Metal tanks: temperature-controlled liquid storage

Temperature-controlled storage tanks are reserved for liquefied gases whose normal boiling point (NBP) is below ambient temperature, and which are therefore characterized by a high effective pressure at site temperature.

When the quantities of liquefied gases to be stored are very large, the number of full-pressure storage units required also becomes very large, as their unit volume is limited by the maximum wall thicknesses achievable. To remedy this restrictive and uneconomical situation, the operating pressure is reduced by lowering the product temperature towards the PNE. In this way, reservoir capacity can be considerably increased, as can the quantities stored, since the liquid is denser.

• Semi-refrigerated tanks (spheres or balloons) operate under reduced pressure, between atmospheric pressure and full pressure at ambient temperature.

• Refrigerated or cryogenic tanks (vertical cylindrical tanks with flat bottoms) operate at approximately atmospheric pressure at PNE.

Naturally, all these tanks feature thermal insulation, which is all the more important the lower the storage temperature.

The article "Metal tanks for liquid storage" is the subject of several fascicles:

— General information [1] ;

— Storage at room temperature [2] ;

— Temperature-controlled storage.

Subjects are not independent of one another; readers will often need to refer to other issues. The issue number is followed by the paragraph or figure number.