An API 570 inspection reporting workflow should make the condition and inspection history of each piping system or circuit traceable from inspection scope through final disposition. The record should connect piping-system identity, circuit/component information, CML or TML locations, thickness measurements, calculations, drawings, findings, photographs, repair information, recommendations, and review records.
Software can organize and calculate from the entered data, but the authorized inspector and responsible engineering or owner-user personnel remain responsible for interpretation and disposition under the applicable inspection program.
1. Define the circuit and inspection scope
Set up the piping circuit, service description, line or equipment identifiers, inspection date, previous inspection reference and applicable scope. Define components and CML/TML locations so a reader can understand what was examined and where. A location should be reproducible from a drawing, isometric, orientation reference, weld, support, nozzle or other field datum.
Use SketchMapp inspection drawing and CML mapping when a visual location record is needed for piping, welds, supports, branches or inspection points. The drawing is most useful when it follows the same naming and orientation used in the thickness table and field notes.
2. Collect and validate CML/TML thickness data
Import or enter thickness readings with the CML/TML identifier, component, measurement date, method, units, nominal or reference thickness and any reading condition. Record calibration or technique information required by the procedure. Review missing points, duplicate locations, inconsistent units and readings that need a second look before trending or calculations are generated.
Photos should identify the component or location and show relevant access, insulation, coating, corrosion, repair or damage context. Attach field notes and NDE reports to the same inspection project so a reviewer does not have to infer which evidence belongs to a reading.
3. Trend thickness and calculate condition indicators
Trend current and previous valid thickness measurements at the same CML/TML where the data are comparable. Corrosion rate is generally based on thickness loss divided by the applicable elapsed time, while remaining life relates the current measured thickness to the applicable required or retirement thickness using the selected corrosion rate. The inspection program should identify the corrosion-rate basis being used, including applicable short-term and long-term data, and should follow the owner-user procedure and current API 570 requirements.
CR = thickness loss / elapsed time
RL = (current thickness − required thickness) / corrosion rate
Retain the readings and dates that produced the result, the required or retirement thickness basis, the selected corrosion-rate convention, rounding and any review override. Identify the limiting or controlling CML/TML where appropriate, along with a negative or implausible trend, a changed location or a reading that is not comparable with the prior data.
4. Compile findings and supporting evidence
Connect findings, recommendations, photos, NDE methods, repair information and next-inspection actions to the affected component or circuit. A report should make clear whether a recommendation is based on thickness, visual condition, a calculation, a process change, a known damage mechanism or another inspection observation.
Keep drawings and CML/TML tables synchronized. If a location changes, document the change and its effect on trending rather than creating a second point with an ambiguous name. For related NDE, the C-Scan / Corrosion Mapping workflow can retain encoded ultrasonic mapping evidence, while Guided Wave / LRUT reporting can document a separate long-range screening examination when that method is included in the inspection scope. Any localized follow-up or characterization should be documented under the applicable examination method and procedure.
5. Review and compile the final API 570 report
Compile the cover and scope, equipment and circuit information, CML/TML thickness tables, trend and corrosion-rate results, remaining-life, minimum-required-thickness, MAWP, or other applicable calculations, drawings, photos, findings, recommendations, NDE reports, repair records and signatures or review fields required by the owner-user's process. Check that the report date, inspection personnel, techniques, limitations and data sources are consistent throughout.
API/NDE reporting keeps the inspection data, calculations, drawings, photos, checklists and report compilation in one project record. It supports the inspection and reporting workflow; it does not replace the API 570 Authorized Piping Inspector, owner-user inspection organization, or engineering review required by the applicable program.
Questions inspectors ask
What is a CML versus a TML?
CML means Condition Monitoring Location. TML means Thickness Measurement Location. Organizations may use the terms differently depending on their procedures and legacy systems. The important control is that each monitored location has a stable identifier, reproducible physical location, measurement history, and clear relationship to the piping circuit and inspection drawing.
Can a calculated remaining life be copied directly into a recommendation?
No. Review the calculation basis, data comparability, damage mechanism, required thickness, uncertainty and owner-user procedure before making a recommendation.
What makes an API 570 report reviewable?
Consistent identifiers, traceable readings, clear drawings, linked photos, stated calculation inputs, documented limitations and a complete final compilation make the decision path readable.