Frequently Asked Questions
Acceptance limits for incomplete fusion imperfections in arc welded joints in steel, nickel, titanium and their alloys (excluding beam welding) are specified in BS EN ISO 5817:2007 (note that acceptance limits for other imperfections are specified too).
Acceptance limits are classified in three different quality levels designated by the letters B, C and D. Level B corresponds to the highest quality requirement, C is intermediate and D is moderate. For each type of imperfection the standard presents sketches and dimensions of the imperfection and the corresponding quality level.
The table below shows a summary of the codes and standards defining acceptance limits for different materials and applications.
| Application | Code/Standard | Title |
|---|
| Steel, Ni, Ti and their alloys |
BS EN ISO 5817:2007 |
Welding – Fusion-welded joints in steel, nickel, titanium and their alloys (beam welding excluded) – Quality levels for imperfections. |
| Aluminium |
BS EN 10042:2005 |
Welding – Arc-welded joints in aluminium and its alloys - Quality levels for imperfections. |
| Pressure vessels |
PD5500:2012 |
Specification for unfired fusion welded pressure vessels. |
| Storage tanks |
BS EN 14015:2004 |
Specification for the design and manufacture of site built, vertical, cylindrical, flat-bottomed, above ground, welded, steel tanks for the storage of liquids at ambient temperature and above. |
| Pipework |
BS2633:1987 |
Specification for Class I arc welding of ferritic steel pipework for carrying fluids |
| Line pipe |
API 1104:2005 |
Welding of Pipelines and Related Facilities. |