Leak detection assembly and method for controlling same

Abstract

The invention relates to a leak detection assembly (1) comprising a leak detector (3) and a high-flow sniffer accessory (21) comprising a common pipe (22) configured to be fluidically connected to a sniffer probe (2) and, in parallel, on the one hand, to a sampling pipe (23) connected to a sniffer valve (15) of the leak detector (3) and, on the other hand, to a pumping pipe (24) connected to a gas inlet valve (8, 9) of the leak detector (3), such that, during use, the primary pumping device (6) applies suction in the sampling pipe (23) via the gas inlet valve (8, 9).

Description

Description Title of the invention: Leak detection assembly and control method. Technical field of the invention

[0001] The present invention relates to a leak detection assembly and a method for controlling the leak detection assembly. Technical background

[0002] A well-known method for checking the airtightness of an object involves performing a tracer gas "sniff test." Using a leak detector connected to a sniffing probe, the presence of tracer gas is detected around an object being tested, which is filled with the gas, usually under pressure. This method relies on detecting the passage of tracer gas through any leaks in the object. The search is carried out by moving the tip of the sniffing probe around the object, particularly in areas likely to have leaks, such as around seals.

[0003] A leak detector using the sniffing method has several important characteristics. One of these is the maximum sampling flow rate that the detector's pumping unit can handle through the probe. Indeed, the higher this sampling flow rate, the faster the sniffing probe can move around the object being tested.

[0004] To increase this collection flow, several solutions are possible.

[0005] It is possible to reduce the rotational speed of the turbomolecular vacuum pump. However, the resulting increase in the limiting vacuum pressure and the decrease in the compression ratio may preclude the use of a mass spectrometer requiring very low operating pressure.

[0006] To increase the sampling flow rate, it is also possible to connect the sniffing probe to a higher-pressure turbomolecular stage. However, this solution can lead to a loss of measurement sensitivity because the tracer gas must travel a longer path in the opposite direction to reach the gas analyzer. Summary of the invention

[0007] One aim of the present invention is therefore to provide an improved leak detection system that can, if necessary, have a high sampling flow rate for op- to reduce the chances of detecting a leak, without modifying a standard leak detector.

[0008] To this end, the invention relates to a leak detection system comprising a leak detector including: - a turbomolecular vacuum pump, - a primary pumping device, - a vacuum line fluidly connected to the primary pumping device, - at least one gas inlet valve configured to allow air to enter the vacuum line or purge gas to enter the vacuum line or the primary pumping device, - at least one fluidly connected sampling valve to an inlet of the turbomolecular vacuum pump, - at least one gas inlet valve and the sampling valve being fluidly connected in parallel to the vacuum line, - a fluidly connected sniffing valve in bypass to a portion of pipe interposed between the inlet of the turbomolecular vacuum pump and at least one sampling valve.

[0009] The leak detector may also include a discharge valve fluidly connected to an outlet of the turbomolecular vacuum pump and fluidly connected in bypass to the vacuum line.

[0010] The leak detector may also include an isolation valve arranged on the vacuum line, and interposed between a fluidly connected intersection to at least one sampling valve and a fluidly connected intersection to the discharge valve.

[0011] The leak detector may also include a gas analyzer fluidically connected to an inlet of the turbomolecular vacuum pump.

[0012] The leak detection assembly further includes a high-flow sniffing accessory comprising a common line configured for fluid connection to a sniffing probe and, in parallel, on one side, to a sampling line configured for fluid connection to the leak detector's sniffing valve and, on the other side, to a pumping line configured for fluid connection to the leak detector's gas inlet valve, so that in use, particularly in high-flow sniffing mode, the pumping device pri- The mayor of the leak detector sucks into the sampling line via the gas inlet valve.

[0013] By repurposing the existing gas inlet valve, accessible from outside the leak detector, in a standard leak detector, using the high-flow sniffing accessory, the sampling flow rate through the sniffing probe is increased without the need for an additional valve in the leak detector. The same leak detector can therefore be used without the accessory in sniffing mode, or without the accessory in vacuum mode, or with the accessory in sniffing mode with a higher sampling flow rate than without the accessory.

