The structure and principle of metal expansion joints

    The structure and principle of expansion joints vary depending on the material used. The following is a specific introduction to metal expansion joints and non-metal expansion joints:

    The structure and principle of metal expansion joints:

    Metal expansion joints are mainly used to compensate for the deformation caused by temperature changes or mechanical vibrations in equipment such as pipelines and containers. Its main structures include corrugated tube type, braided type, spherical type, and hinged type.

    The bellows expansion joint consists of two end flanges, a middle bellows, a compensating shaft, etc. When pipelines or containers are subjected to thermal expansion and contraction deformation, corrugated pipes absorb the stress caused by deformation through axial or transverse expansion and contraction, achieving compensation effect.

    The braided expansion joint is composed of flanges at both ends, braided body, guiding device, etc. The woven body is made of stainless steel wire and can absorb displacement and deformation in various directions.

    A spherical expansion joint consists of two hemispherical bodies and a flange. When a pipeline or container deforms, the hemispherical body can rotate and tilt to absorb the deformation.

    The hinge type expansion joint is composed of flanges at both ends, hinges, inner sleeves, etc., and absorbs deformation by changing the angle of the inner sleeve end through the hinge.

    The working principle of metal expansion joints mainly utilizes the expansion and contraction, elasticity, and flexibility of metal materials. When the temperature in the pipeline system rises, the metal expansion joint can freely expand and absorb the amount of thermal expansion; When the temperature drops, it can freely contract and absorb heat shrinkage. In addition, metal expansion joints can absorb vibrations in the pipeline system, change the direction of the pipeline, and thus protect the normal operation of the pipeline system.

    The structure and principle of non-metallic expansion joints:

    Non metallic expansion joints are mainly used to compensate for axial, angular, lateral, and their combined displacements caused by thermal deformation, mechanical deformation, and mechanical vibration in pipelines. Its main structure includes skin, stainless steel wire mesh, insulation cotton, and other parts.

    As the main expansion body of non-metallic expansion joints, the skin is composed of multiple layers of composite materials such as silicone rubbr or high silica polytetrafluoroethylene and alkali free glass fiber, used to absorb expansion and prevent air and rainwater leakage.

    Stainless steel wire mesh serves as an inner lining to prevent debris from entering the expansion joint and prevent the loss of insulation material.

    Thermal isulation cotton takes into account both insulation and airtightness, and is composed of fiberglass cloth, high silica cloth, and various types of insulation cotton felt.

    The working principle of non-metallic expansion joints is mainly to utilize their elastic deformation function. When the pipeline undergoes thermal deformation, mechanical deformation, or mechanical vibration, non-metallic expansion joints can compensate for these displacements, educing pipeline deformation and improving pipeline service life. At the same time, it also has functions such as sealing, shock resistance, vibration reduction, and noise reduction.

    In summary, expansion joints play an important compensation and protection role in pipeline systems through their unique structure and principles, ensuring the normal operation of pipeline systems and extending their service life.