Leak test method and test apparatus

Abstract

The invention relates to a test method and test apparatus for detecting leaks in a valve unit, such as a ball valve, comprising a mandrel for sealing a valve housing connection end. At least one mechanical arm with at least one gas detection probe is moved into a position relative to a gas leak passage of the valve housing outer surface or the mandrel. Air trapped in the closed valve housing is evacuated by at least one evacuation unit. A tracer gas is supplied into the closed valve housing and any gas leak is detected by the gas detection probe. A control unit controls the movement of the mechanical arm to correctly position the gas detection probe relative to the valve unit.

Description

[0001] Invention Field The present invention relates to a method for leak testing of a valve (e.g., a ball valve), comprising placing a valve element within a test unit, introducing tracer gas into the valve element, and detecting gas leakage from the valve element.

[0002] The present invention also relates to a test apparatus for valve leakage testing as described above. Background Technology

[0003] As is well known, ball valves are widely used in pipelines to regulate fluid flow by frequently opening and closing the valve element. This can lead to valve seat wear and potentially internal or external leaks, resulting in production losses over time. Therefore, ball valves need to be tested after production to verify the quality of welding and sealing. If no leaks are detected, the ball valve passes the test and is ready for use.

[0004] A widely accepted testing method is hydraulic pressure testing. With the valve element in a semi-open position, a test fluid (e.g., water) is introduced into the ball valve, blocking the open port of the valve body. The ball valve is then pressurized for a test period, during which a worker visually inspects the outer surface for water droplets or wet spots. Afterward, the valve element is closed, and water pressure is applied to one side of the ball valve. The water pressure is then monitored to detect any pressure drop. This testing method requires manual visual inspection, which depends on the worker's experience and knowledge. Furthermore, it is difficult to convert pressure drop per unit time into an accurate leakage rate.

[0005] Another widely accepted testing method involves introducing gas into the ball valve with the valve element in a semi-open position, followed by blocking the open port of the valve body. The pressurized ball valve is then immersed in a container of water for a test period, during which a worker visually inspects the outer surface of the ball valve or the water surface for air bubbles. Afterward, the valve element is closed, and air pressure is applied to one side of the ball valve. The air pressure on the other side of the ball valve is then monitored to detect any pressure increase. Optionally, a bubble tube is connected to the other side, and the number of bubbles is counted. This testing method requires manual visual inspection, which depends on the worker's experience and knowledge, and requires stable workpiece and ambient temperatures. Furthermore, it is difficult to convert pressure decay per unit time into an accurate leakage rate. Moreover, the test setup is highly dependent on the stable temperature of the valve components and the surrounding environment.

[0006] A pressurized ball valve can be placed in a vacuum chamber instead of a water-filled container, and air can be evacuated from the vacuum chamber. The pressure inside the vacuum chamber is then monitored to detect any pressure increase. Afterward, the valve element is closed, and pressure is applied to one side of the ball valve. Gas is then evacuated from the other side of the ball valve, and the pressure is monitored to detect any pressure increase. This test method requires packing material inside the ball valve and in the vacuum chamber to reduce volume and test time. Furthermore, due to many potential factors that can adversely affect the test results, complex test equipment is required. Additionally, due to the test time, this method is not suitable for testing ball valves with a nominal diameter greater than 50 (DN50 and above). It also requires more test units arranged in parallel.

[0007] Vacuum chambers can be used with tracer gases (typically a mixture of helium and nitrogen). However, helium is scarce and expensive. Furthermore, helium is known to adhere to steel surfaces, which can contaminate test equipment and results, especially after an explosion or large gas leak. Therefore, cleaning of the test equipment and valve units is necessary, which is time-consuming and increases overall cost.

[0008] WO 2019 / 131536 A1 discloses a test apparatus for a partially assembled valve unit, wherein the partially assembled valve unit is disposed within the test apparatus and the valve opening is closed by clamping fixture components against the valve housing port. A housing forming a gas detection chamber is lowered above the valve stem housing portion, wherein a packer element is attached to the valve stem. The gas detection chamber housing is equipped with a gas sensor and a fan. Hydrogen tracer gas is then supplied to and pressurized into the valve housing, where an exhaust sensor monitors the internal gas pressure. Any gas leaks are detected by the gas sensor in the gas detection chamber.

