Flare lines and stacks are the plant's pressure relief made visible, and they punish coatings three ways at once: service temperatures that exclude ordinary systems, violent thermal cycling between idle and flaring, and access that arrives once per turnaround if at all. A coating decision here lives with the plant for years.
Reading the real temperature
Flare headers idle warm and spike hot during relief events; tips and upper stacks see the most brutal swings. The coating must be rated for the spike, not the average, and rated for cycling explicitly, because repeated expansion is what cracks over thick or wrongly chosen films. This is classic silicone aluminium territory, applied thin per the earlier failure guide in this series, over blasted steel or qualified inorganic zinc.
The cycling trap
A line rated by its flaring temperature may spend most of its life near ambient, collecting condensation, coastal salt and, on insulated sections, the full corrosion under insulation problem in the recognised danger band. Insulated flare knockout drums and headers deserve CUI qualified systems, not stack paint.
Working with the access you get
Stacks need rope access or scaffolding plus a shutdown for anything near the tip, so coating scope should ride every planned flare outage. Survey by drone beforehand, fix the scope, and stage materials so the window is spent applying, not procuring. Fast cure at steel temperature matters more here than on any ground level asset; the scaffold clock is expensive.
Specify inspection into the system
Choose systems whose condition can be judged visually at distance, aluminium finishes show rust bleed early and honestly, and record DFT properly at application because nobody measures a stack twice.
MENA Industrial Supplies quotes flare and stack systems with temperature and cycling data from Dubai stock, same working day, via the oil, gas and refinery coatings page.