Method for determining remaining resource of rubber packing washers used in oil pipeline junctions

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 Ecp 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 Ecp, while as allowed values Δd1, Δd2 ≤ 3%; 25% ≤ Ecp ≤ 70%. After that remaining rings with least values of relative compression deformation Ecp are utilized to prepare geometrical samples of given geometrical shape. Remaining resource ΔT is determined from following formula: years, where ki - 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, Tn - period of operation of rubber packing washers since production year - marking of manufacturing plant, until moment of determining ΔT, years, f=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

 

The invention relates to methods for the study of strength properties of materials o-rings for collapsible pipelines (NRC), with quick coupling, and can be used in the operation of the NRC.

Quick coupling made in accordance with GOST 20772 Devices connecting to the technical means of filling, pumping, loading-unloading, transportation and storage of oil and oil products. Types, basic parameters and dimensions. General technical requirements", Moscow, Publishing house of standards, 1989, p.2, 3, 11.

In recent years more and more urgent becomes the problem of oil supply and oil regions of the Far North, Siberia and the Far East. To solve this problem have found wide application sets the NRC, providing the possibility of building a year-round transport line length of up to 150 km, the average rate of installation in the tundra ˜2.5 km per day, with the supply of 3,000 tonnes/day, the payback period of capital investment is 1 year. The application of the NRC determined by a number of advantages over welded pipelines: they have a relatively low cost structures, have the potential of rapid construction and reuse in new projects. The use of mobile connections compensates for power without istia soil and thermal deformation of the pipe, eliminating the special construction of the joints and allows to plan without prior NRC leveling areas.

Rubber o-ring is the most significant element of quick couplings, ensuring the integrity of the NRC as a whole. The seal is achieved by the pressure of the pumped fluid, which sealing edge rubber o-rings are pressed against the pipe (cuff) and the cowl, the degree of tightness increases with increasing internal pressure. In the absence of overpressure tightness is ensured by compressing the edges of the ring to the sealing surfaces during Assembly.

One of the issues for the effective implementation of the NRC is the determination of residual life of rubber o-rings, ensuring the integrity of the network as a whole.

In one set of the NRC type PMTP-150 length of 150 km are operated simultaneously to 30,000 rings. In addition to the significant cost of the rings (90000-150000$ for one set), you should consider the costs associated with the dismantling of the mounting rings during scheduled maintenance on the existing pipeline in waterlogged conditions, rugged terrain of Siberia and the Far North, as well as huge losses to emergency spills of oil and oil is Reducto on the ground (containment and collection of soil, their disposal, land reclamation, surface water purification and so on) and penalties to the polluter in case of seal failure connections use rings with depleted residual resource.

Currently used planned maintenance system replacement rings NRC (average life to retirement - 15 years "Manual of field pipelines", Military publishing house, 1968, s) does not allow to fully ensure the reliability and ecological safety of the NRC, as well as to objectively evaluate the technical condition and residual life of rubber sealing rings when operating in different climatic zones for transportation of a wide range of petroleum products, as well as their impact on the performance properties of the rings, performance, and suitability for further use in the compounds of the NRC during operation, including the step of warehousing.

There is a method of assessment of technical condition of the sealing rings (TU 38 1051962-90 "Ring rubber o-field pipelines"), including the preparation of samples of a given geometric shape, definition of conditional tensile strength, and elongation at break, hardness shore a, temperature limit of the fragility of the sample before contact with nettar what the product is and comparing that performance with a given value. Rejecting at least one of the indices from a given value of the ring are considered to be unhealthy.

The disadvantage of this method is that all the physico-mechanical parameters are determined before contact with petroleum products that adequately characterizes the state of the rings only at the stage of acceptance testing (production), while the rubber sealing rings are products of multiple use and definition of these indicators before contact with petroleum products does not take into account the main types of impacts on the properties of rubber o-rings during a typical life cycle, it is not possible to assess their condition and determine the remaining lifetime in the operation.

There is a method of assessment of technical condition of rubber products according to GOST 7338-90 Plate rubber and rubber. Technical conditions", Moscow, Publishing house of standards, p.7-11, 15-16, 19-20, which are preparing samples of a given geometric shape for measuring conditional tensile strength, and elongation at break, shore hardness, temperature limit fragility, then measure the physical and mechanical properties of the samples, compare them with the target values, the results of the error which is judged on the technical condition of the sealing rings, and excluded samples with indices do not match.

The disadvantage of this method is the determination of above to contact with oil, which does not allow to evaluate the technical condition of the seals and to determine their residual life during operation of the NRC.

The imperfection of methods of definition of indicators to assess the technical condition of the rubber sealing rings is the cause of reduced reliability and efficiency of the NRC.

