METHOD FOR DETERMINING REMAINING RESOURCE OF RUBBER PACKING WASHERS USED IN OIL PIPELINE JUNCTIONS Russian patent published in 2006 - IPC G01N1/28 G01N33/44 

FIELD: technologies for researching durability properties of packing washer materials for collapsible oil pipelines.

SUBSTANCE: in the method for determining remaining resource of rubber compacting curves utilized in oil pipeline junctions, preparation of samples of given geometrical shape is performed, measurement of source hardness conditions for stretching, relative elongation during tearing, Shore hardness, temperature fragility limit, comparison of aforementioned values to given values, culling of washers, sample coefficients of which do not correspond to given values. Remaining samples are exposed to oil product after extraction from oil product samples are thermostatted, cooled down to normal room temperature, and then the same physical-mechanical coefficients are measured again with limit values. Before preparation of samples with given geometrical shape, washers are organized in batches of same manufacturing plant and production year, additionally measured are external d₁ and internal d₂ washer diameters for each batch, relative compression E_cp deformation of same washers. Their deviation from standard is calculated and culling of aforementioned washer batches is performed on basis of allowed values Δd₁, Δd₂ and E_cp, while as allowed values Δd₁, Δd₂ ≤ 3%; 25% ≤ E_cp ≤ 70%. After that remaining rings with least values of relative compression deformation E_cp are utilized to prepare geometrical samples of given geometrical shape. Remaining resource ΔT is determined from following formula: years, where k_i - coefficient, characterizing alteration of remaining resource ΔT dependently on climatic zone input of operation of rubber packing washers, is taken as i - climatic zones I₁ - II₁₂, additional information, T - average lifetime of rubber packing washers until removal from operation in accordance to technological characteristics provided by manufacturing plant and/or operation instructions, in years, T_n - period of operation of rubber packing washers since production year - marking of manufacturing plant, until moment of determining ΔT, years, f_pδ=9,4 MPa - minimally allowed value of conditional hardness for stretching after thermostatting of sample, MPa.

EFFECT: reliable trustworthiness of results of estimation of remaining resource under dynamic conditions of rubber packing washers in oil pipeline junctions with simultaneous increase of ecological safety due to decreased risk of emergency spilling of oil products.

4 dwg