GOST R 52890-2007
GOST R 52890−2007 nondestructive testing. Acoustic method of control of stresses in material of pipelines. General requirements
GOST R 52890−2007
Group Т59
NATIONAL STANDARD OF THE RUSSIAN FEDERATION
Nondestructive testing
ACOUSTIC METHOD OF CONTROL OF STRESSES IN MATERIAL OF PIPELINES
General requirements
Non-destructive testing. Evaluation of stresses in material of pipelines by ultrasound method. General requirements
OKS 77.040.10
Date of introduction 2010−01−01
Preface
The objectives and principles of standardization in the Russian Federation established by the Federal law of 27 December 2002 N 184-FZ «On technical regulation», and rules for the application of national standards of the Russian Federation — GOST R 1.0−2004"Standardization in the Russian Federation. The main provisions"
Data on standard
1 DEVELOPED by the Nizhny Novgorod branch of Institute of machines science named. A. A. Blagonravova of the Russian Academy of Sciences (IMASH NF), a limited liability company «INCOTEC» (LLC «INCOTEC»), Open joint stock company «Scientific-research center of control and diagnostics of technical systems» (OAO «nits KD»)
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 December 27, 2007 No. 584-St
4 INTRODUCED FOR THE FIRST TIME
Information about the changes to this standard is published in the annually issued reference index «National standards», and the text changes and amendments — in monthly indexes published information «National standards». In case of revision (replacement) or cancellation of this standard a notification will be published in a 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
Introduction
Installation and operation of pipeline systems associated with the impact on their stress state of many different factors that it is not always possible to take into account in strength calculations, constructed and operated pipelines. Direct measurements of mechanical stresses at the control points of the pipeline system can be effectively used to verify the correctness of these calculations and for operational diagnostics of technical condition of pipeline facilities.
One of the most promising methods for measuring mechanical stresses in the material without its destruction is an acoustic method based on provocations effect — the linear dependence of the velocity of propagation of elastic waves from stresses reliable experimental determination which ensured thanks to modern measurement technology.
This standard was developed in order to provide methodological basis for the application of the method of acoustic strain gauges to verify the results of strength calculations of complex piping systems, as well as to determine the actual stress state of the material of pipelines for various purposes.
1 Scope
This standard applies to acoustic echo method for determining uniaxial or biaxial (axial and circumferential) stresses of the 1st kind in the material of the piping in conditions of elastic deformation.
This standard specifies the basic requirements for the procedure of determining the mechanical stresses averaged over the thickness of the material and the area of the ultrasonic beam, using bulk ultrasonic waves propagating in the pipe wall in the radial direction. Specified by the standard method of acoustic strain gauges can be used for bench testing the pipe in situ, at installation, commissioning and operation.
Installed standard method can be used for a thin (with respect to inner pipe diameter to wall thickness not less than 20) of seamless and welded metal pipes with a diameter of 325 mm, used for construction of the main and technological pipelines.
2 Normative references
This standard uses the regulatory references to the following standards:
GOST R 8.625−2006 State system for ensuring the uniformity of measurements. Resistance thermometers of platinum, copper and Nickel. General technical requirements and test methods
GOST 12.1.001−89 System safety standards. Ultrasound. General safety requirements
GOST 12.1.004−91 System safety standards. Fire safety. General requirements
GOST 12.1.005−88 standards System of labor safety. General hygiene requirements for working zone air
GOST 12.1.019−79 System of standards of occupational safety. Electrical safety. General requirements and nomenclature of types of protection
GOST 12.1.038−82 standards System of labor safety. Electrical safety. The maximum permissible values of the touch voltage and currents
GOST 12.2.003−91 System safety standards. Equipment production. General safety requirements
GOST
GOST 12.3.002−75 System safety standards. The process of production. General safety requirements
GOST 2768−84 Acetone. Specifications
GOST 2789−73 surface Roughness. Parameters and characteristics
GOST 10587−84* epoxy-Dianova uncured. Specifications
______________
* Standard valid only on the territory of the Russian Federation.
