Introduction
Surge analysis is a critical aspect of ensuring the operational integrity and safety of natural gas and LPG pipeline systems. At iFluids Engineering, we conduct comprehensive transient hydraulic studies to evaluate and mitigate surge events caused by rapid valve closures, pump trips, and emergency shutdowns. Our methodology, aligned with global standards such as ASME B31.4, focuses on predicting pressure transients and safeguarding pipelines against potential overpressure scenarios and mechanical fatigue.
Key Observations Across Projects
- Steady-State Hydraulic Modeling: Developed detailed steady-state models reflecting real-world operating conditions, validated against site-specific operational data.
- Transient Surge Simulations: Simulated various critical events using PIPENET Vision and other industry-leading transient analysis tools to predict surge pressures.
- Code Compliance: Ensured adherence to ASME B31.4 and Good Engineering Practices for pipeline surge analysis, including pressure evaluations against Maximum Allowable Operating Pressure (MAOP).
- Equipment Studied: Evaluated the behavior of Booster Pumps, Remote Operated Valves (ROVs), Pressure Control Valves (PCVs), and surge protection devices.
- Mitigation Strategies: Where necessary, recommendations such as optimized valve closure times, coordinated pump trip sequencing, and surge protection systems were proposed to ensure safe transient response.
Conclusion
Through a structured approach to surge analysis, iFluids Engineering ensured the safe, reliable, and compliant operation of natural gas and LPG pipeline systems. Our studies offer practical mitigation strategies that enhance system resilience, minimize downtime risks, and protect critical energy infrastructure.
1. Surge Analysis for Natural Gas Pipeline Cross Country Pipeline for IOCL LPG Terminal Project in Kochi – Jayathe Petrotech Engineers
iFluids Engineering was engaged to perform a comprehensive Surge Analysis for an LPG import terminal pipeline system designed for transporting refrigerated Propane and Butane. The study focused on evaluating surge pressures, ensuring mechanical integrity, and validating compliance with international standards under various operational scenarios. The 20-inch cross-country pipeline system spanned approximately 3.5 km, connecting marine unloading arms at the jetty to the LPG storage and blending facilities at the terminal.
Project Scope and Methodology
The surge analysis methodology involved two critical phases
- Steady-State Hydraulic Simulation:
Developed a detailed model of the pipeline system under normal operating conditions, incorporating real-world parameters such as flow rates, pressures, pipeline specifications, and pump operations. - Transient Surge Simulation:
Conducted advanced simulations using PIPENET Vision software to predict the pipeline’s hydraulic behavior during rapid valve closures, pump trips, and emergency shutdown scenarios.
Critical equipment, including Remote Operated Valves (ROVs), Booster Pumps, and LPG Pipeline Transfer Pumps, was modeled and assessed. - Pipeline Design Standard:
All analysis was performed adhering to ASME B31.4 – Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids, ensuring that the surge pressures remained within the Maximum Allowable Operating Pressure (MAOP).
Key Equipment and Systems Studied
- Marine Unloading Arms for Propane and Butane
- Booster Pumps
- Butane and Propane Heaters
- 20-inch cross-country LPG transportation pipeline
- Remote Operated Valves (Ball Type) at key control points
- Blending Skid and Mercaptan Dosing Systems
Each equipment behavior was modeled under dynamic transient conditions to verify system stability and operational safety.
Observations and Results
- Safe Surge Margins: Transient pressures observed during ROV closures and pump trips remained within the design limits, ensuring mechanical integrity.
- Operational Resilience: No requirement for additional surge protection devices was identified under standard operational configurations.
- Code Compliance: The pipeline was verified for stress and surge conditions in accordance with ASME B31.4 requirements, confirming its suitability for the intended operational loads.
- Optimization: Recommendations were made for controlled valve closures and operational best practices to enhance surge protection naturally through system design.