ISO/TC 44/SC 5 - Testing and inspection of welds

This document specifies techniques of digital radiography with the object of enabling satisfactory and repeatable results. The techniques are based on generally recognized practice and fundamental theory of the subject. This document applies to the digital radiographic testing of fusion welded joints in metallic materials. It applies to the joints of plates and pipes. Besides its conventional meaning, “pipe”, as used in this document, covers other cylindrical bodies such as tubes, penstocks, boiler drums and pressure vessels. This document specifies the requirements for digital radiographic X- and gamma-ray testing by either computed radiography (CR) or radiography with digital detector arrays (DDAs) of the welded joints of metallic plates and tubes for the detection of imperfections. It includes manual and automated inspection with DDAs. Digital detectors provide a digital grey value image which can be viewed and evaluated using a computer (Annex E). This document specifies the recommended procedure for detector selection and radiographic practice. Selection of computer, software, monitor, printer and viewing conditions are important, but are not the main focus of this document. The procedure specified in this document provides the minimum requirements for radiographic practice which permits exposure and acquisition of digital radiographs with equivalent sensitivity for the detection of imperfections as film radiography (specified in ISO 17636-1). This document does not specify acceptance levels for any of the indications found on the digital radiographs. ISO 10675 provides information on acceptance levels for weld inspection. If contracting parties apply lower test criteria, it is possible that the quality achieved will be significantly lower than when this document is strictly applied.

This document specifies techniques of radiographic testing of fusion-welded joints in metallic materials using industrial radiographic film techniques with the object of enabling satisfactory and repeatable results. The techniques are based on generally recognized practice and fundamental theory of the subject. It applies to the joints of plates and pipes in metallic materials. Besides its conventional meaning, “pipe” as used in this document covers other cylindrical bodies, such as tubes, penstocks, boiler drums and pressure vessels. This document does not specify acceptance levels for any of the indications found on the radiographs. The ISO 10675 series provides information on acceptance levels for weld evaluation. If contracting parties apply lower test criteria, it is possible that the quality achieved will be significantly lower than when this document is strictly applied.

This document specifies the sizes of test specimen and the procedure for carrying out transverse tensile tests in order to determine the tensile strength and the location of fracture of a welded butt joint. This document applies to metallic materials in all forms of product with joints made by any welded butt joint.

This document specifies the techniques for manual ultrasonic testing of claddings on steel applied by welding, rolling and explosion using single-transducer or dual-transducer probes. The test is intended to cover detection of two-dimensional or three-dimensional discontinuities in the cladding and in the region of the interface. This document does not give acceptance criteria nor define the extent of testing.

This document specifies the method to be used when describing test specimen location and notch orientation for the testing and reporting of impact tests on welded butt joints. This document applies to impact tests on metallic materials in all forms of product made by any fusion and pressure welding process. It is used in addition to the ISO 148 series and includes test specimen denomination and additional reporting requirements.

This document gives recommendations for specimen preparation, test procedures and their main objectives for macroscopic and microscopic examination.

This document specifies acceptance levels for the phased array ultrasonic testing technique (UT-PA) of full-penetration welds in low-alloy and/or fine-grained steels in the wall thickness range from 3,2 mm to 8 mm which correspond to the quality levels of ISO 5817. These acceptance levels are applicable to indications detected according to ISO 20601.

This document specifies acceptance levels for indications from imperfections in aluminium butt welds detected by radiographic testing. If agreed, the acceptance levels can be applied to other types of welds (such as fillet welds etc.) or materials. The acceptance levels can be related to welding standards, application standards, specifications or codes. This document assumes that the radiographic testing has been carried out in accordance with ISO 17636‑1 for RT-F (F = film) or ISO 17636‑2 for RT-S (S = radioscopy) and RT-D (D = digital detectors).

This document specifies acceptance levels for indications from imperfections in butt welds of steel, nickel, titanium and their alloys detected by radiographic testing. If agreed, the acceptance levels can be applied to other types of welds (such as fillet welds, etc.) or materials. The acceptance levels can be related to welding standards, application standards, specifications or codes. This document assumes that the radiographic testing has been carried out in accordance with ISO 17636‑1 for RT-F (F = film) or ISO 17636‑2 for RT-S (S = radioscopy) and RT-D (D = digital detectors).