[0009] As described, if no gas leak is detected, the valve unit assembly is completed, and the assembled valve unit is placed in another, larger testing device. The entire valve unit is located in another, larger gas detection chamber, where the valve stem is rotated to bring the valve element to a semi-open position. Hydrogen tracer gas is then supplied to the valve housing and pressurized, where any gas leaks are detected by a gas sensor in the larger gas detection chamber.

[0010] US2020 / 0109999A1 discloses a test apparatus for leak testing of a valve unit (e.g., a ball valve), wherein the test valve is positioned on a fixed fixture, and a cover is placed on the test valve to form an isolated inspection chamber. A gas sensor is disposed in a fixed position within the cover. A search gas is supplied to and pressurized into the test valve, where any search gas leaking from the test valve is measured by the gas sensor.

[0011] US2019 / 0302045A1 discloses a similar test apparatus for leak testing of valve units (e.g., ball valves), wherein the test valve is located in an isolated inspection chamber. Gas sensors are mounted on rotatable arms suspended from upper and lower arcuate plate elements on a cover housing. These arms are driven by servo motors to rotate from a retracted position to an extended position close to the outer surface of the test valve.

[0012] In a dissimilar technical field, WO2023 / 057107A1 discloses a leak testing method for detecting leaks at joints in a piping system within a refrigerator. A camera and light source are positioned relative to the refrigerator to determine the measurement location. A gas detection probe, positioned at the free end of a robotic arm, moves between the measurement locations to detect any tracer gases leaking from the refrigerator. This robotic system, without modified test settings, cannot be used for leak testing of ball valves.

[0013] Therefore, it is desirable to provide an improved or at least alternative method for testing valve units.

[0014] Purpose of the invention One object of the present invention is to overcome the problems of the prior art described above.

[0015] One object of the present invention is to provide a test method and test equipment that allow for automated testing of ball valves.

[0016] One object of the present invention is to provide a test method and test equipment that allows for faster and more functional testing of ball valves. Summary of the Invention

[0017] One object of the present invention is achieved by a test method for detecting leakage in a valve unit, as described in claim 1, comprising: - A valve unit is provided, the valve unit having a valve housing having a central part and two connecting ends coaxially arranged, wherein the connecting ends extend outward from the central part, wherein a valve element is disposed inside the central part, the valve element being disposed relative to at least one valve seat within the central part; - Use a spindle to seal the connection end of the valve body; - The tracer gas is supplied to the closed valve housing via at least one gas inlet, and the valve housing is pressurized; wherein - Positioning at least one gas detection probe relative to the outer housing surface of the valve housing or relative to at least one gas leakage channel in at least one spindle, the at least one gas detection probe being configured to detect tracer gas leaking from the valve unit, wherein the at least one gas detection probe is disposed on the free end of at least one robotic arm, and wherein the movement of the at least one robotic arm is controlled by a control unit.

[0018] This invention provides an improved method for testing valve unit leaks compared to traditional leak testing methods. By using tracer gas detection instead of measuring pressure increases or decreases, it provides rapid and accurate detection of both internal and external leaks. Due to the minimal number of replaceable parts in the testing equipment, this invention achieves faster changeover times. The faster testing time also eliminates the need for filling materials and vacuum chambers.

[0019] A valve unit, with at least pre-assembled valve elements and a valve seat, is simply positioned in the test equipment. The valve body is then sealed by clamping a mandrel against the connecting end. If the mandrel is not already connected, the gas supply unit and exhaust unit are connected to it. The operator can then select the type of leak test on the control unit and adjust or input the test time, test pressure, or other test parameters before starting the leak test.

[0020] The gas detection probe can be operated manually by a worker during testing, or automatically as described below. This allows for localized gas detection at potential leak points, rather than overall gas detection in a vacuum or gas detection chamber. Therefore, faster gas detection is achieved due to its smaller volume and higher mixing concentration.

[0021] In one embodiment, the valve unit is a ball valve, and the valve element is a ball having at least one through hole.

[0022] This invention is particularly suitable for leak testing of ball valves, as it is desirable to reduce downtime and accelerate the overall testing time for multiple valve units. However, this invention can also be used for leak testing of other valve unit types.