GOST 17299−78 ethyl Alcohol technical. Specifications
GOST 26266−90 nondestructive testing. The ultrasonic transducers. 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 related information published monthly indexes 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 Symbols and abbreviations
3.1 this standard applies the following designations:
| — axial stress, MPa; | |
| — circumferential stress, MPa; | |
| — pulse delay of elastic shear waves, polarized in the axial direction, at the current level of stress, MS; | |
| — pulse delay of elastic shear waves, polarized in the axial direction, with the initial stress level, MS; | |
| — pulse delay of elastic shear waves, polarized in the circumferential direction, at the current level of stress, MS; | |
| — pulse delay of elastic shear waves, polarized in the circumferential direction, with the initial stress level, MS; | |
| — pulse delay of elastic longitudinal waves at the current level of stress, MS; | |
| — delay pulse longitudinal elastic wave at the initial stress level, MS; | |
— intrinsic acoustic anisotropy of the material, calculated by the formula | |
|
— coefficients kostopoulou communication, 1/MPa; |
| — the relative change in the pulse delay of the shear wave, polarized along the direction of the uniaxial stress, if it is changed to 1 MPa; | |
| — the relative change in the pulse delay of the shear wave polarized transversely to the direction of the uniaxial stress, if it is changed to 1 MPa; | |
| — relative change of the delay pulse longitudinal waves when the voltage of 1 MPa; | |
|
— coefficients provocations regard to biaxial stress state, MPa; |
|
— coefficients provocations relationships for a uniaxial stress state, MPa; |
| — the temperature of the tubing in the area of control the initial value of the voltage, °C; | |
| — the temperature of the tubing in the area of control with the current value of the voltage, °C; | |
| — thermoacoustic coefficient, 1/°C, | |
where |
— relative change of the delay pulse longitudinal waves when the temperature changes by 1 °C; |
| — the relative change in the pulse delay of the shear wave when the temperature changes by 1 °C. |
;
3.2 this standard applies the following abbreviations:
NA — stress state;
OK — the object of control;
SI — measurement means;
PEP — piezoelectric Converter.
4 General provisions
4.1 Measuring axial and circumferential stresses in the measuring point are performed using customroot in accordance with the General requirements [1].
4.2 Principle of the method is based on the existing in the field of elastic deformations of a linear dependence of velocity of propagation of bulk elastic waves in the direction perpendicular to the plane of action of the stresses, of mechanical stresses in the axial and circumferential directions.
4.3 thin-walled tubes loaded by internal pressure, stresses in radial direction are small in comparison with the stresses in axial and circumferential directions. Therefore, the stress state considered locally flat, dependence of velocity of propagation of bulk elastic waves from the radial stresses are neglected.
4.4 For measuring the axial and circumferential stresses under biaxial stress state using shear waves, polarized in the directions of action of the stresses and longitudinal waves.
For measuring uniaxial stress use shear waves polarized along and across the direction of action of tension, or shear wave, polarized along the direction of the voltage, and the longitudinal wave.
The direction of wave propagation is radial (perpendicular to the plane of action of the measured voltages).
4.5 diagram of the testing of the material corresponds to the echo method of ultrasonic testing. Method of excitation of elastic vibrations — pin. The form of the radiated signal is «pulse» with a high-frequency (ultrasonic) filling the envelope smooth and effective duration (at the level of 0.6 of the maximum amplitude) 2−4 period of the fundamental frequency.
4.6 Radiation and reception of acoustic signals provides a specialized transceiver (combined) transducers of longitudinal and shear waves according to GOST 26266.
4.7 the Measured voltages are averaged by volume of the ultrasonic beam, determined by the transverse dimensions of the probe and the thickness of the material. As a rule, the principal stresses in the plane perpendicular to the radial direction. Stress values counted from the initial level corresponding to the initial values of the acoustic parameters ,
and
.
4.8 there are two modes of determination of mechanical stress according to the ultrasound measurements: an acoustic strain measurement, when the initial delays of the two shear with perpendicular polarization, and longitudinal waves is determined directly at the point of measurement to the occurrence of the desired voltage and non-zero acoustic stress measurement when the values of the initial acoustic parameters determined on samples of the pipe material or in some other indirect way. The procedure of a nonzero acoustic tensometry and evaluation of measurement error in this mode is described in Appendix A.
4.9 the Coefficients provocations (KOIS) used to transition from acoustic parameters to the «power» (voltage) are characteristics of the material, determined by the modules of its linear and nonlinear elasticity. Value KOIS for pipe steels must be determined with a maximum relative error of ±10%.
4.10 Effect of temperature on the accuracy of the voltage measurement into account by using thermo-acoustic coefficient.
5 safety Requirements of the work
5.1 measurements and processing of their results allow operators with skills in the operation of equipment of ultrasonic nondestructive testing, able to use national and industry normative and technical documents on the acoustic control techniques, trained to work with used C and are certified for knowledge of safety regulations in the relevant sector of industry.
5.2 When carrying out the determination of mechanical stresses by the acoustic method, the operator should be guided by GOST 12.1.001, GOST 12.2.003, GOST 12.3.002 and rules of technical safety for operation of electrical installations churchyard 12.1.019 and GOST
5.3 Work is performed in accordance with the safety requirements set out in the instruction manual of equipment, part of the used SI.
5.4 General hygiene requirements for working zone air — according to GOST
5.5 At the organization of works on determination of stresses by the acoustic method must be met fire safety requirements according to GOST
6 Requirements for measuring instruments
6.1 as SI apply collected from production equipment, or specialized devices for determining voltages (hereinafter — the devices) are certified and verified in the prescribed manner.
6.2 SI should contain the set of probes, providing radiation and reception of shear and longitudinal elastic waves.
6.3 If necessary, the composition of SI include a contact thermometer with the characteristics according to GOST R 8.625.
6.4 Requirements for the allowable error of measuring instruments
On the basis of information about the values of the coefficients kostopoulou connection ,
,
material OK used SI for which permissible absolute error of measurement of delay
where (3−5) — metrological supply;
where — the minimum absolute value coefficient kostopoulou connection OK;
permissible absolute error of voltage measurement;
— yield strength of the material.
6.5 Requirements for software of measuring instruments
6.5.1 Algorithmic part of the software needs to perform the calculation of acoustic parameters with an accuracy in accordance with 6.4.
6.5.2 Software must consider the conditions of carrying out acoustic measurements on «OK», in particular temperature.
6.5.3 Primary acoustic information for each zone of control must reside on external media, protected from unauthorized access.
6.6 Auxiliary devices and materials
6.6.1 Grinding tool for surface preparation according to GOST
6.6.2 Degreasing liquid (alcohol according to GOST 17299 or acetone GOST 2768) for surface preparation.
6.6.3 Contact liquid (epoxy resin according to GOST 10587).
7 requirements of the test object
7.1 wall Thickness of the pipe must be at least 20 times smaller than the diameter of the pipe.
7.2 the surface Temperature at the measuring point: 0 °C-80 °C.
7.3 Before installing the probe surface is cleaned of dirt, scale, rust and degreased.
7.4 the Class of surface roughness at the point of measurement is not lower than 2,5 (GOST 2789).
7.5 Distance from point of measurement to the weld is not less than twice the wall thickness of the pipe.
7.6 Viscosity of the contact liquid at the temperature of measurement should correspond to the viscosity of the epoxy resin at a temperature of 25 °C: 12−25 PA·s (GOST 10587).
8 preparation for measurement
8.1 Study certificates for the tubing material.
8.2 Determine the type of stress state of pipeline (uniaxial or biaxial).
8.3 Determine the location of the measuring points and choose the circuit for measuring voltages.
8.4 the state of the surface at selected points in compliance with the conditions of the measurements (7.3, 7.4).
8.5 Dimensions of the prepared surfaces have three times exceed the corresponding dimensions of the piezoceramic plates probes.
8.6 put a layer of contact liquid on the prepared surface of the pipeline.
8.7 Set the probe on the surface of a pipeline, connect them to the device (performed simultaneously for the three probes in one housing or in series to the transducer of the separate version).
8.8 turn on the device, check its performance when displaying video device timebase of the received signals.
8.9 Check the quality of the acoustic contact (on the screen of a monitor device without any visible distortion shall be observed repeatedly reflected pulses, the delay of which when the score from the first reflected pulse should be the values that provide the desired in accordance with 6.4 accuracy of measurement voltage).
8.10 Check on the time scan additional pulses are caused by either having to measure additional reflecting surfaces (faults, layers) or improper orientation of the transducer of shear waves relative to the axes of symmetry of the material.
8.11 If necessary measured in selected points of the surface temperature of the pipeline with an accuracy of ±1 °C.
9 Order of measurements
For each type of wave used in the measurement, perform the following operations:
9.1 At the time scan choose «first» echo-pulse (generally, the first reflected pulse) and a following second echo pulse to measure the delay of the pulse during its run of double thickness material.
