External floating roof tank double deck type an external floating roof tank is a storage tank commonly used to store large quantities of petroleum products such as crude oil or condensate.
Floating roof double deck pontoon.
In my humble opinion the double deck arrangement would be a more robust design but may cost extra and a detailed techno economic evaluation would be needed to arrive at the optimum option.
The low single deck is the more efficient of the two for 30 to 170 foot diameter tanks.
Over the years jm dixon associates has undertaken the design of many floating roofs both double and single deck for world renowned clients such as philips 66 exxon mobil and ineos.
The sketches shown illustrate the above single deck and double deck floating roof with the critical components for these structures.
A double deck type floating roof has two complete decks covering the entire liquid surface.
Figure 1 4 single deck pontoon type floating roof bob.
Types of external floating roof consist of.
The roof is consisted of a portion divided by the ring and radial bulkheads into several compartments and a portion called the flexible bay.
These include new builds together with the evaluation of existing roof designs for suitability such as analysing the various flotation cases and repair.
Double deck pontoon roofs which are designed with concentric annular pontoons with radial bulkheads in each pontoon section.
It consists of an open topped cylindrical steel shell equipped with a roof that floats on the surface of the stored liquid.
Single deck pontoon type figure 1 4 double deck figure 1 5 special buoy and radially reinforced roofs floating roof tank will be further discussed in details in later chapter.
The two preferred configurations for external floating roofs are the double deck and the low single deck with 30 minimum pontoon area.