METHOD OF DETERMINING TIGHTNESS IN STRENGTH TESTS Russian patent published in 2015 - IPC G01M3/26 

FIELD: testing equipment.

SUBSTANCE: in the method of determining the tightness of hollow products in strength tests, the test medium is supplied under pressure to the test product from the power source, and for a predetermined period of time the weight of the test medium is determined, which has leaked from the test product, for which temperature and pressure are measured upstream the control valve supplying the test medium to the product, as well as the pressure behind this valve, the position of the closure body of the control valve is measured, according to the measured position of the closure body the coefficient of carrying capacity is determined, the pressure differential on the valve is measured, the differential is divided by the amount of the pressure upstream of the valve, according to the division results the nature of the gas flow from the valve is determined, and then the instantaneous flow rate of the test medium is calculated by the formula: - for subcritical flow regime of the test medium from the control valve, and by the formula: - for supercritical flow regime of the test medium from the control valve, where the G is instantaneous flow rate of the test medium through the control valve; K_V is coefficient of carrying capacity of the control valve, depending on the position of the closure body K_v=f(x); x is the position of the closure body of the control valve; P is pressure upstream the control valve; ΔP is the differential pressure on the control valve; T is the temperature of the test medium; R is gas constant. For a specified period of time the instantaneous flow rates are averaged, and the value of leak is obtained, which characterises tightness of the test product.

EFFECT: ability to determine tightness of objects in each test cycle without distortion of loading programs, with a constructive compactness of technical means necessary for its implementation, which expands significantly the scope of the proposed method, especially when strength tests of various types of aircraft pressurised compartments.

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