The closest technical solution, taken as a prototype, is a method of assessment of technical condition of the rubber o-ring pipe connection (RF Patent No. application No. 2002123656/12 (025140) dated 05.09.2002, "Method of assessment a rubber o-ring pipe connection, the decision to grant patent for invention dated 20.01.2004 year). The known method involves the preparation of samples of a given geometric shape of the rings, the measurement of initial conditional tensile strength, and elongation at break, hardness shore a, temperature limit fragility, comparing them with predetermined values, the rejection of the rings, the indices of the samples which do not match, the exposure of the remaining samples in the oil at a temperature of (70±2)°With at least (120-2) h, termostatico the s samples after extraction of the oil at a temperature of (70± 2)°With at least (72-2) h, cooled to room temperature, the definition of the same physico-mechanical properties and comparing the measured parameters with valid values, equal to:

fp∂, MPa, ≥9,4 - conditional tensile strength;

εR∂, %, ≥111 - elongation at break;

62,1 ≤N, a unit shore a, ≤92,4 - hardness shore a;

TChr.∂that °, ≤ minus 24 - temperature limit of fragility. The disadvantage of the prototype is that the residual resource is set indirectly by the results of coordination with valid values and not defined quantitatively (years of service), are not taken into account:

climatic zoning of the territory of the Russian Federation, significantly affect the service life of rubber products (rubber goods);

the manufacturer (method of manufacture) and the year of issue;

dynamics of changes in the operation (storage) of the geometric dimensions and the relative deformation of the compression rings that define the possibility of placing the rings in the joints of pipes;

the most significant indicators of the assessment of the rings NDT methods and their rejection in case of mismatch with valid values;

residual life assessment using the principle of "weak link", including preliminary OTB is akuku, ranking and selection of rings with the lowest values of relative strain compression", adequately characterizing elastic properties;

individual duration, temperature control of samples, ancient, carved out of the ring, after exposure to petroleum products, due to their rate of evaporation of rubber at a temperature of (70±2)°due to different fractional composition of individual hydrocarbons, forming part of the pumped liquid environments, as well as the establishment of numerical values of time of incubation after exposure to work environments

conventional tensile specimens cut from the rings, as the most important characteristic (more likely to change during operation and storage rings) indicator for determining the residual life, as well as exponential law of distribution changes over the average life of the rings.

The basis of the invention is to create a new method qualification for a more accurate and comprehensive definition of the residual resource and operational properties of rubber o rings.

The technical result of the invention is to improve the reliability of the results of residual life assessment in a dynamic environment, the rubber seal is s rings in the joints of oil pipeline, with a simultaneous increase of ecological safety by reducing the risk of accidentally spilled petroleum products.

The technical result is achieved due to the fact that in the method for determining the residual life of the rubber o-rings used in the joints of pipelines, including the preparation of samples of a given geometric shape of the rings, the measurement of initial conditional tensile strength, and elongation at break, hardness shore a, temperature limit fragility, comparing them with predetermined values, the rejection of the rings, the indices of the samples which do not match, the exposure of the remaining samples in the oil at a temperature of (70±2)°With at least (120-2) h, temperature control of the samples after extraction of oil at a temperature of (70±2)°With at least (72-2) h, cooled to room temperature, the definition of the same physico-mechanical properties and comparing the measured parameters with valid values, equal to:

fp∂, MPa, ≥9,4 - conditional tensile strength;

εR∂, %, ≥111 - elongation at break;

62,1 ≤N, a unit shore a, ≤ 92,4 - hardness shore a;

TChr.∂that °, ≤ minus 24 - temperature limit fragility, according to the invention prior to the preparation of samples of a given geometric shape of the ring is formed in one factory the year, additionally measure the outer d1and internal d2the diameters of the rings of each batch, the relative deformation of the compression ESGthese rings are counting their deviation from the normative and produces rejection of batches of rings value Δd1that Δd2and ESGthe valid values take

25%≤FSG≤70%; Δd1that Δd2≤3%,

then of the remaining rings with the lowest values of relative deformation ESGprepare samples of a given geometric shape, and the residual life determined by the following dependencies

where ΔT is the residual life, years;

ki- coefficient, which characterizes the change in residual life ΔT depending on the climatic region of the i operation of the rubber o-rings accept:

i - climate areas I1II12(reference data);

T is the average service life of rubber sealing rings to the cancellation (according to the specifications of the manufacturer and/or user guide), years;

Tn- the period of operation of rubber sealing rings with year of release (marking of the manufacturer) before determining ΔT, years;

fp∂=9,4 MPa - minimal is valid but the value of the conditional tensile strength of the sample;

fpj- the value of the conditional tensile strength after temperature of the sample MPa.

In addition, the technical result is achieved by the fact that when used as a medium jet or diesel fuels temperature control of the samples after soaking in oil at a temperature of (70±2)°To provide for (120-2) h, and that when used as a medium of oil, prepared for the transportation of temperature control of the samples after soaking in oil at a temperature of (70±2)°To provide for (168-2) PM

Figure 1 presents the block diagram of the method for determining the residual life of the rubber o-rings used in the connections of oil pipelines;

figure 2 - rubber sealing ring mark R. 150;

figure 3 - sample in the form of bilateral blades, carved out of the ring, to define condition tensile strength (fpand relative elongation at break (εp) with indication of the geometric dimensions;

figure 4 is a graphical dependence of changes in the rate of conditional tensile specimens cut from rubber o-rings after operation in different climatic zones: temperate cold I1II4moderately warm II5II8, hot dry-II9II12.

Rubber sealing ring has a profile reminiscent of the "swallow's tail" (figure 2). Geometrical dimensions of the ring - external d1and internal d2diameters, as well as their deviation Δd1and Δd2from the set are crucial when installing the rings on the cuff or in the flare pipe connections.

Relative deformation compression ESGallows to estimate the elastic properties of the sealing rings.

The presented algorithm (figure 1) numbers from 1 to 28 indicated stages (operations) of the method for determining the residual life of the rubber o-rings used in the joints of oil pipeline.

