Flexible connection for steam pipes

It’s very rare; if it does exist, it’s to prevent thermal expansion and pipe deformation

I think it shouldn’t be called a flexible connection; it should be called an expansion joint. This is installed to prevent the pipeline from shifting and deforming due to expansion and contraction. Expansion joint definition: A fitting used to compensate for changes in pipe length, also known as a telescopic joint or compensator. Expansion joints are primarily used to compensate for the thermal expansion and contraction of pipes due to temperature changes, as well as to provide length compensation when adjustments are necessary during pipe installation. They mainly come in three structural types: elbow-type expansion joints, bellows expansion joints, and sleeve expansion joints. 　　Elbow-type expansion joint: A type of expansion joint in which the pipe is bent into a U-shape or another shape (Figure 1), and the elastic deformation capacity of this shape is utilized for compensation. Its advantages are good strength, long service life, and the ability to be manufactured on-site; its disadvantages are large space consumption, high steel usage, and high frictional resistance. This expansion joint is widely used in various steam pipes and long pipelines. 　　Bellows expansion joint: A type of expansion joint made from a metal bellows. It can extend and contract along the axis direction, and it also allows for a small amount of bending. Figure 2 shows a common axial bellows expansion joint, which is used to compensate for axial length changes in pipelines. To prevent the compensation amount from exceeding the allowable limit, protective tie rods or rings are installed at both ends of the bellows, and guide supports are provided on the pipes connected to them. There are also elbow-type and transverse expansion joints, which can be used to compensate for the angular and lateral deformation of pipes. The advantages of this type of expansion joint are space savings, material conservation, and ease of standardization and mass production; the disadvantage is its shorter lifespan. Bellows expansion joints are generally used in pipes with moderate temperatures and pressures and relatively short lengths. As the production technology of bellows improves, the application scope of this type of expansion joint is expanding. 　　Sleeve expansion joint: It consists of an inner sleeve and an outer sleeve that can move relative to each other in the axial direction (Figure 3). The space between the inner and outer casings is sealed using a stuffing box. Ensure that the tubes at both ends move along the same axis when in use. Guiding brackets are installed at both ends of the expansion joint. Its advantage is that it presents low flow frictional resistance and a compact structure ； The disadvantage is poor sealing performance and high thrust on the fixing bracket. Sleeve expansion joints are mainly used in water pipelines and low-pressure steam pipelines.

Prevent thermal expansion, pipe deformation, and internal stress. Generally, soft connections refer to metal expansion joints or compensators; when equipment expands due to heat, the pipes need to move as well, and that’s why metal expansion joints are required.

It serves to absorb shocks in high-pressure pipelines

What you might be referring to is an expansion joint, which is used to address the displacement caused by thermal expansion of pipes

Steam pipes can only use natural compensation or metal compensators; packing compensators cannot be used.

I agree with what was said on the 3rd floor. Do you mean a compensator by \"soft connection\"? It is recommended to use natural compensation in steam pipelines as much as possible to eliminate stress and thermal expansion; only when that isn’t sufficient should reliable compensators be considered

Generally, thermal pipelines use self-compensation to absorb thermal expansion and reduce thermal stress; expansion joints, also known as flexible joints, are used at the connection points of certain equipment in order to prevent the stress exerted by the pipes on those connections from exceeding the forces and moments that the equipment itself can tolerate. It is generally not recommended for use in steam pipelines. It is only used when stress calculations cannot be carried out. Is this the type of compensator the original poster is talking about?

The soft connection mentioned by the poster is likely a compensator. The amount of expansion of the pipeline should be determined based on specific steam parameters as well as the pipe’s diameter, wall thickness, and material. The compensating capacity of the compensator must meet the requirements regarding the flexibility of the pipeline; in some cases, a flexibility analysis is necessary.

Flexible connection: It is used to accommodate natural settlement between different buildings. Used for radial deformation compensation of pipelines.

It is rare to see on steam pipes; natural expansion joints are generally used instead.

Pipe expansion compensation to eliminate thermal stress