Maintaining Flare Tip Health

Abstract

Maintaining flare tip health is essential to ensure safe disposal of flammable hydrocarbons in any oil and gas industries. This paper presents best practices (from operation, to maintenance and inspection) to ensure the health of large flare tips. The flare tip mixes flammable fluids and air into the required concentration and velocity to maintain stable ignition and combustion. These flare tips are vulnerable to damages caused by burn backs that may result in serious threats to plant safety & integrity, as well as exorbitant replacement costs. We will outline how we comprehensively mitigated thermal buckling failures in HP flare tips to improve the asset life and availability of these safety critical flare systems. In the past, we recorded frequent flare tip failures in the four stage HP flare system of trains 3 & 4. Replacement of these expensive tips was planned during major turnarounds. Meanwhile, the root cause analysis revealed that the thermal bucking tip failures can be attributed to "burn back". Inadequate purge gas flow, poor reliability of burn back detectors, inadequate design, control measures and project specifications were identified as causes for the burn back. It was recommended to replace the fuel gas as a purge gas medium with nitrogen. This permanently preserved the integrity of the flare tips, while avoiding fuel gas wastage. In addition, the following best practices were recommended to maintain a healthy flare system. Improve the design and reliability of burn back detectorsChange the inspection approach to thermographic surveysImprove the pilot flame, burn back detectors and alarm system to provide low flow alarms for purge gas The implementation of these recommendations enhanced the asset life and availability of the safety critical flare system, as proven by the thermographic survey, which shows colder operating conditions of the flare tips.