Why Lines Get Pigged
Liquids and debris collect in low spots of gas lines, cutting capacity and feeding corrosion. Cleaning pigs sweep the line; inline inspection tools measure wall loss and cracks. The two are a sequence: the line must be clean and predictable before inspection data is worth paying for.
What the Rules and Standards Say
Pipeline rules under 49 CFR 192 address pig and scraper traps in design and operation, and integrity management sends operators to inspection tools when a line cannot be verified another way. API 1163 governs inline inspection: the tool must be validated for the anomaly types and sizes it reports, and the results assessed by qualified people.
Trap Safety and the Run Plan
A launcher and receiver are pressure vessels in disguise. The procedure: verify pressure is bled, confirm the trap is isolated, open slowly, and never assume. The run log should record pig type, launcher and receiver pressures, volumes, and what came out, because that log feeds the corrosion program and the integrity file.
The record that closes the loop
Pigging the Line rests on the same field data as the rest of the operation: tickets, timesheets, approvals, and inspections. The same discipline shows up in Pipeline integrity for gathering lines and Operator qualification for pipeline work and Compressor station maintenance. If those records live in notebooks, email, and memory, start with an operations audit.