SU1589095A1 - Method of testing articles for air-tightness - Google Patents

Abstract

This invention relates to the monitoring of the tightness of hydraulic systems and hydraulic units. The purpose of the invention is to increase reliability by taking into account the volume of the product. The product and the container of a known volume are filled with liquid up to a test pressure. Then they are connected in series with a measuring container at atmospheric pressure, and the mass of the drained liquid from the product and the container is measured. The product is then filled with a liquid under test pressure and the change in pressure is measured over a holding time. The leakage of the product is judged by the pressure change taking into account the measured mass values. 1 il.

Description

The invention relates to a testing technique and can be used in monitoring tightness and internal leakage of hydraulic units and hydraulic systems.

The aim of the invention is to increase the reliability by taking into account the volume of the product.

The drawing shows a diagram of a device for implementing a method for testing products for tightness.

The device contains a capacity of 1 dp of storing liquid, the inlet pipe. Tani with pump 2, filter 3, cranes 4-6 and drain line with a crane

7. A pneumohydraulic accumulator is connected to the injection line.

8, the pressure in which is monitored by a pressure gauge 9, as well as by means of a crane 10, a container 11 of known volume is connected. By the crane 12, the injection line is connected with the measuring tank 13, made in the form of an open glass. Quantity merged in capacity

liquids are determined using the yoses 14. The pressure in the test article 15 is controlled by a pressure gauge 16.

The method is carried out in the following way.

The volume of the container 11 is determined with a portion of the pipeline connected to it up to the crane 10 (V). This is accomplished by volumetric, weighing, or geometric calculations. Similarly, the volume of fluid in the connecting lines between the product and the taps 6 and 7 (V) is determined.

To check the tightness of the test product 15, for example a hydraulic unit, is connected to the injection and discharge lines of the test bench. The taps 4-7, 10 are opened, the pump 2 is turned on. The liquid is pumped through the product 15 until the gas is completely removed. Next, overlap the valve 7 and raise the pressure in the battery 8, the tank 11 and the product 15 to the test. The control is carried out (L

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The pressure gauge 9 is closed. The taps 4-10 are turned off, the pump 2 is turned off, the valve 12 is opened, relieving pressure from the drain pipe. Next, open the valve 10, draining the liquid from the tank

11, Determine its weight m. Shut off the valve 10. Open the valve 6 and drain the liquid into a measuring container

13 of product 15. The weight of the slurry liquid is determined. Shut off the tap

12, open the valve 5, the connection of the device with the pneumohydraulic accumulator 8. Block the valves 5 and 6,

: The product 15 is held for a given time and the pressure gauge 16 is recorded with a drop in pressure during the exposure time. The leakage is determined by the following relationship;

..U.-A-DR,

at

t.

w

where t.

m

/ if

LR

the amount of liquid displaced from the products 15 into the measuring capacity 13 the amount of liquid displaced into the measuring capacity 13 from capacitance 1 of a known volume of ka4) (the sample of the compressibility of the liquid under pressure

test;

pressure drop

during the removal of product 15.

This relationship relates to the case when the pressure in the product and in the tank is set the same before the drains. It is advisable to determine the weight of the drained portions of the liquid, rather than the volume, since this results in more accurate leakage values. The determined amount of leakage is compared with the allowable value and a conclusion is drawn on the suitability of the product 15. The volume of the internal cavity of the test product 15 is determined.

V,

, V, m

The obtained value is entered in the passport of the product 15. The operations of controlling the volume of the cavity of the product 15 are mandatory not only for hydraulic systems, but also especially for fuel units and containers.

At the end of the test, the system is reset, the product 15 is disconnected and preserved.

The use of the proposed method ensures the accuracy of the control when measuring small leaks. Technological capabilities are being expanded, as the volume of the internal cavity of the product is additionally determined or monitored. The introduction of the test method allows to reduce the omission of defective products and thereby increase the reliability of the products in operation.

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F o I

The method of testing products for leak tightness by filling the product with a liquid under test pressure, measuring the change in pressure over the time of the test, by which the product is not leaking, is about the fact that

increase the reliability by taking into account the 5 volume of the product, pre-fill the product and the container of a known volume with a liquid under test pressure, connect them with measuring containers under atmospheric pressure, and measure the mass of the drained liquid from the product and from the container, and leaks are judged based on measured mass values.

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V

Editor E. Kopcha

Compiled by L. Vikhl Ev Tehred L. Serdyukova

Order 2533

Circulation 446

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

ten

Proofreader N. Revska

Subscription

Claims (1)

Claim I The method of testing the product for tightness by filling the product with liquid under test pressure, measuring the change in pressure through the holding time, which is used to judge the leakage of the product, which can be done in order to The indicated dependence refers to the case when the pressure in the product and in the container are set equal before draining. It is advisable to determine the weight of the drained portions of the liquid, and not the volume, since this gives more accurate leakage values. A certain amount of leakage is compared with an acceptable value and give a conclusion on the suitability of the product 15. Strengthening reliability by taking into account 35 volumes of the product, they pre-fill the product and a container of known volume with liquid under test pressure, connect them to measuring tanks under atmospheric pressure, and measure the mass of drained liquid from the product and from the tank, and the leakage is judged by the measured mass values. Compiled by L. Vikhlyaev Editor E. Kopcha Tehred L. Serdyukova Corrector N. Revskaya Order 2533 Circulation 446 Subscription VNIIIPI of the State Committee for Inventions and Discoveries at the State Committee for Science and Technology of the USSR 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and Publishing Plant Patent, Uzhhorod, st. Gagarina, 101