JPS59206735A - Method and apparatus for testing leakage of fluid in pipe, cylinder or the like - Google Patents

Abstract

PURPOSE:To perform a fluid leakage test easily, rapidly and precisely by forming a sealed space inside a pipe, cylinder or the like by two base bodies stored inside the pipe, cylinder or the like while keeping a uniform space over the whole periphery of the inside of the pipe, cylinder or the like and two seal bodies and feeding pressure fluid to the sealed space. CONSTITUTION:A tester is inserted by a guiding wheel 1 so that a seal press 3 is located on a seam position in a steel pipe P to be tested and the width direction centers of the two seal bodies 4, 5 formed on the external periphery of the base bodies are bent in the ring diameter direction by pulling back an air cylinder device 10 to adhere the seal bodies 4, 5 to the inside of the steel pipe P over the whole periphery. The whole peripheral adhesion of the seal bodies 4, 5 allows a ring-like sealed space S to be secured between the inner periphery of the steel pipe P and the external periphery of the base body 2. When high pressure air is supplied from pressure fluid supplying courses 11a, 11b to the insides of the seal bodies 4, 5 and high pressure air is supplied from a pressure fluid supplying course 12 to the sealed space S, the existence of a pinhole on a welded seam of the steel pipe P can be tested by observing soap bubbles.

Description

[Detailed Description of the Invention] [Technical Field] The present invention provides a method for distributing gas or liquid to various types of pipes such as welded pipes, fume pipes, concrete pipes, etc. at the joints of the pipes. The present invention also relates to a method for testing fluid leakage of pipes and a fluid leakage testing machine for pipes for testing whether or not there is a pinhole that causes fluid leakage at other appropriate locations.

<Prior art> Conventionally, in order to test whether or not there is a pinhole that may cause fluid leakage at a joint or other appropriate location of a pipe, both ends of the pipe are covered and pressure is applied inside the pipe. supply fluid;
Either the liquid leaked from the outer surface of the tube or the liquid was applied to the outer surface of the tube to form bubbles.

However, in this method, when welding the lid, it takes time to weld and remove the lid. In particular, when the diameter is large, the time required to weld and remove the lid cannot be ignored. In addition, pipes with large diameters or made of many pipes have a large internal volume when both ends are capped, and a large amount of pressure fluid must be supplied for testing, which takes a long time. The pressure fluid must be recovered before the lid is removed, so if the pressure fluid is a liquid, a drain device must be provided, or if it is a gas, a blow valve must be provided, which is complicated and time-consuming. Ta. In addition, if the pinhole that causes fluid leakage is extremely small at the joint or other appropriate location of the tubing, the fluid leakage test is performed over the entire length of the tubing, so the fluid leakage point cannot be detected. If you are not sure if the pressure on the pressure gauge is slightly decreasing after several hours, you may find that there is a pinhole in an unexpected place after thorough inspection of the fitting, lid, and other places. In such cases, the test took a long time. Also, if you want to perform a fluid leakage test on a steel pipe that is being welded and buried deep underground, or on a steel pipe that is already buried deep underground, do not cover the bottom end of the steel pipe as it is not possible to do so. There is a need for a method and a fluid leak testing machine for testing steel pipes for fluid leakage.

<Purpose of the Invention> The present invention was devised as a result of intensive research in view of the above points, and is capable of forming a sealed space within the necessary minimum range at a desired location inside a tube and by feeding pressure fluid into it. The present invention provides a method for testing fluid leakage of pipes and a fluid leakage tester for pipes, which allows fluid leakage testing to be easily, quickly, and reliably performed by knowing whether or not the pressure fluid comes out of the pipe. be.

<Structure of the Invention> Therefore, in the present invention, the fluid leakage tester for tubes is capable of being inserted into and taken out from the inside of the tube, sealing two places on the inner circumferential surface of the tube cheek, and testing the inside of the tube cheek. It is formed in a donut-shaped sealed space along the circumference, and has a structure that allows pressure fluid to be supplied to the sealed space, and the fluid leakage test method for pipes and cylinders uses such a fluid leakage tester. The system is designed to form a closed space at a desired location inside the tubing, feed pressure fluid into it, and check whether the pressure fluid exits the tubing or not.