To justify operating parameters temperature after aging in various petroleum studies were performed on samples widely produced of rubber sealing rings on the following parameters that characterize the physical condition of the rings: the conditional tensile strength fpcharacterized by extreme resistance to mechanical destruction; elongation at break εpallows, directly or indirectly, to evaluate highly elastic and elastic properties of rubber when exposed to strain tensile, compression, bending, shear and others; shore hardness a N characterizes the resistance is tulemast material impact point load, the combination of the elastic properties and the modulus of elasticity; temperature limit of the fragility of TXPcharacterizes the resistance of rubbers, operation rings NRC in different climatic zones.

Set (table 1)that the time of incubation of the samples until complete evaporation of the working environment (stabilization of the values of the physico-mechanical) for various petroleum products is: motor gasoline - (72-2) h; diesel and jet fuel (120-2) h; oil - (168-2) PM

The authors determined that the most significant indicator prone to change during the service life of rubber sealing rings, is conditional tensile strength fp. The dynamics of the conditional tensile strength of samples cut from rubber o-rings after operation in various climatic regions according to GOST 16350 "the Climate of the USSR. Zoning and static parameters of climatic factors for technical purposes," presented on figure 4. It is established that the most intensive decrease in nominal tensile strength relative to its original value (13,0 MPa) occurs in areas of operation with hot and dry climate (dependence), while in areas of moderate warm (dependence "b") and cold climate (dependence "and") firmly the local properties fall within acceptable values (f p∂=9,4 MPa, the dependence d) 2-3 times slower.

Based on the results of the research of the rings are in operation in different climatic zones, revealed that to determine the residual life must be considered conditional tensile strength. Studies have allowed to determine the coefficients of the change of the residual resource depending on the climatic region of operation:

Thus, the method of determining the residual life of the rubber o-rings used in the joints of pipelines, is that in addition enter the stages presented in figure 1:

the formation of groups of similar products - ranking parties rings on years of production and manufacturing (production method) - stages 2, 3;

NDT - diagnostics of a technical condition on the most important indicators characterizing the geometric and elastic parameters of the rings (the outer dimension d1internal d2diameters, the relative deformation ESG- steps 4, 5, 6;

assessment of technical condition and reject lots of rings on the results of the error with valid values changes outside Δd1and vnutrennih the Δ d2diameters, the relative deformation ESGduring operation and storage (Δd1that Δd2>3%, 25%>FSG>70%) - stages 7, 8, 9;

the selection of rings with the lowest allowable values of relative deformation of the compression stage 10, making them samples of a given geometric shape - stage 11, the definition of the baseline (step 12) conditional tensile strength, and elongation at break, hardness shore a, temperature limit of fragility - stages 13, 14, 15, 16;

comparison of indicators with target values - stage 17 and the rejection of batches of rings on the results of the error with the given values (fp<11.8 MPa; εp<130%; 69>N, unit shore A>84; TXP>-30° (C) stage 18;

extract the remaining samples in the oil for (120-2) hours at a temperature of (70±2)°and thermostatic control of temperature (70±2)°With within the specified period of time (step 19), caused by the evaporation rate of individual hydrocarbons included in liquid environments:

the gasoline - (72-2) h;

diesel and jet fuel (120-2) h;

oil, prepared for the transportation - (168-2) h;

the definition of indicators after incubation (stage 20) nominal tensile strength fpjrelative elongation at times is ive ε pj, shore hardness A Hjtemperature limit of the fragility of Txpj- stages 21, 22, 23, 24;

comparison of the parameters obtained after incubation with valid values (step 25) and the rejection of batches of rings on the results of the error with dopustimij values (fpj<a 9.4 MPa; εpj<111%; 62,1>Hj, a unit shore A>92,4; Txpj>minus 24° (C) stage 26;

determination of residual life ΔT and make recommendations to the consumer - stages 27, 28.

The method is implemented as follows.

Example 1. In stock, Tyumen (climatic region is moderately cold, II4, kII 4=3) kit collapsible pipeline in unheated room in boxes stored rubber sealing rings, 1991, 1993, 1996 and 1999 release received from Kursk and the Ural manufacturers RTI. Rubber o ring P-150 Kursk plant RTI made by casting under pressure, and the Ural plant of rubber - molding method.

To determine the residual life of the rings, stored, perform sorting of the rings to form parties (3000 PCs) manufacturers and years of production. Sorting is done on the basis of embossed marks printed on the outside surface of the ring and containing a designation of the rings, Tova is tion of the manufacturer and year of manufacture (figure 2).

To measure external d1internal d2diameters and relative deformation ESGparties select 20 piece of rings each manufacturer and year of manufacture. Measured values of d1d2and ESGknown methods, calculated as the percent deviation of the diameters of the rings (Δd1that Δd2from their normative values (table. 2, 3), comparing the obtained values of ESGthat Δd1that Δd2with a valid, defined experimentally:

25%≤FSG≤70%; Δd1that Δd2≤3%.

When the misalignment of at least one of the valid values produces rejection of all the investigated party rings. Test results determined that the ring of the Kursk plant edition 1991(№№2, 3, 12, 14, 17) and the Ural plant 1991 (№№6, 8, 10, 12, 14, 16, 17, 18, 20) and 1993 (No. 7, 16) years of release have excess deviation geometric dimensions Δd1that Δd2and / or relative compressive deformation ESG and all are subject to rejection. Marriage party rings Kursk plant 1991 and Ural plant 1991, 1993 release.