[0014] The leak detection system may also include one or more of the features described below, taken alone or in combination.

[0015] The high-flow sniffing accessory may include a flow reducer arranged on the pump line, such as a pilot-operated variable conductance valve configured to control the value of a flow to a predetermined value.

[0016] The high-flow sniffing accessory may include a flow reducer arranged on the sampling line, such as a controllable variable conductance valve configured to control the value of a flow to a predetermined value.

[0017] The variable conductance valve can be configured to be controlled based on information representative of the pumping load of the turbomolecular vacuum pump.

[0018] The high-flow sniffing accessory may include an additional fluidically connected air inlet valve in bypass of the pumping line.

[0019] The high-flow sniffing accessory may include an additional isolation valve arranged on the common line.

[0020] The pump line may include additional fluid connectors arranged on the leak detector and the high-flow sniffing accessory to allow fluid connection of the pump line between the leak detector and the high-flow sniffing accessory.

[0021] The sampling line may include additional fluid connectors arranged on the leak detector and the high-flow sniffing accessory to allow fluid connection of the sampling line between the leak detector and the high-flow sniffing accessory.

[0022] The common line and a sniffing probe conduit may include additional fluid connectors arranged on the high-flow sniffing accessory and the sniffing probe conduit to allow fluid connection between the high-flow sniffing accessory and the sniffing probe.

[0023] The leak detector may include a purge valve. The purge valve may be a three-way valve, the first way being fluidly connected to the vacuum line upstream of the inlet of the primary pumping device in the direction of gas flow, the second way being fluidly connected to an interstage of the primary pumping device, the third way being an air inlet, in particular accessible from outside the leak detector in particular to allow fluid connection to a source of purge gas.

[0024] A gas inlet valve of the leak detector fluidly connected to the pumping line can be the purge valve of the leak detector.

[0025] A gas inlet valve of the leak detector fluidly connected to the pumping line can be an air inlet valve of the leak detector.

[0026] The invention also relates to a method for controlling the leak detection assembly described above, in which the high-flow sniffing accessory is fluidically connected, on the one hand, to the leak detector and, on the other hand, to the sniffing probe, and in which, during testing, particularly in high-flow sniffing mode, the opening of the sniffing valve, the air inlet valve, and the isolation valve is controlled, and in particular the closing of the additional air inlet valve, if applicable, and the sampling valves. The additional isolation valve is opened, if applicable, or controlled to open, if applicable.

[0027] During testing, particularly in vacuum mode, the pressure in the object being tested or in the test chamber containing the object being tested can be returned to atmospheric pressure by opening the air inlet valve and the additional air inlet valve if applicable. Brief description of the figures

[0028] Other advantages and features of the present invention will become more apparent upon reading the following detailed, but not limiting, description of a particular embodiment of the invention, and with reference to the accompanying drawings, in which:

[0029] [Fig.1] Figure 1 is a representation of a fluidically connected leak detector to a sniffing probe in sniffing mode.

[0030] [Fig.2] Figure 2 is a representation of the leak detector of Figure 1 fluidically connected to an object to be tested in vacuum mode.

[0031] [Fig.3] Figure 3 is a schematic representation of an example of a high-flow sniffing leak detection assembly comprising the leak detector of Figure 1 fluidically connected to a high-flow sniffing accessory fluidly connected to a sniffing probe.

[0032] [Fig.4] Figure 4 is a representation of the leak detection assembly of Figure 3 fluidly connected to an object to be tested, in vacuum mode.

[0033] [Fig.5] Figure 5 is a schematic representation analogous to Figure 1 for another example of a high-flow sniffing accessory.

[0034] In these figures, identical elements bear the same reference numbers. Detailed description

[0035] The following embodiments are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. Simple features of different embodiments can also be combined or interchanged to provide other embodiments, without departing from the scope of the invention as defined by the claims.

