Test Leak Device

Abstract

To provide an improved refillable test leak device and filling method. [Solution] The housing 11 of the test leak device 10 has a through opening 22 connecting the interior 20 with the surroundings outside the device 10, and a membrane 25 that can be placed in the through opening 22 and allows the test fluid or a component of the test fluid to pass through. The membrane member 24 is configured to be releasably fastened to the housing 11 and comprises a carrier member 42 that blocks the through opening 22 when fastened, so that when the carrier member 42 is removed to expose the through opening 22, the interior 20 can be filled with the test fluid through the through opening 22. The carrier member 42 has an outlet conduit 44 that completely passes through the carrier member 42. The outlet conduit 44 is blocked by the membrane 25 so that only the test fluid or a component of the test fluid can leak from the interior 20 through the membrane 25 to the outside.

Description

[Technical field]

[0001] The present invention relates to a test leak device for performing a functional test and calibration of a leak detection device. [Background technology]

[0002] Typically, a gas leak detection device includes a test chamber that can be evacuated, and a test object filled with gas or liquid is placed inside the test chamber. A gas analyzer is connected to the test chamber. The gas analyzer analyzes the gas sucked from the test chamber to detect leak gas leaked into the test chamber from a leak in the test object, or liquid that has leaked from the leak and evaporated. At this time, it is extremely important to be able to estimate the size of the leak from the amount of leaked gas detected. For this purpose, a test leak device is used that contains a predetermined amount of a known test gas or test fluid. The test leak device is provided with a leak that shows a known permeability to the contained fluid and / or has known dimensions. Typically, the test leak device is used to perform a functional test or calibration of the gas leak detection device.

[0003] The leak in the test leak device may be designed as a membrane. The leakage rate (leak rate) of the membrane depends on the permeability of the membrane body for each test gas or test fluid, the membrane temperature, the temperature and vapor pressure of the test gas / fluid, the wettability of the inner / fluid side of the membrane, and the air permeability of the outlet side of the membrane (i.e., outside the test leak device).

[0004] For example, EP 2 447 694 B1 describes a liquid-filled test leak which leaks gas or vapor or a gas-borne liquid component as a result of the liquid's inherent vapor pressure or by the liquid permeating through a solid layer of a membrane.

[0005] The leakage rate of a membrane-type test leak depends on whether and to what extent the inside of the membrane is wetted with liquid. In this regard, whether the membrane is in direct contact with the liquid or only with the vapor of the liquid can have a large effect on the leakage rate. To stabilize the leakage rate, it is desirable to prevent the liquid from reaching the membrane or to ensure that only the vapor of the liquid is in contact with the membrane.

[0006] DE 10 2014 200 907 B4 describes a reference degassing system which comprises a reservoir containing a fluid or a fluid mixture. A transfer vacuum chamber surrounds the reservoir. The chamber pressure in the transfer vacuum chamber is below 10 kPa.

[0007] DE 10 2020 116 939 A1 (Patent Document 3) describes a test leak device in which the base of a reservoir for a test fluid tapers conically towards a membrane. The membrane is fixed by means of a screw. It also describes the presence of a separate filling opening for filling the reservoir with the test fluid. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] European Patent No. 2447694 [Patent Document 2] German Patent Invention No. 102014200907 [Patent Document 3] DE 102020116939 Summary of the Invention [Problem to be solved by the invention]

[0009] SUMMARY OF THE PRESENT EMBODIMENT It is an object of the present invention to provide an improved refillable test leak device. [Means for solving the problem]

[0010] A test leak device according to the present invention is defined by the features of claim 1. A method according to the present invention is defined by the features of claim 10.

[0011] The test leak device according to the present invention comprises an interior surrounded by a housing and capable of being filled with a test fluid. The housing is provided with a through opening connecting the interior with the environment outside the test leak device. A membrane permeable to the test fluid or components of the test fluid is attached to the through opening so that the test fluid or components of the test fluid can pass from the interior through the through opening to the outside via the membrane. The membrane preferably exhibits a known permeability that is predetermined so that the test fluid leaves the test leak device with a known leakage amount.

[0012] In contrast to the unique configuration of the present invention in which the test fluid is filled into the interior through the flow opening (through opening), in the prior art, a separate filling opening is provided for this purpose, and the flow opening blocked by a membrane is used only to leak the test fluid from the inside to the external environment.

