GOST R 55046-2012
GOST R 55046−2012 Technical diagnostics. Assessment of a residual resource it is long maintained steel pipes based on the results of mechanical testing of samples. General requirements
GOST R 55046−2012
Group Т59
NATIONAL STANDARD OF THE RUSSIAN FEDERATION
Technical diagnostics
ASSESSMENT OF A RESIDUAL RESOURCE IT IS LONG MAINTAINED STEEL PIPES BASED ON THE RESULTS OF MECHANICAL TESTING OF SAMPLES
General requirements
Technical diagnostics. Evaluation of residual resource of long used steel pipelines on the basis of samples mechanical tests results. General requirements
OKS 77.040.10
Date of introduction 2014−01−01
Preface
1 DEVELOPED by Autonomous non-commercial organization «Scientific-research center of control and diagnostics of technical systems» (ANO «nits KD»), Academy of Sciences of the Republic of Bashkortostan (RB Academy of Sciences), State unitary enterprise «Institute of problems of transport of power resources» (GUP IPTER), non-state professional educational institution «Engineering center «Technology» (NPOU its «Technique») limited liability company «Gazprom Transgaz Ufa» (LLC «Gazprom Transgaz Ufa»)
2 SUBMITTED by the Technical Committee for standardization TC 132 «Technical diagnostics"
3 APPROVED AND put INTO EFFECT by the Federal Agency for technical regulation and Metrology dated November 8, 2012 N 700th St
4 INTRODUCED FOR THE FIRST TIME
Application rules of this standard are established in GOST R 1.0−2012 (section 8). Information about the changes to this standard is published in the annual (as of January 1 of the current year) reference index «National standards» and the official text changes and amendments — in monthly information index «National standards». In case of revision (replacement) or cancellation of this standard a notification will be published in the upcoming issue of the monthly information index «National standards». Relevant information, notification and lyrics are also posted in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet (gost.ru)
Introduction
Pipelines in areas of seismic activity in the area with periodic landslide phenomena, karst processes within the boundaries of cities and settlements, in places of crossing of railway and automobile roads exposed to static and cyclic loads.
Studies have established that such conditions of loading during long-term operation of the pipelines give rise to changes of the microstructure of metal due to the processes of strain aging and delayed fracture (gradual reduction of the strength at normal temperatures).
As a result of these processes result in structural changes:
1) degradation of mechanical properties of the metal that determine the efficiency of the pipelines.
The causes of land degradation are metal embrittlement and reduce strength of the relationships between the crystal grains.
The basic mechanisms of embrittlement of metal of long-operated pipelines are:
— accumulation of dislocation barriers;
— the evolution of dislocation structures;
— the formation and growth of nuclei of new carbide phases;
— a set of atoms in the tetrahedral voids of the EAC-grid ferrite;
a decomposition of cementite and the fragmentation of the pearlitic grain, etc.;
2) the reduction of corrosion resistance of metal piping, which is primarily the breakdown of cementite, accompanied by the grinding of his records and the extension of grain boundaries. Grain boundaries are obstacles to dislocation movement, gives rise to the hardening of crystals, resulting in additional internal stresses and the conditions for the occurrence of stress corrosion. The result is reduced resistance to metal corrosion.
Existing methods of estimation of residual resource of pipelines is based on considering the influence of local technological, structural and operational defects that occur in the presence of zones of stress concentrators; the mechanical and geometrical heterogeneities; corrosion damage; cracks and discontinuities of various kinds.
In the lengthy operate, by virtue of these structural changes, the occurrence of the limit state can occur in defect-free pipelines.
Therefore, the definition of a residual resource of the pipeline should be based on the establishment of the real physical state of the metal depending on the operating time and load.
1 Scope
This standard applies to pipelines operated in the field within the original set (design) of life and after they are exceeded.
The standard establishes General requirements for calculation-experimental methods of residual life assessment and for a decision on repair of pipelines; the replacement of individual components and the decommissioning of pipelines on the basis of the results of mechanical tests of samples cut from them.