Under Δd1that Δd2and ESGvalid values of the remaining colesanti (Kursk plant 1993, 1996, 1999 the ODA issue and Ural plant of 1996, 1999 issue) take not less than 7 PCs. (with probability q=0.95, and RD 50-690-89 "guidelines. Reliability in engineering. Methods of estimating reliability parameters from experimental data".- M.: Izd. standards, 1990, p.15-16) with lower values of compressive deformation 25%<FSG<70% (marked in the table. 2 and 3), made of samples of a given geometric shape to determine the source of performance - contingent tensile strength fp0relative elongation at break εp0, shore hardness And H0temperature limit of the fragility of THR.

Samples for the determination of physical-mechanical indicators are manufactured in accordance with the requirements of GOST 269-66 "rubber. General requirements for physical and mechanical tests and standards in the method of determining the index (cutting blanks of the desired thickness is produced from the rings, and the cutting of samples from them is shancevym knife, the shape and size of which is determined by the configuration of the sample and measured by indicator):

conditional tensile strength and elongation at break according to GOST 270-75 "rubber. The method of determining uprugoopticheskii tensile property" is determined on samples in the form of bilateral shoulder blades, the form of which is shown in Fig. 3, the total length L=115 mm, width W is some part=(25± 1,0) mm, length of the work area 1=(25±0,5) mm and a width of narrowest part b=(6,0+0,4) mm. the Essence of the method consists in stretching the sample at a constant speed until the gap and measuring the strength and elongation of the sample at the moment of rupture;

hardness shore a according to GOST 263-75 "rubber. Method for determination of hardness shore" is defined on the plate with parallel planes. The essence of the method consists in measuring the resistance of the sample to dive into it indenter;

temperature limit fragility according to GOST 7912-74 "rubber. Method of determining the temperature limit of fragility" is determined on samples in the form of strips with a width (6,0±0,5) mm and a length of 25 mm, the Essence of the method consists in determining the highest temperature at which a cantilever and the cooled sample is subjected to bending upon impact with constant speed, is broken or cracked.

Identifying the source of physico-mechanical properties of the samples (table. 4, 5) and comparing them with the set:

fP0,MPa,≥11,8;

εP0,%,≥130;

69≤N0, a unit shore a,≤84;

Txp.0that °C ≤ minus 30,

rejected samples, physical and mechanical properties which do not match the specified values, and, accordingly, party rings, of which the prepared samples (Kursk plant 1993, Ural plant 1996). The remaining education is s, suitable for show, put in fuel TS-1, heated to a temperature of (70±2)°and at this temperature was kept for (120-2) PM

After extraction from the fuel TS-1 samples thermostatic at a temperature of (70±2)° h for (120-2) hours after their temperature is cooled down to room temperature, then determine the values of the same physico-mechanical characteristics of known methods (table 6,7) and compared with permissible values:

fpj, MPa, ≥9,4;

εpj,%≥111;

62,1≤,addara, ≤92,4;

Txp.jthat °C ≤ minus 24.

When the misalignment of the results obtained with valid values reject the investigated party rings. Set (table 6, 7)that the physico-mechanical properties of all samples after incubation correspond to valid requirements. To calculate the residual life choose the smallest value of the conditional tensile strength after temperature fpj. Determine residual life AT ring (Kursk plant 1996, 1999, and Ural plant of 1999 release) according to the following dependence

years

Kursk plant RTI:

ΔT1996=3(15-8)ln10,1/,4=2 years;

ΔT1999=3(15-5)ln12,8/9,4=9 years.

Ural plant of rubber:

ΔT1999=3(15-5)ln10,4/9,4=3 years.

According to the results of tests of specimens cut from rubber o-rings P-150 stored in the composition of the collapsible pipeline PMTP-150 in Tyumen, found that physical and mechanical properties of the material rings are within acceptable values and can be maintained (stored) within:

2 years for rings 1996 and 9 years 1999 issue of the Kursk plant RTI;

3 years for rings 1999 issue of the Ural plant of rubber, then these rings will be written off and disposal of the established order.

Example 2. To determine the residual life of a rubber o-ring P-150, operated as part of the initial section (length 17 km and 3000 pipe joints) collapsible pipeline the Talakan-Vitim in the Republic of Sakha (Yakutia) for eight years for oil pumping carry out the dismantling of 20 randomly selected compounds "Bell". Rubber sealing ring (20 PCs extracted from the socket ends of the pipe segments and marking on the outside surface of the ring determine the manufacturer and year of manufacture (figure 2).

It is determined that the ring is made in Saransk plant RTI in 1996 by casting under pressure is receiving

Measured values of d1d2and ESGknown methods, calculated as the percent deviation of the diameters of the rings (Δd1that Δd2from their normative values (table. 8), comparing the obtained values of ESGthat Δd1that Δd2valid:

25%≤FSG≤70%; Δd1thatΔd2≤3%.

Test results determined that all rings correspond to the allowed values.

Take 7 pieces of rings with lower values of compressive deformation 25%≤FSG≤70% (observed*in table. 8), made of samples of a given geometric shape to determine the source parameters.

Identifying the source of physico-mechanical properties of the samples (table. 9) and comparing them with the set: fp0, MPa,≥11,8; εP0, %, ≥130; 69≤N0, a unit shore a, ≤84; Txp.0that °C ≤ minus 30, it was found that the obtained values correspond to the allowed values.

