Conventional NDT
Positive material identification (PMI)
A single carbon-steel component in an alloy line can fail in service within months. Positive material identification confirms that pipes, fittings, valves, bolting and weld metal are the alloy the design specifies, before they go into service and after repairs, and it is a core part of any material verification programme.
XRF and OES
- X-ray fluorescence (XRF): fast, non-destructive, no surface burn; identifies alloying elements such as Cr, Mo, Ni and Nb. It cannot measure carbon.
- Optical emission spectroscopy (OES): measures carbon and the light elements as well, so it can separate L-grade from standard stainless and confirm carbon content where it matters; leaves a small burn mark.
Building a material verification programme
API RP 578 sets out how to decide which components to verify, how many and when: new construction, maintenance replacements, warehouse spares and existing systems where a mix-up is suspected. The programme defines the sampling, the acceptance criteria for each grade and how non-conforming items are tagged and removed.
Typical scope
- Alloy piping, fittings and valves in hydroprocessing, high-temperature and corrosive service.
- Weld metal on alloy welds.
- Bolting and gaskets in critical joints.
- Warehouse and spare-parts verification.
How we deliver it
Positive material identification (PMI) is carried out to a written procedure approved for the scope, naming the code and edition, the equipment and calibration, the coverage and the acceptance criteria. The procedure and each technician’s certification are submitted for the client’s review before mobilisation.
Work is planned and supervised by ASNT Level III personnel; our founder holds ASNT NDT Level III in UT, RT, MT, PT and VT. Reports state the coverage achieved and any limitations, so the engineer reading them knows what was examined and what was not, and any reportable finding is raised the same day.
Governing codes and standards
- API RP 578 (material verification programme for new and existing alloy piping systems)
- ASTM E1476 (metals identification, grade verification and sorting)
- Owner specification for sampling and acceptance
What you receive
- PMI log per component with measured composition and grade match
- Non-conformance list with tagged items
- Instrument check records against certified reference materials
Industries served
- Refining and petrochemical
- Chemical processing
- Power generation
- Fabrication shops and suppliers
Frequently asked questions
Can XRF tell 304 from 304L stainless?
No. The difference is carbon content, which XRF cannot measure. Optical emission spectroscopy is used when carbon content has to be confirmed.
Talk to an inspection engineer
Send the equipment list or drawings, the inspection you need and your timing. Quotes are prepared for each scope and region.
Request a QuoteRequest an inspection quote (RFQ)
Tell us the asset, the method, where it is, the governing code, your dates, the size of the job and the report you need. We reply with questions or a quote. Affordable, accessible, fully customizable — no published pricing.
Or email the same details to info@atlantisndt.com. Mobilisation: North America; confirm your location in your RFQ.
Speak to an ASNT NDT Level III
Atlantis NDT provides ASNT Level III consulting, NDT training to ASNT SNT-TC-1A, inspection management software and independent report validation. Request a free consultation and we will return a tailored quote — affordable, accessible and fully customizable to your programme.