API standard 650 welded steel oil storage tanks freeboard

The seal of floating roof API standard 650 welded steel oil storage tanks is a device used to reduce the evaporation loss of the storage liquid in the annular space between the tank wall and the outer ring plate of the floating roof. The common sealing forms include mechanical seal, elastic filling seal, lip seal and secondary seal. No matter what kind of seal, the seal must be combined with the floating roof effectively to reduce the evaporation loss of the liquid in the floating roof.

Allowable Design Stresses
The maximum allowable design stresses for the API standard 650 welded steel oil storage tanks materials outlined in Q.2.1 shall be in accordance with Table Q-3.The values for the allowable design tensile stress given in Table Q-3 for materials other than bolting steel are the lesser of (a) 331/3% of the specified minimum ultimate tensile strength for the material or (b) 662/3% of the specified minimum yield strength, but they are 75% of the specified minimum yield strength for the stainless steel, nickel alloy, and aluminum materials. Allowable test stresses are based on the limitation of API 620 oil tank storage standard Q.8.1.3.

One of the most widely used design codes is the API 650 Standard, from the American Petroleum Institute. The main objective of this standards API standard 650 welded steel oil storage tanks is, through the requirements contained in its various sections, to facilitate the purchase and construction of vertical, aboveground, welded fabricated tanks assuring that required safety regulations are met.