The sample is placed in the Talakan oil field, at a temperature of (70±2)°and at this temperature was kept for (120-2) PM

After extraction of the oil samples thermostatic at a temperature of (70±2)°h for (168-2) hours after their temperature is cooled down to room temperature, then determine the values of the same physico-m is a mechanical indicators of well-known methods (table. 10) and compared with permissible values: fpj, MPa, ≥9,4; εpj, %, ≥111

62,1≤Hj, a unit shore a, ≤92,4; Txp.jthat °C ≤ minus 24.

19
Table 8

The results of the tests of the rings R 150 Saransk plant RTI selected from the initial phase of a collapsible pipeline "Talakan-Vitim"
№ p/pYear
1996
d1mmΔd1,%d2mmΔd2, %ESG, %
Norma188,23,00155,03,0025-70
1to 188.80,32155, 2mm0,1355
2EUR 188.40,11155,90,6057
3RUR 188.60,21155,60,3756
4188,50,16of 156.61,0553
5189,80,87155, 2mm0,1351*
6188,9 0,38was 155.30,1950*
7190,41,17155,40,2658
8190,81,38154,1-0,6155
9192,02,02of 156.61,0659
10of 188.30,05156,00,6550*
11191,81,91155,40,2651*
12188,50,16155,90,5656
13EUR 188.40,11155,50,3261
14188,20,00157,2the 1.4459
15to 190.51,22157,01,2957
16192,62,34155,40,2346*
17RUR 188.60,21155,80,5248*
18188,90,37156, 3mm0,8547*
RUR 188.60,21156,00,6550*
20190,91,43155,80,5255

Table 9

The results of determining the source of physico-mechanical characteristics of the samples of rings R 150 Saransk plant RTI
№ p/pYear
1996
fp0, MPaεp0, %H0, a unit shore aTHRthat °
Set valueNot less 11,8At least 13069-84Not above 30
114,015581-31
214,915780-33
314,515078-35
414,915580-32
514,315879-30
615,015582-30
7 15,515080-33
Table 10

The results of determination of physical and mechanical properties of samples of rings R 150 after thermostating Saransk plant RTI
№p/pYear
1996
fpj, MPaεpj, %Hj, a unit shore aTxp.jthat °
Valid value : Not less 9,4No less than 11162,1 to 92.4Not above 24
113,513088-29
214,113787-27
313,985-29
413,112588-27
514,313887-28
613,013590-28
713,112988-27

Set (PL. 10)that the physico-mechanical properties of all samples after incubation correspond to ultimum requirements. To calculate the residual life choose the smallest value of the conditional tensile strength after temperature fpj. Determine residual life ΔT for rings according to the following dependence

Saransk plant RTI:

ΔT1996=3(15-8)ln 13,0/9,4=7 years.

According to the results of tests of specimens cut from rubber o-rings P-150, operated as part of a collapsible pipeline "Talakan-Vitim", it is established that the physical-mechanical characteristics of the material rings are within the allowable limits and can be operated to pump oil within the period not exceeding 7 years, after which these rings should be replaced and utilization of the established order.

Using the claimed method, the authors were able to precisely determine the residual life of the sealing rings, which ensured reliable operation NRC Talakan-Vitim for 8 years. For the entire period of operation, the NRC had no accidents and malfunctions associated with the spill and pollution.

Thus, the method of determining the residual life of the rubber o-rings used in the joints of pipeline adequate to assess the health and remaining life of rubber sealing rings, in the process of exploitation the AI to improve reliability, environmental safety and efficiency of the NRC.

The invention can be used to determine the technical condition for newly manufactured rings (new), for rings, stored, and former or operating when you are defining their residual life. This non-destructive methods have received a valid (acceptance) values

25%≤FSG≤70%; Δd1that Δd2≤3%

and mathematical calculation formula for determining the residual life of rubber sealing rings taking into account climatic regions and year specific plant.

Sources of information

1. GOST 20772-81 Device mounting technical means for filling, pumping, loading-unloading, transportation and storage of oil and oil products. Types, basic parameters and dimensions. General technical requirements, Moscow: Publishing house of standards, 1989, p.2, 3, 11.

2. Manual of field pipelines, Moscow: Military publishing house, 1968, s.

3. THE 38 1051962-90 Ring rubber o-field pipelines, DF, VNIMI, 1990, p.7-9.

4. GOST 7338-90 Plate rubber and rubber. Specifications, Moscow: Publishing house of standards, 1990, p.7-11, 15-16.

5. RF patent for application No. 2002123656/12 (02510) dated 05.09.2002, Method of assessment a rubber o-ring pipe connection. The decision to grant patent for invention dated 20.01.2004, (prototype).

6. GOST 16350-80 the Climate of the USSR. Zoning and statistical parameters of climatic factors for technical purposes, Moscow: Publishing house of standards, 1986, 2-3.

7. RD 50-690-89 guidelines. Reliability in engineering. Methods of estimating reliability parameters from experimental data, Moscow: Publishing house of standards, 1990, p.15-16.

8. GOST 269-66 rubber. General requirements for physical and mechanical tests, Moscow: Publishing house of standards, 1980, p.1-2.

9. GOST 270-75 rubber. The method of determining uprugoopticheskii tensile property, Moscow: Publishing house of standards, 1980, p.1-2.

10. GOST 263-75 rubber. Method for determination of hardness shore a, Moscow: Publishing house of standards, 1975, p.1-2.

11. GOST 7912-74 rubber. Method of determining the temperature limit of fragility, Moscow: Publishing house of standards, 1974, p.1.

