LIGHTNING PROTECTION OF EXTERNAL FLOATING ROOF TANKS

Lightning strikes are always a risk on a storage tank, but effective bonding between the floating roof and the shell can reduce the risk of sparks SINCE 2013, at the Iranian Oil Terminal facility located in Kharg Island, more than 12 fire incidents have occurred due to lightning strikes. In 2015, one strike resulted in simultaneous fires in five tanks, and staff noticed that all damaged tanks had a mechanical sealing system, leading them to question the safety of mechanical sealing systems regarding the lightning impacts. Due to the location of tanks in Kharg Island, at a height of 60 m above the sea level, lighting strikes in wet seasons, especially in November and December, are inevitable1. It is therefore necessary to take preventative and special measures against this natural phenomenon in order to eliminate or reduce its destructive impacts. This article, aside from looking at the destructive consequences of lighting, standards, experiences, practiced recommendations and scientific achievements of other organisations, will evaluate maintenance and modifications of floating roof devices (bonding of components). DIFFICULTIES WITH API RP 545 RECOMMENDATIONS FOR ABOVEGROUND...