Flare Network Analysis
A flare network analysis evaluates the entire flare disposal system to ensure the flare header, sub-headers, knockout drum, piping, and flare tip can safely handle the combined relieving loads from multiple PSVs, control valves, and blowdown valves — especially during simultaneous emergency events.
Unlike relief valve sizing (which is usually single device, worst case basis), flare analysis considers system-wide interaction.
Objectives:
When is Flare Network Study Needed?
Even small changes can cause major flare issues, such as sudden backpressure increase, requiring revalidation every time load is added.
Key Checks Performed
| Parameter | What is checked | Why it matters |
|---|---|---|
| Header Hydraulics | Pressure drop & Mach number in piping | prevents choking / reduces vibration |
| Combined Load Scenarios | Sum of relief + blowdown sources | worst-case simultaneous events |
| KO Drum Sizing | Liquid hold-up, disengagement | avoid liquid carryover to flare stack |
| Flare Tip Performance | Burn efficiency, radiation | ensures environmental & personnel safety |
| Backpressure Allowable | Ensure relief valves operate correctly | Excessive backpressure can reduce PSV capacity |
Usually, tools like Aspen Flare System Analyzer or HYSYS Dynamics are used for this.