The national standard for non-metallic expansion joints in China is JB/T 12235-2015. This standard specifies in detail the technical requirements, test methods, inspection rules and requirements for marking, packaging, transportation and storage of non-metallic expansion joints. Non-metallic expansion joints, also known as non-metallic compensators, are mainly used to absorb the thermal displacement in the pipeline system to eliminate the stress in the system, while also playing the role of vibration isolation and vibration reduction.
Overview of the main contents of the standard:
Terms and definitions: Clarifies the technical terms and definitions of non-metallic expansion joints and related components.
Product Classification and Product Marking: Describes different types and marking methods of non-metallic expansion joints for easy identification and selection.
demand: Specifies the material, design, manufacture and performance requirements of non-metallic expansion joints, including but not limited to dimensional tolerances, material properties, pressure and temperature tolerance, etc.
Test Methods: Various test methods used to verify the performance of non-metallic expansion joints are introduced, such as airtightness test, pressure test, etc.
Inspection rules: The requirements of factory inspection and type inspection are specified to ensure product quality.
Marking, packaging, transportation and storage: Provides guidance on product identification, packaging methods, transportation precautions and storage conditions.
Classification criteria:
Non-metallic expansion joints can be classified in the following ways:
By shape: Round, rectangular and shaped non-metallic expansion joints.
According to connection mode: Flange type, tube type non-metallic expansion joint.
According to structural form: Straight, corrugated and flanged non-metallic expansion joints.
According to media: High temperature non-metallic expansion joints and normal temperature non-metallic expansion joints.
Technical requirements:
The technical requirements of non-metallic expansion joints relate to their material selection, structural design, machining accuracy and performance parameters. For example, the material selection of ring belts and metal structural components needs to meet specific temperature, pressure and corrosion resistance requirements. In addition, the surface of ring belts of non-metallic expansion joints should not have obvious defects, such as scratches, cracks, interlayers and peeling, and all parts of welds should be free of cracks, non-penetration, non-fusion and other problems.
When designing and manufacturing non-metallic expansion joints, manufacturers must strictly adhere to JB/T 12235-2015 standard to ensure that the quality and safety performance of the products comply with national specifications.