[0023] The gas detection probe can be positioned at the free end of a robotic arm, where the movement of the robotic arm and consequently the movement of the gas detection probe are controlled by a control unit. The robotic arm can have at least six degrees of freedom (6 DOF). This allows for automated movement of the gas detection probe.

[0024] A robotic arm equipped with a gas detection probe can be used for internal and external leak testing of valve units. This reduces test equipment changeover time and the total number of parts. No vacuum chamber, water chamber, or gas detection chamber is required.

[0025] The movement of the robotic arm, and consequently the movement of the gas detection probe, can be autonomously controlled by the control unit. Alternatively, a worker can control the movement of the robotic arm via a user terminal within the control unit. A single robotic arm or at least two robotic arms can be positioned relative to the valve unit within the testing equipment. This allows for localized gas detection at gas leak points or along key points on the outer surface of the valve housing.

[0026] In one embodiment, a valve element is connected to one end of a valve stem element, the other end of which is further connected to a rotating unit, wherein the valve element rotates between a first test position and a second test position.

[0027] The stem element or valve stem can be connected to an electric actuator or rotary unit, which can be controlled by a control unit. Alternatively, the valve stem can be connected to a manual rotary unit. This allows the valve element to be rotated (twisted) to a first test position or a second test position during leakage testing. The rotation of the valve element can be performed automatically by the control unit, thereby reducing manual labor during testing.

[0028] In one embodiment, before or during the supply of tracer gas, air inside at least a portion of the closed valve housing is exhausted through at least one gas outlet.

[0029] During the internal leak test, the valve element can be closed, and one side of the valve housing can be vented by the venting unit, while the other side of the valve housing can be supplied with tracer gas by a gas supply source. Once the first step of the internal leak test is completed, tracer gas can be extracted from the other side of the valve housing through the venting unit, while tracer gas is supplied to one side of the valve housing through the gas supply source. Once the second step of the internal leak test is completed, tracer gas is extracted from one side of the valve housing through the venting unit.

[0030] Alternatively, the valve element can be rotated to a second test position for an external leak test. Tracer gas can then be supplied to the entire valve housing via a gas supply source. Once the external leak test is complete, the tracer gas is extracted from the valve housing via an exhaust unit.

[0031] During internal or external leak testing, the gas pressure can be increased to and maintained at a predetermined test pressure at a predetermined test time. Furthermore, air or tracer gas in the valve housing can be vented to and maintained at a predetermined negative pressure.

[0032] In one embodiment, gas leak detection is performed automatically by the control unit.

[0033] The control unit can be programmed to autonomously perform internal and / or external leak tests, minimizing manual labor. This also reduces testing time, as the same gas detection probe is used for both tests. The flow of tracer gas and / or air evacuation can be controlled by the control unit.

[0034] In one embodiment, an internal gas leak test is performed when the valve element is in a first test position, and an external gas leak test is performed when the valve element is in a second test position, wherein the same gas detection probe is used to detect gas leaks in both the internal and external gas leak tests.

[0035] The valve element can be rotated to a first test position for internal leakage testing using the rotating unit. Furthermore, the valve element can be rotated to a second test position for external leakage testing using the rotating unit. The rotating unit can also be used to rotate the valve element to other positions, such as the closed position and the open position.

[0036] Using the same gas detection probe allows for faster switching between test settings because there is no need to replace or switch different gas detection sensors. Furthermore, changes to the flow of the tracer gas and the venting air can be performed without reconnecting the corresponding flow lines between the mandrel, gas supply source, and venting unit. Therefore, the same overall test setup can be used for both types of leak tests.

[0037] In one embodiment, the testing method further includes a step of cleaning the valve unit before and / or after detecting gas leaks in the valve unit.

[0038] After the leak test is completed, the valve housing can be cleaned using an exhaust unit and an optional separate air inlet. The air inlet can be located on the gas supply unit and connected to a streamlined system. Ambient air can be drawn into the valve housing and exhausted through the exhaust unit to remove any residual tracer gas inside the valve housing and valve elements. Optionally, clean air or another cleaning gas can be supplied to the valve housing through the exhaust unit. The air can flow through a filtration system before entering the valve housing as clean air. This allows for effective removal of tracer gas from the valve unit after the leak test.

