National Size Standard for Expansion Joints

The national dimensional standards for expansion joints vary according to different countries and regions, and these standards are usually formulated and published by the standardization bodies of their respective countries. Here are some of the main national size standards:

1. China Standard (GB/T)

• Standards such as GB/T 12465-2002 "Definition of Nominal Pressure of Pipeline Components and Its Use Regulations" will involve pipeline components, including the size and pressure grade of expansion joints.

• GB/T 16749-2018 Corrugated Expansion Joints for Pressure Vessels also contains dimension regulations for metal corrugated expansion joints.

• ASME B16.5 and ASME B16.47 respectively specify standards for flange connections in different size ranges, which have a direct impact on the flange connection dimensions of expansion joints.

• The ANSI/AWWA C207-07 standard deals with rubber joints, including dimensions and connection requirements.

• EN 1092-1 specifies the dimensions and joining standards for flanges and applies to expansion joints on the European market.

• ISO standards such as ISO 10397 relate to requirements and test methods for rubber and plastic corrugated expansion joints and may indirectly include dimensional specifications.

These standards will typically define the nominal diameter of the expansion joint (usually expressed as DN), the size of the flange, the layout of the bolt holes, and parameters such as the axial, transverse, and angular displacement capacity of the expansion joint. For example, based on the information provided earlier, we can see some specific size parameters:

• For a small size expansion joint, such as a nominal diameter of 32 mm (about 1.25 inches), the length may be 95 mm, allowing an axial displacement of 6 mm to 9 mm, a transverse displacement of 9 mm, and an angular displacement of 15°.

• For larger size expansion joints, such as those with a nominal diameter of about 150 mm, which may be 165 mm in length, the allowable axial displacement is 13 mm, the lateral displacement is 19 mm, and the angular displacement is 15°.

Please note that these data are for example purposes only, and actual size standards vary depending on the specific application and the type of expansion joint. When designing and sourcing expansion joints, reference should be made to the latest national or industry standards to ensure that the expansion joints are compatible with other components in the system and meet safety and performance requirements.