METHOD TO ASSESS A STATE OF THE RUBBER SEALING RINGS OF THE TUBULAR CONNECTIONS Russian patent published in 2004 - IPC

FIELD: methods to study mechanical properties of sealing rings materials.

SUBSTANCE: the invention is dealt with methods to study mechanical properties of sealing rings materials of the tubular connections, for example, of "bell of pipe-type" and may be applied at setting terms of replacement of the sealing rings of the pipes connections. The method of assessment of the state of the rubber sealing rings of the tubular connections provides, that at the first stage they make preparation of samples to have the given geometrical form for taking measurements of the tensile strength conditions, of the relative elongation at breaking strength, Shore's hardness A, a friability temperature limit. Then the samples physical-mechanical parameters are measured, compared with the given values, and basing on the results of any mismatch they judge about the technical state of the sealing rings, and reject the samples, parameters of which do not meet the given figures. Then the second stage begins, at that the left samples are placed in a petroleum product and kept there for no less than 120 hours at the temperature of (70±2)° C. Then the samples are taken out from the petroleum product, subjected to thermostating treatment for no less than 72 hours at the temperature of (70±2) °C , cooled down to the ambient temperature, and their physical-mechanical parameters are measured. In case of even one parameter of each sample has a deviation from a legitimate value, the sealing rings, out of which the samples were prepared, are considered faulty. At that as the legitimate value they take a conditional breaking strength - f_рд ≤ 9.4 MPa and the relative elongation at the tensile strength as -_{εрд ≤ 111 %, Shore's hardness A - 92.4 ≤ Нд; a Shore's hardness A unit ≤ 62.1, a temperature limit of friability – Txp. д ≥ minus 24°C. The method allows reliably and comprehensively to assess the technical state and operational features of the rubber sealing rings.}

EFFECT: the invention allows reliably and comprehensively to assess the technical state and operational features of the rubber sealing rings.

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