ISO 23278:2015 download free.Non-destructive testing of welds Magnetic particle testing Acceptance levels.
I Scope
ISO 23278 specifies acceptance levels for Indications from imperfections in ferromagnetc steel welds detected by magnetic particle testing.
The acceptance levels are primarily intended for use during manufacture examination. NOTE They can also be used for In-servke inspection.
The acceptance levels in ISO 23278 are based on detection capabilities that can be expected when using techniques specified In ISO 17638 and parameters recommended In Annex A. The acceptance levels can be related to welding standards, application standards, specifications or codes. Such a relationship is shown In ISO 17635 for 1St) 58 17.
Acceptance levels for grouped indications are not covered by ISO 23278.
2 Normafive references
The following documents, in whole or in part, are normatively referenced In ISO 23278 and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (induding any amendments) applies.
ISO/TS 18173, Non-destructive testing — General terms and defrnitions
3 Terms and definitions
For the purposes of ISO 23278, the terms and definitions gwen in ISO/IS 18173 and the foliowingapply.
3.1
linear indication
indication having a length greater than three times its width
3.2
non-linear indication d
Indication having a length less than or equal to three times its width
4 Testing parameters
Many parameters, either individually or in combination, will affect the ability of a technique to detect imperfections of a given size and orientation with respect to the condition of the test surface.
Detection of small imperfections is highly dependent on the surface condition of the weld and the detection media used. Examples of the application of these parameters to give a high probability of detection are given in Annex A.
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.
Acceptance levels prescnbed for linear indications are those corresponding to the evaluation level. lndtcations lower than this shall not be taken into account. Acceptable indications do not have to be recorded.
Any adjacent indications separated by less than the major dimension of the smaller shall be assessed as a single, continuous indication,
Local grinding may be used to improve the classification of all or lust part ola test surface, when It Is required to work to a higher detection limit than that expected by the existing weld surface condition.
Acceptance levels are given in Table1.
5.2 Removal ofmperfections
Where the product specdication permits. local grinding may be used to reduce or remove imperfections which are thecause of unacceptable indications All such areas shall be retested and evaluated with the same magnetic system and technique.