INPUT CONTROL OF PRODUCTS
MAIN PROVISIONS
GOST 24297-87
STANDARDS PUBLISHING HOUSE
Moscow
STATE STANDARD OF THE UNION OF THE SSR
Introduction date 01.01.88
This standard establishes the basic provisions for the organization, conduct and presentation of the results input control raw materials, materials, semi-finished products and components (hereinafter referred to as products) used for the development, production, operation and repair of industrial products.
1. GENERAL PROVISIONS
1.12. The decision to tighten, weaken or cancel the input control is made by the consumer in agreement with the State Acceptance and the representative office of the customer based on the results of the input control for the previous period or the results of operation (consumption) of products.
2. ORGANIZATION OF INPUT CONTROL
2.1. Input control is carried out by the input control unit, which is part of the technical control service of the enterprise (association).
2.2. The main tasks of incoming control are:
1) checking the availability of accompanying documentation for products, certifying the quality and completeness of products;
2) control of compliance of the quality and completeness of products with the requirements of design and regulatory and technical documentation and its application in accordance with the permit protocols;
3) accumulation of statistical data on the actual level of quality of the products obtained and the development on this basis of proposals for improving the quality and, if necessary, revising the requirements of scientific and technical documentation for products;
4) periodic monitoring of compliance with the rules and terms of storage of products of suppliers.
Workplaces and personnel performing incoming control must be certified in the prescribed manner.
Measuring instruments and test equipment used for input control are selected in accordance with the requirements of the NTD for controlled products and GOST 8.002-86. If the metrological means and methods of control differ from those specified in the NTD, then the consumer agrees on the technical characteristics of the means used and methods of control with the supplier, State Acceptance and (or) with the representative office of the customer.
To carry out tests, checks and analyzes related to incoming control, products can be transferred to other divisions of the enterprise (laboratories, control and testing stations, etc.).
3. PROCEDURE FOR INPUT CONTROL
3.1. Products accepted by the Quality Control Department, the representative office of the customer, the State Acceptance Committee of the supplier enterprise and received with the accompanying documentation drawn up in the prescribed manner are allowed for incoming inspection.
3.2. When conducting input control, it is necessary:
1) check the accompanying documents certifying the quality of the products and register the products in the logs of the results of the input control ();
2) control the selection of samples or samples by warehouse workers, check the completeness, packaging, labeling, appearance and fill out the act of sampling or sampling;
3) conduct product quality control according to technological process input control or transfer samples or samples for testing (analysis) to the appropriate department.
3.3. The unit that received samples or samples for testing (analysis) conducts tests in deadlines and issues to the incoming inspection department a conclusion on the compliance of the tested samples or samples with the established requirements.
3.4. Results of tests or analyzes (physical and mechanical properties, chemical composition, structures, etc.) must be transferred to production along with proven products.
3.5. Products accepted based on the results of incoming inspection with a corresponding mark in the accounting or accompanying documents should be transferred to production.
Marking (branding) of accepted products is allowed.
3.6. Products received from the supplier before the input control must be stored separately from those accepted and rejected by the input control.
3.7. Products rejected during the incoming inspection should be marked “Rejected” and sent to the reject vizolator.
4. REGISTRATION OF THE RESULTS OF THE INPUT CONTROL
4.1. Based on the results of the input control, a conclusion is drawn up on the conformity of the products with the established requirements and a register of the results of the input control is filled out.
4.2. In the accompanying documents for the products, a note is made about the input control and its results, the products are marked (branded), if this is provided for by the list of products subject to input control.
4.3. In accordance with the products established requirements the input control unit decides to transfer it to production.
If non-compliance with the established requirements is detected during the input control, the products are rejected and returned to the supplier with a complaint.
In case of repeated receipt of low-quality products or receipt of them in large quantities, the consumer reports this to the territorial body of the Prosecutor's Office at the location of the supplier.
4.4. Based on the results of the input control, the consumer, if necessary, informs the supplier's ministry, the customer's representative office and (or) the State acceptance body at the supplier enterprise, and in the absence of the latter, the territorial body of the State Standard at the location of the supplier to take measures in accordance with the requirements imposed on them with functions ().
4.5. For electrical and radio products accepted by the customer's representative office, information is sent to the customer's head institute for these products ().
departmental subordination of the enterprise
INTELLIGENCE
on the supply of raw materials, materials, semi-finished products and components in violation of the requirements of the NTD (TU standards) for the period from _______________________ to ___________________
Note. If the materials and components are accepted by the State Acceptance Committee or the representative office of the customer, this is indicated in the note.
APPENDIX 3
obligatory
Information submission form
INFORMATION DATA
1. DEVELOPED AND INTRODUCED by the USSR State Committee for Standards
DEVELOPERS
M. G. Iofin(topic leader); L. V. Ermilova(topic leader); Ya. G. Ostapchuk, cand. tech. sciences; A. A. Bogatyrev, cand. economy sciences; I. I. Chaika, cand. economy sciences; S. G. Atamas; S. A. Afonin; Yu. F. Afanasiev; K. V. Lebedev, Ph.D. tech. sciences; Y. S. Vartanyan, cand. tech. Sciences.
2. APPROVED AND INTRODUCED BY Decree State Committee USSR according to the standards of 04.06.87 No. 1809.
3. REPLACE GOST 24297-80
4. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS
5. Reissue. April 1993
GUIDANCE DOCUMENT
the dateintroductions 01.07.91
This guidance document establishes a method for manual input ultrasonic testing (UT) of the metal quality of cold-worked, heat-worked and hot-worked seamless pipes made of carbon, alloy and austenitic steels used for the manufacture of chemical, oil and gas equipment.
The guidance document applies to pipes with a diameter of 57 mm or more with a wall thickness of 3.5 mm or more.
It is allowed to use mechanized ultrasonic testing of pipe metal according to the instructions developed by specialized technological organizations.
The guidance document was developed in accordance with the requirements of the Rules for the Design and Safe Operation of Pressure Vessels, GOST 17410, OST 26-291, technological instructions TI 101-8-68, OST 108.885.01.
1. GENERAL PROVISIONS
1.1. Ultrasonic testing is carried out in order to identify internal and external defects of pipes such as shells, cracks, sunsets, delaminations, captivity and others without deciphering the type, shape and nature of the detected defects, indicating their number, depth and conditional dimensions.
1.2. The need for ultrasonic testing of pipe metal at consumers is established in the following cases:
When supplying pipes that have not been subjected to hydraulic tests and (or) replacement of tests for control by physical methods in accordance with the instructions of clause 3.9 of the Rules for the Design and Safe Operation of Pressure Vessels and clause 2.3.9 of OST 26-291;
When using pipes manufactured according to technical requirements without the use of non-destructive testing methods, in order to assess the continuity of the metal and sort pipes, taking into account the requirements of TU 14-3-460 and other documentation that provides for ultrasonic testing, and their subsequent application, for example, for steam pipelines and hot water;
With the introduction of incoming ultrasonic testing of pipes at the consumer plant by decision of the design or technological department.
1.4. Ultrasonic testing is carried out after the elimination of unacceptable defects found during visual testing.
1.5. The inspection does not guarantee the detection of defects in the end sections of the pipe at a length equal to half the width (diameter) of the working surface of the transducer.
1.6. Control documentation containing deviations from the requirements of this guidance document or incorporating new control methods should be consistent with specialized organizations industries (NIIkhimmash, VNIIPTkhimnefteapparatura, etc.).
2. EQUIPMENT
2.1. Flaw detectors and transducers
2.1.1. When testing pipe metal, ultrasonic pulsed flaw detectors of types UD2-12, UD-11PU, DUK-66PM or others that meet the requirements of this guideline should be used. To control pipes for delamination, it is allowed to use ultrasonic thickness gauges of the Quartz-6 type or others.
2.1.2. Thickness gauges and flaw detectors once a year, as well as after each repair, are subject to mandatory state or departmental verification. During verification, visual inspection and determination of specifications appliances in accordance with guidelines according to verification and requirements of GOST 23667.
The dead zone should be no more than:
8 mm - for inclined transducers with an input angle of 38° and 50° for a frequency of 2.5 MHz;
3 mm - for inclined transducers with an input angle of 38° and 50° for a frequency of 5 MHz and PC transducers for frequencies of 2.5 and 5 MHz.
Instead of surface treatment, the use of stabilizing supports and nozzles is allowed (see).
3.3.4. AT laboratory room The ultrasound must be:
Ultrasonic flaw detectors with sets of typical transducers, standard and test samples;
AC supply with a frequency of 50 Hz and a voltage of 220 (127) and 36 V;
Chargers type AZU-0.4 or others;
Voltage stabilizer for mains voltage fluctuations exceeding plus 5 or minus 10% of the nominal value;
Reel with portable network cable;
Ground bus;
A set of metalwork and measuring tools;
Contact medium and cleaning material;
Work tables;
Racks and cabinets for storing equipment and materials.
3.4. Surface preparation under control
3.4.1. Pipes must be cleaned of dust, abrasive powder, dirt, oils, paint, flaking scale and other surface contaminants and numbered. Sharp edges at the end of the pipe must not have burrs.
3.4.2. On the outer surfaces of the pipes there should be no dents, nicks, traces of cutting, leakage, splashes of molten metal and other surface irregularities.
In case of application machining the surface must have a roughness Rz ≤ 40 - according to GOST 2789.
3.4.3. Quality control of surface preparation should be checked by employees of the technical control service. It is recommended to prepare surface cleaning samples.
The pipes are presented to the flaw inspector fully prepared for inspection.
3.4.4. To ensure acoustic contact between the surfaces of the transducer and the product, it is recommended to use the contact media specified in the reference.
