Pipeline integrity management is a cornerstone of safe and reliable oil and gas transportation. Pipelines carry crude oil, natural gas, refined products, and other hydrocarbons across vast distances, often through challenging terrain and environments. A structured inspection checklist ensures that operators can identify, assess, and mitigate threats to pipeline integrity before they result in leaks, ruptures, or environmental incidents. This guide covers the essential elements of a comprehensive pipeline inspection program.
Why Pipeline Inspection Matters
Pipeline failures can have devastating consequences, from environmental contamination and property damage to loss of life. Regulatory frameworks such as PHMSA regulations in the United States, CSA Z662 in Canada, and ASME B31.8 internationally require operators to maintain formal integrity management programs. These programs rely on regular inspections to detect corrosion, mechanical damage, material defects, and other threats. A thorough inspection checklist provides the structured approach needed to comply with these regulations and protect both people and the environment. Operators who invest in proactive inspection programs consistently report fewer incidents and lower lifecycle costs compared to reactive maintenance strategies.
Inline Inspection (ILI) / Pigging
Inline inspection tools, commonly known as smart pigs, are the primary method for assessing the internal condition of pipelines. Proper planning and execution of ILI runs is critical to obtaining reliable data.
- Verify pipeline geometry and confirm the line is piggable with no restrictions, tight bends, or reduced-bore valves that could trap the tool
- Select the appropriate ILI tool technology (MFL, ultrasonic, caliper, or combination) based on the expected threat types
- Confirm launcher and receiver are clean, functional, and equipped with appropriate pressure ratings and signaling devices
- Review ILI run data for metal loss, dents, ovalities, and crack-like features against acceptance criteria
- Schedule and execute dig-site verification of reported anomalies to validate ILI tool accuracy
External Corrosion and Coating Assessment
External corrosion is one of the leading causes of pipeline failure. Regular assessment of the external coating and corrosion protection systems is essential for maintaining pipeline integrity.
- Conduct close interval potential surveys (CIPS) to assess cathodic protection effectiveness along the pipeline route
- Perform direct current voltage gradient (DCVG) or alternating current voltage gradient (ACVG) surveys to locate coating defects
- Inspect above-ground sections, road crossings, and river crossings for visible coating damage or corrosion
- Verify soil-to-pipe potential readings meet the NACE SP0169 protection criteria at all test stations
- Document coating condition at excavation sites including coating type, adhesion, and any holiday defects
Cathodic Protection System Checks
Cathodic protection (CP) is the primary defense against external corrosion on buried pipelines. Regular monitoring ensures the system is providing adequate protection.
- Read and record rectifier output voltage and current at all CP stations on a monthly or bi-monthly schedule
- Measure pipe-to-soil potentials at all permanent test stations and compare against protection criteria
- Inspect sacrificial anodes where applicable and assess remaining anode life
- Check for electrical shorts, stray current interference, and bond wire integrity
- Verify that CP system adjustments are documented and logged for regulatory reporting
Right-of-Way and Patrol Inspection
Regular patrol of the pipeline right-of-way identifies external threats such as third-party encroachment, ground movement, and unauthorized activities.
- Conduct aerial or ground patrol at prescribed intervals to identify encroachments, excavation activity, or land disturbances
- Verify pipeline markers, warning signs, and cathodic protection test stations are visible and in good condition
- Inspect for evidence of soil erosion, slope instability, or water course changes that could expose or stress the pipeline
- Document and report any unauthorized construction activity within the pipeline easement
Valve and Fitting Inspection
Mainline valves, branch connections, and associated fittings are critical components that require regular inspection to ensure operability and integrity.
- Operate mainline block valves through full stroke to confirm they open and close properly
- Inspect valve actuators, gearboxes, and associated controls for leaks, corrosion, or mechanical wear
- Check flange connections and bolting for leaks, corrosion, and correct gasket condition
- Verify emergency valve closure systems and remote actuation capability are functional
Leak Detection System Verification
Leak detection systems provide continuous monitoring of pipeline operations and early warning of potential releases. They must be regularly tested and validated.
- Verify computational pipeline monitoring (CPM) system is calibrated and alarm thresholds are set correctly
- Test SCADA communication links between all remote terminal units and the control center
- Confirm pressure and flow transmitter accuracy through field calibration checks
- Conduct leak detection system sensitivity tests at prescribed intervals per regulatory requirements
- Review and document alarm response procedures with control room operators
Hydrostatic Testing and Reassessment
Hydrostatic testing remains a primary method for confirming pipeline pressure-containing capability and is required for new pipelines and as a reassessment method for existing lines.
- Prepare a detailed hydrotest procedure specifying test pressure, hold duration, temperature correction, and acceptance criteria
- Verify test equipment calibration including pressure recorders, gauges, and temperature monitors
- Ensure environmental containment and disposal plans for test water are in place and approved
- Monitor pressure and temperature continuously during the hold period and document all readings
Best Practices
- Develop a written integrity management plan that identifies all credible threats and prescribes inspection methods and frequencies for each
- Integrate ILI data, CP survey results, and patrol findings into a single GIS-based pipeline integrity database
- Use risk-based inspection scheduling to focus resources on the highest-risk pipeline segments
- Conduct management of change reviews for any modifications to operating conditions, products transported, or third-party activities
- Train field personnel on pipeline damage recognition and near-miss reporting procedures
- Maintain accurate pipeline attribute data including material, wall thickness, coating type, and installation date for every segment
How Checksheets Helps
Checksheets streamlines pipeline integrity inspections by providing digital checklist templates tailored to each inspection type, from ILI run planning to CP surveys and valve inspections. Field technicians can complete checklists on mobile devices, attach photos and GPS coordinates, and submit results instantly to the integrity management team. The platform automatically tracks inspection schedules, flags overdue items, and generates compliance reports that satisfy regulatory requirements. By centralizing all inspection data in one platform, Checksheets gives pipeline operators the visibility they need to make informed decisions about maintenance priorities and capital investment.