What are the key considerations for flare system hydraulic design?

Design considerations: peak relieving load (often governs sizing), back pressure limits at relief valves (<10% set pressure typically), multiple load cases (fire, power failure, cooling failure), relief device staggering in manifolds, liquid knockout capacity, and flare tip sizing for smokeless capacity. Pressure drop calculated using compressible flow equations accounting for varying density. Network analysis software handles multiple simultaneous reliefs. Include: purge gas requirements, pilot gas, steam requirements if applicable, and knockout drum sizing for liquid carryover.