Pipeline Inspection

Pipeline inspection is the verification of line integrity during fabrication, installation and operation. In fabrication the emphasis is on weld quality and material traceability; in operation it is on wall thinning caused by corrosion.

The aim is to prevent leakage and rupture on the line, to show that the operating pressure is safe for the remaining wall thickness, and to estimate remaining life.

• Process piping
• Steam and hot-fluid lines
• Fuel and chemical transmission lines
• Fire-fighting lines
• Compressed-air and gas lines

In industrial inspection the schedule comes not from legislation but from the project's inspection and test plan (ITP). Hold points and witness points are defined in the contract and inspection takes place at those points. Recurring checks during operation are planned under the asset integrity programme.

• Material certificates and traceability (EN 10204)
• Welding procedure (WPS/WPQR) and welder qualification
• Visual examination of weld seams
• Non-destructive testing: seam inspection by RT, UT or PAUT
• Wall-thickness measurement and corrosion assessment
• Pipe supports, hangers and expansion arrangement
• Valves, flanges and connecting elements
• Hydrostatic or pneumatic pressure test
• Integrity of paint and coating
• Corrosion-under-insulation (CUI) risk assessment

• ISO/IEC 17020
• EN 13480 series
• ISO 15649
• ISO 13847
• EN ISO 5817
• ISO 9712

• Ultrasonic thickness gauge
• Radiography or phased-array UT equipment
• Magnetic particle and penetrant consumables
• Hydrostatic test pump and calibrated pressure gauges
• Weld seam gauges
• Holiday detector (on coated lines)

1. 1Review of the Inspection and Test Plan (ITP)The project specification, the standard to be applied, hold/witness points and acceptance criteria are clarified.
2. 2Document and Material CheckMaterial certificates (EN 10204), welding procedures (WPS/WPQR) and personnel qualifications are verified.
3. 3In-process InspectionManufacturing is halted at the defined hold points; dimensional, assembly and pre-/post-weld checks are performed.
4. 4Non-destructive TestingThe NDT methods required by the specification are applied; method and extent are set according to the weld class and the product standard.
5. 5Final Inspection and TestingDimensional checks, hydrostatic/pneumatic testing or a functional test are carried out.
6. 6Reporting and Documentation PackageInspection reports, NDT reports and test records are compiled in the manufacturing data book.

A discontinuity in a weld beyond the acceptance standard, thickness falling below the calculated minimum or a pressure drop during the pressure test are findings that cannot be accepted. Suspicion of corrosion under insulation calls for a separate inspection programme.

• Details of the inspection body and the inspection personnel
• Project, specification and standards applied
• Item and lot inspected, with traceability data
• Findings of the document check (material certificates, WPS/WPQR)
• Inspection and test results
• References to the NDT reports
• Nonconformity reports and their close-out status
• Conclusion and release statement

Inspection activities are carried out under ISO/IEC 17020, which requires the impartiality of the inspection body, the competence of its personnel and the validity of the inspection methods. Under the impartiality rule, a party that maintains or repairs an item of equipment cannot carry out the independent inspection of that same equipment. EUROLAB holds internationally recognised accreditation under ISO/IEC 17020, granted by accreditation bodies that are signatories to the ILAC mutual recognition arrangement; because accredited scope is defined per inspection type, it is confirmed in writing at the quotation stage.

• Machinery Inspection
• Welding Inspection
• Structural Steel Inspection