GB/T 50938-2013 in English

1 General Provisions

1.0.1 This code is drafted with view to regulating the design and construction of low temperature steel storage tanks in petrochemical engineering.
1.0.2 This code is applicable to the design and construction of steel vertical cylindrical above ground single containment tank, double containment tank and full containment tank storing hydrocarbon or ammonia with boiling point of 0~-165℃ and with design pressure not greater than 50kPa.
This code is not applicable to the membrane tank and the primary liquid container adopting pre-stressed concrete only.
1.0.3 Low temperature steel storage tanks in petrochemical engineering shall not only include the storage tank and its integral parts, but also include the following contents:
1 Connection between the storage tank and external pipeline shall include the following contents:
1) The groove end face of the first girth joint of the welding connection;
2) The end face of the first threaded joint of screwing connection;
3) The first flange sealing surface of flange connection;
4) The first sealing surface of special connecting piece or pipe fitting connection.
2 Flat covers for connecting pipe and access hole and their fasteners.
3 Insulation for the bottom, shell, roof and connecting pipe of the storage tank.
4 Internal structural members of the storage tank.
5 Anchoring structure of the storage tank.
1.0.4 The design and construction of low temperature steel storage tanks in petrochemical engineering shall not only meet the requirements stipulated in this code, but also comply with those in the current relevant ones of the nation.

2 Terms

2.0.1 Operating pressure
The gauge pressure for the gas-phase space of the storage tank roof under operating state.
2.0.2 Design pressure
The design maximum gauge pressure for the gas-phase space of the storage tank roof.
2.0.3 Design negative pressure
The design maximum negative pressure for the gas-phase space of the storage tank roof.
2.0.4 Test pressure
The gas-phase gauge pressure for the roof of storage tank in the test process.
2.0.5 Set pressure
The action pressure of the pressure relief device.
2.0.6 Minimum design temperature
The set temperature of the medium during the storage tank design.
2.0.7 Design metal temperature
The design temperature of metal part.
2.0.8 Maximum design liquid level
The permissible maximum liquid level of the storage tank.
2.0.9 Maximum normal operating level
The maximum liquid level of the storage tank under operating state.
2.0.10 Single containment tank
The primary liquid container equipped with insulation layer or the storage tank composed of primary liquid container and steam tank.
2.0.11 Double containment tank
The storage tank composed of the primary liquid container and the secondary storage tank which can limit liquid leaking but cannot limit gas leaking.
2.0.12 Full containment tank
The storage tank composed of the primary liquid container and the secondary storage tank which can limit liquid and gas leaking.
2.0.13 Primary liquid container
The inner tank storing low-temperature refrigerating fluid in single containment tank, double containment tank and full containment tank under normal operating condition.
2.0.14 Secondary liquid container
The outer tank capable of containing low-temperature refrigerating fluid in double containment tank and full containment tank.
2.0.15 Inner tank
Self-supporting cylindrical metal storage tank.
2.0.16 Outer tank
Self-supporting steel or concrete cylindrical storage tank.
2.0.17 Roof
The structure located on the roof of shell which isolates the medium from the atmosphere and withstands the steam pressure.

Foreword I
1 General Provisions
2 Terms
3 Basic Requirements
3.1 Tank Types
3.2 General Requirements
4 Materials
4.1 General Requirements
4.2 Metal Tank
4.3 Concrete Member Materials
5 Metal Parts Design
5.1 General Requirement
5.2 Primary and Secondary Liquid Containers
5.3 Vapor Container
5.4 Suspended Roof
5.5 Connecting Pipe
5.6 Connection for Bottoms of Primary and Secondary Liquid Containers
5.7 Connection of Primary and Secondary Liquid Containers
5.8 Other Requirements
6 Concrete Structure Design
6.1 General Requirement
6.2 Liquid Tightness
6.3 Reinforced Concrete Storage Tank
7 Insulation
7.1 Selection, Performance and Test of Insulating Material
7.2 Outer Protection
7.3 Insulation System Design
7.4 Insulation Construction
8 Construction, Inspection and Acceptance of Metal Parts
8.1 General Requirements
8.2 Material Management
8.3 Prefabrication
8.4 Site Installation
8.5 Welding
8.6 Inspection
9 Concrete Components Construction
10 Test
10.1 Hydrostatic Test
10.2 Pneumatic Test
Appendix A Primary Physical Properties of Media
Appendix B Design Information of the Storage Tank
Appendix C Seismic Design Requirements
Appendix D Test for Steel Bar
Appendix E Common Insulating Materials and Purposes
Explanation of Wording in this Code
List of Quoted Standards