What is the function of a compensator?

Release time:

2021-12-13

　　What is the function of a compensator?

　　1. The compensator absorbs axial, lateral, and angular thermal and cold deformations of the pipe.

　　2. The expansion amount of the bellows compensator facilitates the installation and removal of valve pipelines.

　　3. Absorb equipment vibrations and reduce the impact of equipment vibration on pipelines.

　　Absorb seismic forces and accommodate deformation of the sinking pipeline.

　　How is the compensator installed and pressure-tested?

　　1. Before installing the compensator, the model, specifications, and pipe support configuration of the bellows expansion joint must meet the requirements of the combined design.

　　2. For expansion joints with liners, ensure that the liner’s orientation is consistent with the flow direction of the medium (install according to the flow markings on the expansion joint). In planar angular expansion joints, the hinge rotation screen should align with the offset plane.

　　3. The expansion requiring a “cold spring” shall be carried out, and the auxiliary components used for pre-deformation shall be removed after the expansion joint has been pre-deformed.

　　4. After the expansion joint is installed, the auxiliary positioning mechanisms and fasteners used to protect it during transportation must be removed immediately. Additionally, the limiting devices should be moved to their designated positions according to design requirements, ensuring that the expansion joint can fully compensate for environmental conditions.

　　5. In addition to the pre-deformation achieved through design-required pre-tensioning pressure or “cold pressing,” bellows deformation methods are also employed to adjust installation deviations in pipelines, thereby preventing any adverse effects on the normal functioning of expansion joints. Otherwise, the service life will be shortened, and the loads on the pipeline system, equipment, and supporting components will increase.

　　6. All movable components of the expansion joint must not be fixed by external components, nor may they restrict the normal movement of the moving parts.

　　7. During the installation of the compensator, welding spatter is not allowed to splash onto the surface of the assembly pattern, causing other mechanical damage to the bellows.

　　8. For expansion joints and their connecting pipes used in gaseous media, during hydrostatic testing, when filling with water, you should consider whether it is necessary to add temporary supports at the joint of the expansion joint to bear the load.

　　9. The water used for the hydrostatic test shall be pure and non-corrosive, with a chloride ion concentration in the water kept below 25 ppm. After the hydrostatic test is completed, any accumulated water should be drained from the bellows as soon as possible, and the inner surface of the bellows shell should be promptly dried.

　　10. Pipe alignment is beneficial. In the absence of other methods to ensure alignment, it can be achieved by laying straight pipes and then installing expansion joints after cutting pipes of equal length.

　　11. Expansion joints do not absorb torque; therefore, during installation, the expansion joint must not be twisted.

　　12. All moving components of the expansion joint must not be fixed by external components, nor may they restrict the normal operation of the moving parts.

　　13. The insulation layer shall be protected by a cover on the expansion joint’s outer casing and must not be applied directly onto the bellows. Chlorine-containing insulation materials are prohibited.

　　14. During installation, welding spatter is not allowed to splash onto the surface of the bellows, causing other mechanical damage to the bellows.

　　15. The support structure must meet the design requirements. It is strictly prohibited to test the pressure inside the pipeline before the support structure is installed, as this could damage the expansion joints.

　　16. The expansion joint allows the nominal system pressure test to exceed 1.5 times the rated pressure.

　　17. When pipelines equipped with expansion joints are in operation, valves should be opened and closed gradually to prevent sudden changes in temperature and pressure within the pipeline, which could damage the supports or expansion joints.

Jiangsu Yaxing

Address: Qingdun Industrial Park, Hai'an City, Jiangsu Province

Phone: 86-513-88483622 ，86-513-88480666,

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