[0039] Using tracer gas eliminates the risk of any residual water remaining in the valve unit after leak testing. Furthermore, there is no need for subsequent heating of the valve unit.

[0040] Optionally, an venting unit and an optional air inlet cleaning valve unit can be used prior to leak testing. Ambient air or clean air can be drawn into the valve housing and exhausted through the venting unit to remove any contaminants from the valve housing and valve components. This makes leak testing more reliable.

[0041] An object of the present invention is also achieved by a test apparatus for detecting leakage in a valve unit, as described in claim 8, comprising: - Spindle, configured as the connection end of the sealing valve unit; - At least one gas inlet connected to at least one gas supply source for supplying tracer gas into a closed valve housing; - At least one gas outlet connected to at least one exhaust unit for discharging tracer gas or air from a closed valve housing; wherein - The testing equipment includes at least one gas detection probe configured to detect tracer gas leaking from a valve unit, the at least one gas detection probe being disposed at the free end of at least one robotic arm, wherein the movement of the at least one robotic arm is configured to be controlled by a control unit.

[0042] This provides an improved testing setup compared to traditional testing equipment. It allows for both internal and external leak testing using the same overall test configuration. The use of tracer gas eliminates the need for large vacuum or water chambers. Compared to traditional testing equipment, this offers a simple and inexpensive testing solution.

[0043] The test apparatus includes a mandrel adapted to seal the connection end of a valve housing. At least one mandrel may be movable, allowing the valve unit to be positioned between and clamped onto the mandrels. The test apparatus includes one or two local gas supply sources, or is equipped with gas connectors for connection to an external gas supply source. The test apparatus includes one or two local exhaust units, or is equipped with gas connectors for connection to an external exhaust unit.

[0044] The mandrel, gas supply source, and exhaust unit are interconnected via a streamlined system. Individual air inlets may be provided on the test equipment, gas supply source, or exhaust unit. These air inlets can be connected to one or two mandrels via the streamlined system.

[0045] The test apparatus also includes one or at least two gas detection probes electrically connected to the control unit within the apparatus. These probes are configured to detect tracer gases leaking from the valve unit. This allows for localized gas detection instead of using a gas detection chamber. Furthermore, no dirt or welding spatter is drawn from the vacuum chamber into the valves within the test apparatus. Consequently, less maintenance is required.

[0046] In one embodiment, at least one mandrel is provided with a local gas inlet channel and a local gas outlet channel, the gas inlet channel being connected to a gas supply source and the gas outlet channel being connected to a gas exhaust unit.

[0047] The first and / or second mandrel may be provided with at least one local gas inlet passage and at least one local gas outlet passage. The gas inlet passage and the gas outlet passage may each have an inlet opening or outlet opening located on an outer surface and an inlet opening or outlet opening located on a surface facing the interior space of the valve housing. The shape of the inlet opening or outlet opening on the outer surface may be aligned with a streamlined system. This allows tracer gas and air to be supplied or extracted via the mandrel.

[0048] Some traditional testing equipment has a single channel that serves as both the inlet and outlet. Therefore, it is not possible to supply tracer gas while exhausting air.

[0049] In one embodiment, the at least one mandrel is further provided with a separate gas leakage channel having an opening on its outer surface.

[0050] The first and / or second mandrel may also be provided with at least one gas leakage passage. The gas leakage passage may have an outlet opening on the outer surface and an inlet opening on the surface facing the interior space of the valve housing. This allows for the detection of internal gas leaks using a gas detection probe. No pressure sensor is required to monitor pressure increases or decreases.

[0051] The testing apparatus may include one or at least two robotic arms, each having a free end for attaching a tool. A gas detection probe can be connected to the free end via a connector. The movement of the robotic arms can be controlled by a control unit, allowing the gas detection probe to be correctly positioned relative to a gas leak passage or the outer surface of the valve housing. This allows the gas detection probe to move automatically between possible leak points on the valve unit. In one embodiment, the testing apparatus further includes a rotating unit configured to be connected to one end of a valve stem element of the valve unit, wherein the rotating unit is configured to rotate the valve element of the valve unit between a first test position and a second test position.

