API standard 650 unanchored tanks sliding friction

Low-pressure storage tanks Fireproofing
Although general fire prevention and fire protection measures are expected to be fully covered by other safety codes, tanks API standard 650 unanchored tanks constructed according to these rules, which may be subject to fire exposure resulting from any cause, shall have their supports suitably fireproofed.
Special consideration shall be given to provisions for ample drainage facilities for accidental spills or leakage of flammable contents from such tanks or adjacent piping and other equipment if the contents may become ignited.
Subject to special considerations in isolated locations, tanks in which flammable liquid products are stored at temperatures well above their average boiling point shall be suitably fireproofed or otherwise protected.

API 650 is the standard for welded tanks for oil storage. It specifies the API standard 650 unanchored tanks design, manufacturing, welding, inspection and installation requirements of oil tanks. API 650 is widely used in storage tanks with internal pressure less than or equal to 2.5 PSI.

The main types of metal storage tanks are vertical dome roof tank, vertical external floating roof tank, vertical inner floating roof tank, spherical oil tank and horizontal oil storage tank. API standard 650 unanchored tanks is vertical tank. The capacity of vertical dome roof oil storage tank is generally less than 10000 cubic meters. The wall plate adopts sleeve type fillet weld, and it is usually installed by inverted or forward installation method during construction.