As the axial stiffness of a wave guide is very small, the axial force generated by internal pressure in a pipeline often affects the planning and application of the pipeline system. Axial forces that do not suffer any constraints and are transmitted to the pipeline system of a wave guide are called "self-excited" (unbalanced) wave guides; axial forces that are constrained by certain organizations or equipment and cannot be transmitted to the wave guide are called "balanced" wave guides. Among them, balanced wave guides can be divided into two types: damping type wave guides that use components such as rods and hinges to resist axial forces; and absorption type wave guides that use the pressure of the job to achieve balance.

Installation Procedure:

1. The length of the installation should not be arbitrarily changed, and the use of the distortion of the expansion joint to compensate for installation errors (such as the compression and elongation mismatch between the pipelines) should not be attempted.

2. For pipe-type expansion joints with guide tubes, it is necessary to ensure that the guide tube direction is aligned with the active direction of the fluid.

3. For flat hinged expansion joints, it is necessary to use the rolling surfaces of the expansion joint and the displacement rolling surfaces to ensure that the expansion joint is in balance during installation.

4. Before transportation, the fixed equipment should not be removed, to ensure that the length of the expansion joint equals the design value. It is necessary to remove this fixed equipment after the assembly of a unit of piping and ensure that the distortion of the expansion joint regains compensation effects.

5. Welding should not be performed on the flexible pipe, and if welding debris flies into the active components of the expansion joint, it will cause the flexible pipe to lose compensation effects.

6. There should be enough space around the expansion joint to ensure that it can move freely within the design range.

7. Before water pressure or vacuum testing, it is not allowed to install any guiding or fixed supports.

8. The lifting position should not be set on the flexible pipe.

9. For flanged connections, it is necessary to weld one flange after adjusting for centering before welding.

10. During operation, it is necessary to regularly repair the expansion joint.