scope:

This standard specifies the acceptance criteria for the ""Time Of Flight Diffraction"" technique (ToFD) of welded joints in ferritic steels, where full penetration is required (simple geometry�s like butt welds). The ToFD technique is proven for fine grain ferritic steels. The acceptance criteria are applicable to examinations carried out in accordance with NVN-ENV 583-6. They may, however be applied in conjunction with other rules, where at least the same level of examination quality is described, provided it is agreed upon by the parties involved. This standard is applicable to the examination of welded joints in fine grain ferritic steels, where full penetration is required with wall thickness from 6 mm up to 300 mm. It may also be used for other types of weld, materials and wall thicknesses, provided the examination has been performed with due consideration of geometry and acoustical properties of the component, and the expected capability of detection is proven to be in relationship with this standard (validation). The acceptance criteria shall be related to the examination techniques as defined in NVN-ENV 583-6. The results shall not be subdivided into planar and non-planar indications. Only indications described in terms of length, height and depth are considered. (cracks, lack of fusion, lack of root penetration, slag etc.) Single diffraction signals are considered separately (gas, porosity etc).