Fire Risk Assessment dan Perancangan Water Spray System untuk Proteksi Tangki TK-725 dan TK-756 Industri Kimia

Abstract

Storage facilities for flammable liquids present a high fire risk due to the presence of combustible vapors, ignition sources, and the potential for domino effects that may result in material losses, operational disruptions, environmental damage, and casualties. One facility with such potential hazards is the isobutanol (IBA) storage tanks TK-725 and TK-726 at Perusahaan Kimia Gresik, which are currently protected only by foam chambers and a hydrant network without a dedicated tank cooling system. This study aimed to analyze the fire risk associated with isobutanol storage tanks and to design a water spray system as a mitigation measure to reduce fire escalation and thermal radiation impacts during fire incidents. The research employed a Fire Risk Assessment (FRA) using the qualitative method proposed by Yung (2008) to identify hazards, evaluate likelihood and consequence levels, and determine risk ratings through a risk matrix approach. The results of the risk assessment were subsequently used as the basis for designing the water spray system in accordance with applicable fire protection standards. The findings indicated that the liquid spill scenario caused by tank overfilling during loading operations had an initial risk level categorized as Moderate to High, with a possible likelihood of occurrence and high consequences. The implementation of a water spray system was recommended as an additional control measure and was found capable of reducing the consequence level from high to moderate, thereby lowering the overall risk level to Moderate. The design calculations showed that the water demand for a single tank was 306.6 m³, while the total water requirement for protecting both tanks reached 613.368 m³. The proposed system is expected to provide adequate cooling to tank surfaces, reduce thermal radiation effects, prevent structural failure, and minimize the potential spread of fire to surrounding facilities.