It is also allowed to use technical vaseline, machine oil, technical glycerin with their subsequent removal from the surface of the pipes.
At elevated temperatures or a large curvature of the surface of the controlled pipes, a contact medium of a thicker consistency should be used. At low temperatures it is recommended to use autoly or transformer oil.
3.5. Selection of inspection parameters and flaw detector setup
3.5.1. The choice of control parameters depends on the outer diameter of the pipe and the wall thickness. The parameters of ultrasonic testing are:
Exit point and transducer boom;
The angle of entry of the ultrasonic beam;
Working frequency;
Ultimate sensitivity;
sounding method;
Speed, scan step.
The main parameters of ultrasonic testing of pipe metal are given in the table.
Optionsultrasoniccontrol
|
pipe diameter, |
wall thickness, |
Entry angle |
Frequency, |
Way |
|
57 to 75 |
3.5 to 6 |
|||
|
St. 6 to 12 |
Direct and singly reflected beam |
|||
|
St. 75 to 100 |
3.5 to 8 |
Single and double reflected beam |
||
|
St. 8 to 15 |
Direct and single-reflected beam (for thicknesses up to 8 mm, inspection by single and double-reflected beam is allowed) |
|||
|
St. 100 to 125 |
||||
|
St. 8 to 12 |
||||
|
St. 12 to 18 |
||||
|
St. 125 to 150 |
||||
|
St. 14 to 24 |
||||
|
St. 150 to 175 |
||||
|
St. 16 to 32 |
||||
|
St. 175 to 200 |
||||
|
St. 20 to 36 |
||||
|
St. 200 to 250 |
||||
|
St. 250 to 300 |
||||
|
St. 300 to 400 |
||||
|
St. 400 to 500 |
||||
3.5.2. The exit point of the ultrasonic beam and the transducer boom are determined according to the standard sample CO-3 - according to GOST 14782.
3.5.3. The angle of entry of the ultrasonic beam is measured using the CO-2 standard sample scale - according to GOST 14782. For transducers with an acoustic axis tilt angle of 30° and 40°, the input angle should be 38 ± 2° and 50 ± 2°, respectively.
3.5.4. To ensure acoustic contact of transducers with curvilinear work surface(p. ), with a flat surface of standard samples CO-2 and CO-3, a thicker contact medium or a removable local bath with a wall height of 2-3 mm should be used.
3.5.5. Setting up a flaw detector with a transducer includes setting the operating frequency, setting the depth gauge, setting the control zone, limiting sensitivity, checking the dead zone.
3.5.6. The operating frequency is set by turning on the corresponding buttons on the top panel (UD-11PU, UD2-12 flaw detectors, etc.), connecting the circuits corresponding to the specified frequency and the converter (DUK-66PM, DUK-66P flaw detectors) or by other means in accordance with the instructions for the operation of the device.
When using foreign flaw detectors, thickness gauges and transducers, instead of the operating frequency of 2.5 and 5 MHz, it is allowed to use frequencies of 2 and 4 MHz, respectively.
3.5.7. The adjustment of the depth gauge of the flaw detector for the inclined transducer is carried out according to the standard sample of the enterprise (see Fig. 1) with rectangular risks made on the outer and inner surfaces of the sample. The beginning of the scale is adjusted according to the coordinates of the risks ( S, L 1), when sounding it with a direct beam (Fig. 3), the end of the scale is adjusted according to the coordinates (2 S, L 2), risks on the outer surface when it is sounded by a single reflected beam. The end of the scale can be adjusted according to the risk on the inner surface when sounding with a double reflected beam (coordinates 3 S, L 3).
Depth gauge setup by coordinates S, L(respectively At, X in a flaw detector) is carried out separately for longitudinal and annular marks on the sample.
Echo signals from control marks in the sample must be installed on the flaw detector screen with a height of at least 30 mm.
The amplitude of the echo-signal from a flat-bottomed hole must be set on the flaw detector screen with a height of at least 30 mm, while taking into account the accepted position of the control zone on the flaw detector screen in accordance with clause 3.5.10.
3.5.14. When searching for defects, set the search sensitivity with knobs (buttons) REDUCTION is 6 dB less (by value).
3.5.15. The correctness of the limit sensitivity setting of the flaw detector with the transducer should be checked every time the equipment is turned on, as well as every hour of operation.
Verification of the characteristics of the transducer should be carried out using standard samples CO-2, CO-3 at least twice per shift as the transducer wears out.
3.5.16. After adjusting the sensitivity limit, check the dead zone by identifying holes with a diameter of 2 mm in standard sample CO-2, located at depths of 3 and 8 mm in accordance with the requirements of paragraph . If the indicated holes are not detected, it is necessary to repeat the setting of the limit sensitivity in accordance with paragraphs. - or replace the converter.
3.5.17. The speed of scanning the pipe surface by the transducer should be no more than 100 mm/s, the scanning step (between adjacent trajectories) should not exceed half the size of the piezoelectric plate in the transducer used.
It is allowed to use other scanning modes if they are specified in the technical requirements for pipes.
4. ULTRASONIC TESTING
4.1. General provisions
4.1.1. When ultrasonic testing of pipes, the following sounding directions should be used:
1) chordal, perpendicular to the generatrix of the cylinder, - to detect longitudinally oriented defects: scratches, scuffs, cracks, etc .;
2) along the generatrix - to detect transversely oriented defects: cracks, shells, etc.;
3) radial, along the radius, - to detect delaminations, sunsets, as well as to measure the wall thickness.
4.1.2. Pipe wall continuity is monitored by the echo-pulse method according to the combined circuit of switching on the transducer in the contact version. In the control process, transverse-longitudinal movement of the transducer is performed at a speed of not more than 100 im/s with a step between adjacent trajectory lines of not more than half the size of the piezoelectric element.
4.1.3. An example of determining the complexity of pipe control is given in.
4.2. Longitudinal defect control technique
4.2.1. To detect longitudinally oriented defects, chord sounding by an inclined transducer should be used when moving it perpendicular to the generatrix of the cylinder along the entire outer surface of the pipe in one direction, and at the ends of the pipes - over a length equal to twice the wall thickness, but not less than 50 mm, in two opposite directions.
Control parameters are selected according to the table.
Sounding is performed by a direct and once reflected beam. If there are interfering signals in the control zone with a direct beam, it is allowed to sound with a single and double reflected beam.
4.2.2. The limit sensitivity setting is carried out according to the longitudinal risks with a depth h in in the standard sample of the enterprise (see) in accordance with the requirements of paragraphs. - .
4.2.3. The diagram of transducer movement along the pipe surface is shown in Fig. 6a. It is recommended to move the transducer along an arc in sectors 100-150 mm long, depending on the diameter of the pipe, followed by turning the pipe to the appropriate angle to control the next sector.
4.3. Method of control of transverse defects
4.3.1. To detect transversely oriented defects, sounding should be used along the generatrices of the cylinder along the outer surface of the pipe in one direction, and at the ends of the pipes - over a length equal to twice the wall thickness, but not less than 50 mm, in two opposite directions. Control parameters are selected according to the table. Sounding is carried out by a direct and once reflected beam, and in the presence of interfering signals in the control zone - by a direct beam, once and twice reflected.
Schemecontrolwallspipes
a - on thelongitudinaldefects; b - on thetransversedefects
Heck. 6
4.3.2. The limit sensitivity setting is carried out according to the transverse risks with a depth h in the standard sample of the enterprise (see) in accordance with the requirements of paragraphs. - .
4.3.2. The diagram of transducer movement along the pipe surface is shown in Fig. 6b.
4.4. Lamination control technique
4.4.1. End sections of pipes subjected to welding, with a wall thickness of at least 10 mm over a length equal to twice the wall thickness, but not less than 50 mm, are subject to control in order to detect delaminations, sunsets. Sounding is performed in the radial direction by a PC transducer at a frequency of 2.5 or 5.0 MHz, while the transducer is installed in such a way that the acoustic axes of both piezoelectric plates are located in the axial plane of the pipe.
4.4.2. The limit sensitivity setting is carried out along a flat-bottomed hole with a diameter d in the standard sample of the enterprise (see) in accordance with the requirements of paragraph.
4.4.3. The diagram of transducer movement along the pipe surface is shown in .
In the absence of delamination, only the bottom signal 1 from the inner surface of the pipe is observed on the screen of the flaw detector. In the presence of delamination, signal 2 from a defect appears in front of the bottom signal, while the bottom signal decreases or completely disappears.
4.4.4. The dimensions and configuration of the bundles are determined by the conditional boundary. The conditional boundary is taken to be the line corresponding to such a position of the center of the transducer above the defect, at which the signal amplitude decreases to a level of 15 mm, corresponding to 0.5 of the amplitude from the flat-bottomed hole.
Outlining the conditional boundary on the surface of the pipe, the dimensions of the bundle and its conditional area are determined.
4.5. Registration of defects
4.5.1. When an echo signal appears in the control zone, the following characteristics are measured:
Reflector location coordinates;
Reflected signal amplitude;
The conditional extent of the defect along or across the axis of the pipe.
The location of unacceptable defects is marked on the pipe surface with an indication of the depth.
The specified characteristics are determined using a flaw detector configured in accordance with paragraphs. - .
4.5.2. The reflector coordinates "Du" and "Dx" are determined using the depth gauge of the flaw detector in accordance with the flaw detector operating instructions on the scale on the screen (DUK-66PM) or on the digital indicator (UD2-12).
4.5.3. The signal amplitude is measured by the height of the pulse on the screen in mm or by the amount of signal attenuation in dB up to a level of 30 mm.
