About Positive Material Identification (PMI)

The Essential Safeguard 

The Essential Quality Procedure for the Global Petrochemical and  Oil & Gas Industry

PMI has the ability to eliminate human error. Fabricators, within their general scope of Quality procedures and when providing material traceability of components built into their product will consider the Mill material test reports (MTRs) or those of the Mill's distributor and this has been the accepted practice over the decades; however, it has been proven that Mill certifications and heat markings in isolation can be unreliable.  Since MTRs are generated at the Mills that provide the raw materials, by the time the material reaches a fabricators' facility, either via a distributor or directly from the MIll, the material will have been through many handling processes increasing the chances of human error in the heat markings, therefore, the MTR should not always be trusted as reliable.   Human error in the stainless steel and nickel alloy fabrication industries is a constant occurrence.  This is a fact.

The simple safeguard against human error (or in some very rare cases deliberate fraud) is in the identification of the material as it is received from the Mill or a distributor of that Mill. In an effort to have complete reliance on Mill Certification for all materials, it is necessary to implement the procedure Positive Material Identification (PMI) to validate raw materials before fabrication of the final product begins and then once more validate the finished product prior to installation. 

To do this we have utilized the latest technology using X-Ray Fluorescence (XRF) hand-held alloy analyzers to perform the required analysis.  

X-ray fluorescence (XRF) is the emission of characteristic "secondary" (or fluorescent) X-rays from a material that has been excited by bombarding with high-energy X-rays or gamma rays. The phenomenon is widely used for elemental analysis and chemical analysis, particularly in the investigation of metals. 

XRF alloy analyzers are portable hand-held devices that perform a non-destructive test on the material at any time in merely seconds.  XRF works by exposing the material to a flux of x-rays.  The atoms then absorb the energy and become temporarily excited and they fluoresce, or emit x-rays. The x-rays emitted by the sample’s atoms possess clearly defined energies that are unique to the elements present in the sample.  By measuring the intensity and energy, the XRF instrument can provide qualitative and quantitative analysis.  In short, it can identify the elements, measure the concentration of each and display them on the unit.   

In using XRF, we can make Positive Material Identification.  The data is then downloaded from the unit and saved for reference and creating reports.