Wall Thickness Measurement
Ultrasonic thickness measurement determines how much material remains in a component by timing an ultrasonic pulse's return from the far wall. It requires access to one side only, so a pipe or vessel can be measured from the outside without being opened, drained or dismantled. Taking readings on a grid produces a corrosion map showing where material loss is concentrated.
Why wall thickness measurement matters
Corrosion and erosion thin a pressure boundary from the inside, where it cannot be seen, until the remaining wall can no longer carry the design pressure. Measuring remaining thickness converts that hidden process into a number that can be trended: comparing surveys over time gives a corrosion rate, and a corrosion rate gives a predicted remaining life. That turns replacement into a planned decision rather than a response to a leak.
What it detects
Where it is applied
- ●Process and utility pipework
- ●Storage tanks and pressure vessels
- ●Structural sections and plate
- ●Recurring inspection programmes tracking corrosion rate
DELIVERED USING ULTRASONIC TESTING (UT)
Applicable Standards
SANS 3577-2, ISO 17640, ASME Section V
Professional Equipment
GE USM Go+ Flaw Detectors, Olympus EPOCH 650, Phased Array Systems
Common questions
Does the plant need to be shut down?
Usually not. Measurements are taken from the outside surface, so equipment can often remain in service. Access, surface condition and temperature determine what is practical on any given asset.
Does insulation or coating have to be removed?
Insulation must be removed at each measurement point for the probe to make contact. Thin, well-bonded paint coatings can often be measured through; heavy or loose coatings are removed locally.
How do we know if the wall loss is acceptable?
Readings are compared against the minimum allowable thickness for the component's design conditions. Repeat surveys establish a corrosion rate, which is what allows remaining life to be estimated rather than guessed.
Where we deliver it
MPIA Services is based in Durban (also known as eMkhomazi), KwaZulu-Natal, and carries out wall thickness measurement on site across all nine South African provinces. Mobile field units travel to the asset, so the work happens in place — on live rail corridors, in yards and depots, and at industrial sites — rather than requiring components to be sent away. See where we work.
Need wall thickness measurement?
Tell us the asset, the standard you need to satisfy and where the work is. We will come back with scope, timing and a quotation.
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