Introduction
Effective Surge Analysis is essential for high-density slurry transportation systems used in iron ore beneficiation and tailings management. Hydraulic transients caused by sudden valve closures or pump trips can result in damaging overpressure or vacuum conditions. iFluids Engineering conducted detailed surge and transient hydraulic studies for thickened slurry pipelines in iron ore processing plants, aligning with ASME B31.3 – Process Piping and using reputed simulation tools to ensure system integrity and operational safety.
Key Observations
- Advanced Modeling Approach: Steady-state and transient simulations will be carried out to evaluate surge behavior for multiple flow scenarios, valve actuations, and pump trips.
- Equipment Analyzed: Simulations included knife gate valves, butterfly valves, centrifugal underflow pumps, flushing water systems, and pipelines will be analyzed for structural performance.
- Standards Compliance: All transient pressure peaks will be verified against the design pressure, as mandated by ASME B31.3.
- Operational Sensitivity: Both dual-line and single-line operating conditions were tested. Negative pressure events during rapid valve closures will be checked to confirm whether they are within acceptable thresholds, confirming no cavitation risk.
- No Additional Mitigation Devices Required: The pipeline systems will be checked to confirm whether they are stable under worst-case transient conditions, confirming the need for surge relief valves or accumulators.
Conclusion
By integrating high-precision modeling, field-aligned inputs, and internationally recognized design codes, iFluids Engineering enables its clients to achieve optimal pipeline safety, reliability, and lifecycle performance.
1. Hydraulic transient analysis for the pipeline transporting Iron ore tailings thickened slurry from High Rate Thickener (HRT) to Paste Thickener (DCT), located at Noamundi Iron Mine in Jharkhand, India.
A comprehensive surge analysis was performed for a thickened slurry and flush water pipeline system designed to transport iron ore tailings from a High-Rate Thickener (HRT) to a Deep Cone Thickener (DCT). The objective was to assess transient pressure conditions during operational upsets such as valve closures and pump trips to ensure system safety and compliance with international engineering standards.
The study involved both steady-state and transient hydraulic simulations, using a simulation software for modeling pressure waves, valve actuation, and pump dynamics.
Codes and Standards Applied
- ASME B31.3 – Process Piping, for pressure containment validation and design compliance
- API 5L Gr. B and IS 1239 Heavy Class, as applicable to carbon steel pipe specifications
Equipment and Components Assessed
- Centrifugal HRT Underflow Pumps and Flushing Water Pumps
- Knife Gate Valves, Butterfly Valves (air-actuated)
- Dual pipeline branches (10″, 14″, 18″) for slurry transfer and flushing
- Piping and fittings rated to 150# pressure class
Simulated Scenarios Included
- Sudden valve closures (suction, discharge, isolation)
- Emergency shutdown of underflow and flushing pumps
- Flushing system valve trips under 300 m³/hr conditions
- Single and dual-line operational modes
Results and Observations
- All maximum surge pressures observed across 30+ scenarios remained within allowable design limits of the pipeline system.
- No cavitation or vacuum-induced failure risks were identified, with negative pressures well above critical thresholds.
- The highest surge pressure observed during flushing system isolation remained safe below the threshold limit.
- The system’s pipeline material thickness and valve pressure ratings were deemed adequate for all transient conditions.
- No additional surge protection devices, such as rupture discs or accumulators, were required.
2. Hydraulic transient analysis for the pipeline transporting Iron ore tailings thickened slurry from High Rate Thickener (HRT) to Paste Thickener (DCT) located at Joda East Iron Mine, Odisha, India.
A detailed surge and transient pressure analysis was conducted for a slurry pipeline system used in iron ore beneficiation. The analysis focused on the underflow pipeline connecting the High-Rate Thickener (HRT) and Deep Cone Thickener (DCT), evaluating the pipeline’s ability to withstand hydraulic transients during pump trips, valve closures, and other unsteady flow events.
The surge study was conducted using advanced simulation software, with all design inputs and safety criteria aligned to ASME B31.3 – Process Piping standards, ensuring the mechanical integrity and operational reliability of the slurry and flush water transfer network.
Scope and Methodology
The pipeline configuration included a 5063-meter carbon steel pipe (8” diameter, API 5L Gr. B), carrying high-density iron ore tailings slurry. Key system components assessed in the surge simulation included:
- Centrifugal Slurry Pumps
- Flushing Water Pumps
- Knife Gate and Butterfly Valves (Air-actuated, at suction, discharge, and isolation points)
- Carbon Steel Piping (as per API 5L Gr. B and IS 1239 standards)
The simulations were executed using a simulation Software for both steady-state and transient conditions. More than 30 scenarios were analyzed, including:
- Pump trips under single and dual-line operation
- Sudden valve closures (suction, discharge, isolation, flush)
- Pipeline flushing system upset cases
Codes and Standards Followed
- ASME B31.3 – Process Piping (for pressure containment and surge limits)
- Material specification: API 5L Gr. B and IS 1239 Heavy Class
- Surge force and vacuum limits validated against standard acceptance criteria
Key Results
- The maximum surge pressure observed was within ASME B31.3 allowable limits.
- Minimum pressures in all scenarios remained above the vapor pressure threshold (no cavitation risk)
- Valve closure time ensured a safe transition without requiring additional surge mitigation equipment
- Surge force values were calculated across multiple pipe segments for structural verification