition, an insulating cylindrical portion 7a that is connected to the outer end of the outer spacer 5B and is fitted onto the tube on the downstream side in the direction of the flow path F is integrally formed with the outer spacer 5B, and is connected to the inner end of the inner spacer 5C. An insulating cylindrical portion 7b that is connected to the side and is fitted inside the tube on the downstream side in the direction of the flow path F is integrally formed with the inner spacer 5C, thereby preventing the formation of a bridge by the fluid inside the tube. Also, the formation of bridges due to earth, sand, dust, etc. outside the pipe is suppressed. or,
Slopes S and S are formed on both ends of the inner surface of the pipe-fitting cylindrical portion 7b, the closer to the end, the more outwardly the surface is located, so that it is possible to suppress resistance to fluid flow. .

Next, another example will be described.

Figure 4 A and B show that before tightening the bolt 3,
A gap is provided between the inner and outer spacers 5B, 5C and the sealing material 5A, and after tightening the bolt 3,
The inner and outer spacers 5B, 5C and the sealing material 5A are brought into close contact with each other.

In FIG. 5, a seal 5A is formed so that, when viewed in cross section, both lateral end portions have an elliptical shape close to a wedge shape.

In FIG. 6, the outer spacer 5C is formed into a flat plate shape in order to accommodate the flat seating surfaces of both flanges 1,1.

To carry out the present invention, a spacer 5 is provided on at least one of the outer and inner parts of the sealing material 5A.
B and 5C may be provided, but it is more convenient to provide both the inner and outer spacers 5B and 5C in order to improve the insulation properties and increase the strength against bending of the pipe. be.

When the cylindrical part 7b is not connected to the inner spacer 5C, it is preferable to make the inner diameter of the inner spacer 5C the same as or smaller than the inner diameter of the cylinder to improve insulation. If the cylindrical part 7a is not connected to the flange 5B, it is recommended that the outer diameter of the outer spacer 5B be the same as or larger than the flange outer diameter to improve insulation. If the distance is sufficiently large, the outer diameter of the outer spacer 5B may be smaller than that of the bolt attachment part.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the flange connection part, Fig. 2 is a plan view of the high voltage insulating gasket, Fig. 3 A and B are enlarged views of the sealing material attachment part, and Fig. 4 A and B are views of another embodiment. 5 and 6 are sectional views of another embodiment, and FIGS. 7 and 8 are sectional views of a conventional example and a comparative example, respectively. 1, 1...Pipe flange, 5A...Sealing material, 5
B, 5C...Spacer.

Claims (1)

[Scope of utility model registration request] In a cross-sectional view, the insulating ring-shaped seal 5A is shaped so that both lateral end portions thereof are wedge-shaped or close to wedge-shaped so as to be brought into pressure contact with the opposing inner surfaces of the engagement grooves 6 formed in each of the pair of pipe flanges 1. Insulating ring-shaped spacers 5B and 5C are formed to have a shape and regulate the spacing between the pipe flanges 1,
A high-pressure insulating gasket is located on both the outer and inner sides of the sealing material 5A, with a ring-shaped spacer 5C on the inner side protruding inward from the inner surface of the pipe flange 1.