This document specifies the application of the time-of-flight diffraction (TOFD) technique to the semi- or fully automated ultrasonic testing of fusion-welded joints in metallic materials of minimum thickness 6 mm. It applies to full penetration welded joints of simple geometry in plates, pipes, and vessels, where both the weld and the parent material are low-alloyed carbon steel. Where specified and appropriate, TOFD can also be used on other types of materials that exhibit low ultrasonic attenuation (especially that due to scatter). Where material-dependent ultrasonic parameters are specified in this document, they are based on steels having a sound velocity of (5 920 ± 50) m/s for longitudinal waves and (3 255 ± 30) m/s for transverse waves. It is necessary to take this fact into account when testing materials with a different velocity. This document makes reference to ISO 16828 and provides guidance on the specific capabilities and limitations of TOFD for the detection, location, sizing and characterization of discontinuities in fusion-welded joints. TOFD can be used as a stand-alone method or in combination with other non-destructive testing (NDT) methods or techniques, for manufacturing inspection, and for in-service inspection. This document specifies four testing levels (A, B, C, D) in accordance with ISO 17635 and corresponding to an increasing level of testing reliability. Guidance on the selection of testing levels is provided. This document permits assessment of TOFD indications for acceptance purposes. This assessment is based on the evaluation of transmitted, reflected and diffracted ultrasonic signals within a generated TOFD image. This document does not include acceptance levels for discontinuities.

This document specifies general requirements for the application of the non-destructive (NDT) metal magnetic memory (MMM) testing technique of the magnetic testing method for quality assurance of welded joints. This document can be applied to welded joints in any type of ferromagnetic products: pipelines, vessels, equipment, and metal constructions, as agreed with the purchaser.

This document specifies terms and definitions for non-destructive testing (NDT) by the technique of metal magnetic memory (MMM) as well as general requirements for application of this technique of the magnetic testing method. The terms specified in this document are mandatory for application in all types of documentation and literature of non-destructive testing, using the metal magnetic memory technique. This NDT technique has the following objectives: — determination of the heterogeneity of the magneto-mechanical state of ferromagnetic objects, detection of defect concentration and boundaries of metal microstructure heterogeneity; — determination of locations with magnetic stray field aberrations for further microstructural analysis and/or non-destructive testing and evaluation; — early diagnostics of fatigue damage of the inspected object and evaluation of its structural life time; — quick sorting of new and used inspection objects by their magnetic heterogeneity for further testing; — efficiency improvement of non-destructive testing by combining metal magnetic memory testing with other NDT methods or techniques (ultrasonic testing, x-ray, etc.) by fast detection of the most probable defect locations; — quality control of welded joints of various types and their embodiment (including contact and spot welding). See ISO 24497-2 for details of this application.

This document specifies the application of the phased array technology for the semi- or fully automated ultrasonic testing of fusion-welded joints in metallic materials of minimum thickness 6 mm. It applies to full penetration welded joints of simple geometry in plates, pipes, and vessels, where both the weld and the parent material are low-alloy and/or fine grained steel. For the testing of welds in other steel materials this document gives guidance. For coarse-grained or austenitic steels, ISO 22825 applies in addition to this document. This document provides guidance on the specific capabilities and limitations of the phased array technology for the detection, location, sizing and characterization of discontinuities in fusion-welded joints. Phased array technology can be used as a stand-alone technology or in combination with other non-destructive testing (NDT) methods or techniques, for manufacturing inspection, pre-service and for in-service inspection. This document specifies four testing levels, each corresponding to a different probability of detection of imperfections. This document permits assessment of discontinuities for acceptance purposes based either on amplitude (equivalent reflector size) and length, or on height and length. This document does not include acceptance levels for discontinuities. This document is not applicable for automated testing of welds during the production of steel products covered by ISO 10893-8, ISO 10893-11 and ISO 3183.

