1 General Provisions
1.0.1 The specification is applied for the design of welded storage tanks of vertical cylindrical steel fixing roof, floating roof and internal floating roof. And the accessories which is also defined in the specification.
The storage tanks which is designed by the specification applies to the storage of non-manual refrigeration, non-severe toxicity oil and liquid medium of chemical industry.
1.0.2 Apart from the implementation of the specification, the treatment shall also be in conformity with relevant standards being now in use in the country.
2 General Requirements
2.0.1 The storage tanks shall be complied at least with design conditions as follows:
1 Fortified intensity of earthquake, wind load, snow load, air temperature condition and the geologic condition;
2 Operating temperature and operating pressure (positive and negative pressure) of storage tanks;
3 The type and density of medium;
4 Corrosion allowance;
5 Diameter, height and volume of storage tanks;
6 The forms of tank roof;
7 Dimensions, forms, quantity, specs of flange for opening connection;
8 Installation place of accessories.
Note: Accessories is the fixed parts which is welded on tank.
2.0.2 Designed pressure shall be the maximum gauge pressure of gas phase space. The designed pressure of fixing roof storage tanks ranges from -490Pa to 6000Pa.
2.0.3 Metal temperature shall be the average temperature of section thickness in storage tanks’ skin.
2.0.4 Designed temperature shall be the possible highest or lowest temperature of tank metal in normal operation. The value range of designed temperature shall comply with the following requirements:
1 Designed temperature of fixing roof storage tanks shall not exceed 250℃.
2 Designed temperature of fixing roof and internal floating roof storage tanks shall not exceed 90℃.
3 The lowest designed temperature of storage tanks shall be higher than -20℃.
4 In cold region, designed temperature shall be the lowest daily mean temperature of that area plus 13℃ if there isn’t heating and heat preservation of storage tanks.
2.0.5 It shall consider of the corrosion action of medium inside the tank and the corrosion of surrounding environment when designing storage tanks.
2.0.6 Additional quantity of thickness shall be calculated by the following formula:
