Plastic bellows is the main compensating element of t […]
Plastic bellows is the main compensating element of the expansion joint. In addition to displacement and deformation during installation and operation, it also bears a certain amount of pressure. In order to ensure the correct installation of the compensator, the following points must be noted:
(1) When installing, carefully check the specifications and models of the compensator, and pay attention to the piping method. In addition, for the plastic bellows compensator with inner sleeve, care should be taken to ensure that the upstream and downstream installation directions of the inner sleeve are consistent with the flow direction of the medium; for hinge type compensators, the hinge rotation plane should be consistent with the displacement movement plane .
(2) Pre-deformation of expansion joints. The plastic bellows compensator should be positioned according to the compensation zero temperature. The compensation zero point temperature is the midpoint of the maximum temperature and the minimum temperature considered by the pipeline design. Install when the ambient temperature is equal to the compensation zero temperature, the compensator does not need to be pre-tensioned or pre-compressed. When installing at the compensation zero point temperature of the non-plastic bellows, the plastic bellows should be reasonably pre-stretched or compressed according to the difference between the ambient temperature and working temperature at the time of installation, so that it is at the point of zero temperature compensation. The best condition, guarantee the best performance.
(3) Hydrostatic test: During the test, the fixed pipe frame installed at the end of the plastic corrugated pipe should be reinforced to prevent the pipe from deforming or rotating. After the test, the water in the plastic bellows should be removed as soon as possible, and the inner surface of the plastic bellows shell should be blown to prevent corrosion.
(4) When installing the plastic bellows expansion joint, the deformation of the plastic bellows cannot be used to correct the installation deviation, and the quality of the pipeline installation must be guaranteed.