[0052] A rotating unit can be connected to the first end of the valve stem to rotate the valve element. The operation of the rotating unit, and consequently the rotation of the valve element, can be controlled by a control unit. The rotating unit can be a rotary actuator, which is electrically, pneumatically, or hydraulically operated. Optionally, a local encoder or angle sensor can be used to determine the rotational position of the valve element. This allows the valve element to automatically rotate between a first test position, a second test position, and other desired positions.

[0053] In one embodiment, the control unit is configured to perform an internal gas leak test when the valve element is rotated to a first test position, and the control unit is also configured to perform an external gas leak test when the valve element is rotated to a second test position.

[0054] This testing equipment can be configured to perform internal and / or external leakage tests using the same overall test setup. Internal and external leakage tests can be performed sequentially on the same valve unit. The steps of both internal and external leakage tests can be controlled by a control unit. This achieves faster and more accurate leakage testing compared to traditional leak testing methods.

[0055] In one embodiment, the control unit is configured to automatically control the operation of the test equipment, thereby automatically performing internal gas leak tests and external gas leak tests.

[0056] The control unit can be configured to perform leak tests autonomously, thereby minimizing manual labor. Alternatively, leak tests can be performed using a semi-automatic procedure.

[0057] In one embodiment, the tracer gas is hydrogen, preferably containing 1-10% hydrogen.

[0058] The tracer gas can be inert or non-toxic, and can be safely dispersed into the surrounding air without the risk of combustion. No additional gas protection is required around the valve unit. The tracer gas can be a hydrogen-containing gas, comprising a mixture of hydrogen and nitrogen or another gas. The amount of hydrogen in the mixture can be between 1% and 10%. This allows the use of non-flammable gases, which will not adhere to steel surfaces. However, other suitable tracer gases, such as carbon dioxide, can also be used.

[0059] Therefore, the need to clean test equipment and valve units after leak testing can be reduced or even eliminated. Attached Figure Description

[0060] The invention is described below by way of example only and with reference to the accompanying drawings, wherein: Figure 1 An exemplary embodiment of the valve unit is shown. Figure 2 It shows Figure 1 A cross-sectional view of the valve unit along the longitudinal axis. Figure 3 An exemplary embodiment of a testing apparatus is shown, wherein the testing apparatus is configured for internal leak detection. Figure 4 The first gas flow of the tracer gas through the second spindle input valve unit is shown. Figure 5 The flow of tracer gas escaping from the valve unit via the second spindle is shown. Figure 6 The second gas flow of the tracer gas through the first spindle input valve unit is shown. Figure 7 The flow of tracer gas escaping from the valve unit via the first spindle is shown. Figure 8 It shows Figure 3 The testing equipment, which is configured for external leak detection. Figure 9 The third gas flow of the tracer gas through the first and second spindle input valve unit is shown, and Figure 10 The flow of tracer gas escaping from the valve unit via the first and second spindles is shown.

[0061] The accompanying drawings will be described one by one below, and the parts and locations in the various drawings will be numbered with the same numbers. All parts and locations indicated in a particular drawing are not necessarily the same as those in that drawing. Figure 1 Let's start a discussion. Specific Implementation Figure 1 An exemplary embodiment of valve unit 1 is shown, which is in the form of a ball valve, such as a floating ball valve. Valve unit 1 includes a valve body 2 made of two housing parts 2a, 2b, which are welded together along a weld 3 extending in the circumferential direction of the valve body 2. Alternatively, the valve body may be composed of a single continuous housing part.

[0063] The valve housing 2 has two connecting ends 5a and 5b attached to the central component 4, wherein the connecting ends 4 face the opposite axial direction of the valve housing 2. The shapes of the connecting ends 5a and 5b are adapted to connect to adjacent pipe sections (not shown). Here, the central component 4 is formed by the two central ends of the housing components 2a and 2b, which are welded together along a single weld 3, as shown. Figure 1 As shown.

[0064] The valve stem 7 is disposed within the valve cover 6, which protrudes from the valve body 2. The valve stem 7 extends along a radial axis, which is perpendicular to the longitudinal axis.

[0065] Figure 2 A cross-sectional view of valve unit 1 along the longitudinal axis is shown. Valve stem 7 also has a second end shaped to connect to valve element 8, which is disposed on at least one valve seat 9. In this exemplary embodiment, the valve element is formed as a sphere with at least one through-hole 10.

