Weld NDT at mining and metals plants: EPOCH or OmniScan

A weld is not the same as "wall thickness"

There is a lot of metal at mining and metals plants: bins, slurry pipelines, steel structures, crane runways, vessels. A thickness gauge answers the question of wall loss. Weld inspection is a different task: lack of penetration, cracks, slag, lack of fusion, bevel geometry.

If an enquiry says "we need Olympus ultrasound", clarify: thickness gauging or weld UT. Otherwise you will buy the wrong class of instrument.

The basic method map is here.

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When EPOCH is enough

The EPOCH 650 and the portable EPOCH 6LT cover classic UT:

• standard butt and fillet welds to an agreed procedure;
• routine inspection after repair or installation;
• work with wedges, DAC/TCG and A-scan documentation.

Choose EPOCH if:

• you have (or will have) a procedure and trained Level II UT personnel;
• the volume is tens or hundreds of metres of weld per year, not a continuous PAUT flow;
• the client accepts a classic UT report without a mandatory C-scan.

At many Kazakhstan sites this is the correct and sufficient entry point into flaw detection.

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When OmniScan (PAUT / TFM) is justified

The OmniScan X3 / X4 is needed when:

• critical welds require encoded scanning and a full map of the zone;
• geometry is complex, access limited, and a high probability of detection is required;
• the tender or standard explicitly specifies PAUT / TFM;
• you have PAUT operators and a procedure — otherwise the instrument sits idle.

PAUT without a procedure is more expensive and less useful than a good EPOCH backed by inspection discipline.

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Typical mining / metals assets

Asset	Usually enough	When to consider PAUT
Water / slurry pipelines after repair	EPOCH	thick-wall critical joints, difficult access
Shop steel structures	EPOCH	assemblies with strict documentation requirements
Vessels / tanks	EPOCH plus thickness gauging	per project / inspection body requirements
New turnkey installation campaigns	EPOCH / PAUT per the specification	if the spec says PAUT — OmniScan from the start

Keep a separate thickness-gauging route for corrosion in parallel — one does not replace the other.

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Link to site reliability

1. Vibration / ESA find the machine that is "alive".
2. Visual inspection plus thickness gauging remove the wall-loss risk.
3. UT/PAUT confirm weld quality after repair or installation.

That is how Olympus NDT becomes part of the reliability programme rather than a one-off paper exercise.

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What to budget for

1. The instrument (EPOCH or OmniScan) plus cables and probes.
2. Calibration blocks and couplant.
3. Personnel training / certification.
4. A report template accepted by your client or inspection body.

The catalogue is in the NDT section. Kit selection is on the Olympus page.