The first invention of this morning, a method for testing fluid leakage of pipes, is as follows:
Two base bodies each having seal circumferential surface portions spaced a certain distance apart in the axial direction, which can be housed inside the tubing to be tested with a substantially uniform gap all around the circumference, and one seal circumferential surface portion. It is installed in a coiled manner and expands in the outer diameter direction of the base by supplying pressure fluid, or bends in the outer diameter direction by being compressed from the axial direction by a movable body provided on the outer circumference of the base, and tightly adheres to the inner surface of the tube all around. A fluid leakage tester for tubing, which has two seal bodies capable of forming a sealed space, is inserted into a predetermined position inside the tubing, and the pressure fluid is supplied and/or the movable body is driven. The seal body is expanded and/or bent in the outer radial direction of the base and electrodeposited on the inner surface of the tube all around to form a sealed space between the base and the inner surface of the tube in the vicinity of the welding part. After that, pressure fluid is supplied to the sealed space from outside the pipe to check whether the pressure fluid leaks outside the pipe. By reducing the pressure, the seal body is reduced in diameter and separated from the inner surface of the tube, and the fluid leak tester for the tube is taken out of the tube, or it is moved to another location and the same procedure is performed thereafter. The test is continued according to the procedure described above, and finally, it is taken out of the tube to indicate a sign of cattle.

In this method, two seal bodies provided on the outer periphery of the base are expanded once in the diameter direction of the tube. 6. The seals are to be in close contact with the inner surface of the class all around, and when inserting the fluid leakage tester into the required position inside the tube, the two seal bodies should be in close contact with the outer circumference of the base body. It is something to put.

The sealed space is formed by inflating two seal bodies, but in order to inflate the seal bodies in the diametrical direction of the tube, the two seal bodies are formed around the outer periphery of the base body in the shape of a tire tube. It is sufficient if it is formed and expands when pressure fluid is supplied.

Another method for expanding the sealing body in the diametrical direction of the tube is that the sealing body is made by wrapping a band of rubber or flexible plastic in an annular manner around the outer circumference of the base and moving the seal body in the direction of the neck axis of the tube around the outer circumference of the base. By remotely driving a movable part that is freely provided, the seal body can be bent so as to be in close contact with the inner periphery of the pipe all around, and the sealed space can be maintained at a predetermined pressure with spring force, and the After this, pressure fluid may be supplied between the seal body and the base body to expand the tubing in the diametrical direction, and the sealed space may be maintained at a higher predetermined pressure by the spring force and fluid pressure.

A closed space does not limit the closing distance at which it is formed. For example, if the purpose of the test is to test fluid leakage from welded joints of steel pipes or caulked joints of Huum pipes, 2.
The interval between the seal bodies may be made slightly larger than the inner seam width so that the sealed space becomes a thin circular space,
Alternatively, if the purpose of the test is to check for the presence or absence of pinholes over the required length of pipes such as fume pipes or concrete pipes, make the sealed space long by placing two seals at the required interval. It is something that can be done.

Further, the sealed space formed inside the tube may be partitioned into a donut-shaped space along the inner circumferential surface of the tube. This can be done if the base of the fluid leak tester has a cylindrical shape that can be accommodated in the tube cheek, and two seals are provided on the outer periphery of the base. Partitioning the closed space into a donut-shaped space is achieved by
Compared to dividing the area by cutting, if the pipe diameter is large or the distance to be sealed is long, the volume of the sealed space is small, and the pressure fluid to be supplied to the sealed space is also small. It is preferred because it has the advantage of requiring only a small amount.

The pressure fluid for inflating the two seal bodies and the pressure fluid supplied to the sealed space formed by the two seal bodies expanding once in the diameter direction of the tubing may be either gas or liquid. Also good. It must be able to be supplied independently. the pressure of the pressure fluid in the tank that expands the seal body; and 2
Balancing the pressure of the pressurized fluid supplied to the sealed space formed by the expansion of the seal body in the diametrical direction of the tube is to This is preferable because there is little directional deformation effect. If the pressure fluid is a gas, it can be supplied by a compressor or an air cylinder. In particular, a method may be used in which a fluid leakage tester is equipped with a micro combiner and the pressure fluid is supplied inside the pipes. Alternatively, pressure fluid may be supplied from the outside through a passage communicating with the closed space inside the container. If it is a liquid, install a constant pressure pump, or use a boost pump, a constant pressure valve with a safety valve, and a return pipe that is connected to the safety valve and can return the liquid to the outside.
A fluid leak tester equipped with a human pass may be used.

