RAVVA

Celebrating 16 Years of Technical Excellence

Floating Roof Tanks

RAVVA – Celebrating 16 years of Technical Excellence Pioneering Development

Floating Roof Tanks

In Ravva, the tank farm consists of five tanks – four tanks to hold Ravva stock, each of 235,000 Bbls capacity & one tank to hold stock from ONGC, of 15,000 Bbls capacity. During the second phase of development in 1996, three crude storage tanks were installed. Due to subsequent increase in the oil production and also to have higher storage capacity, fourth crude storage tank was installed in June 2002. Like the earlier three storage tanks, this tank was also equipped with a deluge system & sprinklers for tank shell cooling. These tanks are of floating roof type with adequate fire protection facilities. These tanks have an open-topped cylindrical steel shell equipped with a roof that floats on the surface of the stored liquid. The roof rises and falls with the liquid level in the tank. As opposed to a fixed roof tank there is no vapour space (ullage) in the floating roof tank (except for very low liquid level situations). Thus, it not only minimises the evaporation loss of the stored liquid but also reduces fire protection requirements and odour emission. At Ravva, Cairn has installed the Double Deck Floating Roof Tanks. Double deck floating roofs consist of two separate steel plates with an air space between them, covering the entire liquid surface. The air space is divided into different compartments guaranteeing the buoyancy even in case of a failure of the lower membrane. They are suitable for all sizes of tanks and especially in Ravva where there are constant high winds.