JP4210123B2 - Flange joint for fluid piping connection - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flange joint for fluid pipe connection (hereinafter simply referred to as a flange joint) that ensures insulation between a fluid pipe and a connection object.
[0002]
[Prior art]
In many cases, a metal pipe connected to a device that uses a conductive body as a part of electrical wiring is required to be insulated from the device so as not to get an electric shock even if the tube is touched.
A simple way to provide insulation between the equipment and the piping is to cut off the current by inserting a rubber tube joint in the middle of the piping, but the rubber tube is exposed. In this case, it is easy to be adversely affected by acids, alkalis, heat, etc., and gas such as hydrogen permeates through the rubber structure and leaks.
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, the thing which gave the insulation to the flange joint by interposing an insulator between a flange and a volt | bolt is proposed by the content shown by patent document 1 or patent document 2, for example.
[0003]
[Patent Document 1]
JP-A-6-101789 [Patent Document 2]
JP 2000-329293 A.
[0004]
[Problems to be solved by the invention]
In the conventional flange joint, since the metal conductive surface is continuous in the fluid passage from the flange to the metal pipe, in the fluid passage, the equipment to be connected and the metal pipe that is the piping are flanges. Even though it is physically insulated, it has a high possibility of causing a discharge phenomenon, and water vapor charged in the fluid passage is allowed to pass though it is physically insulated. In this case, the insulation against the water vapor cannot be ensured.
In addition, if the bolt is a stud type that is screwed into the connection destination, voltage is applied to the bolt head (nut), which may cause a discharge phenomenon between the bolt head and the metal pipe. is there.
[0005]
[Means for Solving the Problems]
The present invention is a flange joint for fluid pipe connection with high insulation, and the structure thereof is provided around a first flange having a first bolt insertion hole provided around an end of a metal pipe, and a connection target An insulating plate is sandwiched between a second bolt insertion hole corresponding to the first bolt insertion hole in the first flange or a second flange provided with a bolt screw-in hole, In the insulator, a third bolt insertion hole is formed in a portion corresponding to the first bolt insertion hole in the first flange, and a fluid passage is formed in a portion corresponding to the metal pipe, An insulating ring having a casing at the end of a cylindrical portion that can be inserted into the first bolt insertion hole by sandwiching the flanged portion of the tube with the flange inserted into the metal pipe between the first flange and the insulating plate. Via bolted It lies in the fact.
[0006]
The insulating ring may include a ring wall that surrounds the head of the bolt to the tip at the periphery of the housing.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of a flange joint for fluid pipe 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 a connection object, The insulating plate 1, the first flange 3, and the second flange 4 are all diamond-shaped and have fluid passages 5, (5, 5) penetrating in the center, and the first bolt insertion holes 1 a on both sides thereof. A second bolt insertion hole 3a and a third bolt insertion hole 4a (a bolt screw hole in the second flange 4) are formed.
[0008]
The first flange 3 and the second flange 4 are respectively formed with O-ring grooves 3b and 4b coaxially with the fluid passage 5 on the contact surface with the insulating plate 1, and O-rings 6 and 6 are formed on the same surface. Are interposed between the insulating plate 1 and the flanges 3 and 4 in a state of being set in the O-ring grooves 3b and 3b.
Further, in addition to the O-ring groove 3 b, the first flange 3 is provided with a recess 7 around the opening surface of the fluid passage 5.
[0009]
8 is an insulating ring, which is made of epoxy resin, and has a casing 8b at the upper end portion of the cylindrical portion 8a that 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. And a ring wall 8c that surrounds the head of the bolt up to the tip at the periphery of the housing 8b.
Also, 9 is a rubber-made tube with a flange, and a rib 10a is provided on the outer periphery of the flange 10, and the recess 10 formed in the first flange 3 is provided with the rib 10a. It has a shape corresponding to the heel portion 10 being made.
In the drawings, 11 and 11 are bolts, and 12 and 12 are washers.
[0010]
