GOSGORTEKHNADZOR OF RUSSIA

Approved
resolution
Gosgortekhnadzor of Russia
dated 11.11.96 No. 44

REGULATIONS
ORGANIZATION AND CARRYING OUT ACOUSTIC-EMISSION CONTROL OF VESSELS, APPARATUS, BOILERS AND PROCESS PIPING

RD 03-131-97

Moscow
NPO OBT
2000

1. General provisions

1.1. Purpose and scope

The rules for organizing and conducting acoustic emission control of vessels, apparatuses, boilers and process pipelines* establish requirements that ensure the organization and conduct of acoustic emission control of objects controlled by the Gosgortekhnadzor of Russia, and apply to acoustic emission control of vessels, apparatus, boilers and process pipelines operating under excess pressure. The use of this document for other objects is allowed only in agreement with the authorities supervising their safe operation.

1.1.1. Basic provisions for the use of the acoustic emission method for monitoring vessels, boilers, apparatus and technological pipelines

The acoustic emission (AE) method provides detection of developing defects by recording and analyzing acoustic waves that occur during plastic deformation and crack growth in controlled objects. In addition, the AE method makes it possible to detect the outflow of a working fluid (liquid or gas) through through holes in a controlled object. These properties of the AE method make it possible to form an adequate system for classifying defects and criteria for assessing the technical condition of an object, based on the real impact of a defect on an object.

The characteristic features of the AE method, which determine its capabilities, parameters and areas of application, are the following:

The AE method ensures the detection and registration of only developing defects, which makes it possible to classify defects not by size, but by their degree of danger.

Under production conditions, the AE method makes it possible to detect a crack increment by tenths of a millimeter. The limiting sensitivity of acoustic emission equipment according to the calculated estimates is about 1× 10 -6 mm 2 , which corresponds to the detection of a crack jump with a length of 1 μm by a value of 1 μm, which indicates a very high sensitivity to growing defects.

The integral property of the AE method ensures control of the entire object using one or several AE transducers fixedly mounted on the surface of the object.

The AE method makes it possible to control various technological processes and processes of changing the properties and state of materials.

The position and orientation of the defect does not affect the detectability of defects.

The AE method has fewer restrictions associated with the properties and structure of structural materials than other non-destructive testing methods.

A feature of the AE method, which limits its application, is in some cases the difficulty in separating AE signals from noise. This is due to the fact that AE signals are noise-like, since AE is a random impulsive process. Therefore, when the AE signals are small in amplitude, the separation of the useful signal from noise is a difficult task. With the development of a defect, when its dimensions approach a critical value, the amplitude of AE signals and the rate of their generation increase sharply, which leads to a significant increase in the probability of detecting such an AE source.

The AE method can be used to control objects during their manufacture - in the process of acceptance tests, during periodic technical examinations, in the process of operation.

The purpose of acoustic emission control is detection, determination of coordinates and tracking (monitoring) of AE sources associated with discontinuities on the surface or in the volume of the vessel wall, welded joint and manufactured parts and components. Sources of AE are recommended, if technically possible, to be evaluated by other methods of non-destructive testing. The AE method can also be used to estimate the rate of development of a defect in order to stop testing in advance and prevent product destruction. Registration of AE allows you to determine the formation of fistulas, through cracks, leaks in seals, plugs, fittings and flange connections.

Acoustic-emission control of the technical condition of the examined objects is carried out only when a stress state is created in the structure, which initiates the operation of AE sources in the material of the object. To do this, the object is subjected to loading by force, pressure, temperature field, etc. The choice of the type of load is determined by the design of the object and the conditions of its operation, the nature of the tests.

1.1.2. Schemes of application of the acoustic emission method of control

1.1.2.1. Acoustic-emission control of the object is carried out. In case of detection of AE sources at their location, control is carried out by one of the traditional methods of non-destructive testing - ultrasonic (UT), radiation, magnetic (MPD), capillary (KD) and others provided for by regulatory and technical documents. This scheme is recommended for use when monitoring objects in operation. At the same time, the volume of traditional methods of non-destructive testing is reduced, since in the case of using traditional methods, it is necessary to scan the entire surface (volume) of the controlled object.

1.1.2.2. Control is carried out by one or more methods of non-destructive testing. If unacceptable (according to the norms of traditional methods of control) defects are detected or if there is doubt about the reliability of the applied non-destructive testing methods, the object is tested using the AE method. The final decision on the admission of an object to operation or the repair of detected defects is made based on the results of the acoustic emission control.

1.1.2.3. If an object has a defect detected by one of the non-destructive testing methods, the AE method is used to monitor the development of this defect. In this case, an economical version of the control system can be used, using a single-channel or few-channel configuration of acoustic emission equipment.

1.1.2.4. The AE method, in accordance with the Rules for the Design and Safe Operation of Pressure Vessels, is used for pneumatic testing of an object as an accompanying method that increases the safety of testing. In this case, the purpose of applying acoustic emission control is to prevent the possibility of catastrophic destruction. It is recommended to use the AE method as an accompanying method for hydrotesting objects.

1.1.2.5. The AE method can be used to assess the residual life and resolve the issue of the possibility of further operation of the object. The resource assessment is carried out using a specially developed methodology, agreed with the Gosgortekhnadzor of Russia. At the same time, the reliability of the results depends on the volume and quality of a priori information about the models of damage development and the state of the material of the controlled object.

1.1.3. Procedure for applying the acoustic emission method

1.1.3.1. Acoustic emission control is carried out in all cases when it is provided for by safety rules or technical documentation for the facility.

1.1.3.2. Acoustic emission testing is carried out in all cases when the regulatory and technical documents for the object provide for non-destructive testing (ultrasonic testing, radiography, MTD, CD and other non-destructive testing methods), but for technical or other reasons, non-destructive testing by these methods is difficult or impossible .

1.1.3.3. It is allowed to use acoustic emission control independently, as well as instead of those listed in clause 1.1.3.2. methods of non-destructive testing in agreement with the Gosgortekhnadzor of Russia.

1.2. Objects of control

This document applies to capacitive, column, reactor, heat exchange equipment of chemical, petrochemical and oil refining industries, isothermal storages, storages of liquefied hydrocarbon gases under pressure, tanks of oil products and corrosive liquids, equipment of ammonia refrigeration plants, vessels, boilers, apparatuses, technological pipelines of steam and hot water and their elements.

2. Requirements for the organization
works, performers and order
preparation for the performance of acoustic
emission control

2.1. Organization of control

Both the performer and the customer are involved in the preparation and conduct of acoustic emission testing. A significant factor influencing the results of acoustic emission testing is the measures that precede it directly. The following actions are performed:

2.1.1. After receiving an official application from the customer, the representative of the contractor conducts a preliminary acquaintance with the object of control in order to study the technical feasibility of conducting control. At this stage, the question of the type of control is decided: acoustic emission control of an object can be one-time, constantly-periodic using portable devices and continuous using stationary devices (monitoring).