This document specifies the sizes of test specimens and the test procedure for carrying out longitudinal tensile tests on cylindrical test specimens in order to determine the mechanical properties of weld metal in a fusion welded joint. This document applies to metallic materials in all forms of product with joints made by any fusion welding process, having joint sizes that are sufficient to obtain cylindrical test specimens with dimensions in accordance with ISO 6892‑1. Unless specified otherwise for specific points in this document, the general principles of ISO 6892‑1 apply.

This document specifies the application of phased array technology for the semi- or fully automated ultrasonic testing of fusion-welded joints in steel parts with thickness values between 3,2 mm and 8,0 mm. This meets the typical range of tube wall thickness values in boilers, which is an important application of this testing technology. The minimum and maximum value of the wall thickness range can be exceeded, when testing level "D" of this document is applied. This document applies to full penetration welded joints of simple geometry in plates, tubes, pipes, and vessels, where both the weld and parent material are low-alloy and/or fine grained steel. NOTE "Semi-automated testing" encompasses a controlled movement of one or more probes on the surface of a component along a fixture (guidance strip, ruler, etc.), whereby the probe position is unambiguously measured with a position sensor. The probe is moved manually. "Fully automated testing" includes mechanized propulsion in addition. Where material-dependent ultrasonic parameters are specified in this document, they are based on steels having a sound velocity of (5 920 ± 50) m/s for longitudinal waves, and (3 255 ± 30) m/s for transverse waves. It is necessary to take this fact into account when testing materials with a different velocity. This document provides guidance on the specific capabilities and limitations of phased array technology for the detection, location, sizing and characterization of discontinuities in fusion-welded joints. Ultrasonic phased array technology can be used as a stand-alone technique or in combination with other non-destructive testing (NDT) methods or techniques, during manufacturing and testing of new welds/repair welds (pre-service testing). This document specifies two testing levels: — level "C" for standard situations; — level "D" for different situations/special applications. This document describes assessment of discontinuities for acceptance purposes based on: — height and length; — amplitude (equivalent reflector size) and length; — go/no-go decision. This document does not include acceptance levels for discontinuities.

This document specifies techniques for the manual ultrasonic testing of fusion-welded joints in metallic materials of thickness ≥8 mm which exhibit low ultrasonic attenuation (especially that due to scatter) at object temperatures from 0 °C to 60 °C. It is primarily intended for use on full penetration welded joints where both the welded and parent material are ferritic. Where material-dependent ultrasonic values are specified in this document, they are based on steels having an ultrasonic sound velocity of (5 920 ± 50) m/s for longitudinal waves and (3 255 ± 30) m/s for transverse waves. This document specifies four testing levels, each corresponding to a different probability of detection of imperfections. Guidance on the selection of testing levels A, B, and C is given in Annex A. This document specifies that the requirements of testing level D, which is intended for special applications, be in accordance with general requirements. Testing level D can only be used when defined by specification. This includes tests of metals other than ferritic steel, tests on partial penetration welds, tests with automated equipment, and tests at object temperatures outside the range 0 °C to 60 °C. This document can be used for the assessment of discontinuities, for acceptance purposes, by either of the following techniques: a) evaluation based primarily on length and echo amplitude of the discontinuity; b) evaluation based on characterization and sizing of the discontinuity by probe movement techniques.

This document specifies acceptance levels for the time‑of‑flight diffraction technique (TOFD) of full penetration welds in ferritic steels from 6 mm up to 300 mm thickness which correspond to the quality levels of ISO 5817. These acceptance levels are applicable to indications classified in accordance with ISO 10863.

ISO 11666:2018 specifies two ultrasonic acceptance levels known as acceptance level 2 (AL 2) and acceptance level 3 (AL 3) for full penetration welded joints in ferritic steels, which correspond to ISO 5817:2014, quality levels B and C. An acceptance level corresponding to ISO 5817:2014, quality level D is not included in this document, as ultrasonic testing is generally not requested for this weld quality. These acceptance levels are applicable to testing carried out in accordance with ISO 17640. ISO 11666:2018 applies to the testing of full penetration ferritic steel welds, with thicknesses from 8 mm to 100 mm. It can also be used for other types of welds, materials and thicknesses, provided the tests have been performed with necessary consideration of the geometry and acoustic properties of the component, and an adequate sensitivity can be employed to enable the acceptance levels of this document to be applied. The nominal frequency of probes used in this document is between 2 MHz and 5 MHz, unless attenuation or requirements for higher resolution call for other frequencies. It is important to consider the use of these acceptance levels in conjunction with frequencies outside this range carefully.

