3D Corrosion Mapping & Pit Depth Measurement Services

Corrosion mapping services for pipe, storage tanks and pressure vessels

Our corrosion mapping is a 3D surface scan of external metal loss — the service an integrity group needs when a pit gauge grid is too slow, too coarse, or too dependent on which technician held the gauge. We scan the exposed surface of pipe at a dig or in the rack, tank shell courses and floor plates during an out-of-service inspection, vessel heads and nozzles during a turnaround, and corroded structural members on pipe racks and platforms. The scan covers 100 percent of the surface in the scanned area, not a sample of points.

This is a surface measurement. It reports how much metal is gone from the outside and where; it does not see through the wall. For remaining wall thickness and internal loss we pair the scan with ultrasonic thickness readings taken by the client's NDT provider or ours, and the report presents both.

Pit depth measurement and wall loss mapping — no pit gauge grid

A pit gauge measures one point and relies on the technician finding the deepest spot. The scan measures every point in the area at a tenth of a millimeter, fits the undamaged surface, and reports depth relative to it, so the deepest point of every pit and the river-bottom profile of every corrosion cluster are found by the software. Output is a color-coded depth map, a feature table with the maximum depth, length, width, and location of each pit or cluster, and a depth grid exported to Excel at the interval your assessment method requires.

Pipeline external corrosion assessment and dent evaluation at the dig site

At an integrity dig the scan is done on the cleaned pipe surface before recoating, in the time the excavation is open. External corrosion is mapped with the orientation and stationing your dig sheet uses, and dents, gouges, and wrinkles are profiled for depth and strain input under ASME B31.8R. Where the dig was driven by an in-line inspection call, the scanned anomaly dimensions are tabulated against the ILI call so the correlation goes straight into the tool-validation record.

Tank floor and shell corrosion mapping for API 653 and API 510 inspections

During an API 653 out-of-service inspection we scan topside floor plate corrosion, shell course pitting, and nozzle and manway areas; during API 510 vessel inspections, heads, shells, and skirt attachments. The depth maps and feature tables are formatted for the inspector's report and for the owner's corrosion-rate and remaining-life calculations. The API 653 or 510 inspector of record keeps the inspection authority; the scan is the measurement behind their findings.

Fitness-for-service input: API 579, B31G and RSTRENG-ready data

The deliverable is built for the engineer who runs the assessment. For API 579 Part 4 and Part 5 local metal loss we provide the critical thickness profiles and the metal-loss grid at the assessment spacing; for pipelines we provide the river-bottom profile and the depth-versus-length data that ASME B31G, modified B31G, and RSTRENG effective-area methods take as input. We do not perform the fitness-for-service calculation unless a licensed engineer is engaged for it; most clients run it in their own software from our data.

Coating damage mapping and weld profile measurement

The same scan quantifies what a coating inspector can only estimate: the area of disbondment, blistering, or mechanical damage as a percentage of the scanned surface, holiday locations, and the profile under failed coating. For welds we measure cap height, toe angle, undercut, and misalignment on pipe and vessel seams, which supports both weld acceptance and fatigue assessment. Coating inspectors working with us use the data on the projects they inspect; it is also sold as a stand-alone service to owners documenting a coating failure claim.

Mechanical integrity inspection support — Houston Ship Channel and 27 US dispatch hubs

Refineries and chemical plants in Pasadena, Deer Park, Baytown, Texas City, La Porte, Beaumont, and Port Arthur are a short drive from our Sugar Land headquarters, and our technicians work under each plant's site-safety, permit, and escort programs. Turnarounds, dig programs, and tank inspections elsewhere are staffed from the nearest regional hub on a project basis. We work under the plant's mechanical integrity program and the inspector of record, as a measurement service, not a replacement for either.