2.1.2. After signing the contract for acoustic emission control, the customer submits to the contractor all the design and technical documentation for the control object, necessary for the control, with actual conditions and modes of operation.

2.1.3. After reviewing the documentation for the facility, the contractor draws up a Work Program for acoustic emission control of the facility*. The work program is approved by the responsible official of the customer enterprise. This should be the chief engineer (technical director) of the enterprise, or a person replacing him.

______________

The Work Program should reflect the activities carried out by the customer enterprise to prepare for the implementation of acoustic emission control, the procedure for carrying out work, highlighting the responsibilities of each work participant, both on the part of the contractor and on the part of the customer. The work program should include organizational and technical measures that ensure the successful implementation of acoustic emission testing. The Work Program should include the following activities:

representation of the premises for the placement of acoustic emission equipment (if necessary). The temperature in the room must be at least 18 ° C, it must be provided with a power supply of 220 V and a power of at least 10 kW;

providing access to the places of installation of AE converters at the control object; The customer, if necessary, must provide lifting mechanisms, install scaffolding, manufacture and install plugs, allocate personnel for auxiliary work, including cutting windows in thermal insulation and cleaning the surface at the installation sites of AE converters (surface cleanliness must be no worse than Rz40); the performer must take all repair workers away from the controlled object for the period of acoustic emission control, stop work at nearby objects, etc.;

ensuring changes in the load on the object in accordance with the loading schedule developed by the contractor;

ensuring two-way communication between the personnel performing control and operational personnel carrying out load changes;

conducting safety briefings and providing specialists conducting acoustic emission control with personal protective equipment and overalls.

Measures for the safe conduct of work are carried out by the customer enterprise.

2.2. Preliminary study of the object of control

Before performing acoustic emission control, the performer must carefully study the object of control in order to obtain data for the development of a specific technology for acoustic emission control of this object. "Object Control Technology"*, which is part of the Program of Work, should be developed on the basis of this document and the data obtained during the study of the object of control. Control technology should be given in the reporting documentation for control.

When developing the Control Technology, it is necessary to have the following data:

2.2.1. Acoustic properties of the material and the controlled object, including the speed and damping coefficients of the waves necessary for performing acoustic emission control, and the impedances of the materials.

2.2.2. Material properties of the object required for acoustic emission control.

2.2.3. Parameters of the object as an acoustic channel.

Acoustic and acoustic-emission parameters are obtained during a preliminary study of the object of control or use known from the technical and scientific literature data.

Based on the data obtained, methodological methods for monitoring the object are developed, and a system is developed (or selected from existing systems and criteria) for classifying AE sources and criteria for evaluating the results of monitoring. It is recommended to coordinate the choice of the AE source classification system and evaluation criteria with a specialized expert organization from among those accredited by the Gosgortekhnadzor of Russia.

2.2.4. The control technology is agreed with the customer before the control is carried out in order to carry out the necessary preparatory work by the customer.

The Control Technology should contain the following information:

a) material and design of the controlled object, including dimensions and shape, type of stored (working) product;

b) data on noise parameters;

c) type and parameters of AE transducers, their manufacturer, information on calibration;

d) AE transducer fastening method;

e) contact medium;

f) cleaning the object after control;

g) layout of AE transducers;

h) type of AE device, its parameters;

i) description of the system and results of calibration of acoustic emission equipment;

j) data to be logged and methods of log;

k) classification system of AE sources and criteria for assessing the state of the controlled object based on the results of control;

l) qualifications of operators.

Data on the object of control and the main parameters of control are entered into the protocol based on the results of acoustic emission control ().

Fully describe the procedure for hydro- (pneumatic) testing; provide graphs of changes in load and temperature over time.

2.2.5. The customer, in accordance with the Control Technology, organizes the preparation of the loading system, creates the necessary reserves of the test medium (inert gas, water, etc.), resolves the preparation of loading devices, lifting mechanisms and other preparatory work specified in the Control Technology. For objects that have been preloaded or under load, the pressure and/or loads must be reduced to a predetermined level. The holding time under reduced pressure should be established on the basis of previously obtained data.

Before testing an object in operation, it is mandatory to have information about:

maximum operating (working) pressure or load during the last year.

test pressure.

2.2.6. When performing control work, the customer puts at the disposal of the contractor a team of employees who ensure the work is carried out. The conditions for the contractor's involvement in auxiliary operations for acoustic emission control of the customer's personnel are determined by the contract.

2.3. Requirements for enterprises and personnel,
conductive acoustic emission control

AE-control of objects is carried out by non-destructive testing laboratories certified in accordance with the established procedure.

(Changed edition, Rev. No. 1)

The conclusion on the results of the control has the right to give a specialist with II or III level of qualification.

A number of requirements are imposed on enterprises that carry out acoustic emission control, which must ensure the performance of work at a high technical level.

The company must have:

license of Gosgortekhnadzor of Russia for the right to carry out work on acoustic emission control;

calibrated control means (AE transducers and acoustic emission equipment);

certified, qualified personnel.

It is recommended to have a package of documents confirming the professional level of the executing enterprise, data on the quality system (Quality Manual), information on previous work on the control of industrial facilities, a list of controlled facilities and enterprises that were provided with acoustic emission control services.

A necessary condition for the performer's readiness to perform work on acoustic emission control is that he has the Control Technology of the controlled object.

3. Requirements for hardware and equipment

The apparatus and equipment used in performing acoustic emission testing includes AE transducers with fastening devices and materials for providing acoustic communication with the test object; AE signal simulators; electronic blocks intended for amplification and processing of AE signals; computing means for processing and presenting the results of control, including software; means providing loading of the controlled object.

3.1. AE transducers

AE transducers determine the control sensitivity and operating frequency range. The operating frequency should be chosen based on the conditions of noise, acoustic attenuation in the object. To control vessels, boilers and apparatuses, it is recommended to use the range of 100-500 kHz. When monitoring process pipelines, the lower frequency range of 20-60 kHz should be used. It should be taken into account that when monitoring objects at lower frequencies, there is a high level extraneous mechanical noise. In the range above 500 kHz, the attenuation of elastic waves in the structure is more pronounced.

The used AE must be temperature-stable in the temperature range in which the control of objects is performed. Their electro-acoustic conversion factor should not change by more than 3 dB over this temperature range. The spread of conversion coefficients for a batch of transducers used in the control of an object should not exceed 3 dB. It is recommended to use predominantly resonant AE.

AE converters must be noise-proof, which is achieved by using the accepted methods of noise protection, as well as the use of differential circuits.

