JPH0442760Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a pressure resistance test device for joints that can perform pressure tests limited to localized joints, and in particular relates to an improved seal ring mechanism. The present invention relates to a pressure test device having a pressure resistance test device.

[Prior Art] Conventionally, in piping and storage tanks, pipes with circular cross sections or pipes and flanges have been joined by various joining means such as welding, screwing, and adhesive. If these joints are incomplete, water leaks and strength decreases, and equipment with joints
It is necessary to perform leakage tests and pressure tests not only on piping and storage tanks, but also to check for leaks.

Many of the devices with joints that are subject to testing have large internal volumes, and large devices are also important subjects for testing, so all devices are subject to testing. As a test method, for example, it is common to close all the openings of the device with blank lids, fill them with gas or liquid, and perform leakage tests and pressure resistance tests.

In this case, it takes a long time to fill and discharge the fluid, and whether it is compressed air or water, it is wasteful to discharge and discard it. In addition, the use of water may cause rust depending on the material, causing rust to occur throughout the entire volume, and a lot of construction costs will be wasted in removing and cleaning it. Additionally, equipment that sucks hydrophobic materials must be completely dry.

Note that an airtightness test is required for equipment that uses gas, but if the test pressure is high and the capacity is large, it is dangerous, so a watertightness test is often used instead. However, even if water does not leak, gas may leak, so this is not a perfect test. If you really want to perform a high-pressure airtight test on large-capacity equipment, you may need to fill most of the volume with liquid and use gas in the parts of the joints needed to check for leaks.

In this case, there is a difference in specific gravity between the gas and the liquid, and it is not easy to seal the gas only in a small part where it is necessary. Furthermore, even when conducting watertightness tests, it is difficult to completely replace the atmosphere inside with liquid.

Even in the case of leakage testing of large-capacity equipment, there is a method that allows the test to be limited to a very limited area of the joint, i.e., the test is carried out in an open state where most of the volume of the large-capacity equipment remains at atmospheric pressure. In order to test a limited portion of a joint that is the subject of testing, it is necessary to form a small-capacity test space portion in the limited portion that encloses a pressurized fluid for testing. Additionally, a sealing mechanism is required to seal this limited test space. In this case, since the inner diameter of the tube body etc. has a fairly large dimensional tolerance, a sealing mechanism corresponding to this is required. In addition, a sealing mechanism that allows sufficient pressure testing is required.

Examples of testing devices for joints between tube bodies are disclosed in Japanese Utility Model Publications No. 54-42955 and Japanese Utility Model Publication No. 48-24775.

[Problems to be solved by the invention] However, as described in Publication of Utility Model Publication No. 54-42955, in a system that employs a packing-type sealing mechanism consisting only of rubber-like elastic bodies, the pressure contact surface undergoes plastic deformation. , high contact force cannot be obtained.
Furthermore, as illustrated in the above-mentioned publication, when a ring-shaped collar is provided to suppress expansion, even higher sealing performance cannot be obtained.

Also, as stated in Utility Model Publication No. 48-24775,
The sealing material that uses rubberized woven fabric and has a circular cross section is an expansion suppression method that only allows for a certain amount of expansion, similar to an air bag, and requires reinforcement to prevent it from expanding beyond a certain size. It seals by linear contact, and when lateral stress is applied, deformation is relatively free and a strong increase in sealing performance cannot be expected.

Further, in a sealing system made of only a rubber-like elastic body, a high degree of pressure resistance cannot be obtained due to the characteristics of the rubber-based viscoelastic body. In other words, as a characteristic of a viscoelastic body, under a constant stress, deformation that is added to the initial elastic deformation over time appears as creep, and the part in the free state changes when a constant stress is applied. It maintains a slow permanent deformation, which appears as stress attenuation at the contact surface. However, when a rubber-based material is used as a sealing material, an appropriate reinforcing structure is required in consideration of the characteristics of the rubber-based viscoelastic body that cause such creep phenomena and stress attenuation.

Therefore, the purpose of this invention is to create a configuration that occupies a small volume related to testing, is safe, and allows for simple and rapid testing.
In particular, in the seal ring mechanism for the pressure test tube, a rubber-like elastic material with good contact properties is used as a sealing material, and its durability, contact strength, and pressure resistance are increased, making it possible to conduct high pressure tests. The company provides pressure testing equipment for the division.

