Welding & Allied Processes

BSI welding and allied processes standards cover specifications, procedures, and tests for use by welders, quality controllers, and manufacturers.

Welding is a process which needs specific controls in order to achieve the required quality. The safety, reliability and cost effectiveness of welded products requires the welds to be of adequate quality. Failing to control welding correctly can result, in the worst case scenario, in catastrophic failure, and loss of life, and at the least, delays, related costs and contractual issues, etc.

BSI publishes standards, guidelines, and specifications to help companies meet welding requirements. These publications cover a wide range of welding disciplines and areas including welder qualification and procedures, welding equipment, consumables, NDT and much more.

BS EN ISO 2553:2019 Welding and allied processes - Symbolic representation on drawings - Welded joints defines the rules on symbolically representing welded joints in technical drawings.

This important international standard is widely used throughout the industry to provide clear, unequivocal and standardized requirements on joint type, geometry, dimensions, and other complementary information. Its use minimizes inaccuracies which can arise if drawings are misinterpreted.

Why should you use this standard?

When technical drawings use consistent welding symbols it helps avoid inaccuracies caused by misinterpretation. This is particularly important when drawings form part of contractual documentation. Symbols should provide unequivocal and standardized requirements on joint type, geometry and dimensions, as well as other complementary information.

This international standard therefore defines the rules to be applied to the symbolic representation of welded joints on technical drawings. This can include information about the geometry, manufacture, quality and testing of the welds. The principles can also be applied to soldered and brazed joints.

This international standard specifies techniques for the manual ultrasonic testing of fusion-welded joints in metallic materials thicker than or equal to 8mm which exhibit low ultrasonic attenuation.

The standard’s guidelines detail specific testing techniques for metals that show weakened ultrasonic levels at temperatures of up to 60⁰C. It’s mainly designed for full penetration weld joints where both the welded and parent material are ferritic. It specifies ultrasonic values based on steels with an ultrasonic sound velocity of (5 920±50) m/s for longitudinal waves and (3 255±30) m/s for transverse waves.

Why should you use this standard?

It 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.

The requirements of testing level D, which is intended for special applications, are in accordance with general requirements, although test 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 0⁰C to 60⁰C range.