AE transducers should be attached to the object using mechanical devices, magnetic holders, or with glue. Devices for installing converters at the facility are selected taking into account its design features. They can be removable (magnetic holders, clamps, clamps, etc.) or in the form of permanently installed brackets.

The preamplifier is placed near the AE converter or directly in its housing. The length of the signal cable connecting the AE converter with the preamplifier, as a rule, should not exceed 2 m, the cable should have a shield to protect against electromagnetic interference. The maximum length of the cable connecting the preamplifier to the device, as a rule, should not exceed 150 m. The signal loss in this cable should not exceed 1 dB per 30 m of length, the electric capacitance should not exceed 30 pF/m.

The AE transducer is installed either directly on the surface of the vessel or using a waveguide. The use of non-directional transducers is recommended. When monitoring linear objects (pipelines), or when monitoring certain areas, it is allowed to use directional AE transducers. For thick-walled objects (providedl<< t» 10 L, where t- wall thickness,l- wavelength at the operating frequency, L- the distance between the AE transducers), the use of surface wave piezo transducers is recommended.

When installing the AE transducer on the test object, the acoustic contact medium must ensure effective acoustic coupling of the AE transducer with the object. The decrease in the signal amplitude during its passage from the object to the AE transducer should not exceed 6-12 dB, which is achieved by using a contact medium with minimal attenuation and acoustic impedance, which contributes to the acoustic matching of the AE transducer and the object. The contact medium should not have an undesirable effect (for example, cause corrosion) on the controlled object. The contact medium must provide reliable acoustic contact during the entire test period at the temperature of the controlled object. As a contact medium, you can use epoxy resin without hardener, machine oil, glycerin and other liquid media. The surface of the test object at the installation site of the AE transducer is cleaned to a cleanliness no worse than Rz 40.

After installing the AE transducer on the control object, their performance is checked using AE simulators. A piezoelectric transducer excited by electric pulses from a generator should be used as an AE signal simulator. The frequency range of the simulation pulse must match the frequency range of the control system.

The generator that excites the simulation converter must meet the following requirements:

pulse repetition rate - 1-1000 Hz;

the amplitude of the generated pulses varies and should provide a change in the amplitude at the output of the control system transducers (taking into account attenuation) in the range of 10-30 mV;

the duration of the exciting electrical pulse should not exceed 0.1-0.2 μs.

As a simulator of AE signals, it is also allowed to use a Su-Nielsen source [a fracture of a graphite rod with a diameter of 0.3-0.5 mm, a hardness of 2T (2H)].

When performing the control, the working AE transducers used must be calibrated using reference AE transducers.

When performing calibration, the determination of the electroacoustic conversion coefficient of the reference AE transducer by measuring the amplitude of the dynamic displacement of the surface of a solid body and the amplitude of the impulse response is carried out using exemplary measuring instruments by bodies (laboratories) accredited by the State Standard of Russia.

Calibration of working AE transducers is carried out by independent laboratories accredited by the State Standard of Russia using standard AE transducers. The determination of the main parameters of the working AE converters is carried out by the owners of the AE converters using reference AE converters. Calibration of AE reference transducers should be carried out once a year. The determination of the main parameters of the working AE transducers should be carried out before each control, but at least once a year. The results are recorded in the passport of the AE converter.

3.2. Acoustic emission equipment

To register AE during testing of large-scale objects, acoustic emission equipment should be used in the form of multichannel systems that allow determining the coordinates of signal sources and AE characteristics with simultaneous recording of loading parameters (pressure, temperature, etc.).

A multichannel acoustic emission system should include:

set of preamplifiers;

cable lines;

blocks of preliminary processing and conversion of AE signals;

Computer with the necessary software;

means of displaying information;

system calibration blocks.

The acoustic emission system can be both stationary and mobile. To control objects of a simple configuration or in cases where it is not required to determine the location of defects, it is allowed to use less sophisticated equipment, i.e. single-channel device (devices), or a multi-channel system in zone control mode.

The acoustic emission system must provide both real-time processing and display of information, as well as processing, display and output to peripheral devices to document the data accumulated during the test after the end of the test.

Such information includes:

numbers of groups of AE transducers that registered the AE impulse, or the number of the AET;

coordinates of each registered AE pulse (this is not required in the zone control mode);

amplitude of the AE pulse (amplitude distribution of the acoustic emission process);

acoustic emission pulse energy, or "MARSE" (Measured Area of ​​the Rectified Signal Envelope - the measured area under the signal envelope), or another energy parameter;

number of emissions (exceeding the discrimination level by the signal);

temporal characteristics of the signal;

load parameters at which the AE impulse was registered (pressure, deformation or temperature);

pulse registration time;

values ​​of the difference in the arrival times of the signals (this is not required in the zone control mode);

Acoustic emission systems are subject to the following general technical requirements, confirmed by a calibration certificate for the equipment:

operating frequency range from 10 to 500 kHz;

unevenness of the amplitude-frequency characteristic within the frequency range no more than ±3 dB;

signal attenuation outside the operating range with an octave disorder relative to the cutoff frequencies of at least 30 dB;

the effective value of the intrinsic noise voltage of the amplifying path is not more than 5 μV;

preamplifier gain 20-60 dB;

gain of the main amplifier 0-40 dB with step adjustment after 1 dB;

the amplitude dynamic range of the preamplifier is not less than 70 dB;

dynamic range of AE signal amplitude measurement not less than 60 dB;

the acoustic emission system must provide the possibility of equalizing the sensitivity of the measuring channels so that the differences do not exceed ±1 dB.

The acoustic emission system must ensure rejection of false events, implemented both at the hardware and software levels.

The system part of the program should provide convenience for the operator to communicate with the computer, enter job orders and change parameters in the interactive processing mode.

The main parameters of the acoustic emission equipment and its modes of operation are recorded in the protocol (). If they change during the test, the reason should be indicated.

4. Carrying out control

Objects must be controlled in their working position. After the preparatory work, direct control work is carried out, which begins with the installation of AE converters on the object.

4.1. Installation of acoustic emission transducers

Each AE transducer must be installed directly on the surface of the object, or an appropriate waveguide can be used. It should be taken into account that in the presence of coloring and protective coatings, as well as the curvature of the object surface and surface irregularities in the contact zone, a decrease in the amplitude of the AE signal and distortion of its shape is possible. If the decrease in the amplitude of the AE signal exceeds 6 dB, the surface of the object at the installation site of the AE transducer must be cleaned of paint or coating without fail.

It is also necessary to provide for the fastening of the signal cable and the preamplifier in order to exclude the loss of acoustic contact and mechanical loading of the AE transducer.