[0066] The valve stem 7 has a first end 7a and an opposing second end 7b. The first end 7a is shaped to be connected to a handle or actuator. The second end 7b is shaped to be inserted into and engage a stem opening 11 in the valve element 8. The valve stem 7 is configured to rotate about a radial axis and to rotate the valve element 8 between a closed position and an open position, such as... Figure 2 As shown.

[0067] Here, the central component 4' forms the central shell component, which is welded to the shell components 2a and 2b along two separate welds 3', as shown. Figure 2 As shown.

[0068] Here, the valve cover 6 is welded to the housing components 2a and 2b along weld 3'', which extends circumferentially along the valve cover 6. Alternatively, the valve cover 6 can be formed as an integral part with the central housing component.

[0069] Figure 3 An exemplary embodiment of the test apparatus 12 is shown, wherein the test apparatus 12 is configured for internal leakage detection. Here, the valve element 7 is rotated to a first test position, such as the closed position.

[0070] A first spindle 13 is disposed at the first connecting end 5a to seal the connecting end. Furthermore, a second spindle 14 is disposed at the second connecting end 5b to seal the connecting end. Thus, a closed space is formed within the valve body 2.

[0071] A first robotic arm 15, equipped with a first gas detection probe 23, is moved to a position relative to valve unit 1 or first spindle 13. Simultaneously, a second robotic arm 16, equipped with a second gas detection probe 23, is moved to a position relative to valve unit 1 or second spindle 14. The first and second gas detection probes 23 are configured to detect tracer gas leaking from inside valve unit 1. Output signals from the first and second gas detection probes 23 are input to a control unit 21, which is configured to control the movement of robotic arm 15 relative to valve unit 1 or spindles 13, 14.

[0072] The tracer gas is supplied to the closed valve housing 2 via a gas supply source 22 through at least one gas inlet. Here, the gas inlet is formed by a gas inlet passage 17 in a first spindle 13 or a second spindle 14. Furthermore, any air in the tracer gas and / or the closed valve housing 2 is extracted via at least one gas outlet passage 18 in the first spindle 13 and / or the second spindle 14.

[0073] Gas leakage passage 19 is formed in the first spindle 13 and the second spindle 14 for detecting internal gas leakage of valve unit 1.

[0074] The rotating unit 20 is connected to the first end 7a of the valve stem 7 and is used to rotate the valve element 8 during a gas leak test. The movement of the rotating unit 20 is controlled by a control unit (as shown by the dashed line) or by a manual operating handle (not shown).

[0075] Figure 4 The first airflow of tracer gas 24 is shown, which is input into valve unit 1 via second spindle 14. The tracer gas 24 is trapped within valve housing 2 between second spindle 14 and valve element 8. The pressure of tracer gas 24 increases to a predetermined test pressure and is maintained at that predetermined test pressure.

[0076] The second gas detection probe 23 is moved to a position relative to the gas leakage channel 19 of the first spindle 13. The amount of gas escaping from the gas leakage channel 19 is monitored during a predetermined test cycle. Therefore, any tracer gas leaking through the valve seat 9 or valve element 8 can be detected by the second gas detection probe 23.

[0077] Optionally, the control unit 21 determines the increase in tracer gas per unit time based on the input measurement value of the second gas detection probe 23. If the increase in tracer gas per unit time exceeds a threshold, an alarm signal may be generated.

[0078] Figure 5 The diagram shows the flow of tracer gas 24 escaping from valve unit 1 via gas outlet channel 18 through second spindle 14 after the test cycle is completed.

[0079] Before supplying tracer gas 24, it passes through the first exhaust unit (see...) Figure 8 The air trapped in the closed valve housing 2 between the first spindle 13 and the valve element 8 is discharged through the gas outlet passage 18 in the first spindle 13.

[0080] Alternatively, through a second exhaust unit (see...) Figure 8 The air trapped in the closed valve housing 2 between the second spindle 14 and the valve element 8 is discharged through the gas outlet passage 18 in the second spindle 14.

[0081] Figure 6 A second airflow of tracer gas 24 is shown, which is input into valve unit 1 via first spindle 13. The tracer gas 24 is trapped within valve housing 2 between first spindle 13 and valve element 8. The pressure of tracer gas 24 increases to and remains at a predetermined test pressure.

