HydroFORM is a two-axis encoded phased-array ultrasonic corrosion-mapping system used to collect position-referenced wall-thickness data over pipes and other surfaces. The scanner uses integrated X and Y encoders together with a local water-column coupling system so the acquisition instrument can associate ultrasonic measurements with their physical scan position and generate a C-scan map of remaining wall thickness.
HydroFORM is designed for corrosion, erosion and abrasion mapping and can also detect certain mid-wall conditions such as laminations or hydrogen-related blistering, depending on the inspection setup and procedure. The resulting C-scan is a spatial representation of ultrasonic data, not a photograph and not a substitute for the original acquisition data, calibration or inspection procedure.
What encoded C-Scan data contains
An encoded scan normally carries coordinate information together with remaining-wall thickness and other gated/amplitude information, depending on the setup, for one or more passes. The project record should retain the component or surface, scan direction, coordinate origin, units, probe or instrument details, calibration information and acquisition conditions. Scan boundaries, overlap, gaps and unusable data should be visible because they affect coverage and interpretation.
For a pipe or shell, the mapped axes may represent axial and circumferential distance or another defined local coordinate system. For a plate or vessel surface, the axes may be X and Y. The coordinate convention must be recorded so a minimum wall, indication or profile can be found again in the field and related to a drawing or report page.
- Confirm the component, surface, scan origin, axes and units.
- Review calibration, coupling, coverage, gaps and acquisition limits.
- Retain the source pass or tile behind each stitched area.
- Review indications, minimum wall and profiles against the inspection procedure.
Scan stitching and alignment
Large areas are often collected as multiple tiles or passes. Scan stitching uses tile alignment and placement to put those pieces into one coordinate space using their position, overlap and alignment information. The reviewer should check seams, duplicate coverage, gaps, orientation and intensity or thickness discontinuities introduced by tile alignment and placement. Stitching makes a larger map readable, but it does not turn missing data into measured data.
A useful review record keeps the source tile or pass associated with the stitched area. That traceability lets a technician return to the original scan when an indication sits across a seam or when a profile needs to be checked against acquisition data.
Indication sizing and minimum wall outputs
Review tools can assist with locating and sizing indications in the mapped data. A reportable area may include a minimum wall value, thickness loss or percent loss, axial and circumferential dimensions, coordinate location, clock reference and an indication status. Sizing rules should be stated in the project procedure, including thresholds, smoothing or filtering, measurement resolution and treatment of neighboring indications.
Minimum wall thickness is the lowest valid thickness measurement within the reviewed dataset after the applicable quality and data-validation checks. It should be tied to its coordinates and source data, not presented as an unsupported single number. Features smaller than the effective spatial resolution or affected by surface/coupling limitations may not be fully characterized.
Corrosion profiles and reporting
A corrosion profile shows thickness or metal loss along a defined line through the mapped indication. Profiles help a reviewer understand remaining-wall variation, metal-loss depth, axial or circumferential extent, and the transition between the affected area and surrounding material. They can support an engineering assessment when the profile quality and selected method allow it, but the profile does not by itself determine fitness for service.
The C-Scan / Corrosion Mapping workflow supports encoded scan import, stitching, indication review, minimum-wall inspection and report-ready outputs. SketchMapp inspection drawing and CML mapping can add an asset or inspection-location view when the mapped area needs a clear field reference.
Questions inspectors ask
Does HydroFORM create the final corrosion assessment?
No. It collects mapped ultrasonic evidence. Interpretation, assessment inputs and engineering disposition depend on the data quality, procedure and qualified review.
Why preserve individual scan tiles after stitching?
Source tiles provide traceability for seams, gaps, alignment questions and repeat review of a reportable indication.
What makes a minimum wall value useful?
It needs a defined coordinate, source measurement, units, quality context and enough coverage to represent the feature being reviewed.