Axial Internal Pressure Bellows Expansion Joint

Nominal Diameter: DN15 - DN5000 mm

Working Pressure: 0.25～4.0 MPa

Design Temperature: -20℃ to 1000℃

Standard: GB/T12777-2008

Product Description

Axial Internal Pressure Compensator (Expansion Joint), consisting of a bellows and structure, absorbs pipeline axial displacement and a small amount of lateral and angular displacement through the flexible deformation of the bellows. The ends are connected to the pipeline flanges or directly welded to the pipeline flanges, or法兰焊接后再与管道法兰连接。The small tie rod on the compensator serves as a rigid support during transportation or for deformation adjustment of the product, and should not be used as a tie rod subjected to balancing pressure thrust. This type of structure is simple and cost-effective, so it should be considered first wherever it is applicable in the pipeline.

Our axially metal bellows expansion joints are optimized with the American EJMA standard design. While meeting domestic market demands, our products are also exported to 22 countries. They are widely used in aerospace, marine, petrochemical, smelting, power plants, information industries, industrial equipment manufacturing, and engineering pipeline systems. They effectively ensure high safety performance for pressure pipelines when transporting various harmful, toxic, flammable, and explosive media, preventing leaks and pollution that could affect marine, atmospheric, and factory environments. The product features include high-temperature resistance, high-pressure resistance, corrosion resistance, fatigue resistance, and wear resistance.

Axial Internal Pressure Bellow Expansion Joint with Flat Flange ConnectionFor bolted connections to piping systems, any type of flange can be applied to metal bellows expansion joints. Forged steel and flat flanges are suitable for pressure and temperature ratings from 2.5 Mpa to 5.0 Mpa, with standard pipe sizes ranging from 15mm to 5000mm. Special flanges, such as slip-on flanges or lug flanges, are available in sizes from 300mm to 1800mm. Custom flanges of any size are available.

Axial internally pressurized bellows expansion joint end pipe connectionAny pipe can be connected and welded onto the bellows and within the pipeline system. Pipe diameters range from 15mm to 10000mm. Carbon steel can be chosen, as well as stainless steel and other alloy steel pipes.

Pressure and thrust are forces generated by the pressure applied to the bellows. This force is the product of the system pressure and the effective area of the bellows. Without an expansion joint, the piping system would be affected by pressure, and the system would not move due to the opposite direction of the pipe and tension. When an unconfined expansion joint is applied to the piping system, the forces in the pipe are absorbed by the expansion joint without affecting the piping system itself. This pressure and thrust must include a main support bracket or a controlled expansion joint to bear the load of the pressure thrust. This main support bracket must be able to withstand the pressure thrust and a small amount of force caused by the offset of the bellows.

Spacing for axial internal pressure bellows expansion joint installation conduit devices

The following illustration depicts the essential factors for the typical installation of an axial expansion joint, which must be strictly adhered to.

Pipe Support G1: Located at a position four times the diameter of the expansion joint pipe, if the expansion joint is an external pressure design, the pipe support is integrated with the expansion joint. In this case, only the pipe clamp over the in-built and intermediate level pipe supports are required. Pipe Support G2: Situated at a position 14 times the diameter of the expansion joint.The main fixed bracket is primary from a design perspective. It must be capable of withstanding the influence of any forces applied to it. These forces include pressure and thrust, the resistance of the bellows stiffness, the frictional resistance of the pipeline, and the inertial force at the bends.

A pipeline alignment device is an indispensable part of a properly designed piping system. The thermal expansion of the pipeline must be controlled so that the bellows only have axial displacement. It is crucial to design the pipeline alignment device to prevent bending and wrinkling of the pipeline.

Jiangsu Zhongxin Bellows Co., Ltd. specializes in the production of expansion joints, bellows, damper doors, metal hoses, and more. Welcome to inquire and place orders from our extensive customer base!