[0082] The second gas detection probe 23 is moved to a position relative to the gas leakage channel 19 of the second spindle 13. The amount of gas escaping from the gas leakage channel 19 is monitored during a predetermined test cycle. Therefore, any tracer gas leaking through the valve seat 9 or valve element 8 can be detected by the second gas detection probe 23.

[0083] Optionally, the control unit 21 determines the increase in tracer gas per unit time based on the input measurement value of the second gas detection probe 23. If the increase in tracer gas per unit time exceeds a threshold, an alarm signal may be generated.

[0084] Figure 7 The diagram shows the flow of tracer gas 24 escaping from valve unit 1 through gas outlet channel 18 in first spindle 13 after the test cycle is completed.

[0085] Before supplying tracer gas 24, it passes through the second exhaust unit (see...) Figure 8 The air trapped in the closed valve housing 2 between the second spindle 14 and the valve element 8 is discharged through the gas outlet passage 18 in the second spindle 14.

[0086] Optionally, through the first exhaust unit (see...) Figure 8 The air trapped in the closed valve housing 2 between the first spindle 13 and the valve element 8 is discharged through the gas outlet passage 18 in the first spindle 13.

[0087] Figure 8Test device 12 is shown, which is configured for external leakage detection. Here, valve element 7 is rotated to a second test position, such as an open or partially open position.

[0088] The first robotic arm 15 and the second robotic arm 16 are moved to their respective positions relative to the outer housing surface of the valve housing 2. Here, the first gas detection probe and the second gas detection probe 23 are configured to detect tracer gas leaking from outside the valve unit 1. Output signals from the first gas detection probe and the second gas detection probe 23 are input to the control unit 21.

[0089] The tracer gas 24 is supplied to the closed valve housing 2 by at least one gas supply source 22 via at least one gas inlet. Alternatively, the tracer gas 24 is supplied to the closed valve housing 2 via a gas inlet passage 17 of either the first spindle 13 or the second spindle 14.

[0090] Any air trapped in the closed valve housing 2 is discharged via at least one gas outlet passage 18 of at least one of the spindles 13, 14. Optionally, air in the closed valve housing 2 is discharged via the gas outlet passage 18 of either the first spindle 13 or the second spindle 14.

[0091] Figure 9 A third gas flow of tracer gas 24 is shown, introduced into valve unit 1 via first spindle 13 and second spindle 14. The tracer gas 24 is trapped within valve housing 2 between first spindle 13 and second spindle 14. The pressure of the tracer gas 24 increases to and remains at a predetermined test pressure.

[0092] One or two gas detection probes 23 are moved to a position relative to the outer housing surface of the valve housing 2. The amount of gas leaking through the valve housing 2 is monitored during a predetermined test cycle. Thus, any tracer gas leaking through housing components 2a, 2b or welds 3, 3', 3'' is detected by the second gas detection probe 23.

[0093] Optionally, the control unit 21 determines the increase in tracer gas per unit time based on the input measurement value from the gas probe 23. If the increase in tracer gas per unit time exceeds a threshold, an alarm signal may optionally be generated.

[0094] Figure 10 The diagram shows the airflow of tracer gas 24 exiting valve unit 1 via first spindle 13 and second spindle 14 after the test cycle is completed.

[0095] Before the tracer gas 24 is supplied, the air trapped in the closed valve housing 2 between the first spindle 13 and the second spindle 14 is discharged through the first exhaust unit 25 via the gas outlet passage 18 in the first spindle 13.

[0096] Alternatively, the air trapped in the closed valve housing 2 between the first spindle 13 and the second spindle 14 can be discharged via the second exhaust unit 25 through the gas outlet passage 18 in the second spindle 14.

[0097] Once the leak test is complete, the valve unit 1 can optionally be cleaned by supplying clean air (e.g., compressed air) into the valve housing 2 via the gas inlet passage 17. The air is then discharged from the valve housing 2 via the gas outlet passage 18.

