Engineering layout of fuel tanks in a tank farm Angan Sengupta * , A.K. Gupta 1 , I.M. Mishra Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee 24766, Uttarakhand, India article info Article history: Received 17 December 2009 Received in revised form 21 May 2010 Accepted 22 June 2010 Keywords: Tank farm Wind effect Cross-wind Safe separation distance Modified point source model abstract The present paper deals with the location of tanks in a tank farm, in chemical and allied industries. Ideally the tanks are so placed and installed that in case of fire, the neighbouring tanks could remain safe. The safe distance of separation among the tanks is calculated in no wind condition, as well as, in the presence of wind. The paper uses the methods available in literature and modifies the point source model to include the effect of wind vector on the flame height during the calculation of safe inter-tank distance. It is found that for wind velocity > 4 m/s, the modified point source model provides appropriate inter-tank distance. However, for no wind and with wind velocity < 4 m/s, the ShokrieBeyler’s method provides safe inter-tank distance. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction Tank farm is a synonym of an oil depot, a facility for storage of liquid chemicals, such as oils, gasoline, diesel, aviation turbine fuel, solvents, petrochemicals, etc. The tank farm is a piece of land on which a number of fuel oil or chemical storage tanks are located or sited together. The storage tanks may also be used to store base blending components, solvents, additives, acids, caustic, chemicals, or finished products. They may also be used as blending vessels. Storage tanks are expensive to build and they require periodic maintenance to keep them in proper condition when storing volatile and flammable liquids. It is, therefore, necessary that they be properly sized and utilized to maximize the return on investment. The safety aspects, apart from periodic maintenance, are extremely important. The recent incident at Jaipur oil depot of Indian Oil Corporation Ltd. where 12 tankers containing 10 5 kl of diesel and gasoline caught fire and the fire continued for a week resulting in several fatalities and about 200 injuries besides damage to property worth 3  10 3 million INR (w75 million USD) is a case in point. This fire caused very serious environmental pollution around Jaipur and its adjoining areas. This incident has underlined the importance of proper layout with safe separation distance to prevent such hazardous episodes. The tank farms usually have a number of tanks of equal heights. However, they may be of varying capacities. Equal height adds to aesthetics and lends them economic credence in the construction of access structures, easy movements of operators from one tank to another and of fire service men during emergency episodes. The tanks may be laid out in square pitch having safe inter-space between them. The inter-tank optimum separation distance is crucial for safe operations, piping design, and maintenance access and emergency/accident control and mitigation measures. The desired inter-tank distance depends largely on the materials/ chemicals to be stored and the capacity of the tanks. The tanks in refineries are generally constructed from steel or polyethylene or fiber glass and are either having fixed roofs and/or floating roofs for storing liquids. Non-steel constructions lower cost considerably, and make them preferred choice for storing corrosive and reactive chemicals. Various regulatory and professional bodies like American Petroleum Institute (API), National Fire Protection Association (NFPA), and Environmental Protection Agency (EPA) have sug- gested standards for such tank layouts in a tank farm. The layout of tanks as distinct from their spacing, should always take into consideration the accessibility needed for fire-fighting and the potential value of a storage tank farm in providing a buffer area * Corresponding author. Tel.: þ91 9012390134; þ91 9433948999. E-mail addresses: angan.sengupta@gmail.com (A. Sengupta), akgd30@ indiatimes.com, akgd30@gmail.com (A.K. Gupta), imishfch@iitr.ernet.in (I.M. Mishra). 1 Scientist and former Head, Fire Research Laboratory, Central Building Research Institute, Roorkee, India. Contents lists available at ScienceDirect Journal of Loss Prevention in the Process Industries journal homepage: www.elsevier.com/locate/jlp 0950-4230/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.jlp.2010.06.016 Journal of Loss Prevention in the Process Industries 24 (2011) 568e574