ISO 9017:2017 specifies the sizes of test specimen and the procedures for carrying out fracture tests in order to obtain information about types, sizes and distribution of internal imperfections such as porosities, cracks, lack of fusion, lack of penetration and solid inclusions on the fracture surface. ISO 9017:2017 applies to metallic materials in all forms of product with joints made by any fusion welding process with a thickness greater or equal to 2 mm.

ISO 22825:2017 specifies the approach to be followed when developing procedures for the ultrasonic testing of the following welds: - welds in stainless steels; - welds in nickel-based alloys; - welds in duplex steels; - dissimilar metal welds; - austenitic welds. The purposes of the testing can be very different, for example: - for the assessment of quality level (manufacturing); - for the detection of specific discontinuities induced in service. Acceptance levels are not included in ISO 22825:2017, but can be applied in accordance with the scope of the testing (see 4.1). The requirements of ISO 22825:2017 are applicable to both manual and mechanized testing.

ISO 19285:2017 specifies acceptance levels for the phased array ultrasonic testing technique (PAUT) of full penetration welds in ferritic steels of minimum thickness of 6 mm which correspond to the quality levels of ISO 5817. These acceptance levels are applicable to indications classified in accordance with ISO 13588.

ISO 23279:2017 specifies how to characterize indications from discontinuities by classifying them as originating from planar or non-planar embedded discontinuities. This procedure is also suitable for indications from discontinuities that break the surface after removal of the weld reinforcement.

ISO 17635:2016 gives guidelines for the choice of non-destructive testing (NDT) methods for welds and evaluation of the results for quality control purposes, based on quality requirements, material, weld thickness, welding process and extent of testing. ISO 17635:2016 also specifies general rules and standards to be applied to the different types of testing, for either the methodology or the acceptance levels for metallic materials. Acceptance levels cannot be a direct interpretation of the quality levels defined in ISO 5817 or ISO 10042. They are linked to the overall quality of the produced batch of welds. Requirements for acceptance levels for NDT comply with quality levels stated in ISO 5817 or ISO 10042 (moderate, intermediate, stringent) only on a general basis and not in detail for each indication. Annex A gives correlations between quality, NDT and acceptance level standards. Annex B gives an overview of the standards linked to quality levels, acceptance levels and NDT methods.

ISO 17637:2016 specifies the visual testing of fusion welds in metallic materials. It may also be applied to visual testing of the joint prior to welding.

ISO 17638:2016 specifies techniques for detection of surface imperfections in welds in ferromagnetic materials, including the heat affected zones, by means of magnetic particle testing. The techniques are suitable for most welding processes and joint configurations. Variations in the basic techniques that will provide a higher or lower test sensitivity are described in Annex A. ISO 17638:2016 does not specify acceptance levels of the indications. Further information on acceptance levels for indications may be found in ISO 23278 or in product or application standards.

ISO 9015-2:2016 specifies microhardness testing on transverse sections of welded joints of metallic materials with high hardness gradients. It covers Vickers hardness tests in accordance with ISO 6507‑1, normally with test loads of 0,98 N to less than 49 N (HV 0,1 to less than HV 5). NOTE Testing ensures that the highest and/or the lowest level of hardness of both parent materials (in the case of dissimilar materials both parent materials) and weld metal is determined. ISO 9015-2:2016 is not applicable to hardness testing of welds with loads of 49,03 N and above, which is covered by ISO 9015‑1. ISO 9015-2:2016 is not applicable to Vickers hardness testing of resistance spot, projection and seam welds, which is covered by ISO 14271. This part of ISO 9015 is not applicable to hardness testing of very narrow welds, e.g. those typically produced by laser and electron beam welding (see ISO 22826).

