SU1585698A1 - Method of testing articles for tighteness - Google Patents

Abstract

The invention relates to the leak tightness control of hollow closed products during vacuum freezing and simplifies the testing process by eliminating the defrosting operation of the test gas. During testing, the content of test gas in the chamber is measured twice in the presence and absence of it in the tested product, leakage is judged by the difference between the two measurements, and removal of the test gas from the product is carried out by freezing. 1 il.

Description

This invention relates to a leaktightness control technique for hollow, wrinkled articles.

The purpose of the invention is to simplify the process of leak testing when evacuating products filled with test gas by freezing the test gas by eliminating the thawing operation of the test gas.

The drawing shows a diagram of a device for testing the leaktightness of a product that implements the proposed method.

The installation includes a vacuum chamber 1, in which the product 2 is placed, filled with test gas. The installation is equipped with a cooling device 3 containing a coil 4, fixed in the casing 5. The casing 5 is mounted in a vacuum chamber 1 by means of brackets 6 attached to the walls of the vacuum chamber 1. The coil 4 is provided with an inlet pipe 7 and an outlet pipe 8 for supply and discharge refrigerant. Chamber 1 is equipped with a leak detector 9, a vacuum gauge 10, a vacuum pump 11 and valves 12-18. To connect equipment and instruments to chamber 1, the installation is equipped with a sealed lead in 19-25. The chamber is equipped with a hatch 26,

The cooling device 3 is equipped with a temperature sensor 27 fixed in the chamber 1 with the aid of a bracket 28.

To control the operation of the installation is the control panel 29 control.

The method of testing products for leaktightness is as follows.

A test article 2, filled with pre-test gas, is placed through a sealed hatch 2 into a vacuum chamber 1, where it is placed in a cooling device 3 consisting of a coil 4 placed in a casing 5. and completely covering the product 2. From the console 29 it turns on vacuum pump 11, which begins to pump air from chamber 1 when valve 13 is open. The degree of vacuum in chamber 1 is controlled by vacuum 10

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five

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rum 10 with the valve 14 open. When the vacuum in the chamber 1 reaches the set value, a command is sent from the vacuum meter 10 to the control panel 29, the valve 12 is opened and the leak detector 9 is turned on

When creating a vacuum in the vacuum chamber 1. Of the product 2, a test gas enters. But at the same time, test gas (for example, carbon dioxide) :) and other gases also flow into chamber 1, the mass number of which coincides with the mass number of test gas from the atmosphere through possible leakages of chamber 1. At this stage of testing, the leak detector 9 does not detect gas from product 2, but the aforementioned additional gas supply to the internal cavity of chamber 1, constituting the background gas content, introduces an error as a result of the tests. These measurements are carried out at the steady state reading of the leak detector 9, indicating a steady state of the inflow and outflow of background and trial Gases.

After the above measurement from the control panel 29, the valves 17 and .18 are opened to supply refrigerant to the coil 4 of the cooling unit 3 to cool the product 2 and transfer the test solid state therein. The temperature of the product 2 is recorded by the sensor 27. After the specified temperature of the product 2 is reached, at which the test gas freezes, the command 27 is commanded from the sensor 27 to control 29, the valves 17 and 18 are closed and the coolant to the negative 4 is stopped. When the test gas freezes ceases to flow from product 2 into chamber 1 (product 2 is evacuated). Then, a test gas is pumped out by the vacuum pump 11, which has arrived from product 2 into chamber 1 before solidification, and during continuous pumping out the background gas content in chamber 1 is measured with stable readings of the leak detector 9.

The leakage of product 2 is judged by the difference between the first and second dimensions.

The method of testing closed products for leaktightness, conducted in this order, simplifies the testing process by eliminating the operation of defrosting the prone gas in the product.

Claims (1)

Invention Formula The method of testing products for tightness, which consists in placing the test product in a vacuum-jj background content of the test gas in the test chamber and measuring the content in the chamber test gas separately with test gas and evacuated product separately, and leakage with d t by the difference between the measured values, characterized in that, in order to simplify vacuum evacuation of the products filled with test gas, freezing is carried out after measurement with an article filled with test gas, and after freezing, the test gas is removed from the vacuum chamber and measured background sample gas content in the chamber The test gas is separated separately when the test gas is filled and the product is evacuated, and leakage is judged by the difference between the measured values, characterized in that, in order to simplify the evacuation of products filled with test gas by freezing the test gas, carried out after the measurement with a product filled with test gas, and after freezing the test gas is removed from the vacuum chamber and measured