Issues that should be noted during the installation of sleeve compensators are essential knowledge that every unit using these compensators must familiarize themselves with before installation. Before installation, a comprehensive inspection of the sleeve compensator is mandatory. Specifically, check whether the outer surface of the inner sleeve is smooth and free of burrs or protrusions; ensure that the joints of each coil in the packing gland are angled at 35° to 40°, and that their openings are arranged in an offset pattern; verify that the connecting pipes and flanges on both sides of the compensator are perpendicular to the axis. During assembly, the gland bolts should be tightened evenly but not excessively tight. A slight degree of tightness can help reduce the thrust on the fixed supports during initial startup.

Issues to Note During the Construction of Sleeve Compensators

Before installation, the outer side of the inner sleeve must be exposed within a 200-mm compression collar. For the manufacturer, this is a conservative value intended to ensure adequate axial thermal displacement caused by thermal expansion in a 40-meter pipeline.

Whether a sleeve compensator functions properly depends to a large extent on the structural integrity of the fixed-end supports. Therefore, in civil engineering design and construction, the embedded steel plates at the upper ends of the support columns must be securely and reliably connected to the civil support structures, with no looseness or gaps allowed. Moreover, the foundation work for the support structures in civil buildings must ensure that the designed strength requirements are fully met. The factory’s foundations adopt a cup-and-socket type. During construction, particularly in the depths of winter, after the columns were erected, two rounds of concrete pouring were carried out. At that time, protective measures were not taken promptly, resulting in freezing phenomena. When the system was put into operation, the compensator showed no signs of expansion or contraction. The fixed support columns began to tilt, prompting a rework effort that successfully eliminated this issue. This clearly underscores the importance of securely anchoring the sleeve to the structure.

The manufacturer of sleeve compensators believes that, when installing and using sleeve compensators, the compensator must be concentric with the pipeline. Specifically, this means that the inner sleeve should be evenly distributed along the inner circumference of the outer sleeve—thus, the inner sleeve and the pipeline must be welded together concentrically without any external forces applied. This ensures that there will be no steam leakage. During factory installation, first weld the pipeline to the fixed end and the outer pipe side. Then, adjust the height of the external sliding supports on the outer pipe so that the pipeline is in a free state and remains concentric with the inner sleeve of the internal compensator. After welding seam A, it can be ensured that the sliding-side pipe remains concentric without any external forces acting upon it.

The outer surface of the inner sleeve of the expansion joint is smooth and precision-finished. During installation, the surface of the sleeve should be kept clean and free of any impurities. When welding pipes, remember to wrap them with a soft material to prevent welding spatter from adhering to the surface. Also, be careful not to weld any other components onto it.

In addition, the sliding plate of the sliding bracket is preferably machined on both sides to ensure it has a smooth, burr-free surface with no welds or protrusions, thereby preventing lateral displacement of the sliding plate and maintaining concentricity.

When the heating network is put into operation, the heating pipes must be kept running for an appropriate duration, and any accumulated water needs to be drained promptly. If the water is not drained properly, water hammer or vibrations may occur in the pipes, which can adversely affect the tightness of the compensators during expansion and contraction.

In Sleeve compensator After the heating network is put into operation, it’s necessary to minimize the number of start-ups and shut-downs—especially to avoid frequent thermal start-ups and shut-downs. This is because each time a start-up or shut-down is performed, the compensator will be activated once, which can shorten its service life.