MSS SP 137
Quality Standard for Positive Material Identification of Metal Valves, Flanges, Fittings, and Other Piping Components
|Publication Date:||1 January 2020|
This Standard Practice provides methods and acceptance standards for Positive Material Identification (PMI) of metal flanges, fittings, valves, pressure boundary parts of valves, and other piping components.
The instrumentation used for PMI testing covered by this Standard Practice shall be optical spectroscopy, X-ray fluorescence, or laser induced breakdown spectroscopy.
This Standard Practice is applicable to the identification process, at point of final inspection or in process inspection during manufacturing.
This Standard Practice describes requirements for semi-quantitative analysis used for material grade identification only. This procedure may not be suitable for certifying the accuracy of material test reports.