JP2006118956A - Leakage testing tool for flange - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a leakage testing tool for flanges capable of safely and accurately measuring the quantity of leakage from connection parts of flanges with simple configuration. <P>SOLUTION: A circumferential groove 12 formed in an adhesion part 3 to be sheathed in a peripheral fastening body 2 forms an air-tight channel 11 circumferentially along a connection part J in a flange together with the peripheral surfaces of flanges 20a and 20b. The whole of gas (A) which has leaked from the connection part J flows into a sampling tube 5 through the channel 11. By measuring the quantity of flow of the gas with a flowmeter, it is possible to accurately measure the quantity of leakage. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a flange leakage test jig, and more particularly, to a flange leakage test jig capable of accurately measuring the amount of leakage at a flange connection portion with a simple structure.

  When a flange is used as a joint for piping or the like, it is necessary to prevent gas or liquid flowing in the piping from leaking at the connecting portion of the flange. For example, many flanges made of sheet metal are generally used in aircraft for weight reduction.

  In the conventional flange leakage test method, the inside of the pipe connected by the flange is pressurized in a sealed state, the amount of pressure drop inside the pipe after a predetermined time is measured, and the pressure that converts the measured value into the amount of leakage There are a descent method, a submerged method in which the pipe connected by the flange is submerged in water, the inside of the pipe is pressurized in a sealed state, the leaking gas is collected and the amount of leakage is measured.

  For example, as a pipe leak test jig, a sealed space is formed by wrapping the joint part from the outside, and the presence or absence of leakage is detected by pressing the sealed space and measuring the pressure after a certain period of time. Has been proposed (see Patent Document 1). This proposal is a kind of the pressure drop method described above, and it is difficult to accurately measure the amount of leakage.

  The submersion method directly measures the amount of leakage, so it can be measured with the highest accuracy. The test method will be described in detail with reference to FIG. A flange 20b used as a pair is closely connected to the flange 20a attached to one end of the pipe 13 using a clamp 18 or the like. The flange 20b on the outside is in a sealed state with an iron plate or the like welded to the central hole to which the pipe 13 is attached. This is installed in a water tank 21 filled with water, and the gas A (oxygen, nitrogen, etc.) pressurized by the pressurizing device 16 is introduced into the pipe 13 from the other end of the pipe 13 through the regulating valve 15. Supply. The pressure inside the pipe 13 is maintained at a predetermined pressure while being confirmed by the pressure gauge 14, and if there is a gap in the connecting portion J of the flanges 20a and 20b in this pressurized state, the supplied gas A will rise as bubbles. The amount of leakage can be accurately grasped by collecting the bubbles with the gas collection container 19 and measuring the amount of collection.

However, the submerging method requires a water tank 21 and water, so that the apparatus is complicated and large, and the test place is limited accordingly. Further, in many cases, bubbles are collected by holding the gas sampling container 19 by hand, and when the closely connected flanges 20a and 20b are detached, the pressurized gas A is ejected, which is a dangerous operation. It was.
JP 2001-133354 A

  An object of the present invention is to provide a flange leakage test jig capable of accurately measuring the amount of leakage from a flange connection portion with a simple structure. Moreover, it is providing the leak test jig | tool for flanges which can be measured safely.

  In order to achieve the above object, a flange leakage test jig according to the present invention is a flange leakage test jig used for measuring a leakage amount from a connection portion of a pair of flanges connected to each other, wherein the leakage test The jig includes a detachable annular outer cover that covers the outer peripheral surfaces of the pair of flanges, a through-hole formed in a thickness direction in a part of the outer cover, and a sampling connected to the through-hole. And the outer cover has a surface formed with a circumferential groove having an airtightness extending in the longitudinal direction, and the through hole is formed to communicate with the circumferential groove. It is what.

