JP2004211877A - Flange joint for connecting fluid pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the insulating property in a fluid channel and to effectively prevent the generation of discharge phenomenon on an outer surface. <P>SOLUTION: An insulating plate 1 is held between a first flange 3 mounted around an end part of a metallic pipe 1 and a second flange 4 mounted on a connected object to insulate the flanges 3, 4 from each other. In the metallic pipe 2, a collar part 10 is held between the first flange 3 and the insulating plate 1, and a tube 9 connected to the insulating plate 1 is inserted to secure the creeping distance. A head part of a bolt 11 is surrounded by a ring wall 8c formed on an insulating ring 8 mounted between the first flange 3 and the bolt 11. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fluid pipe connection flange joint that secures insulation between a fluid pipe and a connection target (hereinafter simply referred to as a flange joint).
[0002]
[Prior art]
BACKGROUND ART Metal piping connected to equipment using a conductive body as a part of electric wiring often requires insulation of the equipment so as not to receive an electric shock even if the pipe is touched.
A simple means to provide insulation between the equipment and the pipe is to interpose a rubber tube joint in the middle of the pipe to cut off the power supply. In this case, the gas is easily affected by acids, alkalis, heat and the like, and a small amount of gas such as hydrogen permeates and leaks through the rubber tissue.
Further, even if a metal pipe is inserted into a rubber tube and fastened with a band or caulked, there is a problem in airtightness and reliability is poor.
On the other hand, a structure in which an insulator is interposed between a flange and a bolt to provide insulation to a flange joint has been proposed, for example, in the contents described in Patent Literature 1 and Patent Literature 2.
[0003]
[Patent Document 1]
JP-A-6-101789 [Patent Document 2]
JP-A-2000-329293.
[0004]
[Problems to be solved by the invention]
In the conventional flange joint, a metal pipe is connected from a flange to a metal pipe.In the fluid passage, a metal conductive surface is continuous. It is separated only by the thickness of the insulator interposed between them, and although it is physically insulated, there is a high possibility of causing a discharge phenomenon, and the passage of charged water vapor etc. in the fluid passage If this is the case, the insulation against the water vapor cannot be ensured.
Further, if the bolt is a stud type screwed into the connection destination, since a voltage is applied to the head (nut) of the bolt, a discharge phenomenon may occur between the head of the bolt and the metal pipe. is there.
[0005]
[Means for Solving the Problems]
The present invention relates to a flange joint for connecting a fluid pipe having a high insulating property, and has a configuration in which a first flange provided around an end of a metal pipe and having a first bolt insertion hole is connected to a first flange. A second bolt insertion hole or a second flange provided with a bolt screw hole corresponding to the first bolt insertion hole in the first flange, and an insulating plate is sandwiched between the first flange and the second flange. In the insulator, a third bolt insertion hole is formed in a portion of the first flange corresponding to the first bolt insertion hole, and a fluid passage is formed in a portion corresponding to the metal pipe, A flange portion of a flanged tube inserted into a metal pipe is sandwiched between a first flange and an insulating plate, and an insulating ring having a flange body at an end of a tubular portion insertable into the first bolt insertion hole is formed. Bolted through Lies in the fact.
[0006]
The insulating ring may include a ring wall that surrounds the head of the bolt up to the tip on the periphery of the flange body.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of a flange connection for fluid piping connection according to the present invention will be described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes an insulating plate sandwiched between a first flange 3 provided around an end of a metal pipe 2 and a second flange 4 provided on an object to be connected. The insulating plate 1, the first flange 3, and the second flange 4 are all diamond-shaped, and fluid passages 5, (5, 5) are provided at the center, and first bolt insertion holes 1 a are provided on both sides thereof. , A second bolt insertion hole 3a, and a third bolt insertion hole 4a (bolt screw holes in the second flange 4).
[0008]
O-ring grooves 3b and 4b are formed on the first flange 3 and the second flange 4 on the contact surfaces with the insulating plate 1 so as to be coaxial with the fluid passage 5, respectively. Are set between the insulating plate 1 and the flanges 3 and 4 while being set in the O-ring grooves 3b.
Further, in the first flange 3, in addition to the O-ring groove 3 b, a concave portion 7 is provided around the opening surface of the fluid passage 5.
[0009]
Reference numeral 8 denotes an insulating ring, which is made of epoxy resin. A flange 8b is provided at an upper end of a cylindrical portion 8a which can be continuously inserted into the bolt insertion hole 3a of the first flange 3 and the bolt insertion hole 1a of the insulating plate 1. A ring wall 8c is provided on the periphery of the flange body 8b so as to surround the head of the bolt to the tip.
