EnviroPro Combustion & Waste Heat Recovery Solutions

Proven and continuously burning flare pilots are critical to the safe operation of any flare system. They are also required by CFR60.18 and various state regulatory commissions. The number of pilots on a flare tip is typically dictated by the diameter of the flare tip. Give EnviroPro a call and we can help you determine the proper number of pilots for your flare. Most pilots use a premix burner design which means the pilot fuel gas, passes through an orifice and enters an eductor that pulls air in. This combustible mixture then travels up to the pilot burner where it burns. Pilots must be monitored to verify stable combustion. The most common method is to use a thermocouple and monitor the temperature at the pilot.

Pilot Ignition Systems: A stable pilot should continue to burn without the assistance of an ignition system. However, there are times, like at start up, when a pilot must be ignited or re-ignited. Below are some of the more common approaches to lighting pilots:

  • High Energy Ignition (HEI): Probably the most common and primary method of pilot ignition for newer systems. HEI systems use an electric probe inserted near the pilot burner to create a spark and ignite the pilot fuel gas/air mixture. Over the last several years these systems have proven very reliable. These systems can easily be automated so that an HEI system will attempt to relight the pilot without the need for operator action.
  • Flame Front Generator (FFG): These systems are also very common and among the oldest technologies. The FFG mixes plant or instrument air with pilot ignition gas (typically natural gas or propane) at grade and fills a line running up to the pilot burner. At grade an electrically generated spark ignites the mixture and the resulting fireball travels up to the pilot and ignites the main pilot fuel gas. These systems can also be made to operate automatically. The disadvantage is that FFGs are temperamental. Moisture or solids can block the fireball from making it up to the pilot. It is also not uncommon for the gas and air mixture to get too lean or too rich and the spark doesn’t ignite. Sometimes over anxious operators don’t allow the line running up to the pilot to completely fill and the fireball “stops short.” All of these disadvantages can be overcome with maintenance and training which EnviroPro can offer. The advantage of these systems is that all items needing maintenance or repair are at grade. It is not uncommon for an automatic HEI system to be the primary method of ignition and a manual FFG to be the backup system.
  • Ballistic Systems: Instead of a fireball made of natural gas and air, a ballistic system sends burning pellet through a guide tube up to the pilot. The pellet shatters on a plate near the pilot or flare tip and these burning shards ignite the pilot and/or waste gas. These systems are often found in production facilities but not very often in process plants.

Contact EnviroPro to learn more about flare pilots and pilot ignition systems.

Contact EnviroPro to discuss your flare applications!