Metal Expansion Joints - ThomasNet

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The Bellows Movement Metal expansion joints are flexible connections installed in piping and ducting systems to accomodate expansion, contraction and vibrations caused by changes in operating temperature, pressure and/or media. The Bellows is the basic element of an expansion joint. The bellows design is predominantly determined by required movement, pressure, temperature, cycle life, materials and corrosion. EagleBurgmann EJS bellows are manufactured by forming corrugations, or convolutions, in thinwalled metal cylinders. These cylinders can be inserted inside each other to form multi-ply bellows. The drawing process does not thin the bellows tube. All bellows are formed in their cold state and optional heat treatment can be performed afterward if required. Introduction to Metal Expansion Joints The ability of metallic bellows bellows to absorb movements and cycle properly is determined by the bellows geometry and material which include total number of convolutions, convolution height, convolution pitch and radius, thickness of material and number of plies. Movement Bellows are designed to absorb axial, lateral and angular movement. Applying torsional movement on bellows should be avoided. If torsional movement is present, appropriate hinge or gimbal hardware is highly recommended to counter the torque. Axial Lateral Angular Metal expansion joints can be used in closed piping systems with movements in the axial, lateral and angular direction or a combination of the three types. • Axial Types: Used in pipeline systems for absorption of movements along the longitudinal axis of the pipeline. Angular Type: Designed with only one bellows; however multiple angular expansion joints can be installed in a pipeline without a fixed point in between. • Lateral Types: Designed to absorb movement as the two ends of the expansion joints are sheared away from each other but are kept parallel For more information about expansion joint design and standard expansion joint products, see our Technical Design Manual. The belllows is the basic element of an expansion joint Universal expansion joint installed for lateral movement 4
Connections, liners and covers that can be fitted to the bellows include: • Plate flanges • Vanstone flanges • Weld ends • Tie Rods/Limit Rods • Special connections • A combination of the different connections At high temperatures or high flow velocities, internal sleeves, or liners, are recommended. The liner protects the bellows from erosion in harsh operating environments. An external cover, or shroud, protects the bellows against mechanical damage during installation, shipping and operation. Mating, or connecting flanges, bolts, nuts and gaskets can also be installed as a part of a complete metal expansion joint solution. Materials Selection of the bellows material is one of the single most important factors to consider in the design of an expansion joint. Some of the factors which influence the type of material include process media, surrounding environment, internal cleaning agents, high temperature or cryogenic service, operating stresses, forming and cold working capabilities, cost and material availability. Bellows are made of one or more plies of stainless steel or other types including: • Austenitic Steel • Incoloys • Inconels • Hastelloys • Other formable materials Expansion Joint Basics An external cover adds protection to the bellows Material selection is an important factor in expansion joint design Connections & Accessories Materials Welding & Testing Welding & Testing Welding is performed according to EN or ASME Code standards. Welding integrity and product quality can be tested using various non-destructive tests (NDT) such as: • Dye Penetrant test • Magnetic Particle test • Helium Leak test • X-ray test • Ultra Sonic test • Pressure • Other tests, such as cold movement check, can also be requested. Tests may be completed in-house or by an independent notified body. See page 17 for more information about our testing capabilities. Welding is performed to EN or ASME standards 5
Page 1 and 2: Metal Expansion Joints Flexible, Re
Page 3: P4. Introduction to Expansion Joint
Page 7 and 8: Multi-ply Bellows has two or more p
Page 9 and 10: Pipe penetration seals are used Pip
Page 12 and 13: Extreme Pressure High Operating Tem
Page 14 and 15: 14 High Temperatures High Pressure
Page 16 and 17: 16 Customized Solutions Special Des
Page 18 and 19: Improve Reliability Increase Servic
Page 20: Technology that expands with you Ar

Metal Expansion Joints - ThomasNet

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