The flare tip is the business end of a flare - the burner at the top of the stack where relief gas finally meets air and burns. Next to it sits a small, permanently lit pilot whose only job is to guarantee that whenever gas arrives, there is always a flame to ignite it. This guide explains the flare tip and how it achieves smokeless burning, the continuously lit pilot and how its flame is proven, and why a pilot flame-out is one of the most important alarms a flare system can send.
Flare Tip & Pilot in one line: The flare tip is the burner at the top of a flare stack where relief and waste gas mixes with air and is combusted. The pilot is a small burner beside the tip that stays lit continuously so any gas reaching the tip is ignited immediately, and its flame is proven by a thermocouple or ionization sensor. Smokeless flare tips inject steam or air to improve mixing and burn cleanly, and a loss of the pilot flame is a critical safety and compliance alarm because it means relief gas could be released unburned.
The flare tip is the specially designed burner at the top of the stack. Its shape and internal features control how the arriving gas mixes with air and burns, and it must cope with an enormous range - from the tiny purge flow that passes most of the time to the massive surge of a major relief event. A good tip burns stably across that whole range without the flame lifting off or flashing back into the stack.
A plain flare burning heavy or rich gas tends to smoke, because there is not enough air mixed in fast enough for complete combustion, leaving unburned carbon as soot. Smokeless flare tips solve this by injecting a second medium to improve mixing and draw in air. Steam-assisted tips inject steam, which entrains air and breaks up the fuel for cleaner burning; air-assisted tips use a blower to force combustion air into the flame. Either way, the aim is to supply enough turbulence and oxygen that the gas burns completely and cleanly rather than smoking.
The amount of assist has to match the flow, and that is a balance. Too little steam or air and the flare smokes; too much and the assist can actually cool or over-aerate the flame, hurting combustion and, in the case of steam, wasting energy. On many flares the assist is modulated against the measured or inferred flare flow so the tip stays smokeless across changing loads rather than being set for a single condition.
A flare cannot be allowed to depend on gas arriving already ignited, because relief flows are intermittent and unpredictable. The solution is the pilot: a small, self-sustaining burner mounted at the tip that is kept alight continuously, fed by its own reliable fuel supply. Whenever relief gas surges up the stack, the ever-present pilot flame ignites it instantly, so gas is never released to atmosphere unburned as long as the pilot is lit.
Because everything rests on the pilot staying lit, its flame must be proven, not assumed. The most common method is a thermocouple positioned in the pilot flame: as long as the flame is present the thermocouple stays hot and reports a healthy temperature, and if the flame goes out the temperature drops and the system knows the pilot has failed. Some flares use flame ionization or optical detection instead, but the principle is the same - a sensor continuously confirms the pilot flame is really there.
Pilots also need to be relightable on demand, so flares carry an ignition system - often a flame-front generator that sends an ignited fuel-air mixture up a line to relight the pilot, or a high-energy electrical igniter. If a pilot blows out in high wind, the ignition system can relight it without anyone climbing the stack. The combination of a proven, continuously lit pilot and a remote ignition system is what lets a flare be trusted to burn whatever it is sent, whenever it is sent.
Of all the signals a flare produces, pilot flame status is among the most important, because a flare with no pilot is a flare that could vent unburned, flammable gas straight to atmosphere. The pilot thermocouple or flame sensor feeds a discrete or analog signal into the control system, and a loss of flame is treated as a high-priority alarm demanding immediate attention and, usually, automatic relighting.
A cloud SCADA such as Merobix can carry the pilot flame status alongside pilot fuel pressure and, where available, the assist flow, so an operator sees not just that the pilot is lit but the health of the system keeping it lit. A drop in pilot fuel pressure, for instance, is an early warning that the pilot could fail, and catching it before flame-out is far better than reacting after. Presenting these tags together turns a single flame signal into a picture of flare readiness.
The flame status also matters for compliance. Regulations and permits generally require that a flare be able to demonstrate a continuous ignition source, so a timestamped record of pilot flame status is evidence that the flare was capable of burning its load throughout the period. A cloud SCADA that logs pilot flame continuously provides that record automatically, and it flags flame-out events for follow-up, so a lost pilot becomes a documented, actioned event rather than something noticed only after the fact.
The flare tip is the main burner at the top of the stack where the bulk of the relief gas mixes with air and burns. The pilot is a small, separate burner beside the tip that stays lit continuously so that any gas reaching the tip is ignited immediately. The tip handles the large, intermittent relief flow, while the pilot guarantees there is always a flame to ignite it.
The most common method is a thermocouple placed in the pilot flame: while the flame is present the thermocouple reads hot, and if the pilot goes out the temperature falls and the system detects the loss. Some flares use flame ionization or optical detection instead. Whatever the sensor, the signal feeds the control system so a pilot flame-out raises an immediate high-priority alarm.
A smokeless flare tip injects a second medium - steam or forced air - to improve how the fuel mixes with air so it burns completely instead of producing soot. Steam-assisted tips entrain air and break up the gas, while air-assisted tips use a blower to push combustion air into the flame. The assist is matched to the flow, because too little causes smoke and too much can cool or over-aerate the flame.
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