1 Scope
This standard specifies the requirements for materials, design, pre-fabrication, erection welding, inspection, examination and testing of vertical cylindrical steel welded low-pressure storage tanks.
This standard is applicable to the design, construction, inspection and acceptance of liquid storage tanks with design pressure (gage) not more than 0.1MPa, vacuum degree not less than -0.49kPa, design temperature higher than -20℃ but not higher than 120℃ and stored at ambient temperature and with gas phase space at its top.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 699 Quality carbon structure steels
GB/T 700 Carbon structural steels
GB 713 Steel plates for boilers and pressure vessels
GB/T 985.1 Recommended joint preparation for gas welding, manual metal arc welding, gas-shield arc welding and beam welding
GB/T 985.2 Recommended joint preparation for submerged arc welding
GB/T 1220 Stainless steel bars
GB/T 3077 Alloy structure steels
GB/T 3274 Hot-rolled plates, sheets and strips of carbon structural steels and high strength low alloy structural steels
GB 6479 Seamless steel tubes for high-pressure for chemical fertilizer equipment
GB/T 8163 Seamless steel pipes for liquid service
GB 9948 Seamless steel tubes for petroleum cracking
GB/T 14976 Seamless stainless steel pipes for fluid transport
GB 24511 Stainless steel plate, sheet and strip for pressure equipment
GB 50009-2012 Load code for the design of building structures
GB 50128 Code for construction and acceptance of vertical cylindrical steel welded storage tanks
NB/T 47008 Carbon steel and alloy steel forgings for pressure equipment
NB/T 47010 Stainless and heat-resisting steel forgings for pressure equipment
NB/T 47015 Welding specification for pressure vessels
JB/T 4730 Nondestructive testing of pressure equipment
JB/T 4736 Reinforcing pad
3 General provisions
The design, construction, inspection and acceptance of the storage tank shall comply with the requirements of both this standard and the current relevant standards and codes.
3.1 Design condition
The design condition (data sheet) of the storage tank shall include at least the following information:
3.1.1 Technical parameters of storage tank body
a) Diameter, height and nominal volume of the storage tank;
b) Name, composition and characteristics (flammability, explosibility and toxicity) of the medium;
c) Design/operating pressure (including positive and negative) and design/operating temperature (including maximum and minimum temperatures) of the storage tank;
d) Density of medium.
3.1.2 Meteorological conditions
a) Basic wind pressure: XXX N/m2;
b) Basic snow pressure: XXX N/m2;
c) Minimum daily average temperature: XXX ℃.
3.1.3 Engineering geological conditions
a) Site category: Category X;
b) Ground roughness: Category X.
c) Seismic fortification intensity: Degree X;
d) Design basic seismic acceleration;
e) Design earthquake group
3.2 Storage tank foundation
The tank bottom plate of the storage tank shall be arranged on a reliable and uniform tank foundation which shall meet the requirements of Annex A.
Foreword i
1 Scope
2 Normative references
3 General provisions
3.1 Design condition
3.2 Storage tank foundation
4 Materials
4.1 General requirements
4.2 Steel plates
4.3 Steel pipes
4.4 Forgings
4.5 Bolts and nuts
4.6 Structural shapes
4.7 Welding materials
4.8 Foreign steels
5 Design
5.1 General requirements
5.2 Tank bottom design
5.3 Sidewalls design
5.4 Tank roof design
5.5 Design of roof and bottom knuckle regions and compression-ring girders
5.6 Tank anchorage
5.7 Opening and opening reinforcement
5.8 Flush-type shell connection
6 Pre-fabrication, erection and welding
7 Inspection, examination and testing
8 Pressure and vacuum-relieving devices
8.1 General
8.2 Pressure limits
8.3 Pressure setting of safety valves
Annex A (Normative) Suggested practice regarding foundations
Annex B (Informative) Calculation example for steel welded low-pressure storage tanks
Explanation of wording in this standard