The location of the AE transducers and the number of antenna groups is determined by the configuration of the object and the maximum spacing of the AE transducers associated with signal attenuation, the accuracy of determining coordinates. Antenna groups and individual AE transducers in zone location should be installed in such a way that the critical places of the object, welds, high voltage zones, branch pipes, repaired areas, etc. entered the control zone. It is necessary to take into account additional attenuation in welds and in areas where there is a change in the wall thickness of the object. The placement of AE transducers is given in the Control Technology (control cards).

Depending on the configuration, the object should be divided into separate elementary sections: linear, flat, cylindrical, spherical. For each section, an appropriate layout of the AE transducers is selected. In addition to the main groups of transducers used to determine coordinates, auxiliary (blocking) groups can be placed on the object for spatial selection of the zone of identified noise sources.

The placement of the AE transducers should ensure control of the entire surface of the controlled object. In some cases, in agreement with the customer, it is allowed to place AE converters only in those areas of the object that are considered important. If 100% overlap of the control zones of the entire facility is not ensured, then this should be noted in the control report with the rationale for using this scheme.

The coordinates of the sources of acoustic emission are calculated from the difference in the time of arrival of signals to the AE transducers located on the surface of the controlled object.

In the case of multichannel location, the distance between the AE transducers is chosen in such a way that the signal from the AE simulator (pencil break) located anywhere in the monitored area is detected by the minimum number of transducers required to calculate the coordinates.

To select the distance between the AE transducers, the attenuation is measured, while choosing a representative part of the object without nozzles, passages, etc., installing the AE transducer and moving (after 0.5 m) the AE simulator along the line in the direction from the AE transducer at a distance up to 3 m. As an AE simulator, it is recommended to use a piezoelectric transducer, or a break in the pencil lead (Su-Nielsen simulator) with a diameter of 0.3-0.5 mm, hardness 2N (2T), with a rod tilt angle of approximately 30 ° to the surface, the rod is extended by 2 .5 mm.

The distance between the AE transducers when using zone location is set in such a way that the AE signal from a pencil break (or a signal from another AE simulator) is recorded anywhere in the controlled area by at least one AE transducer and has an amplitude not less than the specified one. As a rule, the difference in the amplitudes of the AE simulator when it is located near the AE transducer and at the edge of the zone should not exceed 20 dB. The maximum distance between the AE transducers should not exceed the distance, which is 1.5 times the threshold. The latter is defined as the distance at which the amplitude of the signal from the AE simulator (pencil lead break) is equal to the threshold voltage.

When monitoring objects with high attenuation of elastic waves, it is recommended to use two operating frequencies - low - in the range of 20-60 kHz and higher - in the range of 100-500 kHz. In this case, high-frequency channels are used to detect and evaluate AE sources. Low-frequency channels should be used to identify those AE sources that can be missed due to the high attenuation of AE signals at high frequency. If significant activity is detected at a low frequency (corresponding to a class II or III source) and there is no registration on high-frequency channels, you should reset the high-frequency AET and repeat the control.

The measurement of the speed of sound used to calculate the coordinates of AE sources is carried out as follows.

The AE simulator is located outside the groups of AE converters on the line connecting the AE converters, at a distance of 10-20 cm from one of them. By conducting multiple measurements (at least 5) for different pairs of AE transducers, the average propagation time is determined. Based on it and the known distance between the AE transducers, the speed of propagation of AE signals is calculated.

4.2. Checking the performance of acoustic emission
instrumentation and channel calibration

The operability of the acoustic emission system is checked immediately after the AE transducers are installed on the controlled object, as well as after testing, by excitation of an acoustic signal by an AE simulator located at a certain distance from each AE transducer. The deviation of the registered AE signal amplitude should not exceed 3 dB from the average value for all channels. If the specified value is exceeded, the cause must be eliminated, otherwise a re-inspection should be carried out.

The level of sensitivity of different groups of AE transducers may vary. In this case, there should be a mark in the control protocol and justification in the report. When evaluating the results of monitoring, it is necessary to take into account the spread in the sensitivity of the channels.

The channel gain and the amplitude discrimination threshold are selected taking into account the expected range of AE signal amplitudes. At the same time, it is ensured that undistorted transmission of AE signals is ensured and the frequency of interference emissions in the channel does not exceed an average of one per 100 s. The threshold value, the number of AE signal spikes, energy, MARSE, amplitude and other necessary characteristics are checked according to the technology recorded in the Control Technology.

In the event that hydrotesting of objects is carried out, all work on setting up the equipment is carried out after the objects are completely filled with water.

4.3. Object loading

After performing the preparatory and adjustment work, the object is loaded. Acoustic emission control is performed in the process of loading the object to a certain pre-selected value and in the process of maintaining the load at specified levels.

When loading the control object with internal pressure, its maximum value - (test pressure) must exceed the permitted operating pressure (operational load) by at least 5-10%, but not exceed the test pressure, determined by the formula:

where R- design pressure of the vessel, MPa (kgf / cm 2); - allowable stresses for the material of the vessel or its elements, respectively, at 20 °C and design temperature, MPa (kgf/cm2); a\u003d 1.25 - for all vessels, except for cast ones; a= 1.5 - for cast vessels (paragraphs 4.6.3. - 4.6.5).

If the maximum test pressure is equal to the test pressure, the holding time for objects in operation should not exceed 5 minutes (clause 6.3.20 of the "Rules for the Design and Safe Operation of Pressure Vessels"), and when tested again manufactured objects is selected in accordance with Table 4.3. (clause 4.6.12. "Rules for the Design and Safe Operation of Pressure Vessels").

Table 4.3

If the maximum test pressure is less than the test pressure, the exposure time when testing newly manufactured objects must be at least 10 minutes.

In acoustic emission control of tanks for storing oil, oil products and other liquid media, the maximum load value is used equal to R Spanish = 1.05 R slave.

During acoustic emission control of objects tested for filling, their holding time at the maximum allowable filling level should be at least two hours.

When assigning the maximum test pressure, the characteristics of the material, the operating conditions of the test object, the temperature, and the history of its loading should be taken into account.

Loading is carried out using special equipment that provides an increase in load - internal (external) pressure according to a given schedule, which determines the loading rate, the holding time of the object under load and the values ​​of the loads. An example of a typical load schedule is given in the reference. Deviation from the typical loading schedule is allowed, with the necessary justification given in the report.

Tests of the object are divided into preliminary and working.

Preliminary tests are aimed at:

checking the performance of all equipment;

clarification of the noise level and adjustment of the discrimination threshold;

pressure testing of plugs and gland seals;

identification of sources of acoustic radiation associated with friction at the points of suspension (attachment) of objects, supports, structural stiffeners, etc.

Preliminary tests are carried out under cyclic loading in the range of 0-0.25 R slave. For objects without cladding and stiffeners, the number of loading cycles is at least 2, for others - at least 5.