4.5.4. The nominal length of the reflector is measured by the length of the transducer movement zone along the pipe axis when longitudinal defects are detected or along a circular arc when transverse defects are detected, within which the echo signal changes from the maximum value to a level of 15 mm, corresponding to half the amplitude of the signal from the risk (see p. ).
4.5.5. Defects are subject to registration, the signal amplitudes from which exceed the level of 15 mm on the screen of the flaw detector, i.e. amplitude level 0.5 from a given control reflector: risks, flat-bottomed holes.
4.5.6. Echoes from defects should be distinguished from interfering signals.
The reasons for the appearance of interfering (false) signals can be:
Irregularities in the pipe surface causing the transducer to wobble and cause air gap under the converter;
Excess contact medium;
Risks and protrusions on the end surfaces of the pipe;
Dihedral angle of the prism (with a small transducer boom);
The delay line of the PC converter.
Interfering signals caused by acoustic contact violation or reflections from the corners and the boundary of the transducer delay line differ in that when the transducer is moved, they do not move along the scan line on the screen of the flaw detector.
The sources of signals moving along the scanning line are determined by measuring the coordinates Dx, Dn of reflectors and analyzing them.
A - point allowable defect, the signal amplitude from which does not exceed the amplitude from the control reflector (risks, flat-bottomed hole);
D - point invalid defect, the amplitude of the signal from which exceeds the amplitude from the control reflector;
BD is an extended (regardless of length) invalid defect, the signal amplitude from which exceeds the amplitude level (30 mm) from the control reflector or an extended invalid defect, the signal amplitude from which exceeds the amplitude level 0.5 (15 mm) from the control reflector, and the length exceeds the allowable value for longitudinal and transverse defects ();
BA - extended allowable defect, the signal amplitude from which exceeds the level of 0.5 amplitude (15 mm) from the control reflector, and the conditional length does not exceed the allowable value for longitudinal and transverse defects; or an extended (regardless of length) defect, the signal amplitude from which does not exceed the level of 0.5 of the amplitude from the control reflector;
P - delamination or other defect (sunset, non-metallic inclusion), the signal amplitude from which exceeds the amplitude from the control reflector (flat-bottomed hole);
RA - delamination or other permissible defect, the signal amplitude from which does not exceed the amplitude from the control reflector (when controlled by the PC transducer).
4.6.3. When measuring the thickness of the RS, the transducer must be installed on the surface of the pipe (p.); as a rule, the acoustic axes of both piezoelectric plates must be in the axial plane of the pipe.
5. EVALUATION OF THE RESULTS OF ULTRASONIC TESTING
5.1. Based on the results of measuring the pipe wall thickness, a conclusion is given on compliance with the requirements specified in the technical specifications for pipes or other NTD.
5.2. The evaluation of pipe metal continuity based on the results of ultrasonic testing is carried out in accordance with the requirements established in the standards or specifications for pipes.
5.3. In the absence of technical requirements for assessing the quality of pipes in standards, specifications, drawings, it is recommended to use regulatory requirements in accordance with .
6. REGISTRATION OF THE RESULTS OF CONTROL
6.1. The results of ultrasonic testing of pipes must be recorded in the registration log, in the conclusion, and, if necessary, in the control card.
6.2. The log should show:
Order number;
Number of controlled pipe;
Pipe dimensions and material;
Standard, TU for pipes;
Technical documentation for ultrasonic testing;
The depth of the risks for setting the sensitivity (see );
The area of the flat-bottomed hole in the sample (see);
Type of ultrasonic flaw detector and thickness gauge;
Transducer type and input angle;
Operating frequency of ultrasonic vibrations.
An example of filling out a journal and designing a control card is indicated in.
It is allowed, if necessary, to give an opinion on a batch of pipes of the same size, one steel grade (with a list of rejected pipes and an abbreviated record of defects in accordance with paragraphs,).
7. SAFETY INSTRUCTIONS FOR ULTRASONIC TESTING
7.1. When carrying out work on ultrasonic testing, the flaw detector operator must be guided by the “Rules for the technical operation of consumer electrical installations” and “Safety regulations for the operation of consumer electrical installations”, approved by the USSR State Energy Supervision Authority on December 21, 1984, as well as GOST 12.2.007.0 “Electrical products. General safety requirements” and GOST 12.2.007.14 “Cables and cable fittings. Safety requirements".
7.2. Persons at least 18 years of age who have been instructed in safety rules (with an entry in the log), who have a certificate of knowledge of the above rules (clause 7.1), as well as the production instructions of the enterprise and this guidance document, are allowed to work on ultrasonic testing.
7.3. Safety briefing is carried out in accordance with the procedure established at the enterprise.
7.4. Fire safety measures are carried out in accordance with the requirements of the "Model fire safety rules for industrial enterprises", approved by the GUPO of the Ministry of Internal Affairs of the USSR in 1975 and GOST 12.1.004 " Fire safety. General requirements".
7.5. Before turning on the flaw detector, the flaw detector operator must make sure that there is a reliable grounding. The grounding of the flaw detector in the workshop must be carried out in accordance with the requirements of GOST 12.1.030 “SSBT. Electrical safety. Protective earth, nulling.
Grounding of ultrasonic flaw detectors is carried out by a special residential portable wire, which should not simultaneously serve as a conductor of the operating current. As a grounding conductor, a separate core should be used in a common sheath with a phase wire, which should have the same cross section as it.
Use neutral wire for grounding is prohibited. The cores of wires and cables for grounding must be copper, flexible, with a cross section of at least 2.5 mm.
7.6. Plug sockets for portable electrical appliances must be equipped with special contacts for connecting a grounding conductor. In this case, the design of the plug connection should exclude the possibility of using current-carrying contacts as grounding contacts. The connection of the grounding contacts of the plug and the socket must be carried out before the current-carrying contacts come into contact; the order of shutdown must be reversed.
7.7. Connecting the flaw detector to the power supply and disconnecting it is carried out by the electrician on duty. At specially equipped posts, a flaw detector can be connected by a flaw detector.
7.8. It is strictly forbidden to work under lifting mechanisms, on unstable shaky structures and in places where damage to the power supply wiring of flaw detectors is possible.
7.9. When used in the control area lifting mechanisms the requirements of the "Rules for the Construction and Safe Operation of Cranes", approved by the USSR Gosgortekhnadzor in 1969, must be taken into account.
7.12. In noisy workshops, it is necessary to use individual noise protection equipment - noise suppressors - in accordance with GOST 12.4.051.
7.13. Where possible, the workplaces of flaw detectorists should be fixed. If welding or other work involving bright lighting is carried out at a distance of less than 10 m from the place of control, it is necessary to install shields.
7.14. Accessories used by the flaw detectorist: oilers, cleaning rags and paper should be stored in metal boxes.
7.15. During ultrasonic testing, one should be guided by the "Sanitary norms and rules for working with equipment that creates ultrasound transmitted by contact into the hands of workers”, No. 2282-80, approved by the Chief State Sanitary Doctor of the RSFSR on December 29, 1980.
7.16. According to the requirements of sanitary norms and rules No. 2282-80 and order No. 700 of 19.06.84 of the Ministry of Health of the USSR, flaw detectorists entering work must undergo a mandatory medical examination. Hired personnel must undergo a periodic (once a year) medical examination,
7.17. After capital and preventive maintenance flaw detectors with transducers must be checked for acceptable levels ultrasonic field - according to GOST 12.1.001. At the same time, the parameters of the ultrasonic field acting on the hands of the flaw detectorist should not exceed the values given in the sanitary norms and rules No. 2282-80. The results of measurements of the parameters of the ultrasonic field must be documented in a protocol in the form 334, approved by order of the Ministry of Health of the USSR dated 04.10.80 No. 1030.
7.19. To protect hands from exposure to contact media and ultrasound during contact transmission, flaw inspectors must work in mittens or gloves that do not allow the contact medium to pass through.
In this case, it is necessary to use two pairs of gloves: outer - rubber and inner - cotton or two-layer according to GOST 20010.
7.20. In the cold and transitional period of the year, flaw detectorists must be provided with warm overalls according to the standards established for this climate zone or production.
APPENDIX 1
Recommended
METHODS OF COUPLING THE SURFACES OF THE TRANSDUCER AND PIPE
1. Treatmentsurfacesconverter
In order to ensure reliable contact, the working surface of the transducer is processed to match the corresponding surface of the pipe being tested. It is recommended to have a set of transducers that covers the range of pipe diameters with an interval of ±10% (for example, with transducer surface radii of 31, 38, 46 mm, the range of tested pipes is covered from 57 to 100 mm).
To mark the case (prism) of the transducer, it is advisable to make transparent templates (made of plexiglass) with risks (a) corresponding to the angles of inclination of the acoustic axis of the transducer (30° and 40°). On the prism of the transducer, a line is drawn through the input point, corresponding to the angle α of inclination of the acoustic axis (see b). The template is applied to the body of the transducer, while the acoustic axis of the transducer must coincide with the corresponding line on the template (see c). Then, an arc with a radius is marked on the transducer R. Initially, the prism is processed with a file or on an emery wheel, and then the surface is finished with a sandpaper, which is placed on a pipe segment. The accuracy of finishing is checked using a template.
As the converter wears out, repeat the above operations.
2. Applicationstabilizingsupports
When testing along a cylindrical surface, it is allowed to use stabilizing supports (Fig. 2) fixed on the transducer. The dimensions of the supports depend on the types and dimensions of the transducers used.
