Internal or External Floating Roof??

[cam478]

Currently I'm working in the selection of the most suitable roof type for 6 crude storage tanks. The storage tanks will be internally heated and externally insulated in order prevent wax formation.

The crude specification and storage conditions are the following:


Stabilised Crude Specification

Specification Unit Value
VP at 37.8 C bara 0.22
RVP, max psia 10.0
BS&W, max vol% 0.5
Flash Point, min ºC 60
Salinity, max PTB 25
Cloud point ºC 60
Pour point ºC 36-42

Crude Storage Conditions
Specification Unit Value
Pressure barg 0
Temperature ºC 75
VP at 75oC psia 11
Density at 75 C Kg/m3 827
Viscosity at 75 C cP 13.3

Note that storage temperature is above of flash point and vapor pressure is high (11 psia)

Tank capacities are: 5 of 50.000 bbl, 1 of 15.000 bbls

I hope that you could helpme to select the most suitable roof tank:
a. Inernal Floating roof (cone or dome),
b. External Floating roof.


thanks for your help