It is recommended that loading during the working test be carried out in stages, with pressure holdings at the level of 0.58× R slave 0.75 × R slave 1.0 × R slave and R Spanish The holding time at the intermediate stages should, as a rule, be 10 minutes.

Loading of objects should be carried out smoothly at a speed at which interference does not occur that exceed the permissible level (see). Recommended pressure rise rates are:

R Spanish /60-R test /20 [MPa/min].

It is allowed to carry out tests with a loading speed less than the minimum specified. In these cases, intermediate exposures can be omitted.

Acoustic emission control of large volume tanks and storage facilities is carried out in the monitoring mode (continuous control) or according to a special program. The loading program for each such object is compiled individually and agreed with a specialized expert organization from among those accredited by the Gosgortekhnadzor of Russia.

As a loading medium, water, the working fluid of the object in the form of liquid media (hydrotest), as well as gaseous media (pneumatic test) can be used.

In the case of hydrotesting, the loading liquid must be supplied through a branch pipe located in the lower part of the vessel, below the level of the liquid filling the vessel.

To reduce the level of noise and interference during the control, all extraneous work on the control object itself and near it should be suspended. Walking on service platforms, the movement of vehicles, welding and installation work, the operation of lifting and transport mechanisms located nearby should be excluded.

When testing objects of great length or large-sized objects, it is allowed to carry out control by stages. The interval between individual stages must be at least 24 hours. It is allowed to control only a part of the object in agreement with the customer.

When testing newly manufactured vessels that did not undergo post-weld heat treatment, it is possible to register AE caused by stress equalization and not associated with the development of defects. Therefore, during the first loading, as a rule, only signals whose amplitude exceeds the threshold level by more than 20 dB and signals recorded during exposure are taken into account. If at the first loading AE sources of class II or III are revealed or indeterminate results are obtained, the vessel must be loaded with the second working cycle of loading without fail with a change in load from 50 to 100% of the test pressure. The classification system for AE sources is given in .

During the loading process, it is allowed to change the sensitivity of the amplifying paths with the obligatory registration of the moment and value of the changes made and the justification given in the acoustic emission control protocol.

Tests are terminated ahead of schedule in cases when the registered AE source reaches class IV. A fast (exponential) increase in the total count, pulse amplitude, energy, or MARSE can serve as an indicator of accelerated crack growth leading to failure. The object must be unloaded, the test is either terminated, or the source of the AE is clarified and the safety of continuing the tests is assessed.

Registration of pressure and temperature (when it changes) is carried out during the entire cycle of lifting and shedding the load. The pressure shall be continuously monitored to within ±2% of the maximum test pressure. The scale of the analog pressure gauge must have a maximum value not less than 1.5 and not more than 5 times the test pressure, the error of the digital instrument must not exceed 1% of the test pressure.

4.4. Noise analysis

The main factor affecting the efficiency of acoustic emission control is noise. When conducting acoustic emission control of objects, it should be taken into account that the main sources of noise are:

splashing of liquid in the vessel when it is filled;

hydrodynamic turbulent phenomena at high loading speed;

operation of pumps, motors and other mechanical devices;

the action of electromagnetic pickups;

impact environment(rain, wind, etc.).

To take measures to reduce the influence of noise on the results of control, it is necessary to separate the noise by type. Depending on the source of origin, noise is divided into acoustic (mechanical) and electromagnetic. Depending on the type of noise signal, they are divided into pulsed and continuous. Depending on the location of the source, they are divided into external and internal. All leaks in the controlled object and loading system must be eliminated before testing.

The minimum noise level, which is determined by the sensitivity of the AE equipment, is associated with the intrinsic thermal noise of the AE converter and the noise figure of the input stages of the amplifier (preamplifier). The inherent thermal noise of the AE transducer with a sensitive element made of piezoceramic should not exceed 5 μV. The noise figure of the input stages of the amplifier should not exceed 6 dB. Therefore, the inherent noise of the AE equipment should not exceed 10 μV (U sha <10 мкВ), приведенных ко входу.

The level of continuous acoustic or electromagnetic noise ( U w ) should not exceedU sha +6 dB ( U w< U pore = U sha + 6 dB). Here U since - threshold voltage.

If this condition is not met, then all measures (technical and organizational) must be taken to reduce the noise level. If it is impossible to reduce the noise to the required value, it is necessary to stop the acoustic emission control. Carrying out control in conditions of increased noise (i.e. when the inequalityU w > U sha + 6 dB) is possible only with scientific and technical substantiation of the possibility of identifying the required AE sources. In this case, the value of the threshold level of the equipment may exceed the value of 20 μV, i.e.U then > U w >20 µV.

Impulse noise (interference) limits are set based on the conditions under which the tests are carried out. It is recommended that the average frequency of recording impulse noise does not exceed 0.01 Hz (i.e.F pom < 0,01 Гц). При невозможности уменьшения частоты регистрации импульсных помех до требуемого значения необходимо прекратить проведение акустико-эмиссионного контроля. Проведение контроля в условиях повышенной частоты регистрации импульсных помех (т.е. при выполнении неравенства F pom > 0.01) is possible only with scientific and technical substantiation of the possibility of identifying the required AE sources.

The effect of electromagnetic interference is reduced by the use of shielding, special radio elements (differential sensors and amplifiers, filters, etc.), as well as gating equipment for the duration of the interference.

All noises must be identified, minimized, and their parameters must be recorded. After setting up the equipment and before performing the operational test, the background noise is checked for 15 minutes, which must be below the established threshold level. When registering noises whose level exceeds the threshold, the noise source must be excluded, or the test must be stopped.

The location of AE sources should be determined with the specified (in the Control Technology) accuracy either using a multi-channel location system or using zone control. The coordinates of AE signal sources are determined in the planar location mode, i.e. the depth of the source is not determined.

The accuracy of multichannel location must be at least equal to two wall thicknesses or 5% of the distance between the AE transducers, whichever is greater.

The errors in the calculation of coordinates are determined by the errors in measuring the time the signal arrives at the transducers. Sources of errors are:

measurement error of time intervals;

the difference between real propagation paths and theoretically accepted ones;

the presence of anisotropy in the velocity of signal propagation;

change in the shape of the signal as a result of propagation through the structure;

superposition of signals in time, as well as the action of several sources;

registration by converters of waves of various types;

error in measuring (setting) the speed of sound;

error in setting the coordinates of the AE transducers.

The value of the controlled area during zone control is determined by the boundary of the object surface around the AE transducer, for which the attenuation of the signal passing from the boundary to the AE transducer does not exceed 20 dB.