ISO 17641-2:2015 specifies the required specimens, the test piece dimensions, and the procedures to be followed to carry out self-restraint hot cracking tests. The following tests are described: - T-joint weld cracking test; - weld metal tensile test; - longitudinal bend test. The tests are designed to provide information about the hot cracking sensitivity of weld metals. The tests are not suitable for the assessment of parent materials. ISO 17641-2:2015 applies primarily to fully austenitic stainless steels, nickel, nickel base, and nickel copper weld metals. This part of ISO 17641 can also be used for other weld metals. ISO 17641-2:2015 describes only how to carry out the tests and report the results. It does not give any acceptance criteria.

ISO 9018:2015 specifies the sizes of test pieces and test specimens, and the procedure for carrying out tensile tests, for determining the tensile strength and location of fractures in welded joints with transverse stressed fillet welds. It is applicable to metallic materials with welded cruciform and lapped joints on plates, where the term plate ? alone or in combination ? refers to plates, sheets, extruded bars or other solid sections. Information concerning the evaluation of test results is not included in this International Standard.

ISO 17643:2015 defines eddy current testing techniques for detection of surface breaking and near surface planar discontinuities, mainly in ferritic materials (weld material, heat-affected zones, base material). Eddy current testing can also be specified for use with non-ferritic materials, for example in an application standard. The techniques can be applied to coated and uncoated objects during fabrication and in service, both onshore and offshore. Eddy current testing can be carried out on all accessible surfaces and on welds of almost any configuration. Unless otherwise specified at specific items in this International Standard, the general principles of ISO 15549 apply. NOTE Eddy current testing is usually performed in the as-welded condition. However, the accuracy of the results can be affected by very rough surface finishes.

ISO 23277:2015 specifies acceptance levels for indications from surface breaking imperfections in metallic welds detected by penetrant testing. The acceptance levels are primarily intended for use during manufacture examination, but where appropriate, they can be used for in-service inspection. The acceptance levels in ISO 23277:2015 are based on detection capabilities that can be expected when using techniques specified in ISO 3452 series and parameters recommended in annex. The acceptance levels can be related to welding standards, application standards, specifications, or codes. Such a relationship is shown in ISO 17635 for ISO 5817 and ISO 10042. Acceptance levels for grouped indications are not covered by ISO 23277:2015.

ISO 23278:2015 specifies acceptance levels for indications from imperfections in ferromagnetic steel welds detected by magnetic particle testing.

ISO/TR 14345:2012 gives guidance on best practice for fatigue testing under constant- or variable-amplitude loading of welded components in the medium- and high-cycle regimes, corresponding to applied loading that results in nominal stresses that do not exceed yield. Low-cycle fatigue testing under strain control is not specifically covered, although the same test specimens can be suitable for either low- or high-cycle fatigue testing. The different steps involved in the manufacture and preparation of the welded specimens and the final presentation and evaluation of the test results are also covered. ISO/TR 14345:2012 does not cover corrosion or high-temperature fatigue testing.

ISO 5173:2009 specifies a method for making transverse root, face and side bend tests on test specimens taken from butt welds, butt welds with cladding (subdivided into welds in clad plates and clad welds) and cladding without butt welds, in order to assess ductility and/or absence of imperfections on or near the surface of the test specimen. It also gives the dimensions of the test specimen. In addition ISO 5173:2009 specifies a method for making longitudinal root and face bend tests to be used instead of transverse bend tests for heterogeneous assemblies when base materials and/or filler metal have a significant difference in their physical and mechanical properties in relation to bending. ISO 5173:2009 applies to metallic materials in all forms of product with welded joints made by any fusion arc welding process.

ISO 22826:2005 specifies the requirements for hardness testing of transverse sections of narrow laser and electron beam welded joints in metallic materials. It covers Vickers and Knoop hardness tests in accordance with ISO 6507-1 and ISO 4545, respectively, with test forces of 0,098 N to just under 98 N (HV 0,01 to just under HV 10) for the Vickers hardness test and test forces up to and including 9,8 N (just under HK 1) for the Knoop hardness test. It is applicable to welds made with or without filler wire. It may not be applicable to the testing of wider hybrid laser/arc welds.