Schememarkupandfine-tuningsurfacesconverter
a - template; b - body (prism); c - marking scheme; g - debugging
Heck. 1
Supportforobliqueconverters
indicativedimensions, mm:
A ≤ H; B = in + 2; With = 8 ÷ 12; S = 2 ÷ 3; r = 5 ÷ 7
n =6 ÷ 15 (dependsfromtypeconverter);
a - sketchsupports; b - schemeinstallationssupports
Heck. 2
Support overhang (size h) relative to the transducer surface is calculated by the formula:
R- outer radius of the pipe;
r- support radius;
n- converter boom;
S- support wall thickness.
Examplecalculation.
When checking a pipe with a diameter of 60 mm and dimensions r= 6 mm, n= 12 mm, S= 2 mm
departure h= 1 mm.
It is allowed to use supports of other designs that provide the necessary position of the transducer, for example, nozzles made of wear-resistant material (fluoroplastic, caprolon, etc.)
APPENDIX 2
Reference
TYPES OF CONTACT MEDIUM
1. ContactWednesdayChernivtsiengineeringfactorythem. Dzerzhinsky (copyrightcertificate № 188116)
1.1. The contact medium is an aqueous solution of polyacrylamide and sodium nitrite in the following ratio (%):
polyacrylamide - from 0.8 to 2.0;
sodium nitrite - from 0.4 to 1.0;
water - from 98.8 to 97.0
1.2. Cooking method
In a vessel with a volume of about 10 liters, equipped with a stirrer with an angular speed of 800-900 rpm, 4 liters of water and 1.5 kg of 8% technical polyacrylamide are loaded, stirred for 10-15 minutes until a homogeneous solution is obtained.
Then add 600 ml of 100% sodium nitrite solution.
2. ContactWednesdayon thebasiscarboxymethyl cellulose(copyrightcertificate№ 868573)
2.1. The contact medium is an aqueous solution of CMC, synthetic soap and glycerin - according to GOST 6259 in the following ratio (%):
soap synthetic fatty acid fractions
C5-C6 or C10-C13 (25% solution) - from 7 to 15;
carboxymethylcellulose (CMC) - from 3 to 5;
glycerin - from 1 to 8;
water - the rest
The industry produces carboxymethyl cellulose grades 85/250, 85/350 and others according to MRTU 6-05-1098 in fine-grained fibrous and powdered states.
2.2. The contact medium is obtained by stirring carboxymethyl cellulose in water for 5-10 minutes, then the solution is kept for 5-6 hours until the CMC is completely dissolved.
Note. The consumption of a contact medium of any kind is approximately 0.3 kg per 1 m2 of pipe.
APPENDIX 3
Recommended
REGULATORY REQUIREMENTS FOR PIPES FOR ULTRASONIC TESTING AND EVALUATION OF METAL CONTINUITY
These regulatory requirements can be used for ultrasonic testing of pipes in the absence of technical requirements in standards, specifications or other regulatory and technical documentation.
The object of control is pipes made of carbon and alloy steel grades St3, 20, 15GS, I5XM, 12X11V2MF, etc.
Technicalrequirements
1. Volumecontrol
1.1. The control of longitudinal and transverse defects is carried out in one direction by inclined transducers, shear waves, in a volume of 100% at the ends of the pipes for a length equal to twice the thickness, but not less than 50 mm, in two opposite directions.
The control of delaminations at the ends of pipes over a length equal to twice the thickness, but not less than 50 mm, is carried out by PC transducers (longitudinal waves).
1.2. Wall thickness control is carried out at the ends of the pipes and in the middle part at four points along the perimeter of the pipe with a step of 90°.
2. Sensitivitycontrol
2.1. Sensitivity during control by transverse waves is adjusted according to rectangular risks - according to GOST 17410 with a depth of 10% of the nominal thickness of the pipe wall, but not more than 2 mm, a width of 1.5 mm, a length of 100 mm.
2.2. Sensitivity during control by longitudinal waves is adjusted according to a flat-bottomed reflector - according to GOST 17410:
Diameter 3.0 mm (area 7 mm2) - for pipe wall thickness up to 10 mm;
Diameter 3.6 mm (. area 10 mm2) - for pipe wall thickness over 10 mm to 30 mm;
Diameter 5.1 mm (area 20 mm2) - for pipe wall thickness over 30 mm.
3. Graderesultscontrol
3.1. Unacceptable defects include:
point and extended defects, the signal amplitude from which exceeds the control level (30 mm);
extended longitudinal defects with a reflected signal amplitude of more than 0.5 of the amplitude of the control mark, the nominal length of which is more than 100 mm for pipes with a diameter of more than 140 mm and more than 65 mm for pipes with a diameter of 57 to 140 mm;
extended transverse defects with a reflected signal amplitude of more than 0.5 amplitude from the control mark, the nominal length of which along the arc of the outer surface is more than 50 mm.
Note. The assessment of the depth of scratches and the conditional length of longitudinal and transverse defects is given on the basis of the norms of the "Technological Instructions for Ultrasonic Quality Control of Pipe Metal" VNIIPTkhimnefteapparatura, Volgograd, 1980, agreed with TsNIITmash, Moscow, 1980, and VNITI, Dnepropetrovsk, 1980 ., designed to evaluate pipes manufactured in accordance with GOST 8731 and used for the manufacture of steam and hot water pipelines for tying the PPR-600 furnace instead of pipes with technical requirements according to TU 14-3-460.
3.2. Inadmissible delaminations include defects, the signal amplitude from which exceeds the signal amplitude (30 mm) from a flat-bottomed reflector.
3.3. Maximum deviations in pipe wall thickness should not exceed:
15%, - 10% - for pipes with a diameter of up to 108 mm;
20%, - 5% - for pipes with a diameter of more than 108 mm.
Note. Thickness deviations are indicated in accordance with the requirements of TU 14-3-160.
APPENDIX 4
DETERMINATION OF CONTROL COURSE
The complexity of ultrasonic testing of a pipe includes the time spent on monitoring longitudinal and transverse defects, delaminations at the ends of pipes, and measuring the wall thickness.
The estimated time to move the transducer depends on the speed and scan step and is determined by the formula:
D- outer diameter of the pipe, mm;
L- pipe length, mm;
l 0 is the length of the pipe section to be checked for delamination, mm;
v- scanning speed, mm/s;
t- scanning step, mm
Taking into account the performance of auxiliary operations (setting the flaw detector, measuring and marking defects, recording inspection results, etc.), additional time is required (up to 20-30% of the calculated one). Thus, the total time for pipe inspection is:
T= (1.2 ÷ 1.3) T 0.
For example, to test a pipe with a diameter of 108 mm, a wall thickness of 10 mm and a length of 3 m (with l 0 =50 mm, v=80 mm/s, t= 6 mm) estimated time T0 = 69 min, total labor intensity T= 83-90 min.
It takes approximately 1 minute to measure the wall thickness for each point (to measure four points in three sections - 12 minutes).
|
№ |
№ |
Mill- |
Mar- |
Length |
Dia- |
Tol- |
NTD |
Type |
Type |
Hour- |
Glu- |
Ultrasound results |
Ras- |
Surname |
Concluding |
|||||
|
measured |
That- |
extended |
||||||||||||||||||
|
Transverse |
||||||||||||||||||||
|
GOST |
DUK-66PM |
D-4.5 |
||||||||||||||||||
|
TU 14-3-460-75 |
UD2-12 |
|||||||||||||||||||
D-4.5: D - point invalid defect; 4.5 - location depth (mm);
BD-0-60: BD - extended invalid defect; 0 - defect on the outer surface; 60 - conditional length (mm);
PA< 10: PА - допустимое расслоение, < 10 - эквивалентная площадь (мм2);
2A-8: 2A - two point allowable defects; 8 - location depth (mm).
Map of ultrasonic testing of a pipe (pipe development Ø 89
3. Transverse defects _________________________________________________________
_____________________________________________________________________________
(absent, available - give a list)
4. Point defects _________________________________________________________
_____________________________________________________________________________
(absent, available - give a list)
5. Bundles _________________________________________________________________
_____________________________________________________________________________
(absent, available - give a list)
The pipe is recognized ________________________________________________________________
_____________________________________________________________________________
(good, defective)
Ultrasound flaw detector ______________________________________________ Signature (surname)
Head of NMK Laboratory _________________________________ Signature (surname)
Rules for the Construction and Safe Operation of Pressure Vessels (1987)
E 1.1.1; E 1.1.3; E 1.3.1; E 2.13.2; In 1.1.1; B 1.1.2; In 1.1.6; B 1.1.7
Sanitary norms and rules for working with equipment that creates ultrasound transmitted by contact to the hands of workers (1960)
Page 1
Incoming inspection of pipes should include all types of checks, including flaw detection, to confirm their compliance with the requirements of standards and specifications. Transportation, preparation and inspection casing pipes must be made in accordance with the manufacturer's requirements.
Incoming control of pipes is carried out for their compliance with the technical requirements set forth in the normative and technical documentation for pipes.
The input control of pipes and fittings of foreign supply is also carried out in accordance with the above provisions.
Pipe incoming inspection areas are specialized organizational units and are not subordinate to shops that produce marketable products. The main task of the sites is to check the continuity of pipes, steel grade, grain size and reject defective pipes as much as possible.
During the incoming inspection, pipes and materials must be checked for defects and deterioration of their quality caused by violations of the established rules for their storage and transportation. During operational control, it is necessary to check the correctness of the preparation of pipes and their assembly for welding, as well as to control the technological parameters of the welding process and the quality of the weld. It is necessary to control the correctness of the geometry of the groove of the welded pipe edges, the size of the gaps in the joints and the displacement of the welded edges. Using preheating it is necessary to control the temperature of the near-weld sections of pipes before and during welding, and in electric resistance welding, check the presence and quality of cleaning the surface of the pipes under the contact shoes of the welding machine.