Before loading the object, the error in determining the coordinates is estimated using a simulator. It is installed at the selected point of the object and the readings of the coordinate system are compared with the real coordinates of the simulator. In this case, the amplitude of the simulated signal varies within the expected range, determined as a result of a preliminary study of the test object. The operation is repeated for different zones of the object structure. In the case when the error in determining the coordinates does not satisfy the specified value, the main sources of errors indicated above should be identified and the control parameters should be adjusted (changing the configuration of the location of the transducers, the distance between the transducers, etc.). the possibility of conducting AE control and reflect in the report.

5. Accumulation, processing and analysis of data

In the process of control, the data are collected and processed promptly. The control system should provide registration and signaling of the AE source corresponding to class IV (catastrophically active source) in real time. After the control of the object, the subsequent processing and analysis of the data is carried out in full.

The accumulation of data is carried out after the selection of the parameters of the AE signals. In the presence of digital recorders, AE signals are stored for the purpose of subsequent analysis of the process.

Processing and analysis of data is determined by the chosen classification system for AE sources and the criteria for evaluating the results of monitoring. All registered AE signals are divided into AE sources depending on their position in the controlled object. Sources are classified depending on the values ​​of their parameters.

AE sources are evaluated in stages, depending on the loading mode and the time spent on control. Each stage should not exceed 4 hours of continuous monitoring. The duration of the entire acoustic emission control is not regulated.

Zone control is used in cases where it is impossible or inappropriate to determine the coordinates of AE sources.

To use this approach, the initial information necessary for the selection and application of a particular criterion is preliminarily prepared;

data processing should be carried out on a computer included in the acoustic emission control system.

The information processing program must ensure the location of AE signal sources by the time of arrival of signals to the AE transducers or by amplitude and display their position in the form of indications of the AE source on the location map (and in the process of control - on the display).

On the location map, zones of increased concentration (clusters) of AE indications are distinguished, which together form a complete image of the AE source.

The location of the obtained zones and the technological topology of the object are compared in order to separate possible sources of mechanical noise not associated with developing defects from AE sources.

Information about the concentration zones of AE indications is recorded and processed using embedded programs to build the prescribed graphs for each selected zone and classify AE sources.

6. Evaluation of control results

After processing the received signals, the control results are presented in the form of identified and classified AE sources.

When making a decision based on the results of acoustic emission control, data is used that should contain information about all AE sources, their classification and information about AE sources whose parameters exceed the permissible level.

The permissible level of the AE source is set by the performer in preparation for the acoustic emission control of a particular object.

Classification of AE sources is performed using the following signal parameters: total count, number of pulses, amplitude (amplitude distribution), energy (or energy parameter), count rate, activity, concentration of AE sources. The classification system also includes the loading parameters of the controlled object and time.

Identified and identified sources of AE are recommended to be divided into four classes - I, II, III and IV:

class 1 source - passive source;

class II source - active source;

class III source - critically active source;

A class IV source is a catastrophically active source.

It is recommended to select a classification system for AE sources and an acceptable level (class) of sources each time during acoustic emission control of a particular object, using the data given in. In some foreign regulatory and technical documents, other classification systems are adopted ().

Each higher class of AE source implies the performance of all actions defined for all sources of lower classes.

With a positive assessment of the technical condition of the object based on the results of acoustic emission testing or the absence of registered AE sources, the use of additional types of non-destructive testing is not required. If the interpretation of the results of acoustic emission testing is uncertain, it is recommended to use additional types of non-destructive testing.

The final assessment of the admissibility of identified AE sources and indications when using additional types of non-destructive testing is carried out using the measured parameters of defects based on normative methods of fracture mechanics, methods for calculating structures for strength and other existing regulatory documents.

7. Documentation
control results

The results of acoustic emission control should be contained in reporting documents - a report, a protocol and a conclusion, which are drawn up by the performer - the organization that carried out the acoustic emission control. The protocol and conclusion are part of the report, they can also be used as independent documents. According to the test results of the same type objects, the customer can be presented with a single report indicating the registration numbers of the control objects.

The report is issued at the request of the customer. At the request of a representative of the territorial body of the Gosgortekhnadzor of Russia, reporting documents must be submitted to the body of the Gosgortekhnadzor of Russia. The transfer of a report or other materials related to the results of the performed acoustic emission testing to a third party (legal entity or individual) may be allowed only with the permission of the customer.

The report on the results of acoustic emission testing should contain comprehensive data on the preparation and conduct of acoustic emission testing, as well as information that allows you to assess the condition of the object and confirm the level of classification of the performer and the specialists who carried out the control, on the basis of which one can judge the reliability of the results.

Requirements for the content of the report on the results of acoustic emission testing are given in the reference. The forms of the protocol and the conclusion are given in the mandatory annexes and (respectively).

All materials (working, draft, etc.) related to the acoustic emission control of the object, as well as reporting documents, must be kept by the contractor for at least 10 years, or until repeated acoustic emission control of the object. When performing repeated acoustic emission control of this object by another contractor, primary materials and reporting documents in full must be transferred to him at the request of the customer.

8. Safety requirements for
control

When performing acoustic emission control, the requirements for technical safety of work in accordance with the current normative documents, including GOST 12.1.019-79. "SSBT. "Electrical safety. General requirements", Rules for the operation of electrical installations of consumers and clause 4.6. "Rules for the design and safe operation of pressure vessels".

9. Liability for violation of requirements
Acoustic Emission Control Rules

Section 9

(Excluded,Change No. 1 )

Annex 1
(Informative)

The results of acoustic emission control are presented in the form of a list of registered sources of acoustic emission (AE), assigned to a particular class depending on the value of the AE parameters. Such an assessment is made for each AE signal source. The assessment of the state of the controlled object is carried out by the presence of AE sources of one class or another in the controlled object.

The use of specific systems for classifying AE sources and criteria for assessing the state of objects depends on the mechanical and acoustic-emission properties of the materials of controlled objects. The choice of the classification system and criteria for assessing the state of the object is carried out using the following classification systems and criteria for assessing the state of the controlled object. It is allowed to use other classification systems and evaluation criteria (and the corresponding values ​​of the AE signal parameters that determine the source classes and evaluation criteria) if there is a justification for their use.

The choice is made before performing acoustic emission testing and is recorded in the Control Technology developed on the basis of this document or brought in line with it. After that, the performer makes the appropriate hardware settings and develops the required software product (if necessary).

P 1.1. Amplitude criterion [MP 204-86]

Calculate the average amplitude A cf at least three pulses with individual amplitude A s for each AE source for the selected observation interval. The amplitude is corrected taking into account the attenuation of AE signals during their propagation in the material.

In preliminary experiments, the boundary value of the permissible amplitude is determined A t :

where U since - threshold value of amplitude discrimination, A c is the value of exceeding the threshold by the AE signal corresponding to the growth of a crack in the material, V 1 and V 2 - coefficients determined from the experiment. The values ​​of these coefficients are in the range 0 - 1.

Sources are classified as follows.