9.2 For the «first» echo-pulse count time corresponding to a certain reference point of the profile of the pulse.
Note — as a reference point, as a rule, choose one of the points of intersection of the zero input.
9.3 For the «second» echo pulse with the same accuracy as for «first», determine the time corresponding to the same reference point of the profile of the pulse.
9.4 the difference In time determine the pulse delay .
Note — If satisfies the inequality
conduct measurement of a time interval between «first» and «-m» echo-impulses
(
is a sequence number of the echo pulse on the time scan), given condition (3). The measurement procedure
similar to the procedure of measurement
.
For matching reference points «first» and «th» echo pulses, and to evaluate the validity degree of phase distortion «
, the» echo pulse using the following relationship:
where is the number of reflections «
, the» echo pulse with respect to the «first»;
— the period of high-frequency filling pulse.
9.5 After you install the piezoelectric transducers measure the initial values of delays to waves of each type used in the measurement. After application of the load measured current values of the delays for the respective waves.
9.6 After the measurement of initial values allowed the removal of the probe from the monitored object reinstall it in the same point for the measurement of current values.
9.7 Obtained for each wave time sweep is recommended to be written to the database for storage and subsequent refinement (as necessary) the values of the time delays.
10 Rules for processing results of measurements
Calculation of mechanical stresses is carried out in accordance with the recommendations of techniques [1].
10.1 NS For the biaxial stress is calculated by the formula:
10.2 NS For uniaxial tension is calculated by the formula:
Note — the First option (using shear waves) is preferable, as it uses the waves of the same type and the algorithm is insensitive to temperature changes. In this case, the formula for determining the stresses can be written in the form
where 
10.3 At small (less than 0.02) values of the parameters ,
they can be written in the form
and consider the value of a parameter of its own anisotropy of the material, and the value of the
where value (
10.4 If the temperature difference (
and current
measurements exceeds 10 °C, the temperature factor values
10.5 If the values that
differ significantly (by more than 1.5% -2%), the material is considered anisotropic and biaxial calculation of NS is carried out according to the formulas:
where ,
the coefficients provocations regard to stresses acting along and across the direction of the tube, respectively.
10.6 Uniaxial stress in anisotropic material is calculated by the formula
either
where ,
the coefficients provocations regard to uniaxial tension acting along and across the direction of the tube, respectively.
11 Rules of registration of testing results
11.1 the results of the control record in the journal, the form of which is given in Appendix B.
Additional information to be logged, the order of registration and storage of the journal (or conclusion) should be set in the technical documents for the control.
11.2 If stress measurements are part of the research work, the results of measurements issued in accordance with the General requirements and rules of registration of reports on research work.
11.3 the results of the retain control until the next control OK.
Annex a (recommended). Measurement of mechanical stress in the mode of a nonzero acoustic tensometry
Appendix A
(recommended)
A. 1 Principle the possibility to measure the voltage in the mode of a nonzero acoustic tensometry, when for any reason unenforceable acoustic measurements before the emergence of the desired voltage, determine the pipe for a particular specification on the basis of existing databases or experimentally.
A. 2 In the mode of a nonzero acoustic tensometry to measure delays of pulses of elastic waves corresponding to the current stress state of the material. Choose base values of time delays of shear and longitudinal waves so that the number of echo pulses was the same for them. If for any reason that is not possible, design algorithms take into account the appropriate conversion factor.
A. 3 If the required databases, the initial values of acoustic parameters corresponding to the unstressed condition of the tube material meeting this specification, is determined experimentally (for no-load parts of the pipe similar to the pipes, samples of the pipe material or directly at the point of measurements by other acoustic or other means). The adequacy of tubes or samples-representatives of the unloaded condition of the material at the point of measurement must be confirmed by reference to Executive documents, certificates or other documents.
A. 4 Basic information for decision-making on possibility of estimating the stress of the pipe material specific specifications in the mode of a nonzero acoustic tensometry are: manufacturing (seamless, one-piece, double seam), strength class and (or) steel grade, manufacturer. Find them in the technical papers on pipe or other means.
