AST 1

The failure of a tank can have several undesirable effects such  as ______. (multiple answers)

• endangering personnel

• affecting the environment

• interrupting  the Operator’s business.

The primary function of a storage tank is to store liquid substance.

This liquid substance may be: (multiple answers)

• feedstock

• Finished products prior to shipping out to customers

• Unfinished petroleum components awaiting for further processing

While in the storage tanks, the stored products may settle out undesirable substances such as: (multiple answers)

• water

• emulsion

• dirt

For pressurized tanks, the very volatility & high vapor pressure product such as LPG &   Butane will be store in a vessel that will withstand product pressure and prevent   any  product vaporization. Due to high volatility & high vapor pressure the vessels are   mounded underground to prevent: (common reason)

• overpressure condition

• rain water to enter the tanks

• thermal radiation in case of any fire nearby.

• external pressure of atmosphere

Atmospheric storage tank is used to:

• store easily vaporized liquid

• store liquid which will not vaporize at ambient temperature.

• store liquid under high pressure

• store liquid with high vapor pressure.

Types of floating roof in AST:

• Submerged Floating Roof (SFR)
• External Floating Roof (EFR) and Internal Floating Roof (IFR)
• Floating Bottom Roof (FBR)
• Semi-Floating Roof (SFR)

Open roof tank of AST is normally used for:

• Storing radioactive materials
• Storing temperature-sensitive liquids
• Storing highly volatile chemicals
• Storing liquids that are not sensitive to atmospheric conditions

Types of roof for fixed roof in AST:

• cone roof

• pyramid roof
• tent roof
• dome roof

Cone roof AST is normally used to store:

• low volatile liquid products

• solid products
• gaseous products
• powdered products

Why nitrogen blanketing system is used in AST that stores volatile products?

• To reduce the pressure inside the tank
• To prevent the formation of flammable mixtures by displacing oxygen and creating an inert atmosphere.
• To enhance the oxygen content in the tank
• To increase the volatility of the stored products