ISO/TR 17641-3:2005 outlines the test methods and procedures for carrying out externally loaded tests to assess susceptibility to hot cracking. The following tests are described: Hot tensile tests Varestraint and Transvarestraint test Flat tensile test. The above tests can provide information about the hot cracking sensitivity of parent materials, weld metals and weldments. Assessment is based upon the measurement of the "brittle temperature range" (BTR) where hot cracks occur. This document applies primarily to austenitic stainless steels, nickel-, nickel-base and nickel-copper alloys, weldments and welding consumables. However, the principles can be extended to other materials such as aluminium alloys and high-strength steels.

ISO 17642-3:2005 specifies the sizes of the backing plates, specimens and procedures for carrying out externally loaded cold cracking tests by implant testing in order to obtain information about the cold cracking sensitivity during welding. This International Standard applies primarily, but not exclusively, to C-Mn and low alloy steels.

ISO 17642-2:2005 specifies the sizes of the test pieces, the specimens and the procedures for carrying out self-restraint cold cracking tests by: CTS (controlled thermal severity) test Tekken (Y-groove) or Lehigh (U-groove) test in order to obtain information about the cold cracking sensitivity during welding. This International Standard applies primarily, but not exclusively, to C-Mn and low-alloy steels.

ISO 17642-1:2004 describes the fundamentals of cold crack formation and the principles of cold cracking tests. These tests can be used to determine the cold cracking sensitivity of welding consumables, parent materials and weld metal. The most common tests are described. In addition, an overview is given of the cold cracking test procedures.

ISO 17641-1:2004 gives an introduction to the fundamentals of hot cracking in weld metals and parent alloys, and briefly describes the tests available for arc welding processes.

ISO/TR 16060:2003 gives a non-exhaustive list of etchants that can be used for the macroscopic and microscopic examination of welds in accordance with ISO 17639 for the following groups of materials: carbon steels and low-alloy steels; stainless steels; nickel and nickel alloys; titanium and titanium alloys; copper and copper alloys; aluminium and aluminium alloys.

ISO 12472:2002 specifies a test method for determining the effective sealing capability of intumescent materials or systems in the context of sealing door-to-frame clearances in timber door assemblies. The method is suitable for evaluating the efficacy of exposed intumescent sealing systems used in conjunction with timber fire resisting doors of up to 1 h fire resistance. It is not suitable for comparing concealed intumescent seals. The results can be applied to proven, single-acting, single-leaf, latched, timber door assemblies of sizes up to that given in the field of direct application.

This part of ISO 9015 specifies hardness tests on transverse sections of arc welded joints of metallic materials. It covers Vickers hardness tests in accordance with ISO 6507-1, normally with test loads of 49,03 N or 98,07 N (HV 5 or HV 10). However, the principles may be applied to Brinell hardness testing (with appropriate testing loads of HB 2,5/15,625 or HB 1/2,5) in accordance with ISO 6506-1 and micro hardness testing in accordance with ISO 6507-1 and ISO 9015-2. NOTE Testing should be carried out to ensure that the highest and the lowest level of hardness of both parent metal and weld metal is determined. This part of ISO 9015 does not apply to test welds in austenitic stainless steels.

ISO 17640:2017 specifies techniques for the manual ultrasonic testing of fusion-welded joints in metallic materials of thickness ≥8 mm which exhibit low ultrasonic attenuation (especially that due to scatter) at object temperatures from 0 °C to 60 °C. It is primarily intended for use on full penetration welded joints where both the welded and parent material are ferritic. Where material-dependent ultrasonic values are specified in ISO 17640:2017, they are based on steels having an ultrasonic sound velocity of (5 920 ± 50) m/s for longitudinal waves and (3 255 ± 30) m/s for transverse waves. ISO 17640:2017 specifies four testing levels, each corresponding to a different probability of detection of imperfections. Guidance on the selection of testing levels A, B, and C is given in Annex A. ISO 17640:2017 specifies that the requirements of testing level D, which is intended for special applications, be in accordance with general requirements. Testing level D can only be used when defined by specification. This includes tests of metals other than ferritic steel, tests on partial penetration welds, tests with automated equipment, and tests at object temperatures outside the range 0 °C to 60 °C. ISO 17640:2017 can be used for the assessment of discontinuities, for acceptance purposes, by either of the following techniques: a) evaluation based primarily on length and echo amplitude of the discontinuity; b) evaluation based on characterization and sizing of the discontinuity by probe movement techniques.