[0013] For this purpose, the diaphragm (membrane) is part of a diaphragm (membrane) member that fits sealingly over or in the through opening. The diaphragm member consists of a carrier member configured to be removably attached to the housing. Preferably, the carrier member consists of a high-rigidity material such as stainless steel. The carrier member is configured to block the flow opening when attached to the housing. To fill the interior with a test fluid, the carrier member is removed from the housing, the interior is filled with a test fluid through the through opening, and the carrier member is then reattached to the housing, thereby blocking the through opening.

[0014] The carrier member is provided with an outlet channel (outlet conduit) which passes completely through the carrier member from a first side to an opposite second side and which is blocked by the membrane in such a way that only the test fluid or components of the test fluid can pass from the interior through the membrane to the exterior. The connection between the carrier member and the housing is necessarily a fluid-tight, i.e. in particular an air-tight connection.

[0015] Typically, the flow opening has a larger diameter than the outlet passage, so that the interior can be quickly refilled with test fluid, for example by a filling nozzle that fits the flow opening, while the diameter of the outlet passage is independent of the diameter of the flow opening and is a size that corresponds to the dimensions of the membrane and the size required for the test fluid to leak out of the interior.

[0016] This allows the test leak device according to the invention to have a technically simple yet highly reliable structure, since refilling through the through opening is easy without the need for a separate filling opening. Whereas conventional test leak devices are either not refillable or can only be refilled through a separate filling opening, in the present invention, the test leak device is refilled by first loosening the attachment of the carrier member to the housing and removing the membrane member from the through opening. Then, the test fluid is filled into the interior through the through opening, for example by inserting a suitable filling nozzle into the through opening. Once filling is complete, the carrier member is reattached to the housing, thereby connecting the carrier member and the housing in a fluid-tight manner, i.e. liquid-tight and gas-tight manner. Only the test fluid or components of the test fluid can leak out from the interior through the membrane.

[0017] The measurement of the permeability of the membrane member can be performed between coupling the membrane to the carrier member and coupling the membrane member to the housing, i.e. the leak rate of the test leak device can be measured and determined based on the quality of the membrane on the carrier member, i.e. independently of the housing.

[0018] The carrier member may be configured as a flange. The outlet passage may be formed in the center of the carrier member. Fastening means for fastening the carrier member to the housing may be provided distributed around the outlet passage.

[0019] In particular, the carrier member may be configured as a flange, which can be attached to a complementary opposing flange of the test chamber such that the test fluid can leak directly from the interior of the test leak device into the test chamber via a flange connection formed therewith. For this purpose, the flange of the test leak device is fluid-tightly and removably attached to the opposing flange of the test chamber. In this way, the function and calibration of the leak detection device can be easily performed without opening the test chamber and installing the test leak device in the test chamber.

[0020] For example, the fastening means may be threaded holes and corresponding threaded openings may be formed in the housing, and each threaded hole may be aligned with the corresponding threaded opening in the fastening state of the carrier member, allowing a screw to be threaded through each threaded hole into the corresponding threaded opening.

[0021] Advantageously, a separate sealing ring is provided between the carrier element and the housing, which surrounds the through-opening in plan view, in particular for sealing the through-opening against the threaded opening or against the threaded bore. The sealing ring can be metallic, for example in the form of a copper ring ("CF Vacuum Technology") or an aluminium ring ("Ultra-Dichtung"). The sealing ring is replaced after the filling process. Metallic seals are preferred here, since, unlike elastomeric seals, they are not only impermeable to gases and liquids, but also do not accumulate gases or liquids and subsequently re-release them. Gas leakage or permeation through the seal would lead to errors in the actual calibration.

[0022] The outlet passage may be cylindrical. The diameter of the outlet passage is smaller than the diameter of the flow opening. The through opening must be large enough to ensure easy, fast filling, while the outlet passage may be small enough to allow the test fluid to leak out of the interior in a concentrated manner with a predetermined leakage rate.

[0023] Preferably, the membrane is configured as a member, for example in the form of a disk, covering the outlet channel. The membrane can be attached to the outside of the carrier member opposite the interior, for example firmly glued or pressed into the carrier member. A recess surrounding the outlet channel can be formed in the surface of the carrier member, into which the membrane fits precisely. Preferably, the membrane in the recess is firmly glued or pressed into the carrier member. The membrane may be covered with a protective grid, which supports the membrane and is attached to the carrier member.