Claims

1. A test method for detecting leakage in a valve unit (1), comprising: - A valve unit (1) is provided, the valve unit (1) having a valve housing (2) having a central part (4) and two connecting ends (5a, 5b), the central part (4) and the connecting ends (5a, 5b) being coaxially arranged, wherein the connecting ends (5a, 5b) extend outward from the central part (4), wherein a valve element (8) is disposed inside the central part (4) and disposed relative to at least one valve seat (9), the valve seat (9) being disposed inside the central part (4); - Use mandrels (13, 14) to seal the connecting ends (5a, 5b) of the valve body (2); - The tracer gas (24) is supplied to the closed valve housing (2) through at least one gas inlet (17) and the valve housing (2) is pressurized; in - Position at least one gas detection probe (23) relative to the outer housing surface of the valve housing (2) or relative to at least one gas leakage channel (19) in at least one spindle (13, 14), the at least one gas detection probe (23) being configured to detect tracer gas (24) leaking from the valve unit (1), wherein the at least one gas detection probe (23) is disposed on the free end of at least one robotic arm (15, 16), and wherein the movement of the at least one robotic arm (15, 16) is controlled by a control unit (21).

2. The test method according to claim 1, characterized in that, The valve unit (1) is a ball valve, and the valve element (8) is a ball having at least one through hole (10).

3. The test method according to claim 1 or 2, characterized in that, One end of the valve element (8) is connected to the valve stem element (7), and the other end of the valve stem element (7) is further connected to the rotating unit (20), wherein the valve element (8) rotates between the first test position and the second test position.

4. The test method according to any one of claims 1 to 3, characterized in that, Before or during the supply of tracer gas (24), air is discharged from at least a portion of the closed valve housing (2) through at least one gas outlet (18).

5. The test method according to any one of claims 1 to 4, characterized in that, The control unit (21) automatically performs gas leak detection.

6. The test method according to any one of claims 1 to 5, characterized in that, When the valve element (8) is in the first test position, an internal gas leak test is performed, and when the valve element (8) is in the second test position, an external gas leak test is performed, wherein the same gas detection probe (23) is used to detect gas leaks in both the internal gas leak test and the external gas leak test.

7. The test method according to any one of claims 1 to 6, characterized in that, The test method also includes the step of cleaning the valve unit (1) before and / or after detecting gas leakage in the valve unit (1).

8. A test apparatus (12) for detecting leakage in a valve unit (1) using the method according to any one of claims 1 to 7, comprising: - Mandrels (13, 14), which are configured as connection ends (5a, 5b) of the sealing valve unit (1); - At least one gas inlet connected to at least one gas supply source (22) for supplying tracer gas (24) into the closed valve housing (2); - At least one gas outlet, said at least one gas outlet being connected to at least one gas exhaust unit (25) for discharging tracer gas (24) or air from a closed valve housing (2); wherein - The test device (12) includes at least one gas detection probe (23) configured to detect tracer gas (24) leaking from the valve unit (1), wherein the at least one gas detection probe (23) is disposed on the free end of at least one robotic arm (15, 16), and wherein the movement of the at least one robotic arm (15, 16) is configured to be controlled by a control unit (21).

9. The testing equipment according to claim 8, characterized in that, At least one of the spindles (13, 14) is provided with a local gas inlet channel (17) and a local gas outlet channel (18), the gas inlet channel (17) being connected to a gas supply source (22) and the gas outlet channel (18) being connected to a gas exhaust unit (25).

10. The testing equipment according to claim 9, characterized in that, At least one mandrel (13, 14) is also provided with a separate gas leakage channel (19) having an opening on its outer surface.

11. The testing equipment according to any one of claims 8 to 10, characterized in that, The test device (12) further includes a rotating unit (20) configured to be connected to one end (7a) of the valve stem element (7) of the valve unit (1), wherein the rotating unit (20) is configured to rotate the valve element (8) of the valve unit (1) between a first test position and a second test position.

12. The testing equipment according to claim 11, characterized in that, The control unit (21) is configured to perform an internal gas leak test when the valve element (8) is rotated to a first test position, and the control unit (21) is also configured to perform an external gas leak test when the valve element (8) is rotated to a second test position.

13. The testing equipment according to claim 12, characterized in that, The control unit (21) is configured to automatically control the operation of the test equipment (12), thereby automatically performing internal gas leak tests and external gas leak tests.

14. The testing equipment according to any one of claims 8 to 13, characterized in that, The tracer gas (24) is a hydrogen-containing gas, preferably containing 1-10% hydrogen.

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