This standard is developed based on the requirements to the procedure of definition of a residual resource of potentially dangerous objects, presented in [1], safety requirements [2]-[8], generalization of the results of research works [9]-[13], as well as domestic and foreign experience of design, installation, operation and technical diagnostics of pipelines.
The standard can be used by enterprises and organizations involved in the operation and diagnostics of pipelines which have exhausted their design resource.
A calculation-experimental method, regulated by this standard permits the use of additional methods of destructive and nondestructive testing samples used for the refinement of estimation of residual resource of the pipeline.
2 Normative references
This standard uses the regulatory references to the following standards:
GOST R 27.002−2009* Reliability in engineering. Terms and definitions
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* On the territory of the Russian Federation restored effect of GOST 27.002−89
GOST R 53006−2008 Estimation of a resource of potentially dangerous objects on the basis of Express methods. General requirements
GOST 12.1.019−79* the System of occupational safety standards. Electrical safety. General requirements and nomenclature of types of protection
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* On the territory of the Russian Federation the document is not valid. Valid GOST R 12.1.019−2009, here and hereafter. — Note the manufacturer’s database.
GOST 12.1.038−82 standards System of labor safety. Electrical safety. The maximum permissible values of the touch voltage and currents
GOST 25.502−79 Calculations and strength tests in mechanical engineering. Methods of mechanical testing of metals. Test methods for fatigue
GOST 166−89 (ISO 3599−76) Calipers. Specifications
GOST 427−75 Rulers measuring metal. Specifications
GOST 1497−84. Metals. Test methods tensile
GOST 6507−90 Micrometers. Specifications
GOST 28840−90 Machine for testing materials in tension, compression and bending. General technical requirements
GOST 28841−90 Machines for testing materials in fatigue. General technical requirements
Note — When using this standard appropriate to test the effect of reference standards in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet or published annually by the information sign «National standards» published as on January 1 of the current year, and on relevant issues published monthly information index «National standards» published in the current year. If the reference standard is replaced (changed), when using this standard should be guided by replacing (amended) standard. If the reference standard is cancelled without replacement, then the situation in which the given link applies to the extent that does not affect this link.
3 Terms and definitions
This standard applies the terminology according to GOST R 27.002, [13], as well as the following terms with respective definitions:
3.1 tubing: the System sequentially connected elements (pipes and components), the destruction of one of them disables the pipeline.
3.2 resource pipeline: Life of the pipeline from the start to the transition to the ultimate state.
3.3 life: the Period of application of the pipeline without taking into account downtime.
3.4 ultimate state of a pipeline: pipeline Technical state, which excluded a further operation.
3.5 remaining life of the pipeline: working on the pipeline since the current diagnosis to the transition into the limiting state.
3.6 degradation of mechanical properties of metals: mechanical properties of metal in time as a result of his-grained changes under the action of long-term loads.
3.7 technical diagnostics of pipeline: definition of the technical condition of the pipeline.
3.8 average residual life: the Mathematical expectation of the residual resource of the pipeline subject to strain aging.
4 Denote
This standard applies the following designations:
| — the average remaining life, years; | |
| — operating time of the pipeline before the current diagnosis, years; | |
the mean time to failure | |
| — mean time to failure of the annealed samples of the metal pipeline; | |
— the number of loading cycles up to the moment of destruction | |
| — average number of loading cycles to failure of the annealed samples; | |
— the number of loading cycles up to the moment of destruction | |
| — average number of loading cycles to failure of the sample of metal operated pipeline; | |
| — average number of loading cycles of the pipeline for one year; | |
| — coefficient of strain aging of the metal pipe; | |
| — the degree of deformation ageing of metal of the pipeline; | |
— tensile strength | |
| — the average tensile strength of annealed samples of the metal pipe, MPa; | |
— tensile strength | |
| — the average ultimate strength of specimens of metal operated the pipeline, MPa; | |
| — coefficient of hardening of metal of the pipeline; | |
| — the number of annealed samples of the metal tubing, tested in static tension; | |
| — the number of samples of metal tubing operated, tested in static tension; | |
| — the number of annealed samples of the metal tubing tested for fatigue; | |
| — the number of samples of the metal operated pipeline tested in fatigue. |
5 General provisions
5.1 Estimation of a residual resource it is long maintained pipeline stages includes:
the accumulation of experimental data on the change of the parameters defining the mechanical properties of the metal;
— calculations for the determination of residual resource of safe operation of the pipeline.
