Flexible steel pipe represents the ability of pipeline to absorb displacement deformation such as thermal expansion and cold contraction through its own deformation.

Hoses are classified according to different materials, but their characteristics are:

1, strong corrosion resistance. Glass fiber reinforced plastic sand pipe and rubber bellows are nonmetallic materials with strong corrosion resistance; The galvanized layer of metal coil corrugated pipe also has good corrosion resistance.

2. The pipeline is flexible. The glass fiber reinforced plastic sand pipe is made of glass fiber, with gravel in the middle to increase stiffness; Bellows are made of rubber (or plastic) materials by hot casting. Some varieties have a metal wire skeleton in the middle, and metal corrugated pipes are rolled with thin iron sheets. These pipes have good axial stiffness, and their stiffness values increase with the wall thickness of the pipes. Compared with reinforced concrete pipe, the larger axial flexible deformation will not damage the pipe itself. The maximum allowable axial deformation is 1% of the pipe length, and the maximum allowable radial deformation is 5% (provided by the manufacturer), which can well adapt to soft soil foundation. Therefore, it can also be called a hose.

3. Simple transportation and installation. The manufacturing length of the pipeline is 6-8 meters, or even longer, with few interfaces and short installation period.

4, the interface construction operation time is short. Mechanical, physical and chemical sealing methods are used instead of concrete tape sealing, and some of them are not even used as concrete foundations, saving the time waiting for concrete curing.