A flare tip has one of the hardest jobs on the plant. It sits out in the weather, cycling through heat, rain, wind and whatever the process decides to send it. When a tip fails early, the alloy is rarely the culprit. More often it is a handful of maintenance habits repeated for years: a purge line left isolated after a job, a gasket pulled from the wrong shelf, a flame detector nobody has inspected since commissioning.

None of those look dramatic on the day. Together they are what turns a fifteen-year tip into a five-year one.

Purge gas: the mistake nobody notices

Purging exists for two reasons. It keeps air from migrating back into the flare header, and it keeps flame from creeping up into the tip and the riser. Get it wrong and there is usually no alarm, no leak, no smell. Just a slow accumulation of risk.

The failures we see most often are mundane:

• Purge isolated for work on the knockout drum, molecular seal or header, then never reinstated because the permit was signed off on something else.
• Flow verified at the panel rather than at the tip, where a blocked strainer or a partly closed valve has quietly cut the rate.
• Purge rate set once at commissioning and never revisited when the seal type, header size or tie-in changed.
• Purge stopped on idle tips to save gas, usually with the best of intentions and the worst of outcomes.

Treat purge verification as a task in its own right, not a box on a checklist. Confirm flow at the furthest point in the system, confirm the isolation is tagged open, and confirm it again before anyone lights a pilot or introduces hydrocarbon. Record the reading. A number in a logbook is what lets you spot a trend six months later.

Gaskets and bolting: cheap parts, expensive damage

A leaking flange at the base of a tip does not announce itself. It burns. That small side flame impinges on the tip, the riser and the support structure, and by the time it is found the metal underneath has been overheated and distorted.

Most of these leaks trace back to selection and fitting. Elastomeric or polymer gaskets used where temperature will exceed their rating. Spiral-wound gaskets with the wrong filler for hot hydrocarbon service. Sheet gaskets cut on site to save a delivery. Gaskets reused after a shutdown because the correct size was not in the store.

Then comes the bolting. Bolts tightened by feel, working round the flange in one pass instead of a star pattern, or tightened to a torque copied from a different flange size. Uneven loading squeezes one side of the gasket and leaves the other loose. Follow the plant specification for material and torque, use a calibrated wrench, and check the joint again after the first thermal cycle — hot re-torquing catches the relaxation that cold torque never will.

A flare tip rarely fails because of the metal. It fails because of what happened to the metal around it.

Flame detection treated as a nuisance

Flame detection earns its keep in exactly the moment nobody wants to think about: a release with pilots out. When detectors are dirty, misaligned or permanently bypassed, operators lose the only reliable signal that the pilots are lit.

Common problems include UV sensors blinded by soot, dust or heavy rain; thermocouples reading ambient because the probe has been knocked or corroded; detectors aimed at the wrong part of the tip after a maintenance rebuild; and bypasses applied during a fault and left in place for months because the alarm was inconvenient.

Clean and check detection as a routine, not as a reaction. Test the loop end to end — sensor, logic and operator display — using the method the manufacturer specifies, and keep a bypass register with a name and a review date against every entry. If a pilot outage does not reliably raise an alarm, you have no idea whether your ignition system works until you need it.

Pilots and ignition left to look after themselves

Pilot assemblies are the smallest, cheapest and most neglected items on the flare. Coke builds up around the pilot tip, the flame gets smaller and less stable, and eventually it blows out in a crosswind. Gas pressure to the pilot header drops as filters load, and nobody notices because the pilot has never been checked while it was cold.

Test igniters on a fixed schedule, inspect pilot tips whenever the flare is isolated, and confirm pilot gas pressure at the header rather than at the supply skid. Relight into a tip that has not been purged, and you risk igniting an air–gas mixture inside the riser instead of at the tip.

Steam and air assist: settings that quietly damage tips

Over-steaming lifts the flame off the tip, destabilises combustion and can extinguish it altogether. Under-steaming leaves a smoking, coked tip where thermal cracking eats into the metal. Both extremes shorten life, and both are usually the result of an assist ratio that was correct for one flow regime and has not been looked at since.

Check the assist rate against actual flow, not design flow. Trim the control valve so it can modulate at low rates instead of hunting. And drain the steam line properly before injecting — a slug of condensate hitting a hot tip is a thermal shock you will pay for later.

Inspection only when the plant stops

Turnaround-only inspection means a tip can run for years with a developing problem nobody can see. Build a lighter routine between shutdowns: visual checks from a safe vantage point, thermal imaging where it is practical, and a written record of anything that changes.

Habits that add years to a tip

1. Verify purge at the tip, every time, and log the reading.
2. Use the specified gasket material and torque, and re-check after the first heat-up.
3. Clean and function-test flame detection on a fixed interval; review every bypass.
4. Inspect and test pilot and ignition systems while the flare is cold.
5. Match assist rates to real flow, and drain lines before injecting steam.
6. Photograph the tip at every opportunity and compare with the last set.

None of this is glamorous work. It is also, in our experience, the difference between a tip that reaches its design life and one that is cut out and replaced while everyone wonders what went wrong. If your flare is due for inspection or you are reviewing maintenance procedures for the next shutdown, it is worth having the tip condition assessed properly before the work scope is fixed — the findings usually change it.

Photo: Gustavo Fring / Pexels