[0024] Preferably, the test leak device according to the present invention does not have a separate filling opening for filling the interior with a test fluid, and the interior can be refilled with test fluid only through the through opening.

[0025] In one embodiment, a cover cap may be provided covering the carrier member and coupled to or attached to the housing, preferably in a releasable manner, the cover cap providing protection for the membrane and the carrier member.

[0026] The housing of the test leak device includes a base, a cover, and at least one sidewall connecting the base and the cover, the base, cover, and sidewall enclosing the interior that can be filled with the test fluid. The test fluid can be a test gas or a test liquid. The membrane is permeable to components of the test gas or the test liquid, thereby allowing only components of the test gas or the test liquid to leak from the test leak device through the membrane.

[0027] An exemplary embodiment of the present invention will now be described in detail with reference to the drawings. [Brief description of the drawings]

[0028] [Figure 1] FIG. [Diagram 2] FIG. 2 is a cross-sectional view of the embodiment of FIG. [Diagram 3] FIG. 2 is an exploded view of one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The test leak device 10 includes a housing 11. The housing 11 includes a base 12, which is integrally connected to a peripheral sidewall 14 that protrudes laterally from the outer edge of the base. A cover 16 is fluid-tightly connected to the sidewall 14, and the base 12, sidewall 14, and cover 16 fluid-tightly enclose an interior 20. In other words, the interior 20 can be filled with a test fluid, i.e., a test gas or test liquid. The base 12, the peripheral sidewall 14, and the cover 16 constitute the housing 11.

[0030] The base 12 is formed with a through opening 22 that connects the interior 20 with the environment 13 outside the test leak device 10. A membrane member 24 including a membrane 25 that is permeable to the test fluid or a component of the test fluid is inserted into the through opening 22. This allows the test fluid contained in the interior 20 to leak out of the test leak device 10 only through the membrane 25.

[0031] The diaphragm member 24 is made of a cylindrical carrier member 42. The rotation axis of the carrier member 42 as a rotating body coincides with the rotation axis of the housing 11 in the state shown in Fig. 2 in which the carrier member 42 is connected to the housing 11, which is rotationally symmetric like the carrier member 42. In Fig. 2, the rotation axes of the carrier member 42 and the housing 11 are indicated by dashed lines.

[0032] The carrier member 42 has an outlet passage 44 extending coaxially through the center of the carrier member along the axis of rotation of the carrier member, completely passing through the carrier member, such that the outer end face of the carrier member 42 facing the environment 13 is connected by the outlet passage 44 to the opposite end face of the carrier member facing the interior 20.

[0033] The side wall 14 is configured as an annular body with a cylindrical circumference that protrudes from the base 12 along the outer periphery of the base 12. The inside 26 of the side wall 14 forms a cone-shaped body that narrows toward the membrane device (membrane member) 24 and the flow opening 22. The lower end of the cone-shaped body on the base 12 side is a central opening that opens into the flow opening 22 and connects to the membrane device 24.

[0034] Since the base 12 and sidewall 14 are integrally connected to one another, the cone on the inside 26 may also be considered a recess in the base 12 .

[0035] Due to the effect of gravity and the narrowing diameter of interior 20 towards flow opening 22 and membrane 25, the test fluid contained within interior 20 moves or flows along inner side 18 towards membrane 25 and into flow opening 22. This causes the membrane to become uniformly wetted with the test fluid as soon as test leak device 10 is placed on a target surface, such as the base of a test chamber of a gas leak detection device (not shown).

[0036] The underside 28 of the base 12 consists of a bulge 30 formed in a dish shape (Teller) that concentrically surrounds the through opening 22. The membrane member 24 is inserted into the lower end of the flow opening 22. The flow opening 22 opens into the interior 20 with a smaller diameter than the membrane member 24. As a result, a cylindrical recess surrounded by the curved portion (bulge) 30 is formed in the base 12, and the membrane member 24 is inserted into the recess. The membrane member 24 is completely contained in the recess.

[0037] The through opening 22 is concentrically surrounded by threaded holes 40 formed in the base 12. Fasteners in the form of screws for fastening the membrane member 24 are inserted into the threaded holes 40 and retained therein by a conventional threaded connection. The carrier member 42 is provided with threaded grooves or ports 46 located concentrically about the outlet passage 44. The threaded ports 46 are aligned with the threaded holes 40 such that a screw 48 passes through each of the threaded ports 46 and threadably engages the threaded holes. This provides a secure but releasable retention of the carrier member 42 to the housing 11.