[0036] The term "upstream" refers to an element that is positioned before another element in relation to the direction of flow of the pumped gas. Conversely, the term "downstream" refers to an element positioned after another element in relation to the direction of flow of the pumped gas.

[0037] An "object to be tested" is defined as an object or installation whose leak-tightness we wish to check.

[0038] "Restrictions" or "flow reducers" or "calibrated orifices" are orifices (variable or not) used to control the flow of gas, for example drilled rubies or variable conductance valves.

[0039] Figure 1 represents an example of a leak detector 3 for checking the tightness of an object to be tested by tracer gas.

[0040] The leak detector 3 includes a turbomolecular vacuum pump 5, a primary pumping device 6 with an inlet fluidically connected to a vacuum line 7 of the leak detector 3, a gas analyzer 4 and a set of fluid lines and valves.

[0041] The primary pumping device 6 includes at least one primary vacuum pump.

[0042] According to one embodiment, the primary pumping device 6 comprises a primary vacuum pump having at least two pumping stages in series.

[0043] According to another embodiment, the primary pumping device 6 comprises two primary vacuum pumps 60, 61, each having at least two pumping stages 601, 602, 603 in series. In the illustrative example, the primary vacuum pumps 60, 61 each have two first pumping stages 601 mounted in parallel, a second pumping stage 602, and a third pumping stage 603. The first pumping stages 601 are mounted in series and upstream of the second pumping stage 602, which is also mounted in series and upstream of the third pumping stage 603. The inlet of the primary pumping device 6 is formed by the inlets of the two primary vacuum pumps 60, 61 connected in parallel to the vacuum line 7.The outlet of one of the primary vacuum pumps 60 can be fluidly connected to the other primary vacuum pump 61, between two pumping stages 602, 603 in series of the primary vacuum pump 61, such as between the penultimate pumping stage 602 and the last pumping stage 603.

[0044] At least one primary vacuum pump is, for example, a dry vacuum pump, such as a diaphragm pump. Each pumping stage has a diaphragm driven by an eccentric, so that the movement of the diaphragm, along with inlet and outlet valves, allows the pumping of a gas.

[0045] The primary pumping device 6 may include another type of dry pump, such as a spiral pump (called "scroll" in English) or may include an oil pump.

[0046] The gas analyzer 4 is fluidly connected to an inlet of the turbomolecular vacuum pump 5, for example to its suction or to a turbomolecular stage of the pump 5. The gas analyzer 4 is for example a mass spectrometer.

[0047] The leak detector 3 includes at least one gas inlet valve, such as an air inlet valve 8 configured to allow air to enter the duct. vacuum lization 7 or such as a purge valve 9 configured to permit an inlet of purge gas into the vacuum line 7 and / or to an interstage of the primary pumping device 6.

[0048] The air inlet valve 8 is configured to allow air to enter the vacuum line 7, for example, near an inlet 10 of the leak detector 3 configured to be fluidly connected to a test object or a test chamber. The air inlet valve 8 allows, in particular, a leak detector 3 operating in vacuum mode, air to enter the vacuum line 7 for the return to atmospheric pressure after the leak test in the test chamber containing a test object and fluidly connected to the inlet 10 of the vacuum line 7, or in the test object fluidly connected to the inlet 10 of the vacuum line 7.

[0049] The purge valve 9 is configured to allow the inlet of a purge gas, such as nitrogen, into the vacuum line 7, upstream of the inlet of the primary pumping device 6, or into the primary pumping device 6, at an interstage of the primary pumping device 6. The line that fluidly connects the vacuum line 7 to the purge valve 9 may include a flow restrictor 11, such as a fixed-conductance orifice, for example, to allow an inlet flow of 50 sccm (i.e., 0.1 Pa·m). 3 / s).

[0050] According to one embodiment, the purge valve 9 is a three-way valve. The first port is fluidly connected to the vacuum line 7 upstream of the inlet of the primary pumping device 6 in the direction of gas flow, via a bypass line, optionally equipped with a flow restrictor 11. The second port is fluidly connected to an interstage of a primary vacuum pump 60, 61 of the primary pumping device 6, such as between the penultimate pumping stage 602 and the last pumping stage 603, or between two pumping stages of a primary vacuum pump. The third port is an air inlet, in particular accessible from outside the leak detector 3, notably to allow fluid connection to a source of purge gas. The fluid switching connecting two of the three ports of the three-way purge valve 9 can alternatively be achieved by two valves.

