API standard 650 floating-roof tanks self-anchored

Allowable Design Stresses
The maximum allowable design stresses for the API standard 650 floating-roof 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.

This standard applies only to API 650 tank API standard 650 floating-roof tanks whose entire bottom is uniformly supported and to API 650 tank in non-refrigerated service that have a maximum design temperature of 93°C (200 °F) or less.

API standard 650 floating-roof tanks belongs to metal oil tank. Metal oil tank is a kind of vessel made by welding steel plate. The common shapes of metal tank are vertical metal tank, horizontal metal tank and spherical metal tank. The advantages of API standard 650 floating-roof tanks etc. metal oil tank are good sealing, not easy to leak, can be installed with heating and insulation function, metal tank can withstand high internal pressure, large vertical metal tank such as API standard 650 floating-roof tanks also has the characteristics of small floor space and large storage capacity.