It is desirable, but not necessary, to be able to detect whether pressure fluid has been supplied to the closed space and the pressure has risen to a predetermined pressure.

The second invention of the present application, the fluid leakage tester for tubes, is characterized by one expansion of a seal body having a gap with the inner periphery of the tube when housed in the cheek of the tube to be tested. It has two seal mounting circumferential parts spaced apart from each other by a required distance in the axial direction of the tube, each having an outer circumferential shape that allows the entire circumference to be in close contact with the inner periphery of the tube when the tube is in contact with the inner circumference of the tube, and is housed in the cheek of the tube. A base body of an appropriate shape and structure in which the space between the two seal mounting peripheral surfaces is closed except for the gap between the seal mounting peripheral surface parts and the inner periphery of the tube, and an airtight and The two movable bodies are slidably provided, and each of the two seal attachment circumferential parts is annularly formed from a flexible material, one end of which is hermetically fixed to the outer circumferential surface of the base, and the other end the two seal bodies that are airtightly connected to the movable body on the entire circumference and whose widthwise centers are bendable outward in the diametrical force direction of the tube; a drive device for driving the body in the axial direction; +ii a first pressure fluid supply path provided so as to communicate between the peripheral surface for attachment of the outer surface of the base body and the corresponding seal body; A second pressurized fluid supply path provided so as to communicate with the closed space.

For the J2 substrate, the entire circumference to the inner periphery of the tube at the time of one expansion of the sealing body whose outer periphery has a gap with the inner periphery of the tube when housed in the cheek of the tube to be tested. The outer circumferential shape that allows for close contact is, for example, if the tube is a steel pipe with a circular, square, or triangular cross section, the outer circumferential shape is one size smaller than the inner circumferential shape of the steel pipe that can be accommodated so that the gap is uniform all around. good,
Further, the base body has two seal mounting peripheral surface portions spaced apart from each other by a required distance in the axial direction of the tube, and a space between the two seal mounting peripheral surface portions when housed in the tube cheek. An appropriate shape and structure in which the seal is closed except for the gap between the seal mounting peripheral surface and the inner periphery of the tube is, for example, a column or cylinder having an outer circumferential shape that is slightly smaller than the inner circumferential shape of the tube cheek. Alternatively, a structure may be considered in which two circular, square, triangular, etc. round plate members facing each other in parallel are connected by a connecting member depending on the cross-sectional shape of the tube. When the base body is formed into a cylindrical shape, both sides of the base body are in communication through the cylindrical space, but in the present invention, when the base body is housed in the tube cheeks, the base body and the two sealing bodies are connected to the tube body. There is no problem since the purpose is to form a closed space along the inner periphery.

The above-mentioned seal body is made of highly elastic and strong rubber or flexible plastic. It is preferable that the movable body is curved so that it is easily curved in only one direction when the movable body moves.

``The two movable bodies are provided on the outer periphery of the base body so as to be able to slide in an airtight manner, and are airtightly connected to the entire circumference of one end of each of the two seal bodies.'' The two movable bodies are driven by the driving device as described in 2. It is sufficient that the base body is curved, and it is preferable that the base body is provided on the outside of both ends of the base body so as to be located on the outside of the two seal bodies, but it is preferably provided on the inside of the two seal bodies. Also good.

The drive device is attached to the base body, and the drive device is attached to the base body.
It is convenient to use one or more fluid pressure cylinder devices that allow the movable bodies to approach and separate from each other.
Any other suitable drive means may be used, such as a combination of a motor and a link machine, or a combination of a pinion and a rack.

- At both ends of the tube in the axial direction of the base body, the inner surface of the tube is attached @1
It is preferable to form a guide wheel that moves in one direction. It is preferable that a plurality of guide wheels be provided at each end and equally spaced in the circumferential direction. The guide ring has the role of smoothly inserting the base body in the direction of the neck axis of the tube, and particularly, for example,
It is essential when inserting deeply into a steel pipe that has been joined to 0 meters, or it is not necessary when the pipe tube to be tested is short.