[0051] According to one embodiment, the air inlet of the purge valve 9 and the air inlet of the air inlet valve 8 are fluidly connected together inside of the leak detector 3 and are accessible from outside the leak detector via the same fluidic connector 29.

[0052] The fluid connection to at least one gas inlet valve 8, 9 is possible from outside a hood of the leak detector 3, the hood being schematically represented by dotted lines in Figure 1.

[0053] The leak detector 3 further comprises at least one sampling valve 12a, 12b, 12c fluidly connected to an inlet of the turbomolecular vacuum pump 5, for example to its suction or to a turbomolecular stage of the pump 5, and a discharge valve 13 fluidly connected to an outlet of the turbomolecular vacuum pump 5.

[0054] Two inlets of the turbomolecular vacuum pump 5 corresponding to two distinct turbomolecular stages of the turbomolecular vacuum pump 5 are for example fluidically connected to at least one respective sampling valve 12a, 12b, 12c.

[0055] At least one gas inlet valve 8, 9, at least one sampling valve 12a, 12b, 12c and the discharge valve 13 are fluidly connected in bypass to the vacuum line 7. In other words, at least one line fluidly connects the vacuum line 7 to at least one gas inlet valve 8, 9, at least one line fluidly connects the vacuum line 7 to at least one sampling valve 12a, 12b, 12c and one line fluidly connects the vacuum line 7 to the discharge valve 13.

[0056] The leak detector 3 further includes an isolation valve 14 arranged on the vacuum line 7, the isolation valve 14 being interposed between a fluidly connected intersection to at least one sampling valve 12a, 12b, 12c and a fluidly connected intersection to the discharge valve 13.

[0057] The leak detector 3 also includes a sniffing valve 15 fluidly connected in bypass to a portion of pipe interposed between the inlet of the turbomolecular vacuum pump 5 and a sampling valve 12a, 12b, 12c, in particular, the portion of pipe connected to the higher pressure turbomolecular stage.

[0058] According to one embodiment, the leak detector 3 includes a pressure sensor 16 configured to measure the pressure in the vacuum line 7.

[0059] According to one embodiment, the leak detector 3 includes a calibrated leak 17, that is to say a known standard leak of the tracer gas and a valve device 18, such as a three-way valve or two valves, allowing the calibrated leak 17 to be put into fluidic communication with an inlet of the turbomolecular vacuum pump 5 or to be isolated.

[0060] The at least one gas inlet valve 8, 9, the at least one sampling valve 12a, 12b, 12c, the discharge valve 13, the isolation valve 14, the sniffing valve 15 and the valve device 18 are, for example, solenoid valves that can be controlled by a control unit of the leak detector 3. The control unit of the leak detector 3 includes one or more controllers or microcontrollers or computers or electronic boards, with memories and programs adapted to control the solenoid valves, in particular according to the pressure measured in the vacuum line 7 via the pressure sensor 16, to start a measurement cycle or a background noise measurement of the leak detector 3 via the gas analyzer 4 and to manage a user interface of the leak detector 3, such as a remote control and / or a control panel.

[0061] In a conventional manner, the leak detector 3 can be fluidically connected to a sniffing probe 2.

[0062] The sniffing probe 2 includes a flow restrictor, for example, an orifice with fixed conductance, arranged in a conduit, to reduce the flow rate of the aspirated gas and thus allow the gas to be pumped at atmospheric pressure. At least one filter may be arranged in the conduit upstream of the flow restrictor to filter out dust. The conduit may be partially formed by a flexible section. It allows the fluidic flow of the pumped gas towards the leak detector 3 (the direction of gas flow is indicated by the arrows visible in Figures 1 to 5).