The flange joint is assembled by, for example, inserting the tube 9 into the metal pipe 2 and placing the flange 10 on the recess 7 and pressing the insulating plate 1 from above to attach the flange 10 to the insulating plate 1 and the first. The plate 3 is sandwiched between.
Next, the second flange 4 is overlapped on the insulating plate 1 to form a three-layer structure, and the cylindrical portion 8a of the insulating ring 8 is moved from the second bolt insertion hole 3a in the first flange 3 to the first of the insulating plate 1. Insert the bolt until it reaches the bolt insertion hole, and tighten it with the bolts 11 and 11 through the washer 12.
When the bolt 11 is tightened, the insulating plate 8 is made of epoxy resin, so that the bolt is not over-tightened.
[0011]
The first and second flanges 3 and 4 and the insulating plate 1 are both substantially rhombus-shaped and are bolted at two locations. These are triangular or circular, or the number of bolting locations is changed. The 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 to the creeping portion of the tube 9 with respect to the metal pipe 2. The insulating property in the inside 5 is kept high, and even if a fluid such as charged water vapor passes, it does not affect the outside.
Further, the tube 9 is sandwiched and supported by the first flange 2 and the insulating plate 1 so that the tube 9 is not displaced or pulled inward even if there is an internal pressure load.
Further, since the head of the bolt 11 is surrounded by the ring wall 8c, the space between the metal pipe 2 and the metal pipe 2 is shielded by the ring wall 8c, and discharge is also prevented.
[0013]
In the above embodiment, the second flange adopts a bolt screw hole instead of the second bolt hole, but in the present invention, it is understood that the bolt hole and the bolt screw hole have the same meaning, The same applies to the relationship between the bolt head and the nut.
Further, the second flange assumes that the connection object is like a container. However, when the connection object is also a metal pipe, the first flange and the second flange are used. It is assumed that the tube is not distinguished from the second flange, and the tube is inserted into the metal pipe in the same manner as the first flange with respect to the second flange, and can be shaped symmetrically.
[0014]
【The invention's effect】
According to the present invention, it is possible to maintain high insulation in the fluid passage by ensuring the creepage distance of the tube. In particular, even when charged water vapor or the like passes through the fluid passage, insulation against the water vapor is ensured. Is done.
In addition, if measures are taken to prevent the discharge phenomenon with a flange cover or an insulating ring, the reliability will be further improved, and gasket bead processing will be applied between the gasket and the flange, resulting in a perfect seal. It becomes.
Furthermore, by supporting, it is prevented from being pulled inward even if there is an internal pressure load.
[Brief description of the drawings]
FIG. 1 is an exploded cross-sectional view of a flange joint according to the present invention.
FIG. 2 is an assembly explanatory diagram of a flange joint.
[Explanation of symbols]
1 .. Insulating plate, 1a .. 1st bolt insertion hole, 2 ... Metal pipe, 3 ... 1st flange, 3a ... 2nd bolt insertion hole, 3b ... O-ring groove, 4 ...・ Second flange, 4a ・ ・ Third bolt insertion hole (bolt screw hole), 4b ・ ・ O-ring groove, 5 ・ ・ Fluid passage, 6 ・ ・ O-ring, 7 ・ ・ Recess, 8 ・ ・ Insulating ring .., 8a..Cylinder part, 8b..Housing, 8c..Ring wall, 9 ... Tube with tube, 10 ... Tail part, 10a..Rib, 11..Bolt, 12 ..

Claims (2)

A first flange that is provided around the end of the metal pipe and includes a first bolt insertion hole, and a second flange that is provided in the connection target and corresponds to the first bolt insertion hole in the first flange. An insulating plate is sandwiched between a bolt insertion hole or a second flange having a bolt screw-in hole, and the insulating plate has a portion corresponding to the first bolt insertion hole in the first flange. A third bolt insertion hole and a fluid passage are formed at portions corresponding to the metal pipe, and the flange portion of the flanged tube inserted into the metal pipe is connected to the first flange and the insulating plate. And a flange joint for connecting fluid pipes that are connected by bolts via an insulating ring having a casing at the end of the cylindrical portion that can be inserted into the first bolt insertion hole. The flange joint for fluid piping connection according to claim 1, wherein the insulating ring includes a ring wall that surrounds the head of the bolt to the tip at the periphery of the housing.

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