The enterprise should carry out incoming inspection of pipes, forgings, parts welded joints and welding consumables for their compliance with the requirements of these Rules, standards, specifications and design documentation.
The enterprise must carry out incoming inspection of pipes, forgings, parts of welded joints and welding consumables for their compliance with the requirements of these Rules, standards, specifications and design documentation.
An analysis of the accident rate for new tubing (with a service life of up to 5 years) showed that due to the lack of pressure testing during the input inspection of pipes, an additional 3% of unnecessary repairs from the total number of PRS occur. Corrosion destruction is typical for tubing of all plants. Pipes of the Nizhnednepropetrovsk pipe-rolling plant are most susceptible to corrosion, followed by Japanese and Austrian pipes. Deviation geometric parameters threads leads to its erosion on the pipes. The percentage of such defects is high in the pipes of the Sumgait, then Nizhnednepropetrovsk, Rustavi, Kamensk-Ural plants. It should be noted high quality threaded connections imported pipes.
An analysis of the accident rate for new tubing (with a service life of up to 5 years) showed that due to the lack of pressure testing during the input inspection of pipes, an additional 3% of unnecessary repairs from the total number of PRS occur. Corrosion destruction is typical for tubing of all plants. Pipes of the Nizhnednepropetrovsk pipe-rolling plant are most susceptible to corrosion, followed by Japanese and Austrian pipes. The deviation of the geometrical parameters of the thread leads to its erosion on the pipes. The percentage of such defects is high in the pipes of the Sumgait, Nizhnednepropetrovsk, Rustavi, Kamensk-Ural plants. It should be noted the high quality of threaded connections of imported pipes.
7.1 Pipe products supplied to construction sites are subject to incoming control, carried out in two stages, which includes survey and rejection (for pipe products subject to technical supervision in accordance with RD-03.100.50-KTN-122-13).
7.2 The first stage of incoming control is carried out by the customer's representative during the unloading of products at the destination. By decision of the customer, the first stage of incoming control is carried out jointly with a representative building control customer. The involvement of specialists from the building control body of the customer at the first stage of incoming control is carried out on a separate application.
7.3 During the implementation of the first stage of input control, the following is performed:
Checking incoming products for compliance with technical requirements, working documentation, quality certificates (or declarations of conformity);
Checking the presence of markings according to requirements normative documents, as well as their compliance with the data specified in the passports and certificates;
Verification of serial numbers of products with technical supervision data for products that have been accepted by the customer’s technical supervision representative at the manufacturing plant and shipped to the customer’s address (only for supervised products supplied by third-party organizations (not OST) that repack MT during work (not included to the OST Development Program) for the reconstruction railway tracks, roads and other communications, and having direct contracts with Transneft Nadzor LLC for construction control and technical supervision services);
Checking the availability of originals (or duly certified copies) of passports and certificates (or declarations of conformity) certifying the compliance of products with the specifications for delivery;
Checking the presence in passports and certificates (or declarations of conformity) of a mark on the acceptance of products by the technical supervision of the customer at the manufacturer's plant;
Inspection of products for shipping damage.
7.4 Based on the results of the first stage of the input control, an input control report is drawn up in the form of Appendix A OR-03.100.50-KTN-120-10. If a decision is made on non-conformity of products, claim work is carried out in accordance with contractual obligations.
7.5 The second stage of control is carried out on a commission basis with the participation of representatives of the work foreman, the quality control service of the contractor, the Customer and the Customer’s construction control and in accordance with technological maps input control, which are part of the agreed and approved WEP, after unloading at the construction site (storage site) using instrumental control tools. The results of the second stage of the input control of the MTR are drawn up by the Act in the form 3.3 VSN 012-88.
7.6 When performing work on the input control of fittings and valves, as well as at the second stage of the input control of pipe products, the following is carried out:
1) survey of pipes and pipeline parts:
For the absence of unacceptable mechanical damage, metallurgical defects and corrosion, including delaminations that go to the edge and surface of products, nicks, scratches, dents on the body and on the ends;
On the value of deviations of the pipe diameter and wall thickness from the nominal dimensions;
To comply with the deviations of the chamfer angle, end cut obliquity, end ovality, pipe curvature and removal of internal weld reinforcement to the requirements of applicable norms and rules;
The thickness of the pipe wall and the thickness of the factory insulation;
To the width of the uninsulated part of the pipe edge;
The angle of cutting the edges of the pipe and factory insulation;
For the availability of accompanying documentation and the completeness of the data provided in it; the presence of the technical specifications of the manufacturer of the products and the compliance of the supplied materials with these technical specifications;
For the presence of marking and its compliance with passport data and the manufacturer's specifications;
For the absence of unacceptable surface defects in welds;
2) control over the repair of pipes with permissible surface defects, according to a technology that meets the requirements of the current rules and regulations, with the execution of acts of the established form;
3) control of the state of shut-off valves (gate valves), check valves, safety and control valves, pumping equipment;
4) control of the correct storage of pipes, pipeline parts, fittings and equipment;
5) checking the availability of originals (or duly certified copies) of certificates (or declarations of conformity) and passports, their compliance with incoming materials, products and equipment (including compliance with the equivalent carbon content design solutions);
6) measurement parameters:
Pipe ends, parts (diameter, ovality, wall thickness, dents);
Outer diameter of the body of pipes, parts;
Deviations of wall thickness at the ends;
Pipe edge parameters, details;
pipe curvature;
Kosina cut ends of pipes, parts;
The quality of the surface and welds of pipes;
Ultrasonic thickness measurement of pipe walls;
7) Bending quality control:
Checking the absence of defects in the stretched part of the seam;
Control of places of deformations of cold bend bends
Checking the ovality of the ends of the bends and the curved part
7.7 Methods and scope of control.
1) Visual and measuring control:
Visual 100% of all pipes, fittings and valves,
Instrumental in the amount of 5% selectively, plus products (pipes, parts), ultrasonic pipe wall thickness measurement in the amount of 5% selectively, if one pipe with unacceptable parameters is detected - 100% control of the entire batch of pipes.
2) For pipes with a factory insulating coating, the following is additionally carried out:
Continuity control of the factory insulating coating (continuity test - 5% of pipes, if a defect is detected, the scope of the check is doubled, if a defect is detected again - the entire batch is rejected);
Measurement of the thickness of the insulating coating (electromagnetic (magnetic) thickness measurement of the insulating coating in the amount of 5% selectively, upon detection of one pipe with unacceptable coating parameters in appearance - 100% batch control).
3) For pipes with factory thermal insulation coating additionally carried out:
Control of the thickness of the thermal insulation coating;
Control of the integrity of the thermal insulation coating.
7.8 Timing of the SC.
7.8.1 The performer of the work shall, in time sufficient for the mobilization of the SC specialists, but not less than 1 day in advance, notify the deadlines for completing the work and presenting them for examination. Notification of the IC body about the need to conduct control measures for the acceptance of work performed, if it is necessary to present work that requires specialized control and measuring equipment, it is carried out within 3 working days.
7.8.2 Deadlines for carrying out routine maintenance for the implementation of construction control during the incoming inspection of pipes, valves, shaped products, equipment and materials during the construction of the linear part of the MN and MNPP should be calculated based on the volume of construction and installation work performed, taking into account 100% visual and 5% instrumental control, but should not exceed 1 working day after the work is submitted for control / examination by the construction contractor.
7.8.3 Completeness control executive documentation carried out by the SC personnel on a daily basis upon completion of the relevant work at the facility.
7.8.4 Routine work on the implementation of construction control during the incoming inspection of pipes, valves, fittings, equipment and materials during the construction of the linear part of MN and MNPP are given in Table 2.
Table 2 - Routine work on the implementation of construction control during the input control of pipes, valves, fittings, equipment and materials.