[0063] When operating the leak detector 3 in sniffing mode (Figure 1), the inlet 10 is closed and the duct of the sniffing probe 2 is fluidically connected to the sniffing valve 15, for example by connecting a fluidic connector of the sampling duct of the sniffing probe 2 to a complementary fluidic connector 30 of the leak detector 3.

[0064] During operation, the air inlet valve 8 is closed. The seal of a test object whose internal atmosphere contains tracer gas can be checked by moving the sniffing probe 2 around the test object. The gas at pressure at- The atmospheric pressure surrounding the object to be tested is drawn through the sniffing probe 2 via the open sniffing valve 15. The pumping capacity is that available at the inlet of the turbomolecular stage. A portion of the gas to be analyzed, possibly containing the tracer gas that reveals a leak, is sampled by the gas analyzer 4.

[0065] This same leak detector 3 can operate in so-called vacuum mode or by spraying (figure 2).

[0066] In this case, the inlet 10 of the leak detector 3 is connected to the internal volume of a test object A, and the presence of tracer gas is detected within the object's internal volume while the tracer gas is injected into the object. Opening the air inlet valve 8 allows air to enter the vacuum line 7. Opening the purge valve 9 allows purge gas to enter the vacuum line 7 or an interstage of the primary pumping device 6.

[0067] During operation, the air inlet valves 8, 9, sampling valves 12a, 12b, 12c, and the isolation valve 14 are initially considered closed. The user initiates a measurement cycle. The isolation valve 14, interposed between the inlet 10 and the inlet of the primary pumping device 6, opens. The pressure decreases in the vacuum line 7. When the pressure measured in the vacuum line 7 becomes less than or equal to a low-pressure threshold, for example, less than or equal to 500 Pa (or 5 mbar), the isolation valve 14 is closed. The discharge valve 13 and one of the sampling valves 12a, 12b, or 12c are opened to connect the turbomolecular vacuum pump 5 and the gas analyzer 4 to the inlet 10 of the detector 3.

[0068] A purge gas is preferably injected at the inlet of the primary pumping device 6 via the purge valve 9. The purge gas improves pumping efficiency by carrying away residual tracer gas and moisture in the gas stream drawn in by the primary pumping device 6.

[0069] The user can perform leak detection by spraying tracer gas around the object to be tested. The gas detector 4 measures an increase in tracer gas when a leak is present in the object being tested.

[0070] According to one embodiment, the inlet 10 of the leak detector 3 is connected to a test chamber containing a test object filled with tracer gas and The device searches for the possible presence of tracer gas in the test chamber. The same operation as leak detector 3 applies.

[0071] At the end of the leak test and after closing the sampling valves 12a, 12b, 12c, isolation valve 14 and the sniffing valve 15, the pressure in the object to be tested or in the test chamber containing the object to be tested can be returned to atmospheric pressure by opening the air inlet valve 8.

[0072] Figure 3 represents an example of a leak detection assembly 1 comprising a high-flow sniffing accessory 21 connected to the leak detector 3 and the sniffing probe 2.

[0073] The high-flow sniffing accessory 21 includes a common conduit 22 configured to be fluidically connected to the sniffing probe 2, more precisely to its conduit.

[0074] The common line 22 is further fluidically connected in parallel on one side to a sampling line 23 connected to the sniffing valve 15 and on the other side to a pumping line 24 connected to the gas inlet valve, here the air inlet valve 8, so that in use in high flow sniffing mode, the primary pumping device 6 draws from the sampling line 23 via the air inlet valve 8.

[0075] In one embodiment, the high-flow sniffing accessory 21 includes a flow restrictor 26 arranged on the sampling line 23. The flow restrictor 26 is, for example, configured to control a flow of a value greater than or equal to 20 sccm (0.04 Pa·m). 3 / s) and / or less than or equal to 100 sccm (0.2 Pa.m 3 / s). The flow reducer 26 is arranged between the breather valve 15 and the intersection going to the pumping line 24 and the common line 22.

