BS EN ISO 23277:2015 pdf free download

BS EN ISO 23277:2015 pdf free download.Non-destructive testing of welds – Penetrant testing – Acceptance levels.
4.1 General
Many parameters, either individually or in combination, will affect the shape and size of a penetrant indication produced by a weld imperfection.
The following items are significant factors that will affect the shape and size of indications.
4.2 Sensitivity
Penetrant materials are classified in accordance with Iso 3452-2, including a sensitivity level which relates to the ability to detect small imperfections. Generally, higher sensitivity materials should be used for the detection of small imperfections.
4.3 Surface condition
Surface condition is directly related to the minimum detectable imperfection size. Best results are normally achieved when inspecting smooth surfaces. Surface roughness or irregularities (e.g. undercut, spatter) can cause high background and non-relevant indications resulting in a low probability of detection for small imperfections.
4.4 Process and technique
Penetrant systems and techniques should be selected according to the test surface condition. In some cases, the choice will have a direct effect on the limits of reliable detection, for example, the removal of excess penetrant by swab cleaning on rough surfaces is not recommended when seeking small imperfections.
Guidance on these matters is given in Annex A and in ISO 3452-1.
5 Acceptance levels
5.1 General
The width of the test surface shall include the weld metal and the adjacent parent metal up to a distance of 10 mm on each side.
Indications produced by penetrant testing do not usually display the same size and shape characteristics as the imperfection causing that indication. For the purposes of this International Standard, it is the size of the indication which should be assessed against the values shown in Table 1.
Indications that are approximately in line, which are separated by less than the length of the smaller indication, shall be considered as a single, continuous indication.
Acceptance levels prescribed for linear indications are those corresponding to the evaluation level. Indications lower than this shall not be taken into account. Normally, acceptable indications shall not be recorded.
Local grinding can be used to improve the classification of all or part of a test surface when it is required to work to a higher detection limit than that recommended by the existing weld surface condition in Table A.1.
NOTE Local grinding is a very often used practice.
Acceptance levels for welds in metallic materials are given in Table 1.BS EN ISO 23277 pdf download.