  According to the present invention, the circumferential groove having the airtightness formed in the outer cover body that covers the outer peripheral surfaces of the pair of flanges and is attached in an annular shape together with the outer peripheral surfaces of the respective flanges in the flange circumferential direction. A simple structure in which an airtight flow passage is formed along the pipe and a sampling pipe is connected to the through-hole communicating with the circumferential groove. The leakage amount from the flange connection is directly reduced through the flow path and the sampling pipe. Measurement can be performed, and measurement with excellent accuracy is possible. In addition, it is safe because the measurement can be performed without getting close to the piping and the surrounding area where the pressure is high.

  Hereinafter, the flange leakage test jig of the present invention will be described based on the embodiments shown in the drawings. In addition, the same code | symbol is attached | subjected about the element same as a prior art example, and description is abbreviate | omitted. FIG. 4 shows an overall outline of a test method using the flange leakage test jig of the present invention. The outer cover 1 is attached in an annular shape so as to cover the outer peripheral surfaces of a pair of flanges 20a and 20b connected to each other to be measured. The flange to be attached is not particularly limited, and can be applied to a general flange.

  FIG. 3 shows the structure of the flange leakage test jig. The outer cover 1 includes a close contact portion 3 that is in close contact with the outer peripheral surface of the flange 20, and a C-shaped outer periphery fastening body 2 that is provided on the outer periphery. One end of the outer periphery tightening body 2 is provided with a connecting tightening portion 6 and the other end is provided with a lock portion 8.

  The connecting tightening portion 6 includes a connecting shaft 10 having a locking portion 7 at the tip and a thread groove on the other end, and a tightening nut 9 screwed into the connecting shaft 10. It is movable in the direction and is rotatably supported at one end of the outer periphery fastening body 2. By rotating the tightening nut 9, the connecting shaft 10 moves in the axial direction. The lock portion 8 has a notch that is rotatably supported on the other end of the outer periphery fastening body 2 and engages with the connecting shaft 10. And the latching | locking part 7 and the lock | rock part 8 engage, and it has the structure where the outer cover body 1 forms a ring shape.

  FIG. 1 shows an example of a cross-sectional shape of the outer cover 1 in a state attached to the flange 20. The contact portion 3 has a circumferential groove 12 on a surface that is in close contact with the flange 20 and has a shape that is in close contact with the outer peripheral surfaces of the flanges 20a and 20b across the connection portion J of the flanges 20a and 20b. And the flow path 11 which the gas A which leaks from the connection part J can distribute | circulate along the outer peripheral surface of the flange 20 by the circumferential groove 12 and the outer peripheral surface of each flange 20a, 20b is formed. In this case, by using a material having airtightness for the close contact portion 3, the circumferential groove 12 has airtightness, and accordingly, the flow passage 11 also has airtightness.

  As another example of the cross-sectional shape of the outer cover 1, as shown in FIG. 2, independent contact portions 3 are provided on both sides of the connection portion J of the flanges 20 a and 20 b so that the contact portion 3 and the outer periphery tightening body 2 The circumferential groove 12 may be formed. In this case, the circumferential groove 12 and the flow passage 11 can be made airtight by using an airtight material for the close contact portion 3 and the outer periphery fastening body 2.

  The material of the close contact portion 3 may be any material that does not leak the leaked gas A from the flow path 11, and is preferably an airtight elastic body. For example, rubber, soft resin, or the like can be used. Moreover, even if it is a porous body etc., if it is a material which has airtightness by compressing, it can be used.

  The outer periphery tightening body 2 causes the close contact portion 3 to be in close contact with the outer peripheral surface of the flange 20 to form the flow passage 11 between the peripheral groove 12 and the outer peripheral surfaces of the flanges 20a and 20b, and leaks from the connection portion J of the flanges 20a and 20b. Any gas can be used as long as the gas A does not leak to the outside of the flow passage 11, and a shape that can be easily attached to and detached from the flange 20 is preferable.

  As a material of the outer periphery fastening body 2, a material having high rigidity and tensile strength and small elongation is preferable. For example, various metals such as steel and steel alloys and resins can be used.