[0076] In one embodiment, the high-flow sniffing accessory 21 includes a flow restrictor 27 arranged on the pumping line 24. The flow restrictor 27 is, for example, configured to control a flow with a value greater than or equal to 300 sccm (0.6 Pa·m). 3 / s) and / or less than or equal to 3000 sccm (6 Pa.m 3 / s). The flow reducer 27 is arranged on the pumping line 24, between the air inlet valve 8 and the intersection going to the common line 22 and the sampling line 23.

[0077] Flow restrictors 26 and 27 are examples of fixed-conductance orifices or controllable variable-conductance valves. The opening of the variable-conductance valves can be controlled to allow a predetermined flow rate.

[0078] In one embodiment, the variable conductance valve of the flow reducers 26, 27 is configured to be controlled based on information representative of the pumping load of the turbomolecular vacuum pump 5, such as the current or power consumed by the motor of the turbomolecular vacuum pump 5. The conductances of the flow reducers 26, 27 can thus be controlled so that the flow passing through the sniffing valve 15 is constant or substantially constant. The measurement sensitivity of the leak detection assembly 1 can then be constant regardless of the value of the flow sampled at the tip of the sniffing probe 2.

[0079] According to one embodiment, the high-flow sniffing accessory 21 includes an additional air inlet valve 28 fluidically connected in a bypass of the pumping line 24. In other words, a line fluidly connects the additional air inlet valve 28 to the pumping line 24, in particular between the air inlet valve 8 and the flow reducer 27. The additional air inlet valve 28 can be controlled, for example, by the control unit of the leak detector 3 or by a control unit of the accessory 21.

[0080] The high-flow sniffing accessory 21 may include an additional isolation valve 25 arranged on the common line 22. The additional isolation valve 25 is arranged, for example, upstream of the intersection leading to the sampling line 23 and the pumping line 24. The additional isolation valve 25 may be controllable, for example by the processing unit of the leak detector 3 or by the control unit of the accessory 21, or it may be automatic, to be controlled to close, for example, in the event of disconnection of the sniffing probe 2 in order to prevent, in particular, the pressure rise in the gas analyzer 4 or in the turbomolecular vacuum pump 5.

[0081] According to one embodiment, the pumping line 24 includes complementary fluid connectors 29 arranged on the leak detector 3 and the high-flow sniffing accessory 21 to allow the fluid connection of the pumping line 24 between the leak detector 3 and the high-flow sniffing accessory 21.

[0082] According to one embodiment, the sampling line 23 includes complementary fluid connectors 30 arranged on the leak detector 3 and the high-flow sniffing accessory 21 to allow the fluid connection of the line sampling 23 between the leak detector 3 and the high-flow sniffing accessory 21.

[0083] According to one embodiment, the common conduit 22 and the sniffing probe conduit 2 have complementary fluid connectors 31 arranged on the high-flow sniffing accessory 21 and the sniffing probe conduit 2 to allow fluid connection between the high-flow sniffing accessory 21 and the sniffing probe 2.

[0084] The high-flow sniffing accessory 21 includes, for example, a housing receiving the flow reducers 26, 27, part of the sampling line 23, part of the pumping line 24, the common line 22, the fluid connectors 29, 30, 31 and, where applicable, the additional isolation valve 25 and the additional air inlet valve 28.

[0085] The leak detector 3 described with reference to figures 1 and 2 can thus operate in high flow sniffing mode due to additional pumping through the air inlet valve 8 (figure 3).

[0086] For this purpose, the high-flow sniffing accessory 21 is connected to the leak detector 3, via the fluid connectors 29, 30 and to the sniffing probe 2 via the fluid connectors 31.

[0087] During operation, the atmospheric pressure gas surrounding the object under test is drawn through the sniffing probe 2 via the open sniffing valve 15 and additional isolation valve 25 on one side, and via the open air inlet valve 8 and isolation valve 14 on the other. The additional air inlet valve 28, if present, and the sampling valves 12a, 12b, and 12c are closed. The discharge valve 13 may be open.