Class I source - a source for which the average pulse amplitude was not calculated (less than three pulses were received during the observation interval);

Class II source - a source for which the following inequality is true: A Wed< A t

Class III source - a source for which the following inequality is true: A cf > A t

Class IV source - a source that includes at least three registered pulses for which the following inequality is satisfied: A cf > A t .

Specific values A t , V 1 and V 2 depend on the material of the controlled object and are determined in preliminary experiments.

P 1.2. Integral criterion [MP 204-86]

For each zone, the activity of AE signal sources is calculated using the expression:

k = 1, 2 +, TO

Number of events in k-th parameter estimation interval;

number of events in k+1st parameter estimation interval;

k- number of parameter estimation interval.

The observation interval is divided into k parameter estimation intervals.

Making an assessment:

F<<1,

F= 1,

F>1.

Calculate relative strength Jk AE source at each registration interval

where A k- average source amplitude for the interval k;

AK- the average amplitude of all AE sources throughout the object, with the exception of the one analyzed for the interval k;

W- coefficient determined in preliminary experiments.

P 1.3. Local dynamic criterion [MP 204-86]

The evaluation is carried out in real time using the following AE parameters:

The number of outliers in the subsequent event;

The number of outliers in the previous event, either;

The energy of the subsequent event;

Energy of the previous event.

Instead of energy, a parameter can be used - the square of the amplitude.

For each event, the following values ​​are calculated:

Or

where - the value of the external parameter at the time of registration of the subsequent event (if time is used as a parameter, then this is the time interval from the beginning of the observation interval);

The value of the external parameter at the moment of registration of the previous event (if time is used as a parameter, then this is the time interval from the beginning of the observation interval).

I class -

II class -

III class -

IV class -

P 1.4. Integral-dynamic criterion [standard NDIS 2412-80, Japan]

P 1.4.1. For each source, determine the concentration coefficient WITH:

where R is the average radius of the AE source.

P 1.4.2. For each source, the total energy is determined:

P 1.4.3. According to paragraphs. P 1.4.1. and P 1.4.2. estimate the position of the point on the plane in the coordinates IgC - lgE (Table P 1.4.1.). The rank of the source is set. The position of the delimiting lines is determined by preliminary experiments.

Table P 1.4.1.

Clause 1.4.4. Form the value R, which characterizes the dynamics of the energy release of the source over the observation interval:

k = 1, 2 +, K.

P . 1.4.5. The source type is set according to Table. Clause 1.4.2.

Table P 1.4.2.

Clause 1.4.6. The source is classified according to Table. P 1.4.3.

Table P 1.4.3.

P 1.5. ASME code criteria.

The evaluation of the control results is carried out in accordance with Table P 1.5. The specific values ​​of the parameters depend on the control conditions, the material of the controlled object and its condition.

P 1.6. AE source classification system in technologyMONPAC

AE sources are divided into classes in accordance with the values ​​of the "power index" and "historical index" parameters. "Power Index" S av is defined by:

where S oi is the signal strength of the i-th event, which is twice the area under the AE pulse envelope.

.

The historical index is determined by the expression:

After calculating the index values ​​for each registered AE pulse, the sources are classified in accordance with Table P 1.6, where the following classification is adopted.

Table P 1.5

JUDGING CRITERIA FOR ZONE LOCATION*

Note:

A. E H, N T, E T and E A - are the specified allowable values ​​of the AE parameters.

B. V TH is a given threshold.

B. T H is the specified soak time.

* According to ASME code

P 1.7. Criterion of continuous AE.

Registration of continuous AE, the level of which exceeds the threshold level of the control system, indicates the presence of a leak in the wall of the controlled object. According to the criterion of continuous AE, the situation is classified as follows:

I - no continuous AE;

IV - registration of continuous AE.

Classification diagram of AE sources in technology MONPAC

H - historical index

Appendix 2
(Informative)

1. GOST 27655-88. acoustic emission. Terms, definitions and designations.

13. Rules for the construction and safe operation of technological pipelines. PB 03-94. Approved by the resolution of the Gosgortekhnadzor of Russia No. 11 dated 02.03.95

14. Rules for the design and safe operation of refrigeration systems. M.: 1991.

15. Rules for the technical operation of electrical installations of consumers and Safety regulations for the operation of electrical installations of consumers ". M.: 1986.

16. ASTM E 569-91 "Standard Practice for Acoustic Emission Monitoring of Structures During Controlled Stimulation".

17. ASTM E 1316-94 "Standard Definitions of Terms Relating to Acoustic Emission".

18. ASTM E 650-92 "Standard Guide for Mounting Piezoelectric Acoustic Emission Sensors".

19. ASTM E 750-93 "Standard Practice for Characterizing Emission Instrumentation".

20. ASTM E 1106-92 "Standard Method for Primary Calibration of Acoustic Emission Sensors".

21. ASTM E 1139-92 "Standard Practice for Continuous Monitoring of Emission from Metal Pressure Boundaries".

22. ASME 1419-91. "Test Method for Examination of Seamless, Gas Filled, Pressure Vessels Using Acoustic Emission".

23 ASME. "Proposed Standard for Acoustic Emission Examination During Application of Pressure" E 00096 (1975).

24 ASME. "Use of Acoustic Emission Examination in Lieu of Radiography", Code Case No. 1968, Section VIII, Division 1 (1982).

25 ASME. "Acoustic Emission Examination of Metallic Vessels During Pressure Testing" Article 12, Subsection A, Section V, Boiler and Pressure Vessel Code (December 1988 Addendum and later editions).

26 ASME. "Acoustic Emission for Successive Inspections. Section XI, Div. 1", Case N-471, Supplement No. 5, Code Cases 1989 Edition, Nuclear Components, Boiler and Pressure Vessel Code. Approval Date: 30 April 1990.

27 ASME. "Acoustic Emission for Continuous Monitoring of Pressure Vessel", Article 13, Section V, Boiler and Pressure Vessel Code.

28.NDIS 2412-1980. "Acoustic Emission Testing of Spherical Pressure Vessels Made of High Tensile Strength Steel and Classification of Test Results".

29. Fowler T.J., Blessing J.A., Conlisk P.J., Swanson T.L. The MONPAC System. Journal of Acoustic Emission, 1989, Volume 8, Number 3, 1-8.

Annex 3
(Informative)

CONTENT REQUIREMENTS
CONTROL REPORT

All sections of the Report are listed.

2. Introduction.

Information is provided that precedes the agreement on conducting acoustic emission control and substantiates the need to perform acoustic emission control of a particular object.

3. Object of control.

All data that may affect the results of acoustic emission testing are given. Describes the controlled item, including material, manufacturing method, manufacturer's name, Short story operation, including operating and emergency conditions, as well as data on load shedding operations for relaxation before monitoring.

