The national standards of expansion joints in China mainly include the following:
GB/T 12777-2008 General Technical Specifications for Expansion Joints of Metal Bellows：
This standard specifies the terms and definitions, classification and marking, requirements, test methods, inspection rules, marking and packaging, transportation and storage of metal bellows expansion joints. Suitable for the design, manufacture and inspection of expansion joints installed in pipes whose flexible elements are metal bellows.
GB/T 12522-2009 Stainless Steel Corrugated Expansion Joint：
This standard replaces GB/T 12522-1996 and specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of stainless steel corrugated expansion joints.
GB/T 16749-2018 Corrugated Expansion Joints for Pressure Vessels：
This standard specifies the terms and definitions, general requirements, classification and marking, materials, design, manufacture, inspection and acceptance, inspection rules, etc. of wave expansion joints for pressure vessels.
GB 16749-1997 Corrugated Expansion Joints for Pressure Vessels：
Although it has been replaced by GB/T 16749-2018, its earlier version stipulates the design, manufacture, inspection, acceptance, storage, installation, basic parameters and dimensions of wave expansion joints of pressure vessels, etc.
In addition, there are industry standards such as:
JB/T 6171-92 Metal multilayer corrugated expansion joint
JB 1121-83 Metal Corrugated Expansion Joints (for Pressure Vessels)
CB 1153-95 Metal Corrugated Expansion Joints (Marine)
These standards cover expansion joints in different fields and applications, such as metal corrugated expansion joints, stainless steel corrugated expansion joints, multilayer corrugated expansion joints, and expansion joints standards in specific industries such as shipbuilding, chemical industry, aerospace, etc.
When designing, procuring or using expansion joints, appropriate standards should be selected according to specific conditions of use and industry requirements. For example, if expansion joints are used for pressure vessels, then GB/T 16749-2018 may be a more directly relevant standard.
Note that standards are updated over time, so in practical applications, you should use the latest version. If you are looking for specific content for a particular standard, you may want to consult the officially released standard documentation or contact the relevant standardization organization for the latest information.