In addition, as shown in FIGS. 1 and 2, the cross-sectional shape is provided by providing flange portions 2a and 2a protruding in the thickness direction on both sides in the width direction so as to be fitted into both outer side surfaces of the connected flanges 20a and 20b. There is no deviation and it can be attached to the flange 20 stably and firmly.
The close contact portion 3 and the outer periphery fastening body 2 are provided with a through hole 4 penetrating them, so that the through hole 4 and the circumferential groove 12 communicate with each other. A sampling tube 5 that guides the leaked gas A to the flow meter 17 is attached to the through hole 4.

  When performing the leak test, the outer cover 1 is attached to the flange 20 so that the close contact portion 3 straddles the connection portion J, and the outer cover 1 is attached to the flange 20, and the lock portion is attached to the connecting shaft 10. The engaging portion 7 is engaged with the lock portion 8 while engaging the notch 8. Thereafter, the tightening nut 9 is tightened, the connecting shaft 10 is moved in the axial direction, the distance between the one end and the other end of the outer periphery tightening body 2 is shortened, and the contact portion 3 is sufficiently close to the outer peripheral surface of the flange 20. Let At this time, the flange portions 2a and 2a of the outer periphery fastening body 2 are deeply fitted into both outer side surfaces of the flanges 20a and 20b, and the both flanges 20a and 20b are firmly connected.

  Thereby, the circumferential groove 12 forms the flow path 11 which has airtightness along the connection part J in the flange circumferential direction with the outer peripheral surface of each flange 20a, 20b.

  Thereafter, when pressurized gas A is supplied to the inside of the pipe 21, all the gas A leaking from the connection portion J of the flanges 20 a and 20 b flows into the sampling pipe 5 through the flow passage 11, and this gas flow rate is measured by the flow meter 17. By doing so, the amount of leakage can be measured accurately. In addition, the measurement can be performed without any human approaching to the pipe 13 or the like where the internal pressure is high, so the safety is improved, the test jig has a simple structure, and no water tank or water is used. , Test site restrictions are also reduced.

It is sectional drawing which shows an example of the cross-sectional shape in the state which attached the leak test jig | tool for flanges of this invention to the flange. It is sectional drawing which shows the other example of the cross-sectional shape of the leak test jig | tool for flanges in the state attached to the flange. It is a perspective view which shows an example of the leak test jig | tool for flanges of this invention. It is the whole outline figure showing the test method using the leak test jig for flanges of the present invention. It is a whole schematic diagram which shows the conventional test method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer body 2 Outer periphery fastening body 3 Close contact part 4 Through-hole 5 Sampling pipe 6 Tightening connection part 7 Locking part 8 Lock part 9 Tightening nut 10 Connection body 11 Flow path 12 Circumferential groove 13 Piping 14 Pressure gauge 15 Control valve 16 Addition Pressure device 17 Flow meter 18 Clamp 19 Gas sampling container 20 Flange 21 Water tank

Claims (4)

A flange leakage test jig used for measuring a leakage amount from a connection portion of a pair of flanges connected to each other, wherein the leakage test jig is a detachable annular covering the outer peripheral surface of the pair of flanges An outer cover body, a through hole formed in a part of the outer cover body in the thickness direction, and a sampling tube connected to the through hole, and the outer cover body is extended in the longitudinal direction. A flange leakage test jig having a surface on which a circumferential groove having airtightness is formed, and wherein the through hole is formed to communicate with the circumferential groove. The flange leakage test jig according to claim 1, wherein a surface of the outer cover body on which the circumferential groove is formed is an elastic body having airtightness. The flange leakage test according to claim 1 or 2, wherein the outer cover body is formed in an annular shape by detachably connecting one end portion and the other end portion, and the circumferential length of the annular shape can be changed. jig. 4. The flange leakage test jig according to claim 3, wherein the outer cover body has flange portions on both sides in the width direction and projecting toward the surface on which the circumferential groove is formed in the thickness direction. 5.

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