SY/T 6859-2020 in English

Three-level Evaluation Method

• Qualitative Method: Risk Matrix Method (Applicable to Preliminary Screening)
• Semi-quantitative Method: Risk Index Method (A scoring system needs to be established)
• Quantitative Method: Monte Carlo Simulation (A complete failure database is required)

Critical Process Nodes

1. Pipeline Section Division (According to the Corrosion Rate Difference ≤0.1mm/a)
2. Failure Mode Identification (Small Leakage/Large Leakage/Rupture)
3. Consequence Quantification (Thermal Radiation Value ≥37.5kW/m² is the Lethal Threshold)

Data quality requirements

Corrosion defect detection data must include: maximum depth, axial length, and circumferential width three-dimensional parameters, and the detection accuracy should reach ±0.1mm.

Typical application scenarios

Example of evaluation of pipe sections in high consequence areas: Use magnetic flux leakage detector to obtain defect data, and calculate the residual strength in combination with API 581 standard. The risk control cost under the ALARP criterion should be ≤$3 million/life year.

Main technical breakthroughs of the 2020 version:

• Added a reliability-based failure probability model (Appendix A)
• Clarified the solid flame model for thermal radiation calculation
• Refine the personnel risk acceptance criteria (IR≤10⁻⁶/year)

Compared with ASME B31.8S: Localization has added special geological disaster evaluation clauses.