Axial External Pressure Bellows Expansion Joint Performance FeaturesAxial externally pressurized bellows expansion joints consist of an inner cylinder, bellows, outer cylinder, and auxiliary components. The bellows, under external pressure, offer good sealing and bending resistance.Absorb large displacement quantityAvailable in single, double, and bidirectional forms. The axial outward pressure bellows expansion joint primarily absorbs axial displacement, featuring large compensation capacity, good insulation performance, and the ability to exclude residual medium.
Axial External Pressure Bellows Expansion Joint Installation and Usage Precautions:
The liner tube direction should be consistent with the medium flow direction (there is a flow direction indicator on the expansion joint).
Ensure the exhaust vent is facing up and the condensate outlet is facing down during installation.
After on-site installation is completed, the small pull rod must be removed.
Axial External Pressure Bellows Expansion Joint Load Thrust Diagram:
The pressure and thrust of an axially externally pressured bellows expansion joint are forces generated by the pressure applied to the bellows. This force is calculated by multiplying the system pressure by the effective area of the bellows. Without an expansion joint, the piping system would be affected by pressure, and due to the opposing direction of the pipe and tension, the system would not move. Once an unrestricted expansion joint is applied to the piping system, the forces within the pipe are absorbed by the expansion joint without affecting the piping system itself. This pressure and thrust must be accommodated by the main fixed support or a controlled expansion joint to bear the load of the pressure thrust. This main fixed support must be capable of withstanding the pressure thrust and a minor force caused by the bellows offset.
Spacing of the导管 assembly for the axially externally pressurized bellows expansion joint
The image below illustrates the critical factors for typical expansion joint installation, which must be strictly adhered to.
Pipe fitting G1:Located four times the diameter of the expansion joint pipe, if the expansion joint is designed for external pressure, the conduit assembly is integrated with the expansion joint. In this case, only the conduit grip over the in-built and intermediate stage conduit assemblies is required.
Pipe Device G2:Located at a position 14 times the diameter of the expansion joint.The main fixed support for the expansion joints of the axial externally pressurized bellows is of primary design importance. They must be capable of withstanding the influence of any forces applied to them. These forces include pressure and thrust, resistance from the bellows stiffness, frictional resistance of the pipeline, and inertial forces at the bends.
The pipeline alignment device for the expansion joints of the pipe with outward pressure bellows is an indispensable part of a properly designed piping system. The thermal expansion within the pipe must be controlled so that the bellows only undergo axial displacement. It is essential to design the pipeline alignment devices to prevent pipe bending and wrinkling. The following three illustrations depict the types of pipeline alignment devices.
Axial External Pressure Bellows Expansion JointTypical Applications:
The illustration shows the typical installation method of a typical externally pressurized bellows expansion joint. The sensitive load requirements of the two devices necessitate very small pressure and displacement on the flanged attachment part. When the externally pressurized bellows expansion joint absorbs all the axial displacement, the two devices can extend due to temperature changes. The conduit assembly is inside the expansion joint, so the next conduit assembly is set at a position 14 times the diameter of the pipeline. This system application can absorb greater displacements than a straight pipe pressure-balanced expansion joint.
Jiangsu Zhongxin Bellows Co., Ltd. specializes in the production of compensators, expansion joints, butterfly valves, metal hoses, and more. Welcome to inquire and place orders from a wide range of customers!