1. The method for determining the residual life of the rubber o-rings used in the joints of pipelines, including the preparation of samples of a given geometric shape of the rings, the measurement of initial conditions tensile strength, and elongation at break, hardness shore a, temperature limit fragility, comparing them with the set is passed by value, the rejection of the rings, the indices of the samples which do not match, the exposure of the remaining samples in the oil at a temperature of (70±2)°With at least (120-2) h, temperature control of the samples after extraction of the oil at a temperature of (70±2)°With at least (72-2) h, cooled to room temperature, the definition of the same physico-mechanical properties and comparing the measured parameters with valid values, equal to: fp∂MPa≥9,4 - conditional tensile strength, εp∂,%≥111 - elongation at break, 62,1≤N, a unit shore a,≤92,4 - hardness shore a, TChr.∂that °, ≤ minus 24 - temperature limit fragility, characterized in that prior to the preparation of samples of a given geometric shape of the ring is formed in one of the manufacturer and year of manufacture, additionally measured of the outer d1and internal d2the diameters of the rings of each batch, the relative deformation of the compression ESGthese rings are counting their deviation from the normative and produces rejection of batches of rings value Δd1that Δd2and ESGthe valid values take Δd1that Δd2≤3%; 25%≤FSG≤70 %, after which the remaining rings with dimensionname relative compressive deformation E SGprepare samples of a given geometric shape, and the residual resource ΔT is determined by the following dependencies:

where ki- coefficient, which characterizes the change in residual life ΔT depending on the climatic region of the i operation of the rubber o-rings accept:

i - climate areas I1II12, reference data;

T is the average service life of rubber sealing rings to the cancellation according to the specifications of the manufacturer and/or user guide, years;

Tn- the period of operation of the rubber o-rings from the year - mark of the manufacturer, before determining ΔT, years;

fp∂=9,4 MPa - the minimum value of the conditional tensile strength of the sample;

fpj- the value of the conditional tensile strength after temperature of the sample MPa.

2. The method according to claim 1, characterized in that when used as a medium jet or diesel fuel temperature control of the samples after soaking in oil at a temperature of (70±2)°To provide for (120-2) PM

3. The method according to claim 1, characterized in that when used as a medium of oil,prepared for the transportation, temperature control of the samples after videri in oil at a temperature of (70±2)°To provide for (168-2) PM



 

Same patents:

FIELD: agriculture, in particular, dairy farming.

SUBSTANCE: method involves determining tightening of teat cup liner before it is inserted into teat cup; acting upon teat cup liner by suspending weight for determining tightening of teat cup liner; providing expansion by introducing internal gauge into teat cup liner which is positioned within teat cup casing. Method allows extent of teat cup liner tightening to be visually detected at any time of machine milking process. Tightening of teat cup liner manufactured integral with milk pipe as well as separately therefrom is determined during operation of milking units.

EFFECT: increased efficiency and reduced milking time.

1 dwg

FIELD: methods and devices for determination of an alcohol concentration in solutions.

SUBSTANCE: the invention presents a method of determination of an alcohol concentration in solutions (versions) and a device for its realization (versions). The first version of the method provides for placement of a bath with the reference and investigated solutions on the path of the optical beam, measuring and introduction into the memory of the computation unit of intensity of the light absorption by the reference solutions, measuring of the intensity of the light absorption of radiation of the investigated solution, processing the data of the measurements of the light absorption. The investigated solution is transilluminated within the range of the wavelengths of 1250-1350 nanometers. Simultaneously with the measurement of the light absorption by the investigated solution measure the concentration of alcohol in it. In compliance with the received values determine a concentration of alcohol in the investigated solution. The second version of the method provides for placement of a bath with the reference solutions and investigated solutions on the path of the optical beam, measurement and introduction into the memory of the calculation device of intensity of the light absorption of radiation by the investigated solution, processing of the received values of the measurements of the light absorption. The investigated solution is transilluminated within the range of the wavelengths of 1250-1350 nanometers, measure the values of density of the reference solutions and the investigated solution, using which determine the concentrations of alcohol and sugar in the investigated solution. The device for the first version contains a computation unit, a conjunction unit, optically coupled a radiating unit, a bath for solution, a measuring photoreceiving device, the output of which is connected through the conjugation unit with the computation unit and the input of which is optically connected through the bath with the radiating unit. The device for measurement of a concentration of sugar in a solution consists of a beam splitter plate and an additional photoreceiving device, the output of which is connected through the conjugation unit with the computation unit. The input of which is optically connected through the beam splitter plate mounted at Brewster's angle to a axis of radiation and the bath with by a radiation unit. And the radiation unit has the wavelength of radiation laying within the range of 1250-1350 nanometers. The device for determination of a concentration of alcohol in the solutions consists of the computation unit, the conjugation unit, the optically connected radiation unit, the bath for solution, the measuring photoreceiving device, output of which is connected through the conjugation unit with the computation unit, the density gage connected with the bath by means of the pipe duct. The output of the density gage is connected through the conjugation unit with the computation unit. The radiation unit has the wavelength of radiation laying within the range from 1250 to 1350 nanometers. The invention allows to improve accuracy of measurements.

EFFECT: the invention ensures an improved accuracy of measurements.

12 cl, 5 dwg

FIELD: fur industry, in particular, method for evaluating pickling quality of leather web in tanning of fur and sheepskin raw material.