| stage number | Name of works or technological stages | Object, control parameters | A document confirming the completion of the stage and the control performed | IC document based on the results of the performed control | ||
| 7.1 | Carrying out routine work on incoming control at the first stage (carried out for pipe products subject to technical supervision in accordance with RD-03.100.50-KTN-122-13). Control of accompanying documents for valves, fittings, equipment and materials. | |||||
| 7.1.1 | Control of the completeness of passports, certificates (or declarations of conformity) of the manufacturer. | The control parameters are determined by RD-93.010.00-KTN-011-15, OR-03.100.50-KTN-120-10, PD and PPR: 1. Compliance of the supplied equipment with the project requirements for strength, performance characteristics, climatic performance and operating conditions. 2. Availability of originals (or duly certified copies) of certificates (or declarations of conformity) certifying the compliance of shut-off valves, fittings with specifications for delivery with an acceptance stamp. 3. Checking the availability of accompanying documentation for spherical bottoms (passports, certificates (or declarations of conformity), specifications): original documents or duly certified copies must be submitted; 4. The presence of markings in accordance with the requirements of regulatory documents. 5. Availability of a passport with signatures and seals of representatives of the QCD and SC. | Constantly. 100% for each document. | 1. Entries in the "Journal of input control". 2. Warnings and instructions. 3. Journal of comments and suggestions. 4.Journal of the customer's IC. 5. Journal of the IC contractor. | ||
| 7.1.2 | Preparatory work before the start of loading and unloading operations. | The control parameters are determined by OR-03.100.50-KTN-120-10, VSN 008-88, Order of Rostekhnadzor 533 dated 11/12/2013, Order 533 dated 11/12/2013, PD and PPR: 1. Preparation of incoming control zones and areas for storing products . 2. Preparation of access roads to and between sites. 3. Ensuring lighting of work places. 4. Laying pipes, shut-off valves, fittings on inventory linings with stops at storage sites. 5. Placement of the necessary lifting mechanisms, compliance of rigging equipment, inventory, tools with design ones. 6. Appointment of persons responsible for the performance of work, labor protection and safe operation cranes. | Visual -100% | 1. Journal of input control. 2. Warnings and instructions. 3. Journal of comments and suggestions. 4. Journal of the customer's IC. 5. Journal of the IC contractor. | Permission to unload pipes, fittings, fittings and store them.** | |
| 7.1.3 | Unloading and storage of pipes, valves, fittings, equipment and materials. | The control parameters are determined by OR-03.100.50-KTN-120-10, VSN 008-88, Order of Rostekhnadzor 533 dated 11/12/2013, OR-03.100.50-KTN-120-10, PD and PPR: 1. Unloading pipes, shut-off fittings, fittings using grips equipped with liners and linings. 2. Compliance of the storage site with the requirements. 3. Storage of pipes. | Visual -100%. Instrumental - 5%. | Roulette. | 1. Journal of input control. 2. Warnings and instructions. 3. Journal of remarks. 4. Journal of the customer's IC. 5. Journal of the IC contractor. 6. Report on the results of testing pipes with factory coating at the first stage of incoming inspection (according to the form of Appendix A OR-03.100.50-KTN-120-10). | |
| 7.1.4 | Carrying out routine work on incoming control at the first stage (carried out for pipe products subject to technical supervision in accordance with RD-03.100.50-KTN-122-13) | 1. Checking incoming products for compliance with technical requirements, working documentation, quality certificates (or declarations of conformity); 2. Checking the presence of markings in accordance with the requirements of regulatory documents, as well as their compliance with the data specified in passports and certificates (or declarations of conformity); 3. Reconciliation of serial numbers of products with technical supervision data for products that have been accepted by the customer’s technical supervision representative at the manufacturing plant and shipped to the customer’s address - only for supervised products supplied by third-party organizations (not OST) that repackage MT in the course of work ( not included in the OST Development Program) for the reconstruction of railways, roads and other communications, and having direct contracts with Transneft Nadzor LLC for construction control and technical supervision services; 4. Checking the availability of originals (or duly certified copies) of passports, certificates (or declarations of conformity) certifying the compliance of products with the specifications for delivery. 5. Checking the presence in passports and certificates (or declarations of conformity) of a mark on the acceptance of products by the technical supervision of the customer at the manufacturer's plant; 6. Checking the products for any damage that occurred during transportation. | Visual -100% | 1. Journal of input control. 2. Warnings and instructions (if the customer's IC authority is involved). 3. Journal of the IC of the customer (in case of involvement of the body of the IC of the customer). 4. Report on the results of testing pipes with factory coating at the first stage of incoming inspection (according to the form of Appendix A OR-03.100.50-KTN-120-10). | ||
| 7.2 | Carrying out routine maintenance on the input control of fittings and valves, as well as at the second stage of the input control of pipe products | |||||
| 7.2.1 | Quality control of pipes, valves, fittings, materials and equipment using instrumental control. | Checking for compliance with OTT and RD-23.040.00-KTN-073-15 in terms of: - the absence of unacceptable mechanical damage, metallurgical defects and corrosion, including delaminations that go to the edge and surface of products, nicks, scratches, dents on the body and at the ends; - deviations of the pipe diameter and wall thickness from the nominal dimensions; - compliance of the value of deviations of the chamfer angle, the obliqueness of the cut of the ends, the ovality of the ends, the curvature of the pipes and the removal of the reinforcement of the internal seam with the requirements of the current norms and rules; - lengths of uninsulated sections of pipe ends; - availability of marking and compliance with its passport data; - the absence of unacceptable defects in welds; - thickness and continuity of the insulating coating. For pipes with heat-insulating coating: - control of the thickness and integrity of the heat-insulating coating. | Visual -100%; Instrumental - in the amount of 5% selectively. Ultrasonic wall thickness measurement in a volume of 5% (at least at five points evenly distributed along the circumference. If a defect is detected, the inspection volume is 100% of the lot. | Magnifier. Roulette. measuring device of geometrical parameters of welded joints with measurement accuracy + 0.1 mm. Ultrasonic thickness gauge. Caliper ШЦ 500-1600 (Depending on the Du of the pipeline). Stenkomer. Pipe micrometer. Micrometer depth gauge. Ruler. Spark flaw detector. | 1. Journal of the customer's IC. 2. Journal of comments and suggestions 3. Warnings and instructions 4. General journal of work 5. Journal of the Contractor's IC. | Permission to use products. Acts of visual-measuring control (In the amount of % control)** |
| 7.2.2 | Monitoring the state of shut-off valves (gate valves) without an electric drive. | Checking the fittings for compliance with the requirements for compliance with the requirements of the project, RD-23.040.00-KTN-073-15 and OTT in terms of: - the absence of unacceptable mechanical damage, metallurgical defects and corrosion; - the absence of delaminations that go to the edge and surface of the products; - absence of nicks, scuffs, scratches, dents on the body, ends and on the connecting surfaces; - the value of the deviation of the wall thickness from the nominal size; - compliance with the project of the deviation of the angle of the chamfer and the factory cutting of the edges for welded gate valves; - ovality at the ends for welded products; - smoothness of movement of all moving parts of the reinforcement; - integrity and absence of damage to the steering wheel, handles (controls), protective insulation. | Visual - 100%. Instrumental - in the amount of 5% of the party. If a marriage is detected, the volume of control is 100% of the batch. | Magnifier. Roulette. Calipers. measuring device of geometrical parameters of welded joints with measurement accuracy + 0.1 mm, Ultrasonic thickness gauge. Caliper ШЦ 500-1600 (Depending on the Du of the pipeline). Stenkomer. Pipe micrometer. Micrometric depth gauge. Ruler. | 1. Journal of the customer's IC. 2. Journal of comments and suggestions 3. Warnings and instructions 4. General journal of work 5. Act on VIC; 6. Conclusion on ultrasonic testing 7. The act of acceptance and transfer of equipment for installation. 8. Journal of the IC contractor. | |
| 7.2.3 | Control of the state of the electric drive of shut-off valves. | The control parameters are determined by OTT-75.180.00-KTN-166-10: - compliance with the requirements of the type project, climatic version and operating parameters of the drive; - smoothness of rotation of the electric drive in manual and el. driving mode; - serviceability of the electric drive and electrical equipment; - tests according to EIC Chapter 1.8 Section 1.8.15. | Visual -100% the whole process of taking measurements. | 1. Journal of the customer's IC. 2. Journal of comments and suggestions 3. Warnings and instructions 4. General journal of work 5. Act of acceptance and transfer of equipment for installation. 6. Protocol for measuring insulation resistance. 7. Act on detected defects e-mail. equipment. 8. Journal of the IC contractor. | ||
| 7.2.4 | Testing of valves for strength, density and tightness. (For fittings not tested as part of the linear part. | 1. Checking the tightness of the stuffing box seal, gasket between the cover and the body, the top seal of the cover-spindle, the tightness of the valve, integrity drainage tubes and factory insulation. 2. Control of hydraulic tests of valves. | Visual -100% of the entire testing process. | 1. Journal of the customer's IC. behind construction. 2. Journal of comments and suggestions. 3. Act hydraulic test shutoff valve. 4. Warnings and instructions. 5. General work log. 6. Journal of the IC contractor. | Shipment permit for export to the route of products that have passed the input control.** | |
| 7.2.5 | Processing the results of input control. | Marking of products examined by building control: "P" - suitable; "R" - requiring repair; "U" - fit after repair; "B" - unsuitable: | Visual method for the presence of markings inside the pipe cavity with indelible paint. | 1. Act on the results of checking products for compliance with technical documentation in the form 3.3 VSN 012-88. 2. Entry in the input control log 3. Customer's IC log. 4. Journal of the Contractor's Inspectorate. | Shipment permit for export to the route of products that have passed the input control.** | |
| * - instruments and control instruments in accordance with OR-91.200.00-KTN-284-09. **- permission of the SC to perform the subsequent stages of work is issued in the cases specified in clause 7.2.16 of OR-91.200.00-KTN-108-16. |
8 The procedure for the implementation of construction control during the input control of insulating and thermal insulation materials, pipeline surface preparation and application of insulating and heat-insulating coating
8.1 During the input control of insulating materials, the following is checked:
Compliance of heat-shrinkable cuffs with the requirements of the project, the manufacturer's specifications, other norms and rules; completeness and warranty period
Conformity physical properties epoxy primer (primer) to the requirements of norms and rules;
Compliance of storage of insulating materials with the requirements of norms and rules;
Compliance of the gas used to heat the insulated joints with the requirements of the working documentation for the composition and climatic modification;
Compliance of hoses and burners used for heating insulated joints with the requirements of normative and technical documentation and technical design.
8.2 During the input control of heat-insulating materials, the following is checked:
Compliance of heat-insulating materials and products with project requirements.
Conformity couplings project requirements, integrity, geometric dimensions.
8.3 Methods and scope of control.
8.3.1 Visual and measuring control:
1) selective inspection of polymer tapes, heat-shrink sleeves and other insulating materials in warehouses - 5% of the total volume, selective quality control of heat-shrink sleeves and tapes:
Inspection (quality and condition of the adhesive layer, absence of through damage, integrity of the couplings),
Instrumental (width, thickness of the tape, adhesion to the primed steel surface and in the overlap) * - 1 sample from the batch, but not less than 1 sample from 50 rolls
2) selectively checking the quality of the primer (glue, primer):
Inspection (homogeneity), package integrity, marking, expiration date
Instrumental - density[*], viscosity*, dry residue*, adhesion* - 1 sample from a batch.
