Description

This Standard specifies requirements for the design and construction of steel tanks for the storage of flammable and combustible liquids. It sets out requirements for tank joints and accessories (e.g. vents, manholes, fill level indicators) and specifies tank testing requirements.

Scope

This Standard applies only to tanks that are used to store substances that are liquid at normal temperatures and pressures.

The shell thicknesses of tanks specified in this Standard are based on the following assumptions:

• a) Stresses on the tank will be comparatively low.
• b) The liquid being stored is no more corrosive than normal petroleum products.
• c) The density of the liquid being stored is not greater than 1000 kg/m3.
• d) The tank needs to be reasonably sturdy for handling and any transport.
• e) An allowance for corrosion needs to be made.
• f) Liquid levels after normal filling will not be substantially above the ‘tank full’ level.
• g) No allowance is made for the effect of filling an extended pipe to a level that is substantially above that of the tank.
• h) The pressure in the vapour space will not exceed 35kPa.
• i) The length-to-diameter ratio of an above-ground tank on two supports does not exceed 5.
• j) The tank shell is not stiffened.
• k) The material of construction is commercial-grade, low-carbon steel.

The possibility of using thinner materials, compensating by shaping, corrugating, bracing or stiffening, is recognized, especially for stainless steel. In such cases the design will need to demonstrate mechanical properties that are at least equivalent to a similar size of tank built to this Standard if such a tank is to be used for flammable or combustible liquids.

This Standard does not insist on compliance with any particular material Standards, or the use of specific grades of materials.