In addition, when the tube to be tested has a large diameter, the weight of the base body, movable body, and drive device becomes too large, and the guide wheel is used to seal the inner surface of the tube tube cheek and the base body (=J River surface). It is essential to ensure a uniform gap between the surfaces all around the circumference.However, it is not necessary when the tubes have a small diameter and the weight of the base body, movable body, and drive device is extremely small.The reason is , even if the guide ring does not ensure a gap between the inner surface of the tube cheek and the seal-receiving circumferential surface of the base, the lower side of the seal-mounting circumferential surface of the base is in contact with the inner surface of the tube tube cheek, and there is a large gap on the upper side. Even if there is, - when the two seal bodies are expanded in the diametrical direction of the tube, the base body rises and the two seal bodies are brought into close contact with the inner surface of the cheek of the tube all around the circumference.

The first pressure fluid supply path and the second pressure fluid supply path are generally formed as passages bored in the base body or the movable body. but.

If the sealing body is expanded in the diametrical direction of the tube and can be brought into close contact with the inner surface of the cheek of the tube all around, the first pressure fluid supply passage may be an opening opened directly in the sealing body, and the second pressure fluid supply passage may be an opening opened directly in the sealing body. The passage may be a passage bored within the thickness of the seal body, and the pressure may be supplied through a tube passed outside the movable body.

The pressure fluid supply device can be a liquid supply system having an air pipe, an air compressor, or a liquid pump, and is provided outside the tubing or integrally with the base body.

A servo motor or a pulse motor may be connected to the guide wheel so that the fluid leakage tester has an active function of automatically entering the inside of the pipe and tubing and knowing how far it has entered. . Additionally, a kite rail may be inserted in advance so that the fluid leak tester can enter the interior of the tubing in a straight line and accurately.

The fluid leakage tester for tubes according to the third invention of the present application is characterized in that when a seal body having a gap with the inner periphery of the tube to be tested is expanded when the tube is housed in the cheek of the tube to be tested, It has two seal attachment circumferential parts having an outer circumferential shape that allows for close contact to the inner periphery of the tube at a required interval in the axial direction of the tube, and when housed in the cheek of the tube. A base body of an appropriate shape and structure in which the space between the two seal mounting peripheral surfaces is closed except for the gap between the seal mounting peripheral surface and the inner periphery of the tube, and a flexible material. It has a tube shape made of two seals, and is provided on the circumferential surface of the two seals so as not to shift, and when pressure fluid is supplied inside, it expands in the radial direction of the ring and is wound around the outer circumference or the outer circumference. The sealing body in which the sealing band is in close contact with the inner surface of the tube cheek all around the tube to form an annular sealed space between the inner circumference of the tube and the outer circumference of the base, and an 81 provided so as to communicate with the inside of the sealing body. It is characterized by comprising a pressure fluid supply path and a second pressure fluid supply path provided so as to communicate with the annular closed space.

In the fluid leak testing machine for tubing of the present invention, the seal body is tube-shaped and expands, so the movable body and drive device for inflating the seal body in the fluid leak testing machine for tubing of the second invention are provided. Not equipped with The base body, the first pressure fluid supply path, and the second pressure fluid supply path can be constructed in the same manner as in the case of the fluid leakage tester for pipes according to the second aspect of the invention. A guide ring and a pressure fluid supply device can be provided as desired and are not necessary.

〈Example 1〉 Fig. 1 shows a state in which the fluid leakage tester for tubes according to the second invention is housed inside the tube cheek and a fluid leakage test is carried out along the neck axis direction of the tube tube. This is a longitudinal side view, and FIG. 2 is a front view thereof.

This fluid leakage tester consists of a cylindrical base body 2, which has four guide wheels 1, 1, and 1.1 at both ends that roll on the inner surface of a steel pipe P in the tube axis direction, and has slits 2a and 2b formed on the outer periphery of a cylindrical base body 2. An annular seal presser 3 is fixed at the center, two annular rubber seal members 4.5 are provided on both sides of the annular seal presser 3, and two annular movable members 6.7 are provided on both sides of the annular seal member 4.5. The entire periphery of both ends of the seal body 4.5 is held between the seal presser 3 and the movable body 6 or 7. A piston of the air cylinder device 10 is housed inside the base body 2 in an arm 8.9 fixed to the end face of the movable body 6.7 and guided in the tube axis direction by engaging the slits 2a and 2b. The head of the rod loa and the bottom of the cylinder IOb are connected, and a hose of a pressure fluid supply means (not shown) installed outside the tube communicates between the seal body 4 and the seal body 5 bored in the base body 2. 1
It is connected to the pressure fluid supply passages 11a, llb, and a hose Pa connection port 13 attached to a second pressure fluid supply passage 12 communicating with the outer periphery of the seal presser 3. Base body 2
There is an O-ring 14 between the seal body 4 and the movable body 6.7.
．． The gap inside 5 is sealed.

