Construction of under-bottom connections for API 650 unanchored tanks

API 650 unanchored 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 650 unanchored 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 650 unanchored tanks also has the characteristics of small floor space and large storage capacity.

Allowable Design Stresses
The maximum allowable design stresses for the API 650 unanchored 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.

Both parties shall confirm the API 650 unanchored tanks material object and the quality of the products, confirm the reasons for the defects and the quality of the products, and sign the quality inspection agreement. Major quality objections shall be reported to relevant leaders in a timely manner, and shall be discussed and solved with the API 650 unanchored tanks steel plant.

Determination of API 650 oil tank container: The total volume should be determined according to factors such as transportation mode and API 650 unanchored tanks fuel supply cycle. For train and ship transportation, the maximum consumption is not less than 20-30 days; the maximum consumption for automobile transportation is not less than 5-10 days.