[Means for Solving the Problems] In order to achieve the above objectives, the inventors first developed a reinforced movable seal ring as a sealing mechanism that can always maintain strong sealing properties that are suitable for rubber-based viscoelastic materials. A reinforced movable seal ring is inserted into the pressurized seal space formed in a groove shape by a ridge on the outer peripheral surface of the annular body, and pressurized fluid is introduced from the bottom to create a strong seal. It is something that brings out one's sexuality.

This reinforcing movable seal ring is a ring made of a rubber-like elastic body and has a square cross section.The ring has a seal lip on the inner diameter side, and a part inside the circumference in the outer diameter direction of the ring is pressed against the object to be pressed. This is to reinforce the seal ring so that it can operate at its full capacity without restricting its operation.

In other words, the reinforcing movable seal ring of this invention is different from a general reinforcing structure that suppresses overall fluctuations by a vertically and horizontally interconnected structure such as a woven fabric.
Reinforcing cords such as tire cords are buried inside the circumferential portion of the seal ring in the outer diameter direction, with the cord direction oriented in the lateral direction, and each independent cord is lined up for reinforcement.

Therefore, when pressure fluid is introduced into the pressurized seal space, the rubber between the cords is not inhibited by the cords and easily expands in the outer radial direction like an accordion, exerting a strong pressing force. If the part that protrudes from the groove-shaped seal space under pressure is made only of rubber-like elastic material, since rubber is a viscoelastic material, it will easily undergo plastic deformation, and the deformation will increase over time. It is a thing,
Although it cannot support high pressure, the reinforced movable seal ring described above has a special reinforcement structure that exerts a strong force to prevent deformation in the lateral direction on the sealing surface. The force in the radial direction is increased and strong pressure resistance is obtained.

A test device that uses this reinforced movable seal ring to perform a pressure resistance test on joints between pipes is
On the outer peripheral surface of the annular body, a pressurized seal space formed in the shape of a groove by a test space of the joint and a protruding edge on the surface side is provided, and this seal space can be easily inserted in the outer radial direction. Insert the above-mentioned reinforcing movable seal ring that expands but does not easily deform laterally, and provide an inlet for introducing pressurized fluid into the test space and pressurized seal space in the peripheral wall of the annular body. composition.

[Function] Therefore, in this pressure test device, if a pressurized seal state is obtained between the reinforcing movable seal ring and the inner surface of the tube body by introducing pressurized fluid into the pressurized seal space, a sealed state is established. A divided test space can be formed, and by introducing a required pressure fluid into this test space, a desired pressure resistance test of the joint can be performed.

The reinforced movable seal ring uses a rubber-like elastic ring with a square cross section, and has a special reinforcing structure, so it can freely expand in the outer radial direction. Since lateral deformation is suppressed on the sealing surface, plastic deformation on the press contact surface is prevented and a reduction in press contact force can be prevented. In addition, the attenuation of stress caused by the creep phenomenon observed in rubber-like elastic bodies is suppressed, ensuring stable and reliable high-pressure sealing performance, and by suppressing lateral deformation, the force in the outer radial direction is reduced. Increased and stronger sealing pressure is obtained. Therefore, even if the test pressure applied from the lateral direction is increased, the deformation and
High pressure tests can be carried out without fear of leakage.

In addition, since the movable seal ring is prevented from deforming in the lateral direction, it easily returns to the space between the projecting edges after the pressure test is completed, so there is no problem in removing the device, and it is also suitable for repeated use. .

Not only can the test space be made extremely small, but the loss of time and fluid is extremely small, making the test simple, quick, and inexpensive. Also, compressed gas can be freely used, making it safe. Leak or pressure tests are performed and test safety is ensured.

[Example] Hereinafter, an example of the implementation of the pressure resistance test apparatus for a joint according to the present invention will be described in detail based on illustrative drawings.

Figure 1 shows a pressure test device for joints with a circular cross section.
This is a cross-sectional view of the TE, and 7 is an annular body having an inner diameter d and an outer diameter D. On the outer peripheral surface of the annular body 7, there are projecting edges 5, 6 on the test space part 1 and on both sides thereof. A pressurized seal space 3 is provided, which is an annular space formed in the shape of a groove, and 2 is a test pressurized fluid inlet provided in the annular body 7;
4 is a pressurized fluid inlet for sealing.