8.4 Timing of the SC.
8.4.1 The performer of the work shall, in time sufficient for the mobilization of the SC specialists, but not less than 1 day in advance, notify the deadlines for completing the work and presenting them for examination. Notification of the IC body of the need to carry out control measures for the acceptance of work performed, if it is necessary to present works that require specialized control and measuring equipment, is made 3 working days in advance.
8.4.2 The timing of routine maintenance for the implementation of construction control during the input control of insulating and heat-insulating materials, preparing the surface of the pipeline and applying insulating and heat-insulating coatings during the construction of the linear part of the MN and MNPP should be calculated based on the volume of construction and installation work performed, taking into account 100% visual and 5% of instrumental control, but should not exceed 1 working day after the work is submitted for control/survey by the construction contractor.
8.4.3 The control of the completeness of execution of the as-built documentation is carried out by the personnel of the IC on a daily basis upon the completion of the relevant work at the facility with a note in the construction control log of the customer and the contractor.
8.4.4 Routine work on the implementation of construction control during the input control of insulating and heat-insulating materials, preparing the surface of the pipeline and applying insulating and heat-insulating coatings during the construction of the linear part of MN and MNPP are given in Table 3.
Note
Table 3 - Routine work on the implementation of construction control during the input control of insulating and heat-insulating materials, preparing the surface of the pipeline and applying insulating and heat-insulating
coatings
| stage number. | Name of works or technological stages | Object, control parameters | Method and scope of control by the UK | Devices and instruments of control* | A document confirming the completion of the stage and the control performed | Document, SC based on the results of the performed control |
| 8.1 | Preparatory work | |||||
| 8.1.1 | Control of compliance of insulating and heat-insulating materials (including repair materials) with the requirements of the project and OTT. | 1. Availability of production certification of the technology of applying an insulating coating and quality control of applying an insulating coating. 2. Availability of passports and certificates of conformity for insulating materials. 3. Correspondence of the batch number on the package with the number indicated in the passport. 4. Compliance with the type of insulating coating specified in the project. 5. No through damage to the insulating coating. 6. Compliance of the completeness of the delivered insulating materials with the requirements of the manufacturer's specifications (TUM linear dimensions, thickness, locking plate, two-component primer, longitudinal applicators) | Visual -100% Instrumental - 5% of the part | Micrometer Vernier caliper Tape measure | 1. Act on the results of checking products for compliance with technical documentation in the form 3.3 VSN 012-88. 2.Journal of input control 3.Journal of comments and suggestions. 4. Prescription 5. Journal of the customer's IC. 6. Journal of the IC contractor. | |
| 8.1.2 | Checking the conditions of transportation and storage of insulating materials, materials included in the set of thermal insulation of joints, instruments and equipment used for applying TUM and heat-insulating sleeves. | 1. Place, method, conditions of storage, excluding their damage, moisture and contamination in accordance with the requirements of technical specifications for materials. 2. Transportation - the integrity of the container. 3. Storage conditions and temperature before use 4. Contents 5. Availability valid documents about verification measuring instruments and equipment | Visual method as materials arrive. | Alcohol thermometer with measurement range - from minus 50°С to 50°С. | 1. Journal of comments and suggestions. 2. Input control log 3. Warnings and instructions 4. Customer's IC log. 5. Contractor's IC log | - |
| 8.1.3 | Simultaneously with the production certification of the technology for applying the FCM, the production certification of the repair technology is carried out, both for the factory insulating coating, and for the repair of the FCM after checking the adhesion for each type of applied factory insulation. | 1. No damage to the insulation coating before lowering | Spark flaw detector with a voltage of 5 kV per 1 mm of pipe insulation thickness + 5 kV for air gaps. Contractor's laboratory in the presence of the UK. | 1.Act of control of the integrity of the insulating coating 2.Prescription 3. Journal of the customer's IC. 4. Journal of the Contractor's Inspectorate. | - | |
| 8.2 | Quality control of applied insulating coatings | |||||
| 8.2.1 | Quality control of insulation of welded joints with heat-shrinkable cuffs in underground and overhead laying oil pipeline | |||||
| 8.2.1.1 | Cleaning the Weld Joint Surface | The control parameters are determined by the instructions of the manufacturers and the specifications for the materials used, PD, RD-23.040.00-KTN-366-09. 1. Degreasing with technical acetone. 2. Drying. 3. Compliance with the design of the materials used for sandblasting. 4. The degree of cleaning of welded joints. 5. The degree of roughness. 6. The degree of dust removal. | Instrumental - 100% welded joints | Cleaning standard, TK-5M Constant - K5 Adhesive transparent tape roughness sample, dedusting template | 1. Journal of insulation and laying works and repair of insulation 2. Journal of comments and suggestions. 3. Prescription. 4. Journal of the customer's IC. 5. Journal of the IC contractor. | |
| 8.2.1.2 | Applying epoxy primer. | 1. Dedusting the joint. 2. Heating of butt joints. 3. Application of epoxy primer. | Visual -100%. Instrumental - 100%. | Contact thermometer. Sticky transparent tape. | 1. Journal of insulation and laying works and repair of insulation 2. Journal of comments and suggestions. 3. Act on the results of checking products for compliance with technical documentation in the form 3.3 VSN 012-88 4. Prescription 5. Journal of the customer's IC. 6. Journal of the IC contractor. | |
| 8.1.2.3 | Application of heat-shrinkable cuffs. | The control parameters are determined by OTT-25.220.01-KTN-200-14, the instructions of the manufacturers of the materials used, PD: 1. Installation of the TUM and the locking plate 2. Compression and heat shrinkage of the cuffs. 3. Uniformity and density of compression of the surface of the welded joint. 4. Absence of corrugations, swellings, air cavities and bubbles, burn-throughs 5. The presence of overlap on the factory coating and overlap in the area of the lock plate. 6. Release of adhesive at the ends of the sleeve after cooling. 7. The value of adhesion to metal, factory insulating coating, welded joint. 8. TUM coating thickness. 9. Checking the adhesion of TUM after thermal stabilization 24 hours after application. | Visual -100% Instrumental - 5% Adhesion - 1 cuff of 10 insulated joints, but not less than 1 per shift. | Ruler. Adhesion meter. The thickness gauge is magnetic. | 1. Journal of insulation and laying works and repair of insulation 2. Journal of comments and suggestions. 3. The act of testing protective coatings welded joints of pipelines 4. The act of determining the adhesion of protective coatings from polymeric tapes 5. Warnings and instructions 6. Journal of the customer's IC. 7. Journal of the IC contractor. | Acts of visual - measuring control (In the amount of % control) |
| 8.1.2.4 | Repair of damaged areas of factory insulation and TUM after checking for adhesion. | 1. Incoming control of repair materials 2. Availability of certified technology for repairing the insulating coating. | Visual -100%. | 1. Journal of insulation and laying works and repair of insulation 2. Journal of insulation repair. 3. Journal of the customer's IC. 4. Journal of the Contractor's Inspectorate. | ||
| 8.1.2.5 | Checking the integrity of the insulating coating and applying heat-shrinkable cuffs. | 1. The correctness of the control in accordance with the operating manual for the flaw detector. 2. No damage to the insulation coating before lowering. | Visual -100%. Instrumental - 100%. | Contractor's laboratory in the presence of an IC engineer. flaw detector electric energized 5 kV per 1 mm pipe insulation thickness + 5 kV for air gaps | 1. The act of monitoring the continuity of the insulating coating. 2. Warnings and prescriptions. 3. Journal of the customer's IC. 4. Journal of the Contractor's Inspectorate. | |
| 8.1.2.6 | If it is necessary to isolate the joints of pipes, bent bends, fittings, LZ, etc. having different types factory insulation is developed, agreed upon and certified in the generally accepted manner, the corresponding technical solution. | 1. No damage to the insulating coating before admission to the trench. | Visual -100%. Instrumental - 100%. Electric flaw detector with a voltage of 5 kV per 1 mm of pipe insulation thickness + 5 kV for air gaps | Contractor's laboratory in the presence of an IC engineer. | 1. The act of monitoring the continuity of the insulating coating. 2. Prescription. 3. Journal of the customer's IC. 4. Journal of the Contractor's Inspectorate. | AOCP/Permit to Lay Pipeline** (if underground laying pipeline, in the event of the expiration of the permit specified in the AOCP for the previous stage of work, is valid for 3 calendar days from the date of issuance of the permit) |
| 8.2.1.7 | Quality control of the insulation of completed underground sections of the pipeline. | 1. The cathodic polarization parameters must comply with GOST R 51164 and RD-29.035.00-KTN-080-10. 2. Connecting a temporary ECP no later than 3 months after backfilling. | Instrumental - 100%. | Customer's laboratory in the presence of SC. | 1. The act of assessing the quality of insulation of repaired areas by the method of cathodic polarization. 2. Journal of comments and suggestions. 3. Prescription. 4. Journal of the customer's IC. 5. Journal of the IC contractor. | - |
| 8.3 | Installation of couplings and couplings with seals at the joints of pipes with a heat-insulating coating | |||||
| Installation of couplings at the joints of pipes with a heat-insulating coating. | Control parameters are determined by OTT-25.220.00-KTN-176-15 and OTT-25.220.00-KTN-179-15. 1. The quality of the application of heat-shrinkable cuffs. 2. Dust removal of applied cuffs. 3. The quality of the installation of couplings. 4. Compliance with the technology of pouring material into couplings. 5. The quality of sealing couplings. | Visual -100% Instrumental - 100% | Probe, ruler. Duct tape | 1. Journal of insulation and laying works and repair of insulation 2. Journal of comments and suggestions. 3. Adhesion test report. 4. Prescription. 5. Journal of the customer's IC. 6. Journal of the IC contractor. | 1.AOCP/Permit for laying the pipeline** (in case of expiration of the permit specified in the AOCP for the previous stage of work, it is valid for 3 calendar days from the date of issuance of the permit) 2.VIC acts (In the scope of % control). | |
| * - control devices and instruments in accordance with OR-91.200.00-KTN-284-09 **- permission of the Investigative Committee to perform subsequent stages of work is issued in cases specified in clause 7.2.16 of OR-91.200.00-KTN-108 -sixteen. |
Incoming inspection of pipes and fittings should be carried out in accordance with the requirements of SNiP 3.01.01.-85*
During the incoming inspection of pipes and fittings, the following should be checked:
- Pipe size
- Number and date of specifications
- steel grade
- Batch number
- The results of mechanical tests with an indication of which numbers of melts these tests refer to
- Hydraulic test results
- X-ray result (if necessary)
On the inner surface of each pipe at a distance of 500 mm from one of the ends, indelible paint must be marked:
- manufacturer
- heat number
- nominal dimensions
- pipe number
- month and year of pipe manufacture
- carbon equivalent
On the outer surface of the pipes, at a distance of 100 mm from the end of the pipe, the following data should be stamped with stamps:
- pipe number
- factory logo
After checking the conformity of the use of pipes for this construction, a visual-measuring control is carried out according to the certificate.