SUBSTANCE: method involves determining quantitative pickling characteristic of leather web of semi-finished product by using time of solving thereof in alkaline solutions, said time depending on number and kind of intermolecular bindings destructed during pickling. Solving of collagen in alkaline solutions depends upon nature of preliminary acidic preparing procedure. Solving is provided in aqueous solution of potassium hydroxide having concentration of 150 g/l and temperature of 18-20 C. Derma solving time is found after preliminary thermal processing at temperature of 60-65 C during 1.5 hours. Method may be employed both in production of fur and sheepskin products and in fur processing.

EFFECT: wider operational capabilities and reduced time for determining quantitative pickling characteristic of skin web.

1 tbl, 1 ex

FIELD: fur industry, in particular, method for evaluating pickling quality of leather web in tanning of fur and sheepskin raw material.

SUBSTANCE: method involves providing testing on parallel groups of fur sheepskin after pickling on three topographic portions of sheep skin surface: skirt, spine and neck portions; processing samples of each group with acid-salt solution for 24 hours; withdrawing sheepskins of each group from acid-salt solution in predetermined time intervals; removing excessive liquid; placing said samples into tensile testing machine and stretching lengthwise of spine line by 40% relative to initial length thereof; holding samples in stretched state for 1 min and withdrawing from tensile-testing machine; leaving samples in free state for 10 min; determining residual elongation value in mm.

EFFECT: reduced time for determining quantitative pickling characteristic of skin web.

2 tbl, 2 ex

The invention relates to methods for the study of strength properties of materials o-rings pipe connections, for example, type “Socket” and can be used to determine the timing of replacement of sealing pipe joints

The invention relates to the field of fur industry, textile, garment industry, and agriculture and is used for determining the density of hair natural and artificial fur when research on the stages of sorting, quality assessment

The invention relates to the field of measuring and test equipment, particularly to a device for measuring the local pressure on the human body, provide compression elements and clothing from elastic materials

The invention relates to the textile industry and can be used to estimate properties of pile materials

The invention relates to the analysis of epoxy resins, namely the determination of hydroxyl groups in the epoxy resin

FIELD: technologies for finding mineral resources, possible use during geological and technological research.

SUBSTANCE: method for finding and estimating quality of mineral resource, including splitting of finding sample onto four fractions: large, heavy-concentrate, average - tails and light, small - slurry, finding therein of negative and positive searching indicating signs and characteristics, estimation of search direction by growth of positive and decrease of negative searching indicator signs and characteristics. As searching indicating signs detection is utilized in searching samples of mineral particles with dissipated form of finding of useful elements, when useful elements are present in mineral particles in small amounts, as an admixture, and with own mineral form and when useful elements are included in main composition of mineral particle. As finding indicating technological characteristics values are utilized, characterizing distribution of these forms among fractions.

EFFECT: possible detection of deposit of light rare-earth elements present in dissipated, soluble form, possible detection of deposit of rare-earth elements.

16 cl, 5 dwg

FIELD: engineering of equipment for taking samples of liquid from pipelines, possible use in oil industry and other industrial branches, where high precision of admixture separation is required.

SUBSTANCE: device for holding sample-taking pipe of slit type on pipelines for liquid includes elements of sample-taking pipe body, flange fixture on mounting branch pipe of output assembly on top of pipeline and sample draining line. Sample-taking pipe of slit type synchronization equipped with second holding assembly, positioned on opposite side of pipeline oppositely to output assembly and made in form of socket with holding elements for supporting ending, provided on body of sample-taking pipe. Fixture on output assembly is mad adjustable in connection of body of sample-taking pipe with intermediate disk, held tight between flanges of mounting branch pipe and sample draining line.

EFFECT: improved mounting precision of sample-taking pipe due to possible correction of its alignment during assemblage and following technical maintenance.

5 dwg

FIELD: medicine.

SUBSTANCE: method involves determining water contents in cadaver muscle tissue not exposed to open fire action, muscle tissue mass before and after drying and antemortem ethanol concentration from formula AMEC = PVC*100%/(100%-(CTWC-M2*100%/M1)*K), where AMEC is the antemortem ethanol concentration in ‰; PVC is the postvital ethanol concentration in ‰; CTWC is the cadaver muscle tissue water contents in ‰; M2 is the muscle tissue mass after drying in mg; M1 is the muscle tissue mass before drying in mg; K is the coefficient equal to 2.11.

EFFECT: high accuracy of the method.

1 tbl

FIELD: veterinary, in particular production of anatomy preparations.

SUBSTANCE: claimed agent includes (ass %): blue oil color 4-50; oleic acid 10-25; purified pine oil 23-24; and balance: ether. Agent of present invention makes it possible to fill all lymph tubes and capillaries and to visualize the most thin circle net in conjunctive, eye tissues and around eye area.

EFFECT: new agent for production of anatomy preparations.

3 ex

FIELD: biology, medicine, in particular histological investigation of shells with natural surface by using light-optical microscope.

SUBSTANCE: claimed method includes surface relief investigation by using plane field microscope in reflected light at one-side falling shadow-forming lighting. Light-reflecting ability of specimen surface is provided by silver impregnation. Said impregnation is carried out by specimen hold in 10 % silver nitrogen solution for 10 min followed by reducing thereof with 1 % ascorbic acid solution for 1 min.

EFFECT: method for investigation of natural shell surface relief of improved quality due to visual representation of surface three-dimension image on tissue level.