A sketch of the vessel or a manufacturer's drawing is given indicating the dimensions and position of the AET.

4. Control conditions.

The conditions under which acoustic emission control is performed are described, including environmental conditions, the level of acoustic noise, vibrations, and electromagnetic interference. The used working fluid (test liquid or gas), the temperature of the working fluid, the environment and the material of the object are given. Measures to reduce the level of interference. Unusual phenomena and anything that can affect the results of acoustic emission testing are noted.

5. Preparation for acoustic emission control.

All activities related to the preparation for acoustic emission testing are described. All preparation operations for testing are given, including the preparation of an object, the rationale for choosing the number of AE transducers and the arrangement of AE transducers, as well as technological operations for the arrangement of transducers, data on wave attenuation.

6. AE source classification system and rejection criteria.

The criteria that are selected for acoustic emission control of this object are described. The substantiation of the choice of a specific type of criteria and their values ​​is given. The classification of AE sources and the actions of operators when registering an AE source of one class or another are given.

7. AE equipment.

The choice of equipment is substantiated, and all essential parameters of the selected AE equipment are given. A complete description of the technical means of acoustic emission control is given, including the name of the manufacturer, model numbers, type and number of transducers used, system amplification, the level of intrinsic electronic noise of the equipment, the technique for calibrating the equipment, and the date of the last calibration. The AE transducers are described, including the manufacturer, the type and parameters of the AE transducer, the year of manufacture and serial numbers, and the procedure for calibrating the AE transducer.

The values ​​of the amplification factors and changes in the parameters of the equipment during the tests are placed in the table.

table

8. Setting up the AE equipment.

Justifications are given for the choice of control parameters and operations for setting up channels and all equipment.

9. Technology Control.

Specific techniques used directly to control this object are given. All deviations from the Control Technology drawn up before the acoustic emission control and the reasons that caused these deviations are noted. It is recommended to include data on p.p. in the Control Technology. 4 - 10 of this appendix.

10. Carrying out acoustic emission control.

The process of acoustic emission control and the actions of operators are described. An analysis of the situations that arise directly during the performance of acoustic emission testing is given.

Given:

a loading schedule that was drawn up in advance, and a really implemented schedule (loading rate, holding times and load values). The reasons for deviations, if any, are indicated;

correlation of test data with acceptance criteria;

a sketch or drawing of the object indicating the position of zones that do not meet the rejection criterion;

any unusual phenomena or observations during testing.

11. Processing and presentation of the results of acoustic emission testing.

The report includes:

graduation map;

acoustic emission control card;

table with description of AE sources;

graphic material reflecting the behavior of AE sources during loading.

The calibration map is a schematic scan of the object indicating the position of sensors and AE signal simulators and calibration results. It is given in the acoustic emission control protocol.

The acoustic emission control map is a diagram-scan of the object, which indicates:

the position of the AE transducers with the corresponding numbering (group number / transducer number);

the position of the main structural elements (stiffening ribs, branch pipes, welds, etc.);

location of defects identified by other methods.

Graphic material reflecting the dynamics of the AE process should be presented in the form of dependency graphs.

All sources of AE identified during the control are described. One of the criteria should be used to evaluate the identified sources of AE. The degree of their danger is assessed in accordance with the chosen classification system.

All those sources that are recognized as not meeting the requirements for the further operation of the controlled object are highlighted (in accordance with the selected features and rejection criteria).

12. Personnel who carried out acoustic emission control.

The specialists who carried out the acoustic emission control are listed. They give the level of their classification, where and when the license was obtained, who issued the certificate of qualification. They report on the experience of specialist controllers and the number of objects controlled by them.

13. Conclusion on the results of acoustic emission control.

The conclusion on the results of acoustic emission control is performed in the form given in. Acoustic emission control data should be kept with site records.

14. Terms used in the performance of control and preparation of the report.

16. Applications. The annexes should contain the protocol and the conclusion on the results of the acoustic emission control (forms of the protocol and the conclusion are given in appendices 4 and this document).

Based on the conclusion on the conducted acoustic emission control, the person responsible for the object makes a record in the passport of the controlled object about the technical condition of the object and the timing of the next control.

2. Organization conducting control: ____________________________________________

3. Data about the object:

manufacturer ________________________________________________________________;

passport ID ___________;

date of commissioning ___________________________;

grade of material ________________________;

GOST (TU) ____________________________;

manufacturing method __________________________________________________________;

wall thickness ________________________ mm;

internal diameter ________________________________ mm;

dimensions of the controlled zone ____________________________________________ m;

working pressure _____________________ MPa (__________________________ kgf/cm);

workspace ________________________________________________________________;

operating temperature _______________________________°С;

surface condition ________________________________________________________;

magnetic properties ___________________________;

wave attenuation characteristics ________________________________________________;

a sketch of the vessel indicating the dimensions and placement of the AE transducers (in the appendix).

4. Additional information about the object __________________________________________

_____________________________________________________________________________

5. Type and test conditions ____________,

working body ___________________, (hydraulic or pneumatic)

temperature of object _______________ and ambient

environment _______________,

brand of loading equipment: ____________________________________________,

test pressure ____________________________ MPa (_____________ kgf / cm 2),

6. Loading curve parameters:

(loading speed ____________________, holding time _____________________,

values ​​of loads at shutter speeds _____________________________________________)

_____________________________________________________________________________

7. Type and characteristics of AE equipment, including the name of the manufacturer,

model and device number __________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

8. Number and type of transducers: ________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

9. Contact environment: _________________________________________________

10. Operating mode of the AE equipment and checking its performance before testing

and after testing):

pre-gain ______________ dB

(_________ dB);

main gain on channels ___________ dB

(____________);

level of discrimination by channels _______________ dB

(____________ µV);

self-noise level (reduced to the input

preamplifier): _____________ dB (_____________________ μV);

operating frequency band: __________-_________ kHz.

11. Changing the parameters of the equipment during the tests: ____________________________

12. Application list:

sketch of the object of control and layout

AE converters;

loading schedule;

AE registration results (Fig._______________________________________________)

Basic information about the results of control:

(including a description of the sources and their distribution by class - "passive",

"active", "critically active", "catastrophically active" - ​​and criteria).

______________________________________________________________________________

______________________________________________________________________________

The survey was carried out:

operators of acoustic

emission control

signaturesurname

I qualification level ______________ (__________________)

signaturesurname

I qualification level ______________ (__________________)

signaturesurname

Object of control: _____________________________________________________________

Who carried out the control: _____________________________________________________

Detailed information about the performed acoustic emission

control is included in the report.

As a result of acoustic emission control during hydro-(pneumo)

testing of the object revealed the following ("passive", "active",

"critically active", "catastrophically active") sources of acoustic

emissions, on the basis of which the following conclusion was made: ________________________

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________