JP2000329273A - Insulating structure for pipe coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure insulation and to facilitate parts control by inserting an insulating spacer between joint flanges, inserting flanged insulating sleeves reaching between the flanges into a flange bolt hole from opposite outer faces, and fastening them by bolts. SOLUTION: An insulating spacer 10 is inserted between the flanges 2 of a flange joint, the spacer 10 is made of hard rubber or a plastic, it has a shape with the diameter reaching the outer diameter of the flanges 2, and a bolt through hole 10a is bored at the position corresponding to the bolt through holes 2b of the flanges 2. Insulating sleeves 11 with flanges 9 are inserted into the bolt through holes 2b, the sleeves 11 are made of the same material as that of the spacer 10, and their lengths are set so that a gap 10b is provided in the through hole 10a of the spacer 10. O-rings 12 seal between flange opposite contact faces 2a. The flanges 9 concurrently serve as insulating washers, such an accident can be prevented that they are forgotten to be fitted, no insulating bolt is required, parts control is facilitated, and electric insulation can be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an insulating structure for a pipe joint.

[0002]

2. Description of the Related Art Conventionally, when a pipe line is electrically cut off and divided, as shown in FIG. 4, hard rubber or plastic insulation is provided between opposed contact surfaces 2a, 2a of flanges 2 of flange joints 1, 1. Generally used is an insulating structure in which a packing 3 is inserted, a bolt 5 provided with an insulating lining 4 is inserted into peripheral bolt holes 2b, 2b of the flange 2, and a nut 8 is fastened via an insulating washer 6 and a metal washer 7. It had been.

[0003]

By the way, the above-mentioned conventional insulating structure has an insulating lining 4 provided on the outer surface of the bolt 5.
It is necessary to provide a thread allowance portion 5a for the nut 8 while securing an insulating surface for the flange 2 so that the bolts 5 provided with the insulating linings 4 having dimensions adapted to the specifications of the flange 2 are prepared. However, there is a disadvantage that the parts management becomes troublesome.

When the nut 8 is screw-fitted to the bolt 5, an insulating washer 6 must be incorporated. However, at least four bolts 5 to be fastened at the time of flange joining are usually 12 and large diameter. In the case of pipes, a larger number of bolts are fastened, and the insulating washer has smaller parts than bolts and nuts, so there is a danger that the insulating washer 6 may be forgotten to be installed. If there is, there is a problem that the insulating effect may be lost.

[0005] Further, since the insulating washer 6 is hidden by the metal washer 7, it is difficult to confirm afterwards and there is a problem that a check error may occur immediately after assembling. SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide an insulation structure for a pipe joint part in which insulation of a pipe joint part of a flange joint can be surely performed and parts management is easy.

[0006]

According to the insulating structure of the present invention, an insulating spacer is interposed between the flanges of the flange joint, and the bolt holes on the peripheral edge of the opposed flange reach from the opposed outer surface to the space between the flanges. A flanged insulating sleeve is inserted, and a bolt that penetrates through the opposed sleeve and fastens the flanges is fastened.

[0007] According to the insulation structure of the pipe joint, the bolt fastened between the flanges is insulated from the flange by the insulating sleeve, so that any bolt can be used. There is no need to prepare insulating bolts, and component management becomes easy. Further, the insulating sleeve inserted into the bolt hole is provided with a flange also serving as an insulating washer, thereby preventing an accident such as forgetting to install the insulating washer.

According to a second aspect of the present invention, in the insulating structure of the pipe joint, the insulating spacer and the insulating sleeve are made of an elastic synthetic resin product.
According to the insulating structure of the pipe joint portion, the insulating spacer itself also functions as a seal packing, so that it can serve both as electrical insulation and as a seal.

[0009]

Next, an embodiment of the present invention will be described. FIG. 1 is a sectional view of a main part of an insulating structure of a pipe joint according to an embodiment of the present invention. Parts having the same structure as in the prior art are denoted by the same reference numerals in the drawing, and detailed description is omitted.

In FIG. 1, reference numeral 10 denotes an insulating spacer which is inserted between the flanges 2 and 2 of the flange joints 1 and 1. The insulating spacer 10 is formed of a material that does not conduct electricity, for example, hard rubber, plastic, or the like. In the illustrated example, the insulating spacer 10 has a shape having a diameter that reaches the outer diameter of the flange 2. A bolt through hole 10a is formed at a position corresponding to the formed bolt through hole 2b.

An insulating sleeve 11 with a flange 9 is inserted into the bolt holes 2b, 2b of the flanges 2, 2. The insulating sleeve 11 is made of the same material as the insulating spacer, and the length of the sleeve 11 is as shown in the drawing.
The length is set to have a gap 10b within the zero through-hole 10a.

Reference numeral 12 in the figure denotes an O-ring, which seals between the flange-facing contact surfaces 2a, 2a. As described above, the insulating structure of the pipe joint portion in this embodiment is insulated by the insulating spacer 10 between the flange-facing contact surfaces 2a and the through-hole of the fastening bolt 5 by the flanged insulating sleeve 11. Thus, electrical insulation between the joints is ensured.

Since the insulation of the fastening portion of the bolt 5 is performed by the insulating sleeve 11 with the flange 9, the flange 9 also serves as a conventional insulating washer when the insulating sleeve 11 is attached, thereby preventing the accident of forgetting to attach the insulating washer. can do. In addition, any bolt and nut can be used as long as the bolt 5 is accommodated in the insulating sleeve 11 and the length for fastening the flanges 2 and 2 is used. There is no need to use, and general use is possible.

Further, since the end of the insulating sleeve 11 is housed in the insulating spacer 10, insulation is ensured. In the above embodiment, the case where the end portion of the insulating sleeve 11 is accommodated in the bolt through hole 10a of the insulating spacer 10 has been described. However, as shown in FIG. Only the surface 2a may be attached so that the insulating sleeves 11 overlap each other.

Further, the bolt 5 may be a headed bolt 5a as shown in FIG. 2 and 3, the same members as those in FIG. 1 are denoted by the same reference numerals, and a detailed description thereof will be omitted. In the above embodiment, the insulating spacer 1
0. The material of the insulating sleeve 11 may be a synthetic rubber or plastic material having elasticity.

In this case, since the insulating spacer itself also functions as a seal packing, it is possible to have both electric insulation and a seal.

[0017]

As described above, according to the insulating structure of the pipe joint portion of the present invention, it is not necessary to prepare an insulating bolt which was conventionally required as a set for each flange joint, and parts management becomes easy. In addition, reliable electrical insulation can be achieved. Also, when the insulating member is formed of an elastic material, electrical insulation and sealing can be achieved simultaneously and with high performance, so that a highly reliable joint can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an insulating structure of a pipe joint according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of another configuration example.

FIG. 3 is a cross-sectional view of a main part of still another configuration example.

FIG. 4 is a sectional view of a main part of a conventional pipe joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flange joint 2 Flange 2b Bolt through hole 5 Fastening bolt 9 Flange 10 Insulating spacer 10a Bolt through hole 11 Insulating sleeve 12 O-ring

Claims (2)

[Claims] An insulating spacer is interposed between flanges of a flange joint, and a flanged insulating sleeve is inserted into a bolt hole on a peripheral edge of the opposed flange from an opposed outer surface to reach between the flanges, and penetrates through the opposed sleeve. And a bolt for fastening between the flanges. 2. The insulating structure for a pipe joint according to claim 1, wherein the insulating spacer and the insulating sleeve are made of an elastic synthetic resin product.