ISO 10675-2:2017 specifies acceptance levels for indications from imperfections in aluminium butt welds detected by radiographic testing. If agreed, the acceptance levels can be applied to other types of welds or materials. The acceptance levels can be related to welding standards, application standards, specifications or codes. ISO 10675-2assumes that the radiographic testing has been carried out in accordance with ISO 17636‑1 for RT-F (F = film) or ISO 17636‑2 for RT-S (S = radioscopy) and RT-D (D = digital detectors). When assessing whether a weld meets the requirements specified for a weld quality level, the sizes of imperfections permitted by standards are compared with the dimensions of indications revealed by a radiograph made of the weld.

ISO 10675-1:2016 specifies acceptance levels for indications from imperfections in butt welds of steel, nickel, titanium and their alloys detected by radiographic testing. If agreed, the acceptance levels can be applied to other types of welds or materials. The acceptance levels can be related to welding standards, application standards, specifications or codes. This document assumes that the radiographic testing has been carried out in accordance with ISO 17636‑1 and ISO 17636‑2. When assessing whether a weld meets the requirements specified for a weld quality level, the sizes of imperfections permitted by standards are compared with the dimensions of indications revealed by a radiograph made of the weld.

ISO 17405:2014 specifies the techniques for manual ultrasonic testing of claddings on steel applied by welding, rolling, and explosion using single-element or dual-element probes. The test is intended to cover detection of two-dimensional or three-dimensional discontinuities in the cladding and in the region of the interface. ISO 17405:2014 does not give acceptance criteria nor define the extent of testing.

ISO 17636-1:2013 specifies techniques of radiographic examination of fusion welded joints in metallic materials using industrial radiographic film techniques. ISO 17636-1:2013 applies to the joints of plates and pipes. Besides its conventional meaning, "pipe" as used in this International Standard covers other cylindrical bodies such as tubes, penstocks, boiler drums, and pressure vessels. ISO 17636-1:2013 does not specify acceptance levels for any of the indications found on the radiographs. If contracting parties apply lower test criteria, it is possible that the quality achieved is significantly lower than when ISO 17636-1:2013 is strictly applied.

ISO 17636-2:2013 specifies fundamental techniques of digital radiography with the object of enabling satisfactory and repeatable results to be obtained economically. The techniques are based on generally recognized practice and fundamental theory of the subject. ISO 17636-2:2013 applies to the digital radiographic examination of fusion welded joints in metallic materials. It applies to the joints of plates and pipes. Besides its conventional meaning, "pipe", as used in this International Standard, covers other cylindrical bodies such as tubes, penstocks, boiler drums, and pressure vessels. ISO 17636-2:2013 specifies the requirements for digital radiographic X- and gamma-ray testing by either computed radiography (CR) or radiography with digital detector arrays (DDA) of the welded joints of metallic plates and tubes for the detection of imperfections. Digital detectors provide a digital grey value (GV) image which can be viewed and evaluated using a computer. ISO 17636-2:2013 specifies the recommended procedure for detector selection and radiographic practice. Selection of computer, software, monitor, printer and viewing conditions are important, but are not the main focus of ISO 17636-2:2013. The procedure specified in ISO 17636-2:2013 provides the minimum requirements for radiographic practice which permit exposure and acquisition of digital radiographs with equivalent sensitivity for detection of imperfections as film radiography, as specified in ISO 17636-1. ISO 17636-2:2013 does not specify acceptance levels for any of the indications found on the digital radiographs. If contracting parties apply lower test criteria, it is possible that the quality achieved is significantly lower than when ISO 17636-2:2013 is strictly applied.