SU1652843A1 - Method and apparatus for checking air-tightness of articles - Google Patents

Abstract

The invention relates to the monitoring of the tightness of closed small-sized products and reduces the energy consumption and inertia of the control, as well as simplifies the equipment used. A device 8 containing a mass spectrometry chamber 1, a nitrogen trap 2, a Lorvacuum pump 4, a high vacuum pump 6, and valves connecting them, 3, 5, 7, is inserted to isolate the internal cavity of the trap 2 from the exhaust system its depressurization. When checking the tightness, the product 15 filled with test gas is placed in the inner cavity of the trap 2, using the latter as a control chamber, with all the valves 3, 5, 7, 8 closed. Seal the cover 10 of the trap 2, turn on the pump 4 and through the valves 5 and 8, the chamber 1 and the trap 2 are pumped out. Then the pump 6 is turned on, the valves 7 and 3 are opened and, according to the leakage detector, the leaktightness of the product 15 is judged. 2 sec. Ff, 3 sg. nd (L

Description

The invention relates to a test technique, namely to the control of the tightness of closed, predominantly small objects.

The purpose of the invention is to reduce energy consumption and inertia of control and simplify the equipment used in controlling small-sized products by excluding from the vacuum system a special vacuum chamber for placing the product.

FIG. 1 shows the layout of the device; FIG. 2 shows a nitrogen trap with a piping dp supplying test gas to the product; by% tr. 3 - the same, without a vessel for liquid nitrogen.

A device for monitoring the tightness, made on the basis of a helium leak detector, contains a mass-spectrometric chamber 1 connected to the internal cavity of the nitrogen trap 2 through the first valve 3 The forvacuum pump 4 is connected via the second valve 5 by mass spectrometry. chamber 1. High vacuum pump 6 connect its input with the internal cavity of the nitrogen trap 2 through the third valve 7. and the output with the for-vacuum pump 4, which is connected to the internal cavity of the acho trap 2 through the fourth net. til 8,

Trap 2 is; opoi Slate cup 9, provided with a lid 10, which is fastened through a hermetic gasket to the bottom, p | I to flanO

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a glass of glass 9 and in which a vessel 12 for liquid nitrogen is placed.

FIG. 2 shows a standard nitrogen trap 2, on the lid 10 of which a pipeline 13 is mounted with a valve 14 for supplying test gas to the test article 15.

FIG. 3, instead of the standard lid 10 of the separate trap 2 with the vessel 12, a technological lid 16 is applied, on which a pipeline 17 is mounted with a valve 18 for supplying test gas to the test article 15.

The valve 19 connects the internal cavity of the trap 2 with the atmosphere, and the valve 20 connects the high vacuum and forevacuum pumps 6 and 4.

The method of monitoring the tightness of closed products is implemented as follows. I

In the initial state, everything is de-energized, all valves are closed. The lid 10 of the nitrogen trap 2 is removed, the test article 15 is placed in it, which is pre-filled with test gas, such as helium, and then the lid is again pulled out 10 with bolts 11 with a glass 9. The foreline pump 4 is turned on, the valves 8 and 5 are opened and pumping out the mass spectrometry chamber 1 and the trap 2, after which the valves 8 and 5 close and open the valve 20. Turn on the power supply of the high vacuum pump 6 and bring it to the operating mode. Then I open the valves 7 and 3 and, judging by the leak detector, judge the tightness of the object 15. To check the tightness of the next product 15, the valves 7 and 3 close, open the valve 19, remove the cover 10, remove the tested product 15, place the new product 15 in glass 9, the cover 10 is mounted, the valves 19 and 20 are closed, the valve 8 is opened, the trap 2 is pre-evacuated, then the valve 8 is closed and the valve 20 is opened, then the valves 7 and 3 are opened and the tightness of the product 15 is monitored. nitrogen 2 nd trap poured liquid nitrogen.

The method implemented according to the scheme shown in FIG. 2 differs from the previous one in the process of testing the tightness of the test article 15 through the pipe 13 and

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valve 14 is supplied with test gas at a predetermined pressure.

The method implemented according to the scheme shown in FIG. 3, involves the installation of a technological cover 16, equipped with a pipeline 17 and a valve 18. At that, not only small objects can be tested, but also objects whose volume does not exceed the volume of the cup 9 of the standard nitrogen trap 2 of the leak detector.

In order to increase the productivity of the control according to the schemes shown in FIG. 2 and 3, several products may be tested simultaneously. In addition, each product is supplied with an individual pipeline and a sample gas supply valve, and then the test gas is supplied alternately to each of the test products.

The use of the internal cavity of the nitrogen trap of a mass spectrometric leak detector as a vacuum chamber while monitoring the tightness of compact closed products allows:

- eliminate the need to use special chambers that were intended to accommodate the tested products;

- to reduce the energy consumption for the production of the control, since there is no need for energy supply of devices for pumping a separate vacuum chamber previously used in the prototype;

- reduce the range of technological equipment (there is no chamber, there are no vacuum hoses and pipelines that communicate the chamber with the leak detector, there is no equipment for pumping out the vacuum chamber);

- to reduce the inertia of the control (in the leak detector, the nitrogen trap is placed in close proximity to the measuring mass spectrometry chamber, which, in comparison with the prototype, shortens the path taken by the molecules of the test gas to the mass spectrometric chamber;

-reduce the complexity of the control;

- to increase the productivity of the control by eliminating the time spent on pumping out a special control chamber.

Claims (2)

1. The way to control the tightness of products, which consists in the fact that A product filled with test gas is placed in a control chamber, which is sealed, pumped out and communicated with a mass spectrometry chamber, a measure of a leak detector, with the help of the latter, the presence of a test gas is determined in the control chamber, which judges the tightness of the product, and due to the fact that, in order to reduce energy consumption and inertia of the control and simplify the equipment used in the control of small-sized products, the internal cavity of the nitrogen trap is used as a control chamber l five 2. A device for monitoring the hermeticity of products, containing a mass spectrometric chamber connected to it by its internal cavity through a first valve, a nitrogen trap, a fore vacuum pump connected to a mass spectrometric chamber through a second valve, and a high vacuum pump connected by its entrance through a third A valve with an internal cavity of a nitrogen trap, and an outlet with an input to a forevacuum pump, characterized in that it is equipped with a fourth valve that communicates the internal cavity of a nitrogen trap with a forevacuum pump. Sos. 73 2 t you 1 Fig.Z