5.2 Calculation of residual resource of the pipeline should include a quantitative evaluation of the mechanical properties of the metal produced on the basis of testing of samples by standard methods; carrying out special fatigue and metallographic analysis at all structural levels (macro, optical metallography, electron microscopy).
5.3 Regulated by the standard method allows to determine the residual resource of the pipeline assigned the term safe operation taking into account the aging and metal fatigue of the pipe wall.
Method does not replace other methods of diagnosing the most damaged sections of pipelines and is complementary to evaluate the health of the pipeline as a whole.
6 security Requirements
6.1 measurements allow operators with skills in the operation of equipment for mechanical testing of metal samples, capable of using relevant national and industry regulatory and technical documents, trained to work with the applied measurement devices and certified for knowledge of regulations of safety in the relevant industries.
6.2 When carrying out the determination of mechanical characteristics necessary to determine the residual resource of the pipeline, the operator must rukovodstvuetsya of technical safety for operation of electrical installations* the graveyard 12.1.019 and GOST
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* On the territory of the Russian Federation the document is not valid. Are POT R M-016−2001 (RD 153−34.0−03.150−00) «Interindustry Rules on labor protection (safety rules) for electrical installations». — Note the manufacturer’s database.
6.3 Work is carried out in accordance with the safety requirements specified in the operating instructions of the equipment that is part of the used measuring instruments.
7 Requirements for measuring instruments
7.1 in determining strength limits as a means of measurement using the testing machine according to GOST 28840.
7.2 When conducting fatigue tests using a testing machine according to GOST 28841, or in specially constructed test device.
7.3 of the line of metal must meet the requirements of GOST 427.
7.4 Calipers should meet the requirements of GOST 166.
7.5 Micrometers should meet the requirements of GOST 6507.
8 sample Requirements
8.1 the Cutting blanks for the manufacture of samples made from the operating pipelines as from the wall of the pipe (base metal) and hazardous areas (welds; places of stress concentration and other defects).
8.2 In accordance with GOST R 53006 samples cut from dangerous areas, in the absence of uniformity with the main metal used for making decisions about the repair and replacement of elements of the pipeline. Samples cut from the pipe wall, used for making a decision on the extension of the resource with an assigned term of safe operation or the output of the pipeline out of service to prevent catastrophic accidents.
8.3 Made two batches of samples.
Each batch should contain samples of:
for fatigue tests, produced in accordance with the requirements of the samples are of type IV according to GOST 25.502;
for static tension testing made in accordance with the requirements of the samples are type I according to GOST 1497.
8.4 the Number of samples should provide a representative sample for assessment after their test of the average residual life of the pipeline with a given confidence probability.
8.5 Single party in the amount of samples 
9 the Procedure for testing samples
9.1 the Specimens intended for fatigue testing, brought to destruction by the cantilever method or pure bending.
9.2 loading Frequency should be no more than 40−50 cycles per minute. The amplitude of the load are chosen based on the maximum voltage that can occur under operating conditions of the pipeline.
9.3 the results of fatigue tests determine the number of cycles to failure of each sample.
9.4 Samples, is designed for static testing, test according to GOST 1497.
9.5 the results of static tests to determine the tensile strength of each sample.
10 Processing of measurement results
10.1 Counting the average number of loading cycles to failure of the annealed samples according to the formula
10.2 calculate the average operating time to failure of the annealed samples according to the formula
Note — With a satisfactory accuracy can be considered 500.
10.3 Counting the average number of loading cycles to failure of samples of metal operated pipeline by the formula
10.4 calculate the degree of deformation ageing of metal of the pipeline by the formula
10.5 calculate the average tensile strength of the metal tubing on the results of tests of the annealed samples according to the formula
10.6 calculate the average tensile strength of the metal operated pipeline by the formula
10.7 calculate the coefficient of hardening of metal of the pipeline by the formula
10.8 calculate the coefficient of strain aging of the metal tubing according to the formula
10.9 calculate the average residual life of the pipeline by the formula
11 the decision on possibility of further operation of the pipeline
11.1 On the basis of data for the assessment of the technical condition of the pipeline and its residual life make the decision on possibility of its further application in accordance with the residual or assigned resource of safe operation or its repair, reduction in operating parameters or the operation termination.