3 cl, 4 dwg

FIELD: metallurgy.

SUBSTANCE: method of finding defects onto surface of ЦМ2А rolled sheets is offered which method consists of pipe degreasing, pipe sampling, sample making and visual checking of surfaces of rolled sheets at magnification of 6-12 times by means of microscope or lens at different foreshortened of illumination. After that, the area occupied by local or continuous defects at sample is estimated and degree of clearness of defects is determined followed by notification on defects estimation at both surfaces of sample.

EFFECT: improved manufacturability of sheets; improved ability of pressing.

2 cl, 3 dwg, 2 ex

FIELD: sampling, particularly devices for withdrawing solid samples from building structures.

SUBSTANCE: die comprises outer part and inner embedded part installed in outer one. Inner part is of cube shape and made of two L-shaped members to divide the inner part into two halves during die removing from concrete. The outer part is provided with handle.

EFFECT: increased sampling easiness, possibility of repeatedly die usage to control cast-in-place concrete strength.

6 dwg

FIELD: wool processing industry, in particular, equipment used in primary wool processing flow lines for sampling of compressed unwashed wool from piles and in enterprises manufacturing wide range of wool articles.

SUBSTANCE: general-purpose mechanical sampler has detachable working tools made in the form of pipe with polished channel and cutting head, which are designed for taking of compressed sample and are mounted on reciprocating support fixed on bed having roller conveyor and carrier support equipped with vertical slots for receiving of wool pile, drive and container adapted for receiving of wool samples and arranged at its rear part. Thrust plate with windows is additionally mounted on bed, said windows being arranged in offset relation with respect to slots of carrier support. Sampler is further equipped with set of instruments made in the form of sharpened rod with pair of double-sided vertical teeth for taking out of fiber cuts so as to keep staple structure thereof and placing taken out wool samples into separate additional container disposed at front side of movable support. Working tools are set in conjunction with pipes in any combination and in random arrangement in the number of at least 2 units. Each pipe is provided with built-in ejector for withdrawal thereof from channel of compressed wool column. Containers for each of two kinds of taken out wool samples are made in the form of open boxes arranged along the whole width of bed.

EFFECT: increased capacity and efficiency in sampling, reduced industrial areas and power consumption.

2 cl, 4 dwg

FIELD: wool processing industry, in particular, equipment used in primary wool processing flow lines for sampling of compressed unwashed wool from piles and in enterprises manufacturing wide range of wool articles.

SUBSTANCE: general-purpose mechanical sampler has detachable working tools made in the form of pipe with polished channel and cutting head, which are designed for taking of compressed sample and are mounted on reciprocating support fixed on bed having roller conveyor and carrier support equipped with vertical slots for receiving of wool pile, drive and container adapted for receiving of wool samples and arranged at its rear part. Thrust plate with windows is additionally mounted on bed, said windows being arranged in offset relation with respect to slots of carrier support. Sampler is further equipped with set of instruments made in the form of sharpened rod with pair of double-sided vertical teeth for taking out of fiber cuts so as to keep staple structure thereof and placing taken out wool samples into separate additional container disposed at front side of movable support. Working tools are set in conjunction with pipes in any combination and in random arrangement in the number of at least 2 units. Each pipe is provided with built-in ejector for withdrawal thereof from channel of compressed wool column. Containers for each of two kinds of taken out wool samples are made in the form of open boxes arranged along the whole width of bed.

EFFECT: increased capacity and efficiency in sampling, reduced industrial areas and power consumption.

2 cl, 4 dwg

FIELD: experimental medicine.

SUBSTANCE: the present innovation deals with preparing hepatic preparations for histological testing. In the course of an experiment on inducing hepatic pathology animals should be perfused with glutaraldehyde formaldehyde fixing agent through portal vein under conditions of narcosis. Then comes perfusion with incubation medium containing 0.2%-digitonin in Flickinger's solution at pH being 7.2 at 20-22°C. After incubation hepatic tissue should be reduced to be placed into 0.2%-digitonin for 4-10 h, and then samples should be washed with 0.1 M cacodylate buffer and postfixed with 1%-solution upon cacodylate buffer for 2 h. Then it is necessary to conduct dehydration to be put into araldite followed by contrasting with uranylacetate and lead citrate. The method enables to increase degree of contrast due to fixing hepatic tissues in situ and optimal matching incubation medium.

EFFECT: higher efficiency.

3 ex

FIELD: automatical aids for sampling liquids.

SUBSTANCE: system for sampling and delivering filtrate has filter submerged into tested medium and connected with collecting tank and vacuum pressure source which is connected with top hole of collecting tank by means of pneumatic pipe. System has sample receiving tank connected with collecting tank and control unit which has first output to be connected with vacuum pressure source. Collecting tank has two separated chambers - washing chamber and dispatching chamber. Lower hole of washing chamber has to be lower hole of collecting tank and side hole of dispatching chamber has to be side hole of collecting tank. Floating valve is installed inside washing chamber to shut off lower and top holes. Filter is connected with lower hole of collecting tank through sampling pipe. Side hole of collecting tank is connected with lower hole of tank for receiving samples through sampling pipe. Flow-type sensor and check valve are installed inside transportation pipe. Output of flow-type sensor is connected with input of control unit; second output of control unit is connected with control input of analyzer.

EFFECT: improved precision of measurement of sample ion composition; prolonged service life of filter.

1 cl, 1 dwg

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