[0088] The pumping capacity through the sniffing probe 2 is that available at the inlet of the turbomolecular stage where the sniffing valve 15 is connected, plus that of the primary pumping device 6 moderated by the flow reducer 27. Part of the gas sampled by the sniffing probe 2 is discharged into the primary pumping device 6. Part of the gas to be analyzed, possibly containing the tracer gas revealing a leak, is sampled by the gas analyzer 4.

[0089] The diversion of functions by the high-flow sniffing accessory 21 of the existing gas inlet valve 8, accessible from outside the detector leaking 3 into a standard leak detector 3, allows an increase in sampling flow without adding another valve in the leak detector 3.

[0090] The same leak detector 3 can thus be used without a high-flow accessory 21 in sniffing mode (Figure 1) or without a high-flow accessory 21 in vacuum mode (Figure 2), or with a high-flow sniffing accessory 21 in sniffing mode with a higher sampling flow rate than without the accessory (Figure 3). For example, it is possible to increase the sampling flow rate by more than a factor of three for a primary pumping device 6 comprising the primary vacuum pumps 60, 61 described, and by a factor of ten for a primary pumping device 6 comprising an oil vacuum pump.

[0091] This same leak detector 3 can operate in vacuum mode without disconnecting the accessory 21 (figure 4), when the high-flow sniffing accessory 21 has an additional air inlet valve 28 fluidly connected in bypass of the pumping line 24.

[0092] In this case, the operation is the same as that described with reference to figure 2 but without disconnecting the high flow sniffing accessory 21.

[0093] Indeed, at the end of the leak test and after closing the sampling valves 12a, 12b, 12c, isolation valve 14, additional isolation valve 25 and sniffing valve 15, the pressure in the object to be tested or in the test chamber containing the object to be tested can be returned to atmospheric pressure by opening the air inlet valve 8 and the additional air inlet valve 28.

[0094] Figure 5 shows another embodiment.

[0095] In this example, the gas inlet valve connected to the pump line 24 is the purge gas inlet valve 9 so that when used in high flow sniffing mode, the primary pumping device 6 draws from the sampling line 23 via the purge gas inlet valve 9.

[0096] In operation, in high-flow sniffing mode, the atmospheric pressure gas surrounding the object to be tested is drawn through the sniffing probe 2 via the open sniffing valves 15 and additional isolation valve 25 on one side and via the purge gas inlet valve 9.

[0097] The pumping capacity is that available at the inlet of the turbomolecular stage where the sniffer valve 15 is connected, plus that of the primary pumping device 6, moderated by the flow reducer 27. A portion of the gases to be analyzed ser, possibly containing the tracer gas that reveals a leak, is sampled by gas analyzer 4.

[0098] This embodiment has the advantage of leaving the air inlet valve 8 free for the vacuum detection mode.