11.2 the Decision is made by the enterprise (organization), performing technical diagnosis and residual life assessment.
Annex a (recommended). An example of the calculation of the average residual life of the pipeline
Appendix A
(recommended)
A. 1 Below provides a typical example of definition of a residual resource of the pipeline of steel grade 17GS operated for 40 years, is laid in the city.
A. 2 On samples cut from the pipeline in accordance with section 8 and tested in accordance with section 9 of this standard, the following source data are obtained for calculation of residual resource:
— average number of loading cycles to failure of the annealed samples 35000;
— mean time to failure of the annealed samples of the metal of the pipeline, calculated according to the formula (2) 70 years;
— average number of loading cycles to failure of samples of metal of the pipeline operated 18500;
— coefficient of hardening of metal of the pipeline 
A. 3 Average number of loading cycles of the pipeline in one year was equal to 500.
A. 4 By the formula (4) calculate the degree of deformation ageing of metal of the pipeline
A. 5 According to the formula (8) calculate the coefficient of strain aging of the metal of the pipeline
A. 6 Average residual life of the pipeline is calculated by the formula (9)
A. 7 Thus, in heavy operating conditions (in the presence of cyclic loads), the pipeline keeps working at least for 60 years.
Appendix B (recommended). Using the results of metallographic studies to assess residual resource of the pipeline
Appendix B
(recommended)
B. 1 Metallographic examination, usually performed to determine the changes of structural-mechanical properties of the metal of the pipeline. Their results can be used to determine the causes of accidents, caused by the development of slowly flowing destructive processes of metal tubing.
B. 2 Results of electron microscopy can be used to determine the average height of the deformation relief on the surface of the pipeline, characterizing the magnitude of the accumulated strain associated with the degree of change in the value of the coefficient of strain aging of the metal tubing.
B. 3 In some cases, after constructing appropriate calibration dependencies on the results of metallographic analysis, it is possible to calculate the average residual life of the pipeline.
Bibliography
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| [2] | Safety rules in the oil and gas industry*. Approved by the resolution of Gosgortekhnadzor of Russia from | |||
________________ | ||||
| [3] | Regulations on the procedure of diagnostics of technological equipment of hazardous facilities of the fuel and energy complex* | |||
| ________________ * The document is not given. For more information, see the package. — Note the manufacturer’s database. | ||||
| [4] | PB 12−529−03 | Safety rules of gas distribution systems and gas consumption. — M.: sue STC «Industrial safety», 2003. 200 p. | ||
| [5] | SNiP 42−01−2002 |
Distribution system | ||
| [6] | FZ-116 Federal law «On industrial safety of hazardous production facilities». Adopted by the State Duma on 20 June 1997 | |||
| [7] | Technical regulation on safety of machinery and equipment*. Adopted by the Government of the Russian Federation. The ruling of 15 September 2009 N 753 | |||
________________ | ||||
| [8] | Technical regulation on safety of gas distribution networks and gas consumption. Adopted by the Government of the Russian Federation. Resolution of 29 October 2010 No. 870 | |||
| [9] | Yamaleev K. M. Aging metal pipes in the process of operation of oil pipeline//Series «Transport and storage of oil and oil products». M.: VNIIOENG, 1990. 64 p. | |||
| [10] | The aging of the oil pipelines/Gumerov A. G. [and others]. M.: Nedra, 1995. 220 S. | |||
| [11] | Method of determining the residual life of pipelines: Pat. 2413195 ROS. Federation. N 2009127940; Appl. 20.07.2009; publ. | |||
| [12] | Bolotin V. V. Forecasting of resource of machines and structures. M.: Mashinostroenie, 1984. 312 p. | |||
| [13] | OST 153−39.4−010−2002 | The technique of definition of a residual resource of oil and gas pipelines and pipelines of the main buildings | ||
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