The effect will now be explained.

First, this fluid leakage tester is smoothly inserted using the guide ring 1 so that the seal presser 3 is located at the joint position in the steel pipe P to be tested. Next, when the air cylinder device 10 is driven to retire, the two movable bodies 6.7 can be moved closer to each other in the axial direction of the steel pipe P. By bending the widthwise center of the seal body 4.5 of !J in the annular radial direction, it can be brought into close contact all around the inner surface of the steel pipe P. This all-around close contact is achieved by utilizing the elastic force of the seal body 4.5. Due to the seal body 4.5 being in close contact with the entire circumference, an annular closed space S is created between the inner circumference of the steel pipe P and the outer circumference of the base body 2.
is ensured. After that, the first pressure fluid supply path 11a, l
By supplying high-pressure air from lb to the inside of the seal body 4.5, the seal body 4.5 can be more strongly crimped onto the inner periphery of the steel pipe P.

In this way, after ensuring the sealing of the annular closed space S by the seal body 4.5, the second pressure fluid supply path 1
2, high pressure air is supplied from the first pressure fluid supply path 11a, llb.
If the air is supplied to the annular closed space S in a manner that balances the pressure of high-pressure air supplied from It can be inspected to see if there are pinholes. Thereafter, the high pressure air is removed from the second pressure fluid supply path 12, and the high pressure air supplied from the first pressure fluid supply paths 11a and 11b is removed, and then the air cylinder device 10 is driven to extend, and the two movable bodies 6. If the diameter of the two seal bodies 4.5 is reduced by returning the seals 7 apart from each other, this fluid leak tester can be taken out of the steel pipe P or moved to another location. If there are pinholes, it will be necessary to re-weld after moving.

In particular, when the base body 2 is cylindrical, the sealed space S can be secured in an annular shape. Therefore, when the diameter of the steel pipe P is large or the steel pipe P is made by joining several pipes, when both ends are capped. Even if the internal volume is large, there is no need to supply a large amount of pressure fluid for testing, which can be done in a short time, and it is easy to design a simple and strong structure. An annular closed space S, not a circular one corresponding to
It has an annular shape that rests on the inner circumferential surface of the steel pipe P, which is subjected to a small pressure of compressed air.Since the elastic force of the seal body 4.5 and the high pressure air are utilized, a high pressure test of, for example, 10 kg/square centimeter is possible. Become.

<Example 2> Fig. 3 shows a state in which a fluid leakage tester for pipes and pipes according to the third invention is housed inside the pipes and a fluid leakage test is performed along the axial direction of the pipes and pipes. FIG.

This fluid leakage tester has a base 15 formed into a cylindrical shape with two ridges 1B and 17 on the outer periphery, and each ridge 16, 17.
An annular groove is formed by screwing together two NANDs 18 and 19, and a tube-shaped seal body 2o, 21 is irremovably fitted into each groove, and a rubber seal is attached to each seal body 2o, 21. A band 22.23 is wound around and the base body 15 is provided with a first pressure fluid supply channel 24.25 and a second pressure fluid supply channel 26-. One side of the tube-shaped seal bodies 2o, 21 in the cross-sectional direction, which is usually depressed, expands and protrudes when constant-pressure air is supplied from the first pressure fluid supply path 24.25, and the seal band 22.23 becomes a steel tube. It has a structure in which the entire circumference is in close contact with the inner circumference of P, and if the high pressure air supplied from the first pressure fluid supply path 24.25 and the high pressure air supplied from the second pressure fluid supply path 2G are balanced, the annular damage can be closed. It is possible to conduct a test in which the pressure of compressed air in the space S is approximately 15 kg/cm2.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional side view taken along the axial direction of the tube, showing a state in which a fluid leakage tester for tubes according to the second invention is housed inside the tube cheek and a fluid leakage test is performed. , FIG. 2 is a front view thereof, and FIG. 3 is a tube tube P showing a condition in which a fluid leakage tester for tube tubes according to the third invention is housed inside the tube cheek and a fluid leakage test is performed. FIG. 3 is a longitudinal cross-sectional side view along the axial direction. 2.15-- Base body, 4.5.20.21-- Seal body 6.7-- Movable body, 10... Air cylinder device (drive device), 11a,
llb, 24.25--first pressure fluid supply path, 12.2
6...Second pressure fluid supply path. 22.23... Seal band, patent Applicant: R Kogyo Co., Ltd. Figure 1 Figure 2 Figure 6