Reference numeral 8 denotes a reinforced movable seal ring made of a rubber-like elastic material such as rubber or plastic, which is inserted into the pressurized seal space 3.

That is, this test device is provided with a test space part 1 on the outer peripheral surface of an annular body and a pressurized seal space part 3 on both sides thereof, and a reinforcing movable seal ring 8 is inserted into this seal space part 3. Pressurized fluid is introduced into the pressurized seal space 3 from the seal pressurized fluid inlet 4, and pressurized fluid is introduced into the test space 1 from the test pressurized fluid inlet 2 to test the joint. This is for leakage and pressure testing. This example shows an example of an annular body, but if the test object has an elliptical or other deformed shape, the shape of the annular body 7 of this device may be deformed to follow that shape. Of course.

FIG. 2 is an enlarged sectional view showing the cross-sectional shape of the reinforcing movable seal ring 8. As mentioned above, this reinforcing movable seal ring made of a rubber-like elastic body is
As shown in the figure, self-sealing seal lips 8a are provided on both sides of the inner diameter side in a protruding manner, and an independent reinforcing cord 9, such as a tire cord without a woven structure, is provided inside the outer circumference of the seal ring. Independent cords are buried and reinforced in parallel, with the cord direction facing the width direction. That is, the independent reinforcing cords are connected only by a rubber-like elastic body, and have flexibility, but are prevented from elongating in the lateral direction by embedding the cords. Further, since plastic deformation of the rubber-like elastic body, which is a viscoelastic body, in the lateral direction is prevented, durability is also increased. By reinforcing it in this way, the reinforced movable seal ring 8 can be freely expanded in the outer diameter direction like an accordion by applying pressure, but the strength in the width direction (axial direction) is increased. ,
It can strongly support deformation in the lateral direction, and by increasing the pressure of the pressurized seal space part 3,
Although increasingly strong pressure contact force is generated against the test object, the rubber-like elastic body of the seal part can maintain a strong sealing function to prevent lateral pressure due to the test pressure. This enables high voltage resistance tests.

Note that this reinforcing movable seal ring 8 can obtain a higher pressure contact surface with the pressure contact surface by forming grooves on the outer circumferential seal surface depending on the condition of the pressure contact surface. Since the pressure contact surface is strongly pressed, high pressure can be maintained in combination with the reinforcing structure.

FIG. 3 is an enlarged cross section of part A in FIG. 1. When the reinforcing movable seal ring 8 is inserted into the pressurized seal space 3, the seal lip 8a is
and the inner flange 6, and contact pressure is generated between both walls, and furthermore,
When pressurized fluid is injected from the sealing pressurized fluid inlet 4, the reinforcing movable seal ring 8 freely and easily expands in the outer diameter direction, and has the function of preventing deformation in the axial direction. The sealing surface 8b strongly contacts the inner surface of the circular body of the measuring object to exhibit sealing properties, and the sealing lip 8a is strongly pressed against the wall surfaces of both flange edges by the pressure of the pressurized fluid itself.
It exhibits even stronger self-sealing.

In other words, this pressurized sealing method can freely perform its sealing function regardless of dimensional tolerances, and furthermore, since the sealing function can be freely changed by applying pressure, the condition of the contact surface can be changed. Not only can it respond to changes, but it also provides reliable and stable sealing.

Next, an example of a pressure test performed by the pressure test apparatus TE for a welded portion between tube bodies in this invention will be specifically described.

FIG. 4 is a cross-sectional view showing leakage and pressure test conditions when two tube bodies are welded together, and the tube body 10 is joined at the joint 11.
This is a case where a leakage and pressure resistance test of this joint 11 is performed.

The inner diameter of general pipe bodies is allowed to have a considerable tolerance, so the test equipment TE
It needs to have an outer diameter D that allows it to be easily inserted into any tube.

Therefore, an allowable interval AI is required between the test device TE and the inner diameter of the tube, and the structure is such that this allowable interval AI is sealed by expanding the reinforcing movable seal ring 8 .

However, the reinforcing movable seal ring 8 made of a rubber-like elastic material is expanded when pressurized fluid is injected from the sealing pressurized fluid inlet 4, and the sealing surface 8b is pressed against the inner surface of the tube, and the test space portion 1 is expanded. It becomes a sealed state.

