Positive Material Identification

Positive Material Identification (PMI) is the process of verifying that metallic components, welds and welding consumables match their specified chemical composition and alloy grade. PMI is critical in pressure equipment, piping and structural applications where material mix-ups can lead to premature failure, safety incidents and regulatory non-compliance.

QMS Asset Integrity provides PMI services using portable X-ray fluorescence (XRF) analysers for rapid, non-destructive alloy verification in the field and workshop. XRF technology identifies the elemental composition of the material in seconds, allowing immediate confirmation of alloy grade against the specified material standard.

PMI is routinely specified under API 578 (Material Verification Program for New and Existing Alloy Piping Systems), AS 3788, and by major owner-operators as part of their quality management and material traceability programmes.

XRF (X-Ray Fluorescence): A portable XRF analyser directs a focused X-ray beam at the test surface. The material fluoresces, emitting secondary X-rays with energies characteristic of the elements present. The analyser detects and quantifies these emissions, providing a complete elemental analysis and alloy grade match within seconds. XRF is excellent for identifying alloying elements such as chromium, nickel, molybdenum, tungsten and titanium.

Surface Preparation: The test area is cleaned to remove paint, coatings, dirt, oil and corrosion products to ensure accurate readings. A small area (typically 10-20 mm diameter) of clean, bare metal is required for each test point.

Testing Locations: PMI is performed on parent material, weld metal and where specified, welding consumables. Multiple test points are taken per component to confirm consistency and detect any mixed materials.