Claims (3)

[Claims] (1) Two base bodies each having a seal mounting circumferential surface spaced a certain distance apart in the axial direction, which can be housed inside the tube to be tested with a substantially uniform gap all around the circumference; After being rolled up and pierced several times, the base expands in the outer diameter direction by supplying pressure fluid.
Or a tube having two seal bodies that can be bent in the outer diameter direction by being compressed in the axial direction by a movable body provided on the outer periphery of the base, and can form a sealed space by closely contacting the inner surface of the tube all around. Insert the tube fluid leakage tester into the required position inside the tube, and by supplying pressure fluid and/or driving the NF moving body, move the two seal bodies in the outer diameter direction of the base (inflating and/or bending). and the entire circumference is brought into close contact with the inner surface of the tube to form a sealed space between the base body and the inner surface of the tube in the vicinity of the welding part, and then a pressurized fluid is supplied to the sealed space from outside the tube. It is inspected to see if there is any leakage of pressure fluid outside the tubes, and after this inspection is completed, the seal body is reduced in diameter by reducing the pressure of the pressure fluid expanding in the seal body, and the inner surface of the tubes is inspected. Either move it away from the tube and take out the fluid leakage tester for the tubes listed in L. Or, move it to another location and continue testing in the same way, and finally take it out of the tubes. A method for testing fluid leakage of pipes and barrels. (2) When the seal body is housed in the tube cheek to be tested and has a gap with the inner periphery of the tube on its outer periphery, the entire circumference can be brought into close contact with the inner periphery of the tube at the time of one expansion. It has two circumferential parts for seal mounting which are in the shape of an outer periphery and are spaced apart from each other by a required distance in the axial direction of the tube, and the space between the two circumferential parts for seal attachment when accommodated in the cheek of the tube is A base body of an appropriate shape and structure that is closed except for the gap between the seal-receiving peripheral surface and the inner periphery of the tube, and two movable bodies that are airtightly and slidably provided on the outer periphery of the base body. , I on each of the above two seal mounting circumferential parts.
If it is provided in an annular shape from a flexible material, the entire circumference of one end is hermetically fixed to the outer peripheral surface of the base body, the entire circumference of the other end is airtightly connected to the movable body, and the center in the width direction can be bent outward in the radial direction of the tube type. Na2
a drive device that is attached to the inside or side of the base body and drives the two movable bodies in the axial direction; a peripheral surface portion for seal pickup on the outer surface of the base body; and a seal body corresponding thereto. and a second pressure fluid supply path provided to communicate with the annular closed space. Type of fluid leakage tester. (3) An outer periphery whose outer periphery has a gap with the inner periphery of the tube when it is housed in the cheek of the tube to be tested, so that when the seal body is inflated, it is in close contact with the inner periphery of the tube throughout the entire circumference. It has two circumferential surface parts for seal mounting having a shape spaced apart by four quarters in the neck axis direction of the tube, and the space between the two circumferential surface parts for seal attachment when housed in the cheek of the tube is a base body of an appropriate shape and structure that is closed except for the gap between the seal mounting peripheral surface and the inner periphery of the tube; and a tube-shaped base made of a flexible material located on the two seal mounting peripheral surfaces. It is provided so that it does not shift, and when pressurized fluid is supplied inside, it expands in the annular radial direction, and the outer periphery or the seal band wrapped around the outer periphery comes into close contact with the inner surface of the tube cheek all around the tube, thereby sealing the inner periphery of the tube. and the outer periphery of the base body, a first pressure fluid supply passage provided to communicate with the inside of the seal body, and a first pressure fluid supply path provided to communicate with the annular sealed space. 1. A fluid leakage tester for tubing, characterized in that it has a second pressure fluid supply path.