SU1566239A1 - Method of checking hermetic sealing of hollow articles - Google Patents

Abstract

The invention relates to the monitoring of the leaktightness of liquid samplers and makes it possible to increase the reliability of the control by bringing the test conditions closer to full-scale ones. The openings of sampler 4 are sealed and immersed in liquid 8. Crane 3 is connected through a transparent tube 2 with an elastic chamber 7. The latter is compressed, creating test pressure in the cavity of sampler 4, uncouple the sampler 4 and chamber 7 and fix the bubbles released from the sampler 4 Then, the last is depressurized, filled with liquid, resealed and communicated with the compressed chamber 7, creating a vacuum in the cavity of the sampler 4. The leakage of the sampler 4 is additionally judged by the size of the liquid column in the tube 2 through the exposure time. 1 il.

Description

3156

The invention relates to a testing technique and allows monitoring the tightness of a fluid sampler.

The aim of the invention is to increase the reliability when monitoring fluid samplers by bringing test conditions to full-scale ones.

The drawing shows a diagram of the device for implementing the method of monitoring the tightness of hollow products.

The device contains a chamber 1 with a liquid, an optically transparent tube 2. One end of the latter is designed to be connected through the drain valve 3 to the cavity of the product - sampler 4. The latter has a plug 5 and a cover 6. The second end of the tube 2 is connected to a source of compressed gas and vacuum made in the form of an elastic elastic chamber 7. Seawater is used as the fluid 8, for example.

The method of monitoring the tightness is carried out as follows. ,

The covers 6 of the test sampler 4 are closed in air, the stopper 5 is closed and the fitting of the open drain valve 3 is connected by a tube 2 with an elastic elastic chamber 7. Immerse the sampler 4 in a low-viscosity fluid, such as seawater under atmospheric pressure, then increase pressure inside the building

Sa of the sampler 4, by sharply compressing the chamber 7 and injecting air from it into the housing of the sampler 4, close the valve 3, leaving the chamber 7 compressed. For the appearance of air bubbles

sampler 4 and chamber 7 pops. For example, when the volume of the sampler is 4 in 1 l and when the capacity of the chamber 7 in 200 ml is, this part of the injected liquid 8 is maximum 5 ml. If the body of the test sampler 4 is sealed, a further flow of fluid

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8 through the transparent plug 2 into the chamber 7 is not observed.

In the case of leakage of the sampler 4, the fluid 8 is sucked into the elastic chamber 7 and the nature of the defect of the sampler 4 is judged by the nature of the suction fluid 8 and the duration of the suction process. Thus, when the crack of the housing is observed visually, the fluid is sucked into the chamber 7 occurs within no more than 15 minutes If there is a microcrack, which was not detected during an overpressure test, at the first stage of testing, and due to the coincidence of the sign of the residual strength of the microhardness of the probe body 4 with the voltage caused by the vacuum, liquid 8 is sucked into chamber 7 for at least two hours.

The advantages of the proposed method in comparison with the known are the improvement in the quality and reliability of the control of the tightness of the samplers 4, due to the fact that, by applying vacuum to the samplers 4 immediately after the load with increased pressure, the casing is still in the state of deformation.

fluids 8, visually observed} expand the range of detected leaks.

it is judged that there are leaks caused by micro-indentations of the body of the sampler 4, in which the direction of the residual stress coincided with the intensity caused by the increased pressure applied to the body of the sampler 4.

Further, if the sample probe 4 is not removed from the liquid 8, it is opened and closed. This is indicated by control tests, which showed the following

The test for leak tightness according to the method of separately increasing pressure on each of the samplers 4 and 60 vacuum samplers 4 were subjected to vacuum alone. 56 samplers 4 withstood vacuum pressure, i.e. 56 same samplers 55, i.e. according to the previously known method, 55 of 60 samplers 4 are sealed as a vacuum. Under the subsequent exposure of each sampler 4 with vacuum immediately after exposure to elevated pressure, the test was passed from the same 55 that previously passed test 34 of the sampler 4.

covers 6 are filled, the cavity of the sampler 4 is filled with liquid 8 under atmospheric pressure, and the valve 3 is opened, thereby connecting the cavity of the sampler with the rarefied (compressed) chamber 7.

At the initial moment of time, a small part of the liquid 8 from the cavity of the sampler 4 enters the tube 2 due to pressure balance

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This is evidenced by control tests, which showed the following.

The test for leak tightness according to the method of separately increasing pressure on each of the samplers 4 and 60 vacuum samplers 4 were subjected to vacuum alone. 56 samplers 4 withstood vacuum pressure, i.e. 56 same samplers 55, i.e. according to the previously known method, 55 of 60 samplers 4 are sealed as a vacuum. Under the subsequent exposure of each sampler 4 with vacuum immediately after exposure to elevated pressure, the test was passed from the same 55 that previously passed test 34 of the sampler 4.

The application of the proposed control method made it possible to reject samplers 4 with latent defects that were not identified using the test method, separately with increased and reduced pressure.

Moreover, a further test of the reliability of the samples taken by these 34 samplers that had passed the tests 4 showed that the samples in 33 of them correspond to the control sample (the control was made with a salinometer). This demonstrates the high efficiency of control of samplers 4. This is important, because the automatic cartridge of samplers 4 contains 26 samplers 4 and periodic monitoring of their tightness, especially in the conditions of research vessel expeditions, should be simple and effective, reducing the likelihood of installation on the object samplers 4 with undetected leaks.

Simplify the implementation of the method. In the proposed method, alternating action on the body of the test sampler 4 with increased pressure and vacuum is implemented with the help of one simplest means - elastic elastic chamber 7, this allows reducing labor costs for control tests in manufacturing sampler 4 and automatic cassettes, as well as reducing forwarding costs

Editor N. Bobkova

Compiled by L.Vihl ev

Tehred M. Didyk Proofreader N. Korol

Order 1216

Circulation 442

VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35 ,. Raushsk nab. 4/5

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Claims (1)

when working at sea due to the timely detection of microcracks from aging of samplers 4, which improves the quality and reliability of hydrophysical studies. Formula invented The method of controlling the tightness of hollow products by sealing the product holes, immersing the product in a liquid, creating an excessive test pressure in the product by connecting it with a source of compressed gas and fixing air bubbles released from the product, which are indicative of the leakage of the product. In order to increase the reliability of monitoring the liquid samplers by approaching the test conditions to full-scale ones, after fixing the bubbles, the product is disconnected from the source of compressed gas tizuyut the product holes, re-seal the holes after the product is completely filled with liquid, connect the product through an optically transparent tube with a vacuum source, create a vacuum in the tube, the absolute value of which is equal to the excess test pressure, and the leakage of the product is additionally judged by tube through hold time. Subscription