During the test, the center part of the test device TE is placed at the joint 11 of the part to be measured, and when pressurized fluid is first injected from the sealing pressurized fluid inlet 4, it expands to the inner surface of the tube body 10, and It is pressed against the inside of the tube body 10 with a surface pressure approximately equal to the pressure of the pressurized fluid. Therefore, by increasing the pressure of the pressurized fluid, the sealing performance is increased.

In addition, from the leakage and the pressure P of the pressure test pressurized fluid that is pressurized into the test space part 1 from the test pressurized fluid inlet 2, the sealing pressurized fluid inlet 4
If the pressure P+α is set to be slightly higher than the pressure P, the pressure P of the test pressurized fluid in the test space 1 will be lower than that of the reinforced movable seal ring 8.
The air is further supported in a balanced state, and the public sealing state is maintained. This sealing pressure is designed to completely maintain leakage and pressure test pressure.
The pressure is adjusted to an appropriate level depending on the actual sealing performance, and is at least equal to or higher than the pressure for leakage and pressure resistance tests.
Therefore, if the joint 11 is coated with soapy water from the outside, the presence or absence of leakage can be easily checked.

In addition, when this test equipment TE becomes large and difficult to handle, or when it is necessary, it may be necessary to use rubber or plastic rollers or sleds (test The device is attached with a moving device (which is slightly larger than the outer diameter D or whose height is adjustable).
Such a moving device also has the additional effect of making it easier to achieve even more uniform placement within the tube.

[Effects of the invention] The pressure resistance test device for joints of this invention not only allows the test space to be minimized, but also has a reinforced movable seal ring in the pressurized seal space that performs a sealing function between the inner surface of the tube and the inner surface of the tube. It has a reinforcing structure that easily expands in the outer diameter direction but does not easily deform in the lateral direction, so effective, stable and reliable pressure contact force against the inner surface of the tube can be obtained.
A good seal is ensured, making it easy to perform high-pressure tests that are not possible with conventional configurations, making complete testing easy and inexpensive, and making testing simpler, faster, and safer. It has characteristics that give it a certain level of character.

In addition, since the movable seal ring is prevented from deforming in the lateral direction, it easily returns to the space between the projecting edges after the pressure test is completed, so there is no problem in removing the device, and it is also suitable for repeated use. .

Furthermore, since the lateral deformation of the part protruding from the flange is suppressed, a reliable pressure contact state can be obtained even when the allowable interval AI between the test device and the tube inner diameter is relatively wide. It also has the advantage of allowing a wide range of allowable distances between the inner diameter of the tube and the test object, which expands the range of test objects, and provides an extremely practical and reliable testing device. It is.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a pressure test device for joints showing an example of this invention, and FIG. 2 is an enlarged sectional view of a reinforced movable seal ring used in the device of this invention.
FIG. 3 is an enlarged sectional view of part A in FIG. 1, and FIG. 4 is a sectional view showing leakage at a joint between two pipe bodies by welding and a pressure resistance test state. 1... Test space section, 2... Test pressurized fluid inlet, 3... Pressurized seal space section, 4
... Pressurized fluid inlet for sealing, 5, 6 ... ridge,
7... Annular body, 8 ... Reinforced movable seal ring, 8
a...Seal lip, 8b...Seal surface, 9...
Reinforcement cord, 10... pipe body, 11... joint part,
TE...Pressure test equipment.

Claims (1)

[Scope of utility model registration request] On the outer circumferential surface of the annular body 7, there is provided a pressurized seal space 3 formed in the shape of a groove by projecting edges 5 and 6 on the test space 1 of the joint portion and on both sides of the test space 1, and in this seal space 3, Seal lips 8 are provided on both sides of the inner diameter side of the ring, which is made of rubber-like elastic material and has a square cross section.
a, and inside the circumferential part in the outer diameter direction of the ring,
A reinforcing movable seal ring 8 is installed by burying independent cords in parallel with each other with the reinforcing cords oriented in the width direction so that they can easily expand in the outer diameter direction but not easily deform in the lateral direction. A pressure resistance test device for a joint portion, which is inserted into the peripheral wall of the annular body 7 and is provided with an inlet for introducing pressurized fluid into the test space portion 1 and the pressurized seal space portion 3.