NDE and NDT: the terms
Non-destructive examination (NDE) and non-destructive testing (NDT) mean the same family of methods: checking a weld, casting or forging for flaws without damaging it. ASME codes tend to say NDE; many European and industry documents say NDT. Specifications use both.
The four common methods
| Method | What it finds | Typical use |
|---|---|---|
| Radiographic testing (RT) | Internal flaws such as porosity, slag and lack of fusion, shown on film or a digital image | Butt welds, castings |
| Ultrasonic testing (UT) | Internal flaws and wall thickness, using sound waves | Thick butt welds, forgings, plate |
| Magnetic particle testing (MT) | Surface and near-surface cracks in magnetic steels | Fillet welds, weld preparations, castings |
| Liquid penetrant testing (PT) | Cracks and pores open to the surface, in any non-porous metal | Stainless steel and non-magnetic alloys, seal faces |
Visual testing (VT) comes first for every weld. Some specifications also ask for positive material identification (PMI) or hardness tests; these are often listed with NDE but are separate checks.
How to read an NDE clause
- What is examined: which welds (butt, fillet, nozzle, attachment), which castings or forgings, and at which stage (before or after heat treatment).
- Method: RT, UT, MT, PT or a choice, and whether one may replace another.
- Extent: 100%, a percentage, spot or random, and how the sample is chosen.
- Acceptance criteria: the code or standard section that sets what is acceptable.
- Personnel: the qualification scheme the examiners must hold, such as ISO 9712 or a company scheme based on ASNT SNT-TC-1A.
- Witness: whether the customer or a third party must witness or review the NDE.
What to check before you bid
Compare each clause with what your design code and standard practice already include. If the specification asks for 100% radiography where you normally do spot, or UT of castings you would not normally test, that is extra cost and time. Price it, or declare it in your technical deviation list. Check also that the methods suit the material and thickness, and that the acceptance code matches the design code. For valves, see casting quality in ASME B16.34, and use the datasheet vs specification checklist.
Proving coverage after you build
- Number every weld on the weld map, and keep the map at the current revision.
- List the required method and extent for each weld from the specification and the ITP.
- Match each weld to its NDE report by weld number. Check the report covers the full length or the agreed sample.
- Check the method on the report is the one required, and the result is accepted against the right criteria.
- For each repair, check there is a re-examination report after the repair.
- Check each examiner's qualification was valid on the date of the examination.
NDE and the ITP
NDE steps are usually listed in the inspection and test plan (ITP), often as review or witness points. The reports then go into the NDE section of the manufacturing record book. Inspectors check them against the weld map at handover.
Doing it with OdysseyGPT
The NDE Coverage Review (beta) matches each weld on the weld map to its required method, checks the RT, UT, MT or PT report exists and covers it, and checks repairs were re-examined, with a citation for every gap. It checks reports; it does not write NDE reports or manage examiner certification. The Welding Qualification Review (beta) checks the procedures and welders behind each weld.
These tools are in beta
The NDE Coverage Review and Welding Qualification Review are in beta. You can request access, and we onboard each team ourselves. Every finding cites the page, sheet or cell it came from, and your engineers decide what to do with it.