Reference numeral 9 denotes a rubber-made flanged tube. A rib 10a is provided around the outer periphery of the flange portion 10, and the concave portion 7 formed in the first flange 3 is provided with the rib 10a. It has a shape corresponding to the formed flange portion 10.
In the drawings, 11 and 11 are bolts, and 12 and 12 are washers.
[0010]
For assembling the flange joint, for example, the tube 9 is inserted into the metal pipe 2, the flange 10 is applied to the concave portion 7, and the insulating plate 1 is pressed from above to connect the flange 10 with the insulating plate 1. Sandwiched between the plates 3.
Next, the second flange 4 is superimposed on the insulating plate 1 to form a three-layer structure, and the cylindrical portion 8a of the insulating ring 8 is connected to the first bolt 3a of the first flange 3 through the second bolt insertion hole 3a. It is inserted until it reaches the bolt insertion hole, and is tightened with the bolts 11 and 11 via the washer 12.
When tightening with the bolt 11, the insulating plate 8 is made of epoxy resin, so that the bolt is not over-tightened.
[0011]
Each of the first and second flanges 3 and 4 and the insulating plate 1 has a substantially rhombic shape and is shaped to be bolted at two places. These may be triangular or circular, or the number of bolted places may be changed. , Design is free.
[0012]
Since the tube 9 is inserted into the metal pipe 2, the flange joint assembled as shown in FIG. 2 is continuously insulated from the insulating plate 1 up to the surface of the tube 9 with respect to the metal pipe 2, and the fluid passage is provided. The insulating property in the inside 5 is kept high, and even if a fluid such as charged water vapor passes through, the outside is not affected.
Further, the tube 9 is supported by being sandwiched between the flange 10 and the first flange 2 and the insulating plate 1, so that even if there is an internal pressure load, the tube 9 is not displaced or pulled inward.
Further, since the head of the bolt 11 is surrounded by the ring wall 8c, the space between the bolt 11 and the metal pipe 2 is shielded by the ring wall 8c, thereby preventing discharge.
[0013]
In the above embodiment, the second flange employs a bolt screw hole instead of the second bolt insertion hole. However, in the present invention, the bolt insertion hole and the bolt screw hole are understood to have the same meaning, The same applies to the relationship between the bolt head and the nut.
Furthermore, the second flange assumes that the object to be connected is like a container, but is used in the middle of piping, and when the object to be connected is also a metal pipe, the first flange and the second flange are used. The two flanges are not distinguished from each other, and the tube can be inserted into the metal pipe with respect to the second flange in the same manner as the first flange, so that the shape can be symmetrical to each other.
[0014]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the insulation property in a fluid passage can be kept high by ensuring the creepage distance of a tube, Especially, even if the water vapor etc. which charged the fluid passage pass, the insulation property with respect to the water vapor is ensured. Is done.
Also, if measures are taken to prevent discharge phenomena beforehand with a flange cover or insulating ring, the reliability will be further improved, and by applying gasket bead processing between the gasket and the flange, the sealing performance will be perfect. It becomes.
Further, by supporting, even if there is an internal pressure load, it is prevented from being drawn inward.
[Brief description of the drawings]
FIG. 1 is an exploded sectional view showing an exploded flange joint according to the present invention.
FIG. 2 is an explanatory view of assembling a flange joint.
[Explanation of symbols]
1 insulating plate, 1a first bolt insertion hole, 2 metal pipe, 3 first flange, 3a second bolt insertion hole, 3b O ring groove, 4 .2nd flange, 4a..3rd bolt insertion hole (bolt screw-in hole), 4b..O-ring groove, 5..fluid passage, 6 ... O-ring, 7 ... recess, 8 ... insulating ring , 8a... Tubular part, 8b... Collar body, 8c... Ring wall, 9... Flanged tube, 10... Flange part, 10a... Rib, 11.

Claims (2)

A first flange provided around the end of the metal pipe and having a first bolt insertion hole, and a second flange provided on the object to be connected and corresponding to the first bolt insertion hole in the first flange. And a second flange provided with a bolt insertion hole or a bolt screw hole, with an insulating plate interposed therebetween. The insulating plate has a portion corresponding to the first bolt insertion hole in the first flange. A fluid passage is formed in a portion corresponding to the third bolt insertion hole and the metal pipe. A fluid pipe connection flange joint which is sandwiched by a bolt and connected by a bolt via an insulating ring having a flange at an end of a tubular portion insertable into the first bolt insertion hole. The fluid pipe connecting flange joint according to claim 1, wherein the insulating ring includes a ring wall surrounding the head of the bolt up to the tip at the periphery of the flange body.

Images