[0038] Between the carrier member 42 and the housing 11, a sealing ring 50 in the form of a copper ring ("CF vacuum technology") is provided which surrounds the outside of the through opening 22 and forms a fluid-tight seal between the carrier member 42 and the housing 11, i.e. no test fluid can pass from said through passage (through opening) into the threaded hole 40 or into the threaded port 46. In the state shown in Figures 1 and 2, only the test fluid can pass through the membrane 25 to the environment 13 outside the interior 20.

[0039] To refill the test leak device 10, the membrane device 24 is first removed from the through opening 22 by unscrewing the screws 48 from the threaded openings 46. The interior 20 is then filled with the test fluid via the through opening 22. The sealing ring 50 is replaced with a new one if necessary, for example if it is worn. The sealing ring is then placed in the gap provided between the housing 11 and the carrier member 42, and the carrier member 42 is then screwed tightly again to the housing 11 by the screws 48. The membrane 25 remains firmly bonded or pressed into the carrier member 42 and does not need to be removed.

Claims

1. A test leak device (10) for inspecting or calibrating a leak detection device, the leak detection device comprising an evacuable test chamber adapted to accommodate a test specimen and / or the test leak device (10), the test leak device (10) comprising an interior (20) surrounded by a housing (11) and capable of being filled with a test fluid, the housing comprising a through opening (22) connecting the interior (20) with the surroundings outside the test leak device (10), and a membrane (25) capable of being arranged in or on the through opening (22) and permeable to the test fluid or components of the test fluid, the membrane (25) is part of a membrane member (24) that fits sealingly over or within the through opening (22); The membrane member is configured to be releasably fastened to the housing (11), and comprises a carrier member (42) that closes the through opening when fastened, so that when the carrier member is removed to expose the through opening (22), the test fluid can be filled into the interior (20) through the through opening; The test leak device (10) is characterized in that the carrier member has an outlet flow path (44) that completely passes through the carrier member, and the outlet flow path (44) is blocked by the membrane (25) so that only the test fluid or a component of the test fluid can leak from the interior (20) to the outside through the membrane (25).

2. A test leak device (10) as described in claim 1, characterized in that the carrier member (42) is configured as a flange, and preferably the flange is configured to be attached to a complementary flange in a test chamber so that the test fluid flows directly from the interior into the test chamber through the membrane and the flange connection.

3. 2. The test leak device (10) of claim 1, characterized in that the carrier member (42) is provided with fastening means distributed on a concentric circle centered on the outlet flow path (44) for fastening to the housing (11).

4. 4. The test leak device (10) of claim 3, wherein the fastening means is a threaded hole (40), which is aligned with a corresponding threaded port (46) in the housing when the carrier member is fastened, so that a screw (48) can be threaded through each threaded hole into the corresponding threaded port.

5. The test leak device (10) of claim 1, characterized in that when the carrier member (42) is fastened and fixed, a sealing ring (50) is provided between the carrier member and the housing (11) that surrounds the through opening in a plan view.

6. 6. A test leak device (10) according to claim 5, characterized in that the sealing ring (50) is made of metal.

7. 2. The test leak device (10) of claim 1, wherein the membrane (25) is a disk covering the outlet flow path (44) of the carrier member (42) and is arranged in a recess surrounding the outlet flow path.

8. A test leak device (10) as described in claim 1, characterized in that the test leak device does not have a separate filling opening for filling the interior (20) with test fluid, and the interior (20) can be refilled with test fluid only through the through opening (22).

9. 2. The test leak device (10) according to claim 1, characterized in that the carrier member is covered by a cover cap (52) connected to the housing.

10. 2. The method for filling a test leak device according to claim 1, loosening the carrier member from the housing to remove the membrane member from the through opening (22); filling the interior (20) with a test fluid through the flow opening (22); fastening the carrier member to the housing so that the flow opening (22) is blocked by the membrane member (24), thereby allowing only the test fluid or components of the test fluid to leak from the interior (20) through the membrane to the exterior; A method comprising:

11. 11. The method of claim 10, wherein the carrier member in the form of a flange is attached to a complementary mating flange in a test chamber so that test fluid flows directly from the interior into the test chamber through the membrane and flange connection.

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