Claims

DEMANDS [Claim 1] Leak detection assembly (1) comprising a leak detector (3) including: - a turbomolecular vacuum pump (5), - a primary pumping device (6), - a vacuum line (7) fluidly connected to the primary pumping device (6), - at least one gas inlet valve (8, 9) configured to allow air to enter the vacuum line (7) or purge gas to enter the vacuum line (7) or the primary pumping device (6), - at least one sampling valve (12a, 12b, 12c) fluidly connected to an inlet of the turbomolecular vacuum pump (5), - at least one gas inlet valve (8, 9), at least one sampling valve (12a, 12b, 12c) being fluidly connected in bypass to the vacuum line (7), - a sniffing valve (15) fluidly connected in bypass to a portion of pipe interposed between at least one inlet of the turbomolecular vacuum pump (5) and the sampling valve (12c), characterized in that the leak detection assembly (1) further comprises a high-flow sniffing accessory (21) including a common pipe (22) configured to be fluidly connected to a sniffing probe (2) and, in parallel, on the one hand, to a sampling pipe (23) fluidly connected to the sniffing valve (15) and on the other hand, to a pumping pipe (24) fluidly connected to the gas inlet valve (8, 9), so that in use, the primary pumping device (6) draws from the sampling pipe (23) via the gas inlet valve (8, 9). [Claim 2] Leak detection assembly (1) according to the preceding claim, characterized in that the high-flow sniffing accessory (21) comprises a flow reducer (27) arranged on the pumping line (24). [Claim 3] Leak detection assembly (1) according to any one of the preceding claims characterized in that the high-flow sniffing accessory (21) comprises a flow reducer (26) arranged on the sampling line (23). [Claim 4] Leak detection assembly (1) according to any one of claims 2 or 3, characterized in that at least one flow reducer (26, 27) is a controllable variable conductance valve. [Claim 5] Leak detection assembly (1) according to the preceding claim, characterized in that the variable conductance valve is configured to be controlled according to information representative of the pumping load of the turbomolecular vacuum pump (5). [Claim 6] Leak detection assembly (1) according to any one of the preceding claims, characterized in that the high-flow sniffing accessory (21) comprises an additional air inlet valve (28) fluidically connected in bypass of the pumping line (24). [Claim 7] Leak detection assembly (1) according to any one of the preceding claims, characterized in that the high-flow sniffing accessory (21) comprises an additional isolation valve (25) arranged on the common line (22). [Claim 8] Leak detection assembly (1) according to any one of the preceding claims, characterized in that the pumping line (24) comprises complementary fluid connectors (29) arranged on the leak detector (3) and the high-flow sniffing accessory (21) to allow fluid connection of the pumping line (24) between the leak detector (3) and the high-flow sniffing accessory (21). [Claim 9] Leak detection assembly (1) according to any one of the preceding claims characterized in that the sampling line (23) has complementary fluid connectors (30) arranged on the leak detector (3) and the high-flow sniffing accessory (21) to allow the fluid connection of the sampling line (23) between the leak detector (3) and the high-flow sniffing accessory (21). [Claim 10] Leak detection assembly (1) according to any one of the preceding claims characterized in that the common conduit (22) and a sniffing probe conduit (2) have complementary fluidic connectors (31) arranged on the high-flow sniffing accessory (21) and the sniffing probe conduit (2) to enable fluidic connection between the high-flow sniffing accessory (21) and the sniffing probe (2). 18 [Claim 11] Leak detection assembly (1) according to any one of the preceding claims, characterized in that a gas inlet valve of the leak detector (3) fluidly connected to the pumping line (24) is a purge valve (9). [Claim 12] Leak detection assembly (1) according to any one of the preceding claims characterized in that a gas inlet valve of the leak detector (3) fluidly connected to the pumping line (24) is an air inlet valve (8). [Claim 13] Leak detection assembly (1) according to any one of the preceding claims, characterized in that the leak detector (3) comprises a three-way purge valve (9), a first way being fluidly connected to the vacuum line (7) upstream of the inlet of the primary pumping device (6) in the direction of gas flow, a second way being fluidly connected to an interstage of the primary pumping device (6) and a third way being an air inlet. [Claim 14] Leak detection assembly (1) according to any one of the preceding claims, characterized in that the leak detector (3) comprises: - a discharge valve (13) fluidly connected to an outlet of the turbomolecular vacuum pump (5) and fluidly connected in bypass to the vacuum line (7), - an isolation valve (14) arranged on the vacuum line (7), interposed between a fluidly connected intersection to at least one sampling valve (12a, 12b, 12c) and a fluidly connected intersection to the discharge valve (13), and - a gas analyzer (4) fluidically connected to an inlet of the turbomolecular vacuum pump (5). [Claim 15] A method for controlling the leak detection assembly (1) according to any one of claims 1 to 14 taken with claim 12 wherein the high-flow sniffing accessory (21) is connected on the one hand to the leak detector (3) and on the other hand to the sniffing probe (2) and wherein during testing, the opening of the sniffing valve (15), the air inlet valve (8) and the isolation valve (14) is controlled. [Claim 16] A piloting method according to the preceding claim, taken together with claim 6, wherein during testing, the pressure in the object to be tested or in the test chamber containing the object to be tested is returned to atmospheric pressure by opening the air inlet valve (8) and the additional air inlet valve (28).

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