On the surface of the pipes are not allowed:
- cracks, flaws, sunsets of any size;
- scratches, risks and scuffs with a depth of more than 0.4 mm;
- local kinks, corrugations and dents;
- delamination at the ends of the pipes.
If delaminations are detected, then, according to the results of additional ultrasonic testing, the ends of the pipes with delamination are subject to cutting. In places affected by corrosion, the wall thickness of pipes or parts should not go beyond the minus tolerances established specifications to supply. Wall thickness measurement in this area must be performed using an ultrasonic thickness gauge with an accuracy of at least 0.1 mm.
Pipes are considered suitable provided that:
- less than 200 mm from the end do not exceed for pipes with a diameter, see GOST 10705-80,20295-80.3262-75, etc.
- deviations of the wall thickness at the ends do not exceed the limit values regulated by the relevant GOST 10705-80,20295-80,3262-75, etc.
- ovality of seamless pipes does not lead them out outside diameter behind limit deviations, GOST 10705-80,20295-80,3262-75, etc.
- the curvature of the pipes does not exceed 1.5 mm per 1 m of length, and the total curvature is not more than 0.2% of the pipe length, the oblique cut of the ends of the pipes does not exceed 2.0 mm.
1.4. It is allowed to clean the surface of pipes and parts of scratches, scratches and scuffs with a depth of more than 5% of the thickness, as well as areas of the surface affected by corrosion, provided that the wall thickness after the elimination of defects does not go beyond the established tolerances.
1.5. It is allowed to correct smooth dents at the ends of pipes with a depth of not more than 3.5% of the pipe diameter. Editing should be carried out with shockless expansion devices. At an ambient temperature below 5 degrees. C, and on pipes of strength class up to 42 and above - regardless of the ambient temperature, straightening should be carried out with mandatory heating by 100 - 150 degrees. WITH.
1.6. It is allowed to repair by welding defects in the edges of pipes (nicks, scuffs) with a depth of not more than 5 mm, followed by mechanical cleaning of the places where defects are corrected until the necessary bevel of the edges is restored.
1.7. The sorting of pipes is carried out by representatives of the construction and installation organization, the customer, the technical supervision of the customer. An act is drawn up for rejected pipes, which should contain the following data:
- Name of the supplier plant
- Pipe diameter and wall thickness
- steel grade
- Certificate number, pipes, heats
- Date of receipt of pipes and time of their inspection
- The exact name of the detected defects, their configuration and location
- The possibility of using pipes for this construction
Pipe quality control does not end with an inspection at the unloading site. Monitoring of the state of the pipes continues during the entire period of pipeline construction.
When accepting pipes with a factory insulating coating, the condition of the coating is also checked by a visual method, and, if necessary, by an instrumental method (using a spark flaw detector). Upon detection of damage, an act is drawn up, which contains the following data:
- Place and date of inspection of the insulating coating of pipes;
- Pipe number and defect location;
- Type of defect (depth, area).
Input control of welding materials.
2.1. For each batch of electrodes, there must be a certificate indicating the brand (type) of electrodes, their diameter, manufacturer, date of manufacture, chemical composition of the wire and the result of testing the properties of the deposited metal. The use of welding consumables without a manufacturer's certificate is strictly prohibited.
2.2. The quality and integrity of the packaging and the guaranteed shelf life are checked.
2.3. To check the compliance of the electrodes with the requirements of GOST in terms of the quality of the coating, at least 10 and no more than 200 electrodes from the batch are selected from each packing place from different packs.
The selected electrodes are subjected to external examination without the use of devices to increase the image. The following defects are measured:
The length of dents, hairline cracks, areas of mesh cracking on the surface of the coating and bare areas of the rod with an error of not more than 1 mm (using a ruler), as well as the presence of bare sections of the rod, the depth of scratches, dents, scuffs, the size of the pores on the surface of the coating.
2.4. The coating of the electrodes must be uniform, dense, durable, without swelling, sagging, tears and cracks, superficial hairline cracks are allowed.
2.5. On the surface of the electrode coating are allowed:
- pores with a maximum outer size of not more than 1.5 of the coating thickness (but not more than 2 mm) and a depth of not more than 50% of the coating thickness, provided that the number of pores does not exceed two per 100 mm of the electrode length;
- surface longitudinal hairline cracks and local mesh cracks in a total number of not more than two per electrode with the length of each hairline crack or crack area not exceeding 10 mm.
2.6. Separate longitudinal scratches with a depth of not more than 25% of the coating thickness, as well as local dents with a depth of not more than 50% of the coating thickness, in the amount of not more than four, with a total length of up to 25 mm on one electrode, are allowed on the surface of the electrode coating.
Two local dents located on both sides of the electrode in the same cross section can be taken as one if their total depth does not exceed 50% of the coating thickness.
2.7. Local scuff marks on the coating surface are allowed if their depth does not exceed 25% of the coating thickness, and their number on one electrode is no more than two.
2.8. The difference in coating thickness in accordance with GOST 9466-75, when controlled with a micrometer, is determined in three longitudinally selected places of the electrode, offset one relative to the other by 50-100 mm in length and 120 degrees in circumference.
The measurement sites should be chosen in such a way that they fall on the central part of the electrode, i.e. retreating from each side of the electrode (from the contact part and its end) by at least 50 mm.
It is allowed to check the difference in coating thickness by other methods and special devices non-destructive method(usually in the middle of the electrode length), providing measurement accuracy with an error of 0.01 mm. In this case, it is necessary to carry out a specific brand of the device or its technical characteristics in the inspection report.
2.9. The difference in the thickness of the electrode coating should not exceed the values indicated in the table. This table does not apply to electrodes supplied according to special specifications.
2.10. The coating should not be destroyed by free fall of the electrode flat on a smooth steel plate from a height:
- 1m for electrodes with a diameter of 3.25 mm or less
- 0.25 m - for electrodes with a diameter of 4 mm or more.
In this case, partial chipping of the coating with a total length of up to 5% of the length of the coated part of the electrode is allowed.
Table 3.1 Permissible difference in thickness
| Nominal electrode diameter, mm | Permissible difference in coating thickness (mm) for different groups of electrodes | |
| 2,0 | 0,090 | 0,080 |
| 2,5 | 0,115 | 0,100 |
| 3,0 | 0,135 | 0,120 |
| 4,0 | 0,180 | 0,160 |
2.11 When checking the welding and technological properties of the electrodes, welding of the corresponding layer of the seam is carried out, for which the controlled electrodes are intended.
Welding is performed in all spatial positions on coils cut from the same pipes for which the electrodes are intended, or similar to them.
2.12. The welding and technological properties of the electrodes, subject to the modes and conditions determined by the passport and technical specifications for electrodes of a particular brand, must meet the following requirements:
- The arc is easily (from the first ignition) excited and burns freely;
- The coating melts evenly, without excessive spatter (with the exception of electrodes with a cellulose type of coating), pieces falling off and the formation of a "visor" that prevents the normal melting of the electrode when welding in all spatial positions;
- The slag formed during welding ensures the normal formation of weld layers and is easily removed after cooling;
- The weld metal has no cracks and surface pores.
2.13. The allowable number of defects in welds is determined in accordance with the requirements of GOST.
2.14. On individual electrodes, the total number of which should not exceed 10% of those selected for testing, it is allowed:
- Increase in the number of pores on the coating surface up to three per 100 mm of the electrode length;
- Increase in the length of surface longitudinal hairline cracks and areas of local mesh cracking on the coating surface up to 15 mm;
- Increase in the total length of dents on the coating up to 37.5 mm;
- Increase in the length of the area bare from the coating, adjacent to the contact end of the electrode protected from coating, up to 75% nominal diameter electrode, but not more than 3 mm;
- Increasing the number of local scuff marks on the coating surface to three.
2.15. If unsatisfactory results are obtained for the surface strength of the coating and the difference in the thickness of the coating of the electrodes, a re-check is carried out on twice the number of electrodes taken from the batch. The results of the retest are final and apply to the entire batch of electrodes as a whole.
2.16. Upon receipt of unsatisfactory results of checking the size and number of gas pores, repeated calcination (drying) of the controlled electrodes is allowed, followed by verification of this indicator.