A. 5 for more information about the acoustic properties of the pipe material get experimentally. To do this, choose at least five control points evenly spaced around the perimeter of the pipe, and the same number of points along the length of the pipe. At these points determine the values of ,
,
c the desired precision. It is desirable to perform measurements on the unloaded parts of the pipeline or similar light pipes. Allowed to measure directly on an operating pipeline, provided that the known values of stresses at the measurement points.
A. 6 Preliminary assessment of the possibility of voltage measurement in the mode of a nonzero acoustic tensometry is based on comparing parameters of the acoustic anisotropy within the specified control points. Calculate the magnitude of the scatter values of the anisotropy parameter on the perimeter of the pipe and
the variation of the anisotropy parameter along its length.
A. 6.1 If the following inequality
it allowed the possibility of voltage measurement in the mode of a nonzero acoustic tensometry, the error of determining the stresses is estimated according to the formulas:
for uniaxial stress state
for biaxial stress state
where ,
— ranges of values
It is recommended to apply the mode of a nonzero acoustic tensometry in that case, if the error does not exceed 30% of the yield strength.
A. 6.2 If 
A. 6.3 If 
In this case, conduct measurements A. 5 not less than two tubes with increasing not less than 2 times the number of measurement points on the perimeter of the pipe.
A. 7 the results of the study the principal possibility to measure the voltage in the mode of a nonzero acoustic tensometry showing the location of measuring points must be in the form of an opinion.
A. 8 Calculation of stress values in the mode of a nonzero acoustic tensometry is carried out according to 10.1 and 10.2 subject to 10.3, while as values for delays ,
,
using the lag values
,
,
obtained in accordance with A. 5.
Appendix B (recommended). Form of measurement Protocol
Appendix B
(recommended)
| «CLAIM» | ||
| Head | ||
| name of the organization | ||
| personal signature, | initials, surname | |
| «____"_ __________________________20_____G. | ||
PROTOCOL
measurement of mechanical stresses
| (object of control, controlled section of the pipeline) | |||||||||||||||
| 1 measurement date | |||||||||||||||
| 2 organization conducting the measurement | |||||||||||||||
| 3 the owner of the object | |||||||||||||||
| 4 information about the object control: | |||||||||||||||
| appointment | |||||||||||||||
| the manufacturer, the manufacturing technology of the pipe | |||||||||||||||
| mode thermal or vibroobrabotki | |||||||||||||||
| diameter, pipe thickness | |||||||||||||||
| surface condition | |||||||||||||||
| for more information about the test object | |||||||||||||||
| 5 conditions of loading of the test object during measurement: | |||||||||||||||
| internal pressure | |||||||||||||||
| working environment temperature | |||||||||||||||
| ambient temperature | |||||||||||||||
| the additional load | |||||||||||||||
| 6 Sketch of the test object showing the location of measurement points and their numbering (in the app) | |||||||||||||||
| 7 Information about the content of the object of control: | |||||||||||||||
| country of origin | |||||||||||||||
| material grade (national, different standard) | |||||||||||||||
| manufacturing technology | |||||||||||||||
| 8 measurement Mode (acoustic strain measurement, non-zero acoustic stress measurement) |
9 table 1 — value of acoustic anisotropy at the measurement points and the number of echo pulses
| The number of point measurements | Material | The anisotropy at the time of measurement, % |
| the conditions for determining the initial values of the delay (for acoustic tensometry) | |||
| the method of determining the initial values for acoustic parameters (for a nonzero acoustic tensometry) | |||
| 10 Name and code of the database |
11 table 2 — measurement Results
| The number of point measurements | The initial values of the delays of the pulses, µs |
Material temperature, °C | The current values of the delays of the pulses, µs | Material temperature, °C | |||
| Voltage value and the measurement error (MPa) | |||||||
| The research done by the operator: | |||
| personal signature |
initials, surname | ||
| Head of laboratory NDT: | |||
| personal signature | initials, surname | ||
Notes
1 In table 1 indicate the number of the echo pulse used to measure the delay:for shear wave, polarized parallel to the tube;
for shear waves polarized perpendicular to the tube;
for longitudinal waves;
2 In table 2 in the columns «Initial value» and «Current values» are allowed instead of the values of the corresponding delays indicate the names of records in the database with the measured values.
Bibliography
| [1] | The method of measurements. Evidence 531/1700 | Steel pipes for pipelines. Methods of measurement of mechanical stresses with method